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The Eco-Core SnowboardBy SnowCore Innovations
Tom Santoro
Chris Grant
Curtis Franklin
December 12, 2006
APD2006-02
ABSTRACT
Natural fiber composites have been heavily investigated in recent years not only because they aremore environmentally friendly than other composite materials but also because of the apparenthigh strength and low density of the fibers. The hemp plant in particular produces high qualitynatural fibers exhibiting strong mechanical properties which are also inexpensive. Our research,engineering analysis and material testing has led us to a material called FlexForm which exhibitsproperties comparable to current core materials on the market, generally various types of woodsand foams. FlexForm is a composite made of jute, a derivative of the hemp plant, and itsimplementation in a sustainable snowboard shows a feasible alternative to current core materials.
The purpose of this report is to present our product solution for a more environmentally friendlysnowboard aimed towards eco-friendly, counter-culture snowboarders.
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TABLE OF CONTENTS
NOMENCLATURE....................................................................................................
INTRODUCTION......................................................................................................
Previous Designs.............................................................................................Design Objectives...........................................................................................
PRODUCT DESCRIPTION.....................................................................................
Conceptual Solutions.....................................................................................
Concept Selection Pugh Matrix.................................................................
Design Requirements Quality Function Deployment..............................
Quantifiable Design Requirements..............................................................
Project Prototypes..........................................................................................
1
2
24
5
5
6
7
9
9
ENGINEERING ANALYSIS....................................................................................
Design Optimization ......................................................................................
13
Material Testing............................................................................................. 13
AESTHETIC ANALYSIS.........................................................................................
16
18
INITIAL MICROECONOMIC ANALYSIS........................................................... 20
MARKETING ANALYSIS.......................................................................................
Modified Microeconomic Analysis...............................................................
22
24
27PRODUCT DEVELOPMENT PROCESS ..............................................................
29PRODUCT BROADER IMPACT............................................................................
CONCLUSION........................................................................................................... 30
RESOURCES............................................................................................................. 32
A-1APPENDIX A: INITIAL SURVEY RESULTS AND QUESTIONS...................
B-1APPENDIX B: PHOTOS OF BENCHMARKED SNOWBOARDS...................
APPENDIX C: ENGINEERING ANALYSIS MODELS...................................... C-1
D-1APPENDIX D: ENGINEERING ANALYSIS SPREADSHEETS.......................
E-1APPENDIX E: CHOICE BASED CONJOINT SURVEY QUESTIONS...........
F-1APPENDIX F: MODIFIED MICROECONOMIC CALCULATIONS..............
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NOMENCLATURE
wc Width of snowboard at centertc Thickness of snowboard at centerwe Width of snowboard at end
te Thickness of snowboard at enda End of snowboard to bindings b Distance between bindingsl Length of contact with grounde Distance between contact surfacesd End of snowboard to contact surfacevi Snowboard deflection for load case iPj Maximum allowable load for load case jW WeightY Engineering objective function Profit
Q Quantity of boards sold per yearP Price per boardC Cost per year Market sizep Price sensitivityd Design sensitivity Microeconomic constantVC Variable costs per snowboardFC Fixed costs of operating per yearx Elasticity of design characteristicxb Base design level of characteristic xQ
1.05xbMarket demand associated with an increase of 1.05 times x
bQb Market demand of base design
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INTRODUCTION
The demand for environmentally sustainable products has skyrocketed within the last decade dueto increasing global sustainability concerns. The winter sports market is no exception anddemonstrates a significant population of people concerned with these environmental issues. Our
survey results show that the average snowboarder is concerned with global warming and is also afrequent newspaper recycler (Appendix A, Survey Results). Based on these points, it is a worthyendeavor to produce a more environmentally sustainable snowboard in order to target thismarket.
Hemp, when compared to glass fibers, has shown an equivalent Youngs modulus, a much lowerdensity and costs roughly half the price [1]. The counter-culture mindset surrounding hemp isalso a very attractive proposition to many snowboarders. Our survey showed that 47% of peoplewho snowboard own a hemp product, whereas only 14% of non-snowboarders own somethingproduced with hemp. Jute is a plant derived from hemp and can be produced in composites at ahigher quality than that of hemp and at a cheaper price. Although 95% of the worlds jute fiber
comes from Bangladesh and India, it should be noted that the industrial growth of the plant islegal in the United States, whereas hemp is not [2].
We feel that there is significant demand for a sustainable snowboard incorporating natural fibersand thus we have decided to design and develop a snowboard concept from the viewpoint of asmall snowboard manufacturing company.
Previous Designs
The sport of snowboarding started in the 1960s, with most of the credit given to a young surfernamed Sherman Poppen. Poppen joined two skis together for his daughter to surf down thehill on snow. He called this creation a Snurfer (Figure 1 below), coming from the words snowand surf.
Figure 1. Poppens early Snurfer
This spark led enthusiasts like Jake Burton, Tom Sims, and Demetrije Milovich to refine theboard shape and create what is known as the modern snowboard. Snowboarding began to pickup momentum in the late-eighties, underwent rapid growth throughout the nineties and was the
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fastest growing sport in the United States at the year 2000. According to the fourteenth annualAmerican Sports Data Superstudy of Sports Participation, the number of people snowboardingincreased 51 percent from 1999 to 2000, whereas skiing only increased by 6 percent. In just afew short years, the number of snowboarders had grown to over 7.2 million participants, gainingquickly on the 14.7 million skiers [4]. This rapid growth placed an extreme demand on the
snowboard manufacturing industry.
Snowboard technology has evolved drastically over its forty-year history. When Jake Burtonstarted creating snowboards in 1977, he attached water ski bindings to a wooden plank. Theevolution has led to rounded tails, hard boots, and plate bindings. Now you can purchase anasymmetrical, twin-tip (shown in Figure 2 below), carving board, or other designs depending onyour own personal riding style.
Figure 2. K2 Zeppelin twin-tip snowboard
There are two types of snowboard construction. The first is the traditional sandwich construction,in which the sidewall is flat and angled to the base. The second type is called capped, shown inFigure 3 below. In this type of construction, the top sheet is pinched over the sides of thesnowboard to meet the steel edge. Both methods are very similar and only have a few differentsteps. The seven most common ingredients in snowboards are the wood or foam core, fiberglass,epoxy, base, topsheet, edges and binding inserts.
Topsheet
Core
Plastic Base Edge
Laminates
Figure 3. Cross section of a capped-construction snowboard
The wood or foam core is the building block of the board and its shape and thickness are thecharacteristics which affect the flex and weight. Wood is a good material choice because it
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contains long fibers that transmit high-frequency vibrations along the board length, resulting in asmooth ride. Foam is becoming more popular as technology advances, but does not have thelong fibers like wood and therefore these boards usually have more ride vibration, or feelchatty. Bolt inserts are integrated in the core for the mounting of bindings and are typicallymade of stainless steel to avoid rusting. The industry standard is a 4x4, 6mm bolt pattern to
make the adjustment, installation, and removal of bindings as simple as possible.
Construction of a snowboard begins by shaping the base. Next, steel edges are attached to theperimeter of the base. These prevent slipping or sliding while on snow and ice and also assist inturning and controlling speed. Next, fiberglass cloth is applied to the top and bottom of the core.This provides the board with much needed torsional resistance and strength without addingsignificant weight. The direction in which the fiberglass is positioned relative to the board lengthvaries from manufacturer to manufacturer. Next, an epoxy system is mixed thoroughly(consisting of a resin and hardener) and applied to both sides of the core and covered infiberglass. The epoxy system saturates the fiberglass and serves as the binder to laminate thewhole board together. A top sheet is placed above the core for aesthetics and the base is placed
underneath. The board is then placed in a shaped press under extreme pressure to give it aformed nose and tail and also to adhere all of the layers together. After the epoxy system cures,the excess material is trimmed away, the edges sharpened and the snowboard is ready forpacking and shipping to the dealer.
Snowboards made using this construction technique range from approximately $250 to $950,depending on the quality of materials used, with most falling in the $300 to $500 price range.Depending on your demand for ride performance, numerous options allow for each user tochoose the specifications which will match his/her needs best. Even given multiple options, oneaspect is not currently a choice for the new snowboard investor - the use of moreenvironmentally friendly, sustainable materials. Fiberglass, the resin system, top sheet and base
are all manufactured from oil, while the wood core comes from trees. With a growing concernand interest in resource conservation and environmentally friendly design, it is clear that therapidly growing snowboard market is yearning for a design that produces the same performancebut uses resources that are sustainable.
Design Objectives
The following are the key design requirements that we have identified for our snowboard designconcept:
- Must be robust: This takes into account mechanical properties such as Youngs modulus,yield strength and impact strength, as well as the overall durability of the board. Anypermanent deformation of the board after riding is unacceptable. This will be quantified withthe properties mentioned as well as the thickness.
- Must provide good ride: The board must perform well on the slopes by providing superbbump absorption, easy turning/carving, and adequate rider stability. While this depends onseveral factors, we will again look at the mechanical properties, as well as tip radii and boardthickness.
- Should be lightweight: A lighter board is easier to maneuver as well as transport. Weightreduction should be accomplished with different materials.
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- Should have a competitive retail price: Reducing price is not our foremost concern, but wewould like to keep it on par with most other snowboards.
- Must be more environmentally friendly: This is our major objective for the project. Wewill quantify this by the percentage of sustainable materials by volume in the snowboard.Hemp is preferred as a sustainable material due to its counter-culture appeal to
snowboarders.- Must have increased possibility for recycling: This is related to the amount of sustainablematerials. However, we must also devise a way to separate sustainable materials from theother materials in the board, which is a challenge.
- Sustainability should be obvious: From a marketing standpoint, we would like people toknow that our board is environmentally sustainable. This could be accomplished with a clearor partially clear topsheet.
- Must be aesthetically pleasing: Visual appeal is a major factor in customer preference ofsnowboards, therefore ours must be able to catch the eye of riders.
- Should be easy to maintain/transport: Snowboards generally require little maintenance,and we would like ours to be no different.
- Must be weatherproof: Given the outdoor nature of the sport, our snowboard must be ableto withstand freezing temperatures, snow, ice, and water without sacrificing performance.- Must include universal bolt pattern: In order to be compatible with the majority of
bindings, the bolt pattern on the board must be the universal 4x4.- Should be easy to ride fakie (both ways): Part of the freestyle element of snowboarding is
being able to switch which end of the snowboard is in front while riding. Riding with theopposite foot from normal forward is called fakie, and can be done with a twin tip board(with equal tip radii).
In addition to serving as measures of how successful the project will eventually be, theseobjectives are used to determine the key engineering parameters of our snowboard designconcept, as accomplished with a Quality Functional Deployment (QFD). Also, concept selectionis achieved by rating how well each concept would meet these objectives with a Pugh matrix.Both the Pugh matrix (Figure 6, page 7) and QFD (Figure 7, page 8) are discussed and shown inthe Product Description section.
PRODUCT DESCRIPTION
Conceptual Solutions
The two main aspects we examined when developing snowboard concepts were the materialconstruction and the shape, with materials taking precedence. The core of a snowboard isgenerally composed of foam in lower quality boards and different types of wood in higherquality boards. Poplar and ash are generally categorized as woods of medium quality and hardsugar maple is generally used in top end boards. The natural fiber based materials shown inFigure 4 on page 6 represent significant areas of improvement from the view of environmentalsustainability. The use of chopped natural fiber composites, hemp and jute in particular, asreplacement for the core as well as woven hemp composites as replacement for the laminates(typically fiberglass) would dramatically increase the percentage of sustainable materials foundin a snowboard.
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Figure 4. Proposed natural fiber materials for snowboard use
Material testing has been completed and is presented below in the Material Testing section onpage 16. Due to time constraints, we focused our investigation on the replacement of the coresince this represents the largest percent volume of a typical snowboard.
Our survey results have shown that the twin tip snowboard design is preferred to the powderdesign (see Appendix A, Survey Results). The directional shape has virtually no demandassociated with it. These designs are shown in Figure 5 below. These results come from ourweb survey which was completed by 74 people at the time the results were analyzed.
Figure 5. Twin tip (A), powder (B), and directional (C) snowboard shapes considered
The design concepts, which are listed in the Pugh matrix (Figure 6, page 7), are based ondifferent combinations of shapes, core materials and laminate materials.
Concept Selection Pugh MatrixAfter comparing several snowboard design concepts, we have found that the most promising
concept is a twin tip board with a hemp composite core and woven hemp laminate. This isjustified by our Pugh matrix analysis, as shown in Figure 6 on page 7. Time limitations have notallowed us to investigate laminate replacements, therefore we have pursued only the replacementthe core material with a natural fiber composite.
(A) (C)(B)
(a) FlexForm Natural Fiber Composite (b) Woven Hemp
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Shape Twin tip Twin tip Twin tip Twin tip Twin tip Powder Powder
Core FoamFiber
composite
Fiber
compositeFoam Wood
Fiber
composite
Fiber
composite
Design Criteria WeightLaminate Fiberglass Fiberglass
Wovenhemp
Wovenhemp
Wovenhemp
FiberglassWovenhemp
Robust 8 D ++ + - + ++ +
Good ride 10 A + 0 - + + 0Lightweight 5 T + ++ + + + ++
Competitive retail price 6 U - + + 0 - +More environmentally friendly 9 M + ++ + + + ++
Increased possibility of recycling 8 . + ++ + + + ++Sustainability is obvious 7 D + ++ + + + ++
Aesthetically pleasing 6 A + + + + - -Easy to maintain/transport 6 T - -- - -- - --
Weatherproof 10 U 0 - - - 0 -Universal bolt pattern 4 M 0 0 0 0 0 0
Easy to ride fakie (both ways) 3 . 0 0 0 0 - -+ 0 61 78 41 53 55 72
0 82 17 7 7 13 14 14- 0 12 22 34 22 21 31
Total 0 49 56 7 31 34 41
Snowboard Design Concepts
Figure 6. Pugh matrix indicates most promising design incorporates natural fibers in both core and laminate
In the Pugh matrix, we examined whether each of six design concepts would be better than (+),worse than (-), or equivalent to (0) our datum snowboard at meeting each design criterion. Thedatum was the Rossignol foam core twin tip board which we previously benchmarked. The basisfor the + and marks in the chart was the research we have done in the last month on bothsustainable natural fiber materials (composite and woven) and how they compare to currentsnowboard construction materials (foam, wood, fiberglass). Quantified details are discussed onpage 9. Overall, we were unsurprised to see that the concept with the highest score incorporatedboth a natural fiber core and laminate in a twin tip design. Unfortunately, time has limited ourinvestigation into the woven fiber laminates and therefore our efforts have been solely on thecore material replacement. This decision was made based on the fact that the core materialrepresents a much larger percent volume within a snowboard.
Design Requirements Quality Function Deployment
On page 4, the key design objectives for our snowboard concept were stated and summarized.These objectives are key ingredients of the Quality Function Deployment (QFD) matrix, shownin Figure 7 on the following page. The design parameters are listed along the top of the matrix,and their contribution to the design objectives is quantified on a 1-3-9 scale. Totaling thesescores gives us an importance rating for each of the parameters, based on how well they help toachieve the objectives. The most important parameters to focus on are the external finish of theboard, the percentage of sustainable materials, and the outside visibility of these sustainablematerials. The QFD also shows the tradeoffs between design parameters in the triangularcorrelation matrix. The important tradeoffs we found were between the mechanical properties(Youngs modulus and tensile strength) and the weight of the board. Ultimately, we wouldprefer to have a strong, heavier board than a weak, lighter board. On the right side of the matrix,our hemp snowboard concept is benchmarked against two existing boards (Appendix B) withdifferent material construction. We expect that our concept will be the best at meeting most ofthe design objectives, although potentially sacrificing aspects such as price and maintenance.These parameters will be used mainly for optimization of the design.
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Figure 7. Quality Function Deployment matrix assisting with parameter importance and benchmarking
Weight Young
'sMo
du
lus
(+)
Tens
ileStreng
th(+)
Impac
tStreng
th(+)
We
ight(-)
Thickness
(-)
Pro
duc
tion
Cos
t(-)
Sus
taina
bleMa
teria
ls(+)
VisibleSus
taina
bleMate
ria
ls(+)
Ex
terna
lFinish(+)
Difference
inTipRa
dius
(-)
Num
bero
fBo
ltHo
les
/P
attern
(std)
Coe
fficien
to
fTherma
lExpans
ion
(-)
HempCompositeSnow
boardConcept
K2ZeppelinWoodCoreSnowboard
RossignolFoamCoreSnowboard
Robust 8 9 9 9 3 3 1 4 5 3Good ride 10 9 3 3 3 3 1 1 4 5 3Lightweight 5 9 9 1 5 3 4Competitive retail price 6 1 1 1 9 3 1 1 4 2 5More environmentally friendly 9 9 1 5 2 1Increased possibility of recycling 8 9 3 4 2 1Sustainability is obvious 7 9 9 4 3 1Aesthetically pleasing 6 3 9 9 1 5 5 2Easy to maintain/transport 6 1 9 1 1 4 4 4Weatherproof 10 1 1 3 9 3 3 4 4Universal bolt pattern 4 1 9 5 5 5Easy to ride fakie (both ways) 3 9 5 5 5
GPa MPa Pa kg mm $ % % 1-10 mm # 1/K4 40 - 2.9 11 - 50 75 9 0 8 -4 6 6 8 5 9 2 3 1 11 12 10
168 108 108 75 127 64 186 162 315 43 42 540.116 0.07 0.07 0.05 0.09 0.04 0.13 0.11 0.22 0.03 0.03 0.04
12 - - - 12 - 0 3 9 0 8 -0.003 - - - 11 - 0 0 4 0 8 -
Normalized
Measurement Unit
Target Value
Importance Rating
Total
5.09 45.9 2.59 11 150 52 10 0 8Hemp Composite Snowboard Concept
K2 Zeppelin Wood Core SnowboardRossignol Foam Core Snowboard
--
-
++
+
+
++
++
-
+- +
+-
++
++ + + + +
+-
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Quantifiable Design RequirementsExamining our design requirements for parameters which can be quantified and eventuallyoptimized, we first looked at the main focus of our project, which is the sustainability of thesnowboard. We have decided to quantify the sustainability by the percentage of sustainablematerials by volume. This is an important quantity which we are targeting to be 50%. Greater
than 50% can be achieved, but this number represents a major improvement already overexisting snowboards.
As important as sustainability is to our design, we cannot sacrifice strength of the board andquality of the ride. Therefore we must look at the key quantifiable mechanical properties,including Youngs modulus, yield and impact strength, and potentially the coefficient of thermalexpansion.
Another quantity which we have optimized is the weight of the board, making it as light aspossible for easy maneuvering. Our target value is 2.9 kg for a board length of 156 cm, which ison par with some of the lighter boards on the market. The weight will depend on quantities we
can change, such as board thickness and width, as well as the densities of the materials used. Weoptimize these parameters by going through a series of core materials, which integrate setdensities into the solver program. The mechanical properties can also be set for each materialand are determined from research and testing; for example, we have determined through testing(described on page 16) that the modulus of the FlexForm natural fiber composite is 5.09 GPa.
While price is not a technical quantity, it is heavily dependent on the values of engineeringparameters. Since our market research indicated that snowboarders are not willing to pay asignificant additional amount despite the sustainability of the board, we need to minimize price.Price will be a function of the amount of each material used, which will have fixed costs on avolumetric basis. Because we do not foresee the need for any new or more complicatedmanufacturing methods in the fabrication of the natural fiber snowboard concept, the focus willbe placed on the materials. Issues dealing with price and cost, as well as potential profits, arediscussed in our Initial Microeconomic Analysis on page 20 and our Marketing Analysis on page22.
The formulation of quantifiable design requirements helps to develop an engineering analysis inwhich parameters are optimized. This analysis is described on page 13.
Project Prototypes
To help visualize and communicate possible solutions, we created a rapid mockup prototype,shown in Figure 8 on page 10. The goal of this prototype was to ensure that each member of theteam understood the order of different layers that would be implemented (Figure 3 on page 3).This prototype was made from scrap products such as different types of foam board and pieces ofcloth, but accomplished its goal, as anyone we showed it to was able to understand (with anexplanation) what different layers would compose our new design.
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Topsheet
Laminates
Figure 8. Initial rapid prototype of snowboard cross section
Next, a CAD model of the cross-section was produced (Figure 9 below) to introduce materialproportions and overall dimensions.
Figure 9. Conceptual snowboard cross section with proposed materials
Then, knowing that our new concept would have the same edge, base and top sheet as most
existing snowboards, we decided to construct the next prototype (alpha) using a section of aRossignol foam core board, pictured in Figure 10 on the following page. The foam core wasremoved by sawing and sanding, until only the fiberglass, base, edges, and top sheet remained.A non-woven composite material made from a blend of jute fibers (a derivative of hemp) andpolypropylene, called FlexForm, was discovered and we hoped to use this material as thereplacement core. However, FlexForm is currently only available in 2mm thick sheets and wehad to epoxy three layers together to achieve the desired thickness for the core. For this
Topsheet
Hemp Composite Core
Plastic BaseEdge
Woven Hemp
Laminates
Core
Base
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prototype we wanted to show what a cross-section of the new design would look like comparedto an existing one.
FlexForm compositecore
(replacement)
Foam core(existing)
Figure 10. Alpha prototype depicting section of foam core board with FlexForm composite replacement
A three-dimensional model of the FlexForm core was created in AutoCAD modeling softwareand was then exported to 3D Studio Max where our topsheet design was applied. Figure 11below shows the 3D rendering of the beta prototype. This design work is particularly importantgiven that the external finish of the board was the top ranked design parameter on our QualityFunction Deployment model (Figure 7, page 8). The design below also incorporates visibility ofthe sustainable core material, a design parameter which ranked third on our QFD.
Figure 11. Three dimensional rendering of the beta prototype
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Our beta prototype was constructed from a 1600x300x6mm sheet of FlexForm. From this sheet,the core was created by cutting out the shape and then tapering the thickness from one end to theother. With the base material on the workshop table, the lay up of the snowboard wascompleted in the following steps: application of epoxy to base, first layer of fiberglass, epoxy,FlexForm core, epoxy, second layer of fiberglass, epoxy. It would be at this point in the
manufacturing process that the board would be placed in a press to shape the tip and tail of theboard and to squeeze excess epoxy out from between the layers. Our design team did not haveaccess to a press at the time of making the beta prototype, so there are no contours to our boardand contains excessive epoxy, making the board heavier than we anticipate for a production levelboard. We also neglected edges and binding inserts in our prototype due to additionalmanufacturing limitations. After allowing the epoxy sufficient time to set, a final topcoat ofepoxy was applied to enhance the glossiness and finish. The triaxial fiberglass, base materialand epoxies were purchased from a snowboard material supplier, SnowboardMaterials.com [10].With the epoxies fully set, the excess fiberglass and base material were cut away and thesidewalls sanded down. The lay up of our beta prototype is shown below in Figure 12.
Figure 12. Beta prototype lay up
A decal of our company logo was then applied to the center portion of the board. The completedbeta prototype is shown in Figure 13 on page 13.
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Figure 13. Completed beta prototype
ENGINEERING ANALYSIS
Design Optimization
Once we decided on our final design concept of a twin tip board with a core made of sustainablematerial and all other materials the same as current boards, the next step was to optimize thedesign. For simplification given the allotted time, two main objectives were examined therobustness, or rigidity, of the board (desire to maximize), and the weight of the board (desire tominimize). Intuitively, we realized that there is a tradeoff between these two objectives. Otherobjectives were either unable to be optimized with engineering analysis, not as important to theoverall design, or too complex to analyze.
To complete the optimization, we needed to decide on the engineering parameters that we couldchange to influence both the robustness of the board and the weight. This led us to look atestablishing several key dimensions as the variable parameters. The variable parameters arelisted in Table 1 and depicted in Figure 14, both on the following page.
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Dimension Designation
Width of board at center wcThickness of board at center tcWidth of board at end weThickness of board at end te
End of board to binding aDistance between bindings b
Length of contact with ground L
Distance between contact surfaces e
End of board to contact surface d
Table 1. Dimensions used as variable engineering parameters for design optimization
we wc we
te tc
l ed l d
a b c = aw w
L
Figure 14. Illustration of board dimensions used in engineering analysis
The analysis models used to compute the objective and constraints in terms of these designvariables were broken up into two groups of functions beam deflections/loads based onequilibrium analyses, and a simplified weight calculation. For the equilibrium analyses, thesnowboard was treated as a beam and five load cases were applied, as listed in Table 2 below.
Load Case Description Result1 Rider standing on board, flat surface Middle deflection, v(L/2)
2 Rider standing on board, upside down Middle deflection, v(L/2)
3 Riding on rail, board longitudinal End deflection, v(0)
4 Board cantilevered, point load on end Maximum load, Pmax5 Board cantilevered, uniform distributed load Maximum load, Pmax
Table 2. Load cases used in equilibrium beam analysis
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This beam analysis was partly inspired by a similar (but more complex) snowboard structuralanalysis conducted at the University of Rome in 2005 [7]. Complete derivations of the functionsfor the results given in Table 2 can be found in Appendix C.1, along with more details on theequilibrium analyses performed.
Weight of the board (specifically the core) can be calculated by multiplying the density wedetermined for the core material by the volume of our core design in AutoCAD, however weneeded to formulate a model for the weight which depended on the variable parameters; this isthe simplified weight model. The simplified weight model is derived and explained in AppendixC.2.
For the engineering optimization, we want to maximize robustness, which would be achieved byminimizing the three deflections in Cases 1, 2, and 3 while maximizing the maximum allowableloads from Cases 4 and 5 (see Appendix C.1 for load case descriptions). Note that absolutevalues are needed for the deflections, since they are originally negative. We also want tominimize weight, and in this case minimize the simplified weight. Based on these decisions, an
objective function was formulated as follows:
Y = [(v1/v1,orig) + (v2/v2,orig) + (v3/v3,orig) + (Ws/Ws,orig)] / [(P4/P4,orig) + (P5/P5,orig)]
Notice that each output value is normalized to its original value based on the averages of thedesign variables collected from snowboard benchmarking.
This objective function Y, the design variables, and other key parameters and constants werecoded into Microsoft Excel for optimization. In addition, the variable dimensions wereconstrained so that they must stay within +/- 5% of the original values, which were based onbenchmarking averages. The material properties that we determined for FlexForm (density,Youngs modulus, tensile strength) were used in the spreadsheet for the calculations. Thespreadsheet also includes intermediate results such as maximum stresses in the snowboard sothat we can easily compare them to numbers such as the yield strength and observe how thelikelihood of failure changes. The original design spreadsheet can be found in Appendix D.1.
The Solver utility, minimizing the objective function, was run several times with different initialvalues. The solutions that were generated confirmed the tradeoff between weight androbustness, and while we were getting very small deflections and large allowable loads, theweight was very high. Although this was actually somewhat desirable, since we are placing agreater emphasis on the board being robust than lightweight, we ended up constraining theweight to a maximum of 2.5% greater than the original. With this additional constraint, wegenerated a solution that is optimized to our design preferences. The original and optimizedvalues for the variable parameters as well as engineering results (including the objectivefunction) are given on the following page in Tables 3 and 4, respectively. In addition, theoptimized spreadsheet can be found in Appendix D.2.
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Dimension Original Value (m) Optimized Value (m)
wc 0.24765 0.23527
tc 0.01 0.0105
we 0.25087 0.25304
te 0.005 0.00525
a 0.46355 0.47255 b 0.35985 0.34186
L 0.127 0.13335
e 1.052 1.0266
d 0.127 0.13335
Table 3. Original and optimized snowboard dimensions
Result Original Value Optimized Value
Y 2 1.65332
Ws 2.65190 kg 2.71820 kg
v1 0.25681 m 0.23163 m
v2 0.45480 m 0.42023 m
v3 0.11523 m 0.09519 m
P4 19.387 N 21.559 N
P5 37.774 N 43.118 N
Table 4. Original and optimized engineering results (note deflections are absolute values)
It is important to note that as far as materials, this engineering analysis was performedconsidering the core of the snowboard only. Because of this, the numbers for deflections andloads do not reflect predicted values for the actual snowboard. For example, the addition of
fiberglass layers greatly enhances the Youngs modulus of the board, which will reduce thedeflections. In this engineering analysis, the deflections, maximum loads, and weights were usedsimply to generate optimum values for the variable dimensions.
Also, since material properties such as density and Youngs modulus are discrete and depend onthe specific material used, these could not be varied continuously. However, we are able tosimply substitute in properties for a given material and observe how the results of theoptimization change from material to material, which ultimately will help us to verify ourmaterial choice.
Material Testing
To determine the validity of our core choice, FlexForm, tensile testing was performed on fourdifferent samples. This allowed us to quantify material properties for this composite.
First, we crafted tensile load testing samples of the FlexForm composite material. This wasachieved by drawing the dog-bone shaped samples (Figure 15 on page 17) in BobCAD, andthen cutting them using the laser cutter in the G.G. Brown machine shop.
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Figure 15. Tensile load testing samples of FlexForm
Each of these samples was tested on the Instron 4206 at a rate of 0.1 inches/minute until failure.
The data was recorded and interpreted using Labview 7.0 and Microsoft Office Excel. Theloading force and microstrain were compared and used to produce the relationship between stressand strain. This relationship was plotted as shown in Figure 16 below. Figure 16 displays thedata for sample D, but all produced very similar plots and values for Youngs Modulus and theultimate tensile strength.
Flexform Sample 'D' Stress-Strain Relationship
0
5
10
15
20
25
30
3540
45
50
0 0.005 0.01 0.015 0.02
Strain
Stress(MPa)
Ultimate Tensile
Strength = 45.9 MPa
Youngs Modulus = 5.09 GPa
Figure 16. Tensile testing results for FlexForm sample D
The testing showed that Youngs modulus was approximately 5.09 GPa, the ultimate tensilestrength was 45.9 MPa, and the density was 801 kg/m3, with the value for Youngs Modulus and
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density being most pertinent to this project. The values obtained for the other samples werewithin 5% of these stated values. The plot does not display a clear yield strength, which leads usto believe that this material may be viscoelastic. However, due to high levels of equipment usefrom ME 395/495, we were limited from doing additional tensile testing at different loadingrates.
To validate our testing results and give reason to believe that this material would functionacceptably as a snowboard core, we compared the material properties of FlexForm to existingsnowboard core materials (polyurethane microcellular foam, birch, ash, maple). Thiscomparison (Table 5 below) showed that FlexForm was on the high end for density, but stillwithin range. The Youngs Modulus of FlexForm was between the values for the foam andwood, which leads us to believe that this material might give a performance between that of afoam and wood core board. Although this does not mean that FlexForm will definitely work as acore replacement, it does suggest that it is a possibility.
Core Material Density (kg/m3) Youngs Modulus (GPa)
FlexForm 801 5.09Polyurethane Microcellular Foam 700-750 0.0032-0.0036
Birch 620-740 14.7-17.9
Ash 490-600 10.9-13.3
Maple 640-780 12.5-15.3
Table 5. Core material comparison
FlexForm Technologies does not commercially produce a 6mm thick sheet of FlexForm, as wedesired. Our contact informed us that the only way to achieve this thickness was to layer three2mm sheets, heat them until the polypropylene binder liquefied, and then let them cool under
pressure to form one sheet. FlexForm Technologies agreed to perform this service and shippedus a 1600x300x6 mm sheet, which was then cut and shaped to our optimized design parameters.Fiberglass, a base and two-part West Systems epoxy were used to complete the assembly.Although we strongly desired to compare our prototype material properties to those of existingsnowboards, the time permitted for this project did not allow for this. Final labs occurring in ME395/495 also severely limited the amount of testing equipment time we had available. However,using a very rough, but practical estimate of flexing different snowboards including our betaprototype by hand, our board seemed to have a reasonable rigidity. Should interest in this projectcontinue into the future, testing of the prototypes Youngs modulus, torsional resistance,binding insert strength and resistance to moisture absorption would be strongly desired.
AESTHETIC ANALYSIS
Our Quality Function Deployment matrix (Figure 7, page 8) shows the external finish of oursnowboard as the top ranked design parameter and the visibility of sustainable materials beingthe third. The importance of these parameters is reflected by the aesthetic design work we havecompleted. Firstly, we have developed a company logo which reflects our eco-friendly values as
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a company. This logo, which incorporates an image of the world encompassed by a leaf, isshown below in Figure 17.
Figure 17. Eco-Core company logo
In order to allow for high visibility of our sustainable core material, a clear topsheet will beimplemented in addition to the clear laminate layer above the core. This topsheet is representedbelow in a 3D Studio Max model and is also shown on our beta prototype (Figure 13, page 13).Our company logo will also be applied to the center portion of the topsheet.
Figure 18. Topsheet graphics
The shape of the snowboard was derived from our market surveys which showed the highestdemand for the twin tip board shape (Appendix A.1). Using Microsoft Excel coupled with aproportionality macro, we were able to evaluate the dimensions of our CAD model based oneleven different proportionalities. The overall proportionality percentage value for our model is51.43%. The output of the Excel proportionality macro and the variable dimensions are shownbelow in Table 6.
Table 6. CAD model variable dimensions used for proportionality analysis
Dimension Value (mm) Minimum (mm) Maximum (mm)
Sidecut Length 1250 1245 1260
300
300
11005
150
150
12
Tail Width 290 285
Nose Width 290 285
Sidecut Radius 11000 11000
Nose Radius 146 140
Tail Radius 146 140
Body Extrusion 7 2
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INITIAL MICROECONOMIC ANALYSIS
This section explains how we optimized the design using a postulated microeconomic analysis,specifically by maximizing profit. Equations 1 and 2 give the profit function where Q is thequantity of boards sold per year, P is the price per board and C is the cost per year.
CQP=
++= dPPQ (1,2)
In equation 2 above, theta () was estimated by researching the current snowboard market. It isestimated that there are 12 million people who currently snowboard [8], of which weapproximate that one-third will be interested in purchasing a new board this year. As the price ofour snowboard approaches zero, we are able to conclude that the interested population is about1% of the total market, equal to 40,000 ().
By researching current and past designs from major snowboard manufacturers we were able to
conclude that the maximum price we would be able to charge for a board would be about $1000.Using this information, combined with value of theta, we were able to determine the pricesensitivity (p = -4000). Demand can increase with optimized parameters of the board, thereforewe can approximate a new demand curve based on our own design parameters. Theseparameters would shift the curve outward without affecting the slope (p). With our optimizedparameters, we estimated that no one would pay more than $1100 for a board, even with ouroptimized parameters, and declared this the new maximum price. With the slope constant, p =
-4000, we were able to determine the new value of theta (n = 44,000). The quantity ( d ) is
equal to the difference between n and and found it to equal 4,000. This quantity represents therelationship between our design parameters and change in price as well as product demand,multiplied by a constant.
The three design characteristics we chose to evaluate in the microeconomic model are weight,stiffness, and percent volume of sustainable materials. Our survey results showed that ourcustomers demand an increase in percentage of sustainable materials in snowboards. Lowerweight and a board with optimized stiffness are also demanded by our consumers. Table 7below shows how each of these changes in design characteristics affect price.
Design Characteristic Effect on Cost (per board)
Weight (Decrease by 10%) +$15
+$10
+$15
Stiffness (Optimized)
Percent Volume of Sustainable Materials(Increase by 50%)
Table 7. Consumer design characteristic optimization and effects on cost
The cost function (equations 3 and 4, page 21) was also difficult to determine and involvedsignificant estimation.
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100000250*)(C
FC+Q(VC)C
+++=
=
dpP(3,4)
Where:VC is the variable cost per board, estimated to equal $250
FC is the fixed cost of operating per year, estimated to equal $100,000
The variable cost per board was estimated using data supplied by our sponsor company. Thefixed cost of operating was a much rougher estimate, encompassing costs such as rent,equipment, licenses, and insurance. This leads to an overall profit equation (5).
100000250*)()( ++++= dpdp PPP (5)
Demand and profit functions were plotted for both the current parameters and our optimizedparameters. This is shown in Figure 19 below.
4 6
Profit from Current Model
Demand from Current ModelProfit from Optimized ModelDemand from Optimized Model
Figure 19. Demand and profit functions for a board with current and optimized parameters
This model shows that when producing this product with current design characteristics, weshould be selling our boards at $625.00 to maximize profit. With the optimized parameters, our
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selling price should be set at $675.00 to maximize profit. It is important to note that according tothis model, the new design parameters should lead to an increase of 2,000 more snowboards peryear and a profit increase of $260,000 of profit per year. According to FlexForm Technologies,the increase of purchasing 2,000 more snowboard cores per year will not lead to a decreased costper unit. Similarly, our sponsor company stated that this increase would not decrease their
variable cost per board. Therefore, we should aim to sell the board with our design parameters ata price of $675.00, hoping to achieve a yearly profit of $720,000. Uncertainty in this analysis isaffected most significantly by the estimated design sensitivity. Should this value be much loweror higher than expected, the predicted profit may change.
MARKETING ANALYSIS
In order to develop a modified microeconomic model which better represents the demand for ourproduct, we re-examined our market size and conducted a choice based conjoint surveyincorporating different levels of price and design characteristics.
After re-evaluating the snowboard market landscape, we realized that the market is dominated bylarge companies. The largest is Burton, which controls roughly 40% of the market, howeverthere are several second-tier companies such as K2, Forum and Gnu that each claim a good sizeof the market as well (5-15%). These companies have all been around for at least a decade, andtheir capital and resources greatly exceed that which our company would be able to obtain atstart-up. Therefore, of the 4 million people that are looking to buy a new snowboard each year,we now estimate that we can capture a maximum of 10,000, or 0.25% of the total market size.This would be a niche market of environmentally-conscious snowboarders, or simplysnowboarders looking for something unique in their board to be distinguished.
To determine customer preferences based on our snowboards key design characteristics, weassembled a choice based conjoint survey. Three levels were assigned to each of the productcharacteristics from the previous microeconomic analysis (weight, stiffness, and percentage ofsustainable materials) as well as price. The survey was administered to approximately 200members of the Michigan Snowboard Club, and the results generated part-worth (beta) valuesthat gave an indication of utility, as shown in Table 8 below.
Weight
Level Light (2.35 kg) Medium (2.55 kg) Heavy (2.75 kg)
Estimated Beta 0.23169 0.24820 -0.47989
Stiffness Factor
Level Low (65) Medium (80) High (95)
Estimated Beta -0.11127 0.19322 -0.08195% Sustainable Materials
Level Low (10%) Medium (35%) High (70%)
Estimated Beta -0.50767 -0.02791 0.53558
Price
Level Low ($300) Moderate ($450) High ($600)
Estimated Beta 0.58615 0.19435 -0.78050
Table 8. Choice based conjoint survey levels and results, indicating utility of characteristics
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It is important to note that the survey was worded in qualitative terms rather than quantitativeterms, such that consumers could relate to their own snowboarding experience. Please seeAppendix E for examples of the choice based conjoint survey questions. It is also important tonote that in order to quantify the stiffness and link it to our design parameters for profitmaximization, we came up with a stiffness factor, described by equation 6 below:
321
54
vvv
PPactorStiffnessF
++
+= (6)
Where Pi is the maximum allowable load in load case i and vj is the deflection in load casej (seeEngineering Analysis on page 13). This way, a higher stiffness factor represents a stiffer board.
The results of the survey can be better interpreted in graphical form with a spline functionapplied. These results are depicted in Figure 20 below.
Stiffness Factor
-1
-0.5
0
0.5
1
0 20 40 60 80 100PartWorths
Weight
-1
-0.5
0
0.5
1
2.30 2.40 2.50 2.60 2.70 2.80PartWorths
% Sustainable Materials
-1
-0.5
0
0.5
1
0 20 40 60 8PartWorths
Clearly, a heavy snowboard is highly undesirable, while there is relative consumer indifferencebetween a light and mid-weight board. While medium stiffness is most desirable, the range ofbeta values is small enough that stiffness is not a significant factor in the minds of consumers.However, the percentage of sustainable materials is a major factor, with a high percentage (70%)being most desirable. Also, price is a major factor in the purchase, as expected. Essentially, welearned from these results that snowboard consumers are willing to sacrifice stiffness for a boardthat is not heavy, has a high amount of sustainable materials, and can be sold at a moderate price.
0
Price
-1
-0.5
0
0.5
1
$- $200 $400 $600 $800PartWorths
Figure 20. Part worth (beta) values for varying levels of design characteristics, indicating market utility
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To formulate a modified demand model with these beta values, we applied the logit model andthen linearized the demand function. Applying the logit model (with the spline function)allowed us to generate theoretical part worth values for the design characteristics on a continuousscale over the ranges specified in the survey. We were then able to linearize the demandfunction for our snowboard by using a Taylor series expansion and quantifying the finite
differences associated with a small movement from a base design board. This base design,which was generated from benchmarking current snowboards, had a weight of 2.65 kg, astiffness factor of 70.3, a medium percentage of sustainable materials (35%), and a price of $450.The linear elasticities were then calculated with equation 7 as:
bb
bxbx
xx
=
05.1
05.1 (7)
Where x is the elasticity of design characteristic (or price) x, xb is the base design level ofcharacteristic (or price) x, Q1.05xb is the market demand associated with an increase of 1.05 timesxb, and Qb is the market demand of the base design. The new linear elasticities are listed in
Table 9 below.
Product Characteristic Linear Elasticity of Demand
Weight -10935.92 boards/kg
Stiffness 41.34 boards/sf
% Sustainable Materials 34.88 boards/percent
Price -16.06 boards/dollar
Table 9. New linear elasticities for snowboard characteristics, determined from survey results
The spreadsheet in which these elasticities were calculated can be found in Appendix F.1.
Modified Microeconomic Analysis
A modified demand model for the snowboard was generated from equation 2 on page 20 byplugging in the new linear elasticities as well as our new market size () of 10,000. The costmodel was also reformulated by examining the necessary resources for producing 10,000 boardsor less per year. The modified fixed cost per year came out to be $990,000, which included thesalaries for 17 employees (2 managers, 3 engineers, 2 marketing/sales reps, 2 maintenanceworkers, and 8 production employees), the cost of snowboard manufacturing equipment [10], thecost of renting a 15,000 square-foot facility in Colorado [11], and utilities [12], plus other minorcosts. The variable cost per board came out to be $15.50 per kg of core material [5] and $110 forthe remainder of the board [10].
With these modified demand and cost models in place, the design parameters of the snowboard(dimensions from Engineering Analysis, page 13) as well as the price were optimized usingMicrosoft Excels Solver to maximize profit while meeting the engineering constraints. Table 10on page 25 shows how the design parameters changed from the original benchmarked values, tothe optimized values from the Engineering Analysis, to the final optimized values from theModified Microeconomic Analysis.
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Dimension Original Value (m)Engineering
Optimized Value (m)
Microeconomic
Optimized Value (m)
wc 0.24765 0.23527 0.24764
tc 0.01 0.0105 0.00971we 0.25087 0.25304 0.25086
te 0.005 0.00525 0.00502
a 0.46355 0.47255 0.46355
b 0.35985 0.34186 0.35985
L 0.127 0.13335 0.127
e 1.052 1.0266 1.052
d 0.127 0.13335 0.127
Table 10. Original and optimized snowboard dimensions (from both engineering and microeconomic standpoints)
The resulting design characteristics from these parameters are shown in Table 11 below. Note
that while weight and stiffness factor are functions of the design parameters, percentage ofsustainable materials is determined exogenously.
Characteristic OriginalEngineering
Optimized
Microeconomic
Optimized
Weight (kg) 2.6519 2.7182 2.5906
Stiffness Factor 70.3 86.6 65.0
% Sustainable Materials 35 70 70
Table 11. Original and optimized snowboard characteristics (from engineering and microeconomic standpoints)
With the design parameters optimized for maximum profit, the revenue, costs, and profitassociated with a range of prices were calculated and plotted, as shown in Figure 21 on page 26.See Appendix F.2 for the base spreadsheet.
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Figure 21. New microeconomic model with modified demand function depicting revenue, costs, and profit
Eco-Core Snowboard Simple Profit Model
$0.00
$500,000.00
$1,000,000.00
$1,500,000.00
$2,000,000.00
$2,500,000.00
$3,000,000.00
$0.00 $200.00 $400.00 $600.00 $800.00 $1,000.00
Product Price
Value Revenue
Cost
Profit
The profit is maximized when the price is set to $440, which is the price at which we will sellour snowboard. At this price, the modified microeconomic model predicts a profit of $344,000.Note that this analysis is only for the first year of operation, and in future years we are assuminga potential market growth of 5%, which will slightly change the optimum price (namely anincrease to $460 in the second year).
In the end, we have used consumer input to optimize our snowboards design parameters andprice in order to maximize profit. When we conducted our Engineering Analysis, we wanted tomaximize stiffness while keeping the weight from being extremely high. However, when theoptimized parameters from the Engineering Analysis are used in the modified microeconomicmodel, the predicted profit is only $191,000, just more than half of the profit predicted with theoptimized parameters from the microeconomic analysis. The reason for this difference isbecause we put too much focus on stiffness, as it turned out that it is not a major factor forconsumers. Our final optimized snowboard design has a low stiffness, but also a relatively lowweight, which is desirable. It is also interesting to note that if the percentage of sustainablematerials is set at 35%, the maximum profit is only $15,000 (which would be accomplished at a
price of $400). Therefore by increasing the percentage of sustainable materials to 70%, we canearn roughly $330,000 more in profit.
As it turns out, replacing the core of the snowboard with the FlexForm natural fiber composite isvery appropriate. While the stiffness of FlexForm is relatively low compared to wood, theweight can kept at a low-medium level, and most importantly, the percentage of sustainablematerials in the board by volume is increased to approximately 70% (based on the relativevolume of the core).
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PRODUCT DEVELOPMENT PROCESS
The block diagram in Figure 22 below depicts the steps required to go from our originalidentification of the demand for a sustainable snowboard to the potential fabrication of a workingnatural fiber snowboard prototype. The design structure matrix (Figure 23, page 28) is similar to
the product development process chart but displays tasks in matrix form to identify straight anditerative transitions (iterative to the right of the diagonal).
Beyond scope of this project
Figure 22. Product development process for snowboard
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1 2 3 4 5 6 7 8 9 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
Identify problem 1
Recognize need and/or want 2 X X
Research existing products 3 Note color of box
Brainstorm ideas to address need/want 4 X Designer
Examine feasability of ideas 5 X X User/Customer
Research ideas 6 X Producer
Discuss pros/cons of ideas 7 X X X Designer and Producer
Market research 8
Select design conept 9 X X
Illustrate concept (alpha prototype) # X
Identify target market # X
Identify customer requirements # X
Identify engineering requirements # X
Develop key design parameters # X X
Determine market utility for design characteristics # X X
Determine market size # X
Determine necessary capital/resources # X
Cost modeling # X
Develop design elasticities # X
Link to design parameters # X X
Benchmark similar products in existence # X
Formulate target values for design parameters # X X
Initial design of product # X
Virtual modeling # X X
Design for emotion # X
Develop aesthetics # X
Design to meet engineering targets # X X X
Design for feasible manufacturing #
Optimize design (max profit, meet eng. constraints) # X X X X X X
Make financial projections # X
Construct prototype (beta) # X X
Internal testing # X
Market testing #
Review design #
Develop manufacturing plan #
Verify financial predictions call for success #
Initial production runs #
Identify/fix problems #
Final product #
There were essentially four main stages of the product development process that were completed.The initial stage, which involved identifying the market demand for a sustainable snowboard,recognizing the desire for a counter-culture board material such as hemp, and brainstormingways to incorporate hemp into a snowboard design was the first step taken. We came up withseveral ways that hemp could be used, but after researching existing snowboard construction andthe construction of hemp composites and weaves, we narrowed our ideas down to a natural fibercomposite core and/or a woven natural fiber laminate.
The next stage, involved selecting the design concept and defining the parameters to startfocusing on. A Pugh matrix was used (Figure 6, page 7) to select the most promising designconcept from a host of material and shape combinations, which turned out to be a twin tip boardwith a natural fiber composite core and woven natural fiber laminate. An alpha prototype(Figure 10, page 11) has been constructed to illustrate our design concept. In conjunction with amarket research survey, a QFD (Figure 7, page 8) was used to translate customer requirements,such as a competitive price and high content of sustainable materials, into design parameters.Our decision to shift our design focus to the core alone (rather than the laminate layer) was alsopart of this stage. Modifying both the core and the laminate layer would entail extensiveengineering analysis that would require additional education and far more time than was allottedfor this course, and was therefore out of the scope for this project.
X
X X X
X X
X
X X
X
XBeyond the scope of this project
Figure 23. Design Structure Matrix tracking the product development process
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The third stage involved optimizing the snowboard design concept from an engineering,manufacturing, marketing, and financial perspective. We completed the engineering andeconomic analyses as described on pages 13 and 20, respectively. Our first survey results, aswell as results from a revised survey, supplied us with marketing input that was used to enhancethe engineering and economic analyses. Specifically, the revised survey, in conjunction with
Sawtooth SSI Web software, provided part-worth values (an indication of utility) for each ofthe design characteristics of weight, stiffness, price, and percent sustainable materials. Thisenabled us to formulate a modified demand model for our product, which led to optimization ofthe design parameters to maximize profit. These values, along with the QFD matrix, helped usto conceptualize and build a prototype with the most desirable characteristics.
Construction of the beta prototype, a full-scale model, was the final stage of this project. Thisrequired obtaining the necessary materials from online resources, stacking the layers, andcompleting assembly by bonding with two-part epoxy. Ideally, a snowboard should beassembled as previously described and then subjected to very high pressures in a snowboardpress and allowed to cure. Lacking this resource, we assembled the board without a press and
still achieved a very aesthetically appealing prototype.
Our final product development process model changed over the duration of this project. Eachteam member created their own plan at the beginning of the project. Goals and the amount ofwork spent on each phase differed slightly between members. As the project progressed, certainlimitations, specifically time, equipment, and extensive knowledge of advanced materials, helpedus to mold our individual plans into one model. We began to see that it was no longer feasible toinvestigate the replacement of both the core and reinforcing layer. We also determined thatphases such as durability testing, completing a production run, or verifying financial predictionsby monitoring sales were advanced stages and were not in the scope of this project.
PRODUCT BROADER IMPACT
As previously described, snowboards have existed in different variations for over forty years,gaining most popularity in the last fifteen. Our product is not a new invention but not all greatideas are. Take the Apple computer corporation for example. Apples and PCs were developedaround the same time and each had their own advantages. However, as time progressed, PCsstarted to dominate the market and Apples sales began to fade. In the late 1990s, however,Apple made changes that addressed the weaknesses of the PC, namely reliability and ease of use.By creating computer and digital media players that were more intuitive, aesthetically appealing,and overwhelmingly reliable, Apple regained a large portion of the market. The samephilosophy is true for our product. Our goal was not to produce the strongest or lightestsnowboard on the market. Rather we focused our efforts on a product that the user could connectto emotionally, aesthetically, and even environmentally.
If we could produce a product that meets current snowboard standards while using materials thatplace less stress on our environment, had an emotional appeal to the counter-culture, and couldhelp to encourage others to be more eco-conscious, we would consider this concept a success. Ifwe found potential ways to reduce weight or achieve better material properties, that would be
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even better but not essential. We feel that this product would be successful especially because ofits emotional and aesthetic appeal.
At the start of this project, our design team members came together with different viewpoints andpassions; each of which were accommodated for within the scope of this project. For example,
Chris has a passion for sporting goods and events whereas Curtis has an interest in the outdoorsports industry and Tom has a borderline obsession with snowboarding. Collectively, all of usare passionate about our planet and decreasing the amount of harm that is being inflicted upon it.Bringing the three of us together provided a multi-dimensional work atmosphere with differentbackgrounds and strengths, granting the team an exceptional opportunity to be successful withthe final product.
It is rewarding as a designer to work on a project that helps people to get outside and enjoy theastounding beauty of the world that we live in. This feeling is so much more rewarding thandesigning a product that encourages people to be inactive like a new video gaming system. Ourteam shares the fundamental belief in staying healthy by remaining active, but doing so while
enjoying the experience. If we can design a product which the user has a positive emotionalconnection to, that person will be more likely to want to get out, use it, and be active. We willthen have created a product that we deem successful.
CONCLUSION
The Eco-Core snowboard started out as an idea that would appeal to the counter-culturesnowboarder. We began by conceptualizing ways to modify the basic components, namely thecore, reinforcing layer, topsheet, base and edges. Of these we decided that the core composes thelargest percent volume of the snowboard and would be a significant modification. Thereinforcing layer, most commonly fiberglass, also posed interest. The team decided that theremaining components either made up a small volume percentage of the board or were notpossible to make more eco-friendly.
Efforts during the first month of the project were focused on looking for alternative materials forthe core and reinforcing layer. We found multiple options for each, but came to the agreementthat with the given time, it was not feasible to work on replacing both components. Havingfound more options for core replacement and more equipment available for testing than for thereinforcing layer, it was decided to focus our future efforts solely on the core. Upon validationtesting, a material called FlexForm was chosen as the best natural fiber replacement. Thematerial properties were between those of wood and foam, materials currently used assnowboard cores. FlexForm Technologies supplied us with a full-size sheet, which we cut toform and modified the taper to match our design. Originally, we had hoped that our sponsorcompany would be able to use our core and their pressing equipment to assemble our prototype,complete with tip curvature, edges, and binding inserts. However, due to internal complications,the company informed us that this would not be possible. Therefore, we decided to do the nextbest option: purchase the supplies and make the prototype in a workshop without the aide of apress. The prototype turned out exceptionally well despite lacking a press but is heavier than
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normal due to the excess epoxy that would normally have squeezed out under the pressingoperation.
We are extremely excited about the outcome of this project but know that future work and testingis required before production can begin. Before a snowboard model can be sold, all
manufacturers insist that boards meet certain torsional resistance and binding mounting strengthspecifications, neither of which have been tested yet. Also, a series of prototype boards wouldhave to be ridden extensively for a period of time to determine if this cores material propertieschange over a period of time. Even if all testing was completed and showed promising results,our team has decided that this is not an idea we would like to pursue. Current snowboardmanufacturers, especially the large companies, are extremely powerful and control such largeportions of the market. We feel it would be very difficult to form a start-up company and besuccessful with only this idea. Had we developed this concept 10 years ago, when snowboardingwas much newer, we might feel differently. The team has decided that the best future for thisconcept and us would be to sell the intellectual property to an existing snowboard company andhave them integrate the idea as another option in their line.
As a team, we would like to thank Dr. Panos Papalambros, the class assistants, BartFrischknecht, Katie Kerfoot, Erin MacDonald and especially Jarod Kelly for his efforts in theconcept development. The enthusiasm and encouragement given was extremely helpful andinspiring.
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RESOURCES
[1] A REEDF Project: Manufacturing Process Development for Natural Fiber ReinforcedThermoplastics for High Stiffness Applications. Professor Pankaj Mallick, University ofMichigan-Dearborn, 2006.
[2] Food and Agriculture Organization of the United Nations: Agricultural Commodities:Profiles and Relevant WTO Negotiating Issues, October 31, 2006,http://www.fao.org/docrep/006/Y4343E/y4343e00.htm.
[3] Dewey & Merrill: Bulletin #404. U.S. Department of Agriculture, 1916.
[4] Arnold, Brandon: History of Snowboarding, About.com, October 3, 2006,http://snowboarding.about.com/cs/basics1/a/history.htm.
[5] FlexForm Technologies: Products, October 30, 2006,
http://www.flexformtech.com/prod/prod.html.
[6] FlexForm Technologies: Molding the Future with Natural Fiber Composites, 2006.
[7] Biancolini, M.E., Reccia, L., and Zanini, A.: Structural Analysis of a Snowboard,University of Rome Tor Vergata. Rome, Italy, September 2005.
[8] Healthlink, Medical College of Wisconsin: Preventing Snowboarding Injuries,November 1, 2006, http://healthlink.mcw.edu/article/976736567.html.
[9] K2 Snowboards: K2 Snowboarding Technology, September 26, 2006,http://www.k2snowboards.com/tech.
[10] SnowboardMaterials.com: Materials, November 22, 2006,http://www.snowboardmaterials.com/pages/materials2.htm.
[11] CityFeet, Commercial Real Estate Listings & News, November 27, 2006,http://www.cityfeet.com/searchspace/detailedlisting.asp?ListingID=1158547
[12] ACHE Energy & Utilities Report: Utilities cost per square foot, 2005,http://www.southalabama.edu/instres/pdf/phys_fac/table6.4.pdf
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APPENDIX A: INITIAL SURVEY RESULTS AND QUESTIONS
A.1: Survey Results
This initial survey was sent to fellow classmates as well as members and officers of the MichiganSnowboard Club. At the time the data for this report was gathered, 71 people had completed the
survey, 57 of which were snowboarders.
Market Demand for Snowboard Attributes
-1.5
-1
-0.5
0
0.5
1
1.5
BetaValue
$275 Retail Price
$350 Retail Price
$425 Retail Price
Directional
Board Shape
No Sus tainable Materials
35% Sustainable Materials
70% Sustainable Materials
Powder
Board Shape
Twin Tip
Board Shape
Figure 24. Market favors cheaper, twin tip snowboards with a high percentage of sustainable materials
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Total Number of Respondents 71 Average Age 20.8
Max Age 35.0
Min Age 17.0
Average Snowboard Experience 2.9
Average Recycling Habits 5.3 Average Board Maintenance Habit 4.2 % of people that own a hemp product 39.4
Average Concern for Global Warming 5.3
Materials Questions
% of people that thought a boardcontained:
Wood 47.9 Plexiglass 43.7
Hair 0.0
Steel 29.6Fiberglass 87.3Plastics 87.3
Wax 52.1 Baby Squirrels 5.6
Glass 5.6
Carbon Fiber 78.9Rubber 11.3
Foam 16.9 Hemp 2.8 Gold 0.0
Aluminum 31.0
Cotton 1.4Table 12. Survey data
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A.2: Survey Questions
The questions on the following page were asked in random order. Six of the questions (2 ofwhich are shown below) were generated using a random combination of three of our snowboardattributes: retail price, board shape and percentage of sustainable materials. The results fromthese questions generated market demand for each attribute as shown in Figure 13 on page A-1.
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APPENDIX B: PHOTOS OF BENCHMARKED SNOWBOARDS
Figure 25. K2 Zeppelin snowboard with twin tip shape, wood core, and fiberglass laminate
Figure 26. Rossignol snowboard with twin tip shape, foam core, and fiberglass laminate
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APPENDIX C: ENGINEERING ANALYSIS MODELS
C.1: Equilibrium Analysis (Snowboard as a Beam)
Using singularity
V = internal shear force, M = internal bending moment, v = vertical deflection, P = loadNote (dV/dx) = -q(x), (dM/dx) = -V(x), EI(d2v/dx2) = M(x)
For center of board Ic = (1/12)wctc3
For end of board Ie = (1/12)wete3
Case 1: Rider standing on board, flat surface, find middle deflection
(note that the board is shaped so that there is a gap between the middle and the ground)
Max bending moment at middle of board, so use Icq(x) = (W/2l)
0 (W/2l)
0 (W/2w)
0+ (W/2w)
0 (W/2w)0
+ (W/2w)0
+ (W/2l)0
(W/2l)
0
Cross Sections
tc
wc
z
y
zte
we
L
ba
l e
w
d l d
w c = a
W/2w W/2wW/2l W/2l
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dV/dx = -(W/2l)0
+ (W/2l)0
+ (W/2w)0
(W/2w)0
+(W/2w)
0 (W/2w)
0 (W/2l)
0+
(W/2l)0
V(x) = -(W/2l)
1+ (W/2l)
1+ (W/2w)
1 (W/2w)
1+ (W/2w)
1
(W/2w)
1
(W/2l)
1
+(W/2l)1
+ C1 C1=0 (V(0)=0)
dM/dx = (W/2l)1
(W/2l)1
(W/2w)1
+ (W/2w)1
(W/2w)
1+ (W/2w)
1+ (W/2l)
1
(W/2l)1
M(x) = (W/4l)
2 (W/4l)
2 (W/4w)
2+ (W/4w)
2 (W/4w)2
+ (W/4w)2
+ (W/4l)2
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Max bending moment at middle of board, so use Icq(x) = (W/2)
-1 (W/2w)
0+ (W/2w)
0 (W/2w)
0+
(W/2w)0
+ (W/2)-1
(Select steps are listed below, otherwise v(x) is found similar to Case 1)
EI (dv/dx) = (W/4)2
(W/12w)3
+ (W/12w)3
(W/12w)
3+ (W/12w)
3+ (W/4)
2+ C3
C30 (dv/dx(L/2)=0)C3 = (W/12) {-3(L/2)
2+ [(L/2-a)
3-(L/2-(a+w))
3]/w}
v(L/2) = (W/48EI) {4(L/2)3
+ [-(L/2-a)4+ (L/2-(a+w))
4]/w} + (C3L)/(2EI)
(note that deflection will be negative, indicating down towards the ground)
Case 3: Riding on rail, board longitudinal (board slide), find end deflection
Note max bending moment at middle of board, so use Icq(x) = -(W/2w)0 + (W/2w)0 + W-1 (W/2w)0 +(W/2w)
0
(Select steps are listed below, otherwise v(x) is found similar to Case 1)
EI (dv/dx) = -(W/12w)3
+ (W/12w)3
+ (W/2)2
(W/12w)
3+ (W/12w)
3+ C3 C30 (dv/dx(L/2)=0)
L
ba
l e
w
d l d
w c = a
W/2wWW/2w
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C3 = (W/12w) [(L/2-a)3-(L/2-(a+w))
3]
EI v(x) = -(W/48w)4
+ (W/48w)4
+ (W/6)3
(W/48w)
4+ (W/48w)
4+ C3 x + C4 C40 (v(L/2)=0)
C4 = (W/48w) [(L/2-a)4-(L/2-(a+w))
4] C3(L/2)
v(0) = C4/(EI)
(note that deflection will be negative, indicating down towards the ground)
Case 4: Board cantilevered, find maximum load on end
L
P
Note max bending moment at end of board, so use Ie
For cantilevered beam with point contact load on free end,v(L) = (PL)
3/(3EI)
Mmax = PL (at x=0)
= (My)/IM = (I)/y and Mmax = [(y/S)I]/y(with y = t/2, and note safety factor S)
Pmax = Mmax/L = [(y /S)I]/[L(t/2)] (use yield strength determined from testing)
(note Pmax is the maximum load the board can take under these conditions before yielding, withsafety factor included)
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Case 5: Board cantilevered, find maximum load if distributed
P/L
L
Note max bending moment at end of board, so use IeFor cantilevered beam with uniform distributed load,v(L) = (PL)
3/(8EI)
Mmax = PL/2 (at x=0)
= (My)/IM = (I)/y and Mmax = [(y/S)I]/y(with y = t/2, and note safety factor S)
Pmax = 2Mmax/L = [2(y /S)I]/[L(t/2)] (use yield strength determined from testing)
(note Pmax
is the maximum load the board can take under these conditions before yielding, withsafety factor included)
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C.2: Simplified Weight Calculation
Weight can be calculated by multiplying the density we determine for the core material by thevolume of our core design in AutoCAD, however we needed to formulate a model for the weightwhich depended on the variable parameters; this is the simplified weight model.
Simplified view from side of board
tc
L/2
L
te
w + b/2a
Simplified side area = As = 2[(1/2)a(tc-te) + (w+b/2)(tc-te) + (L/2)(te)]
For width, average value used wavg= (wc+we)/2
Then simplified volume = Vs = AswavgAnd simplified weight = Ws = Vs
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APPENDIX D: ENGINEERING ANALYSIS SPREADSHEET
D.1: Snowboard Design Spreadsheet with Original Values
The EcoCore Snowboard DesignChris Grant, Tom Santoro, Curtis Franklin - APD Fall '06
Objective Functions Fixed Values
Actual weight, Wa 1.551017974 kg V Density, 801 kg/m *from Curtis
Simplified weight, Ws 2.651897642 kg Vs Volume, V 0.001936 m *from AutoCAD
Objective Function, Y 2 *MINIMIZE* Binding width, w 0.136525 m *from benchmarkin
Case 1 middle deflection, v1 0.256808232 m (see equil. analysis) Board length, L 1.56 m
Case 2 middle deflection, v2 0.45479827 m (see equil. analysis) Young's modulus, E 5.09E+09 Pa *from testing
Case 3 end deflection, v3 0.115225764 m (see equil. analysis) Tensile yield strength, t 4.34E+07 Pa *from testing
Case 4 max load, P4 19.38703348 N M4/L Weight of rider, W 734 N (165 lbs)
Case 5 max load, P5 38.77406695 N M5/L Safety factor, S 1.5
Design Variables Intermediate Results
Center width, wc 0.24765 m Center moment of inertia, Ic 2.06E-08 m
4
(1/12)wctc3
Center thickness, tc 0.01 m End moment of intertia, Ie 2.61E-09 m4
(1/12)we te3
End width, we 0.25087 m Front to binding, c 0.46355 m a (twin tip)
End thickness, te 0.005 m Simplified area from side, As 0.013282 m (see weight calc.)
Rear to binding, a 0.46355 m Simplified volume, Vs 0.003311 m (see weight calc.)
Between bindings, b 0.35985 m Case 1 max moment 394.4549 N-m (see equil. analysiContact length, l 0.127 m Case 1 max stress 95567507 Pa (see equil. analysiContact to contact, e 1.052 m Case 2 max moment 464.3684 N-m (see equil. analysiF/R to contact, d 0.127 m Case 2 max stress 1.13E+08 Pa (see equil. analysi
Case 3 max moment 178.1084 N-m (see equil. analysi
Constraints avg Case 3 max stress 43151637 Pa (see equil. analysiBoard length (a, b) 1.56 m Case 4 max moment 30.24377 N-m *I/y
Board length (l, d) 1.56 m Case 4 max stress 2.89E+07 Pa t/S
Ws max 2.718195083 kg 2.651897642 Case 5 max moment 30.24377 N-m *I/y
wc min 0.2352675 m 0.24765 Case 5 max stress 2.89E+07 Pa t/Swc max 0.2600325 m 0.24765
tc min 0.0095 m 0.01 Original Values (before optimization)
tc max 0.0105 m 0.01 Ws 2.651898 kg
we min 0.2383265 m 0.25087 Y 2
we max 0.2634135 m 0.25087 v1 0.256808 m
te min 0.00475 m 0.005 v2 0.454798 m
te max 0.00525 m 0.005 v3 0.115226 m
a min 0.4403725 m 0.46355 P4 19.38703 N
a max 0.4867275 m 0.46355 P5 38.77407 N
b min 0.3418575 m 0.35985b max 0.3778425 m 0.35985l min 0.12065 m 0.127l max 0.13335 m 0.127e min 0.9994 m 1.052e max 1.1046 m 1.052d min 0.12065 m 0.127d max 0.13335 m 0.127
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D.2: Snowboard Design Spreadsheet with Optimized Values (after running Solver)
The EcoCore Snowboard Design - OPTIMIZEDChris Grant, Tom Santoro, Curtis Franklin - APD Fall '06
Objective Functions Fixed ValuesActual weight, Wa 1.551017974 kg V Density, 801 kg/m *from Curtis
Simplified weight, Ws 2.718195081 kg Vs Volume, V 0.001936 m *from AutoCAD
Objective Function, Y 1.653319478 *MINIMIZE* Binding width, w 0.136525 m
Case 1 middle deflection, v1 0.23163278 m (see equil. analysis) Board length, L 1.56 m
Case 2 middle deflection, v2 0.42022958 m (see equil. analysis) Young's modulus, E 5.09E+09 Pa *from testing
Case 3 end deflection, v3 0.09518749 m (see equil. analysis) Tensile yield strength, t 4.34E+07 Pa *from testing
Case 4 max load, P4 21.55880379 N M4/L Weight of rider, W 734 N (165 lbs)
Case 5 max load, P5 43.11760759 N M5/L Safety factor, S 1.5
Design Variables Intermediate Results
Center width, wc 0.2352675 m Center moment of inertia, Ic 2.27E-08 m4
(1/12)wctc3
Center thickness, tc 0.0105 m End moment of intertia, Ie 3.05E-09 m4
(1/12)we te3
End width, we 0.253036651 m Front to binding, c 0.472546 m a (twin tip)
End thickness, te 0.00525 m Simplified area from side, As 0.013899 m (see weight calc.)
Rear to binding, a 0.47254625 m Simplified volume, Vs 0.003394 m (see weight calc.)
Between bindings, b 0.3418575 m Case 1 max moment 379.1728 N-m (see equil. analysisContact length, l 0.13335 m Case 1 max stress 87709750 Pa (see equil. analysisContact to contact, e 1.0266 m Case 2 max moment 452.582 N-m (see equil. analysisF/R to contact, d 0.13335 m Case 2 max stress 1.05E+08 Pa (see equil. analysis
Case 3 max moment 166.322 N-m (see equil. analysis
Constraints avg Case 3 max stress 38473377 Pa (see equil. analysisBoard length (a, b) 1.56 m Case 4 max moment 33.63173 N-m *I/y
Board length (l, d) 1.56 m Case 4 max stress 2.89E+07 Pa t/S
Ws max 2.718195083 kg 2.651897642 Case 5 max moment 33.63173 N-m *I/y
wc min 0.2352675 m 0.24765 Case 5 max stress 2.89E+07 Pa t/S
wc max 0.2600325 m 0.24765
tc min 0.0095 m 0.01 Original Values (before optimization)
tc max 0.0105 m 0.01 Ws 2.651898 kg
we min 0.2383265 m 0.25087 Y 2
we max 0.2634135 m 0.25087 v1 0.256808 m
te min 0.00475 m 0.005 v2 0.454798 m
te max 0.00525 m 0.005 v3 0.115226 m
a min 0.4403725 m 0.46355 P4 19.38703 N
a max 0.4867275 m 0.46355 P5 38.77407 N
b min 0.3418575 m 0.35985b max 0.3778425 m 0.35985l min 0.12065 m 0.127l max 0.13335 m 0.127e min 0.9994 m 1.052
e max 1.1046 m 1.052d min 0.12065 m 0.127d max 0.13335 m 0.127
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APPENDIX E: CHOICE BASED CONJOINT SURVEY QUESTIONS
Below are two examples of the choice based conjoint surveys questions from our secondmarketing survey. A total of 12 questions of this style were asked of the respondent.
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APPENDIX F: MODIFIED MICROECONOMIC CALCULATIONS
F.1: Modified Linear Elasticities of Demand
ribute Information from Conjoint Survey Our Final Product Finite Differencing
eight (kg) Specification Part Worth Spline Functions Specification Part Worth Splinvel 2.35 2.55 2.75 Weight 2.65 -0.029712 2.784492524 -0.6807396t. Beta 0.23169 0.2482 -0.47989 Stiffness 70.3 0.06363 73.85918273 0.13864333
% Sustainable 35.0 -0.02791 36.75 0.00326182ffness factor Price 560 -0.463531 588 -0.6810558
vel 65 80 95t. Beta -0.11127 0.19322 -0.08195 "v" % of Market that Chooses Our Product
Our Product -0.46 73% Sustainable Materials No Choice -1.45 27%
vel 10 35 70t. Beta -0.50767 -0.02791 0.53558 Linearized Elasticities
Market Size Var "v" % of Market Qm dQ
ce Total Consumers 10,000 Weight -1.11 58% 5847.00433 -10
vel 300.00$ 450.00$ 600.00$ Qm 7297 Stiffness -0.38 74% 7442.43202 41
t. Beta 0.58615 0.19435 -0.7805 % Sustainable -0.43 74% 7358.09176 34
Price -0.68 68% 6847.31523 -16
gineering Model
bjective Functions Fixed Values
tual weight, Wa 1.551017974 kg V Density, 801 kg/m *from Curtis
mplified weight, Ws 2.651897642 kg Vs Volume, V 0.001936352 m *from AutoCAD
jective Function, Y 2 *MINIMIZE* Binding width, w 0.136525 m
se 1 middle deflection, v1 0.256808232 m (see equil. analysis) Board length, L 1.56 m
se 2 middle deflection, v2 0.45479827 m (see equil. analysis) Young's modulus, E 5.09E+09 Pa *from testing
se 3 end deflection, v3 0.115225764 m (see equil. analysis) Tensile yield strength, t 4.34E+07 Pa *from testing
se 4 max load, P4 19.38703348 N M4/L Weight of rider, W 734 N (165 lbs)
se 5 max load, P5 38.77406695 N M5 L Safety factor, S 1.5
sign Variables Intermediate Results
nter width, wc 0.24765 m Center moment of inertia, Ic 2.06375E-08 m4
(1/12)wctc3
nter thickness, tc 0.01 m End moment of intertia, Ie 2.61323E-09 m4
(1/12)we te3
d width, we 0.25087 m Front to binding, c 0.46355 m a (twin tip)
d thickness, te 0.005 m Simplified area from side, As 0.01328225 m (see weight calc.)
ar to binding, a 0.46355 m Simplified volume, Vs 0.003310734 m (see weight c