Virtual BAJA SAEINDIA 2016

TEAM BRAHMAPUTRA TEZPUR UNIVERSITY

TEAM ID-17227

• TEAM BRAHMAPUTRA • TEZPUR UNIVERSITY

TECHNICAL AND PERFORMANCE SPECIFICATION

• Overall width : 60.575 inch

• Overall length : 85.817 inch

• Rear track width : 52.482 inch

• Front track width : 52.482 inch

• Wheel base : 62.243 inch

• Ground clearance : 11.762 inch

• Maximum speed : 41 kmph

• Kerb weight : 338.879 kg

• Passenger capacity : One seater

• Centre of gravity height : 13.855 inch

• Vehicle type : All terrain vehicle

• Stopping distance(40 kmph): 13.04 meter

• Vehicle height from ground : 54.607 inch

• Engine : Briggs & Stratton 10 HP OHV

Intek four stroke , 305 cc , air

cooled

Fig 2: VIEW FROM BACK Fig 1: ISOMETRIC VIEW

Fig 3: SIDE VIEW Fig 4: FRONT VIEW

ROLL CAGE DESIGN AND ERGONOMICS• Material used for primary and secondary members: AISI 4130 Chromium Molybdenum cold rolled seamless tube• Carbon content: 0.30%• Outer diameter of primary and secondary members, D0 = 25.4 mm• Thickness of primary and secondary members: 3 mm• Internal diameter, Di = 19.4 mm• Yield strength of AISI 4130, Sy=460 MPa• Young’s modulus, Ex = 205GPa

• Total length of tube = 38.43 metres• Overall weight of roll cage = 41.314 kg ≈ 412.996 N

1> Calculation for Bending Strength : Polar moment of inertia, I= 3.14*(D0

4 - Di

4)/64 = 13471.805 mm4

Distance to extreme fiber, c = 25.4/2 = 12.7 mm ∴ Bending Strength = SyI/c = 487.955 N-mAnd, Bending Stiffness=ExI = 2761.720 N-m2

2>Ergonomics specification:a) Spacious enough to accommodate a 95th percentile male and 5th percentile femaleb) Comfortable seating and viewing angle. c) Suitable reach limitd) Better visibilitye) Clearance requirements are fulfilledf) Easy entrance and exit.

Fig 5: ROLL CAGE DESIGN

Fig 6: ERGONOMICS- LATERAL CLEARANCEFig 7:ERGONOMICS- HEAD CLEARANCE

CAE BASIC PROCESS AND ITS APPLICATIONS

Fig 10: FRONT IMPACT (STRESS)

Fig 13: SIDE IMPACT(STRESS)

Fig 15: ROLLOVER(STRESS)

Fig 9: TORSIONAL(STRESS)

CALCULATIONS INVOLVED:Estimated mass of vehicle=338.879 kgLet, G=Estimated mass of vehicle × gWhere,g=accelaration due to gravity ≈ 10 m/s2

Hence,G=338.879 × 10 = 3388.79 NNet Force applied= 4G= 3388.79 × 4= 13555.16 N

ROLL CAGE ANALYSIS

Fig 8: FRONT IMPACT(DEFORMATION)

Fig 11:SIDE IMPACT(DEFORMATION)Fig 12:ROLLOVER(DEFORMATION)

Fig 14:TORSIONAL(DEFORMATION)

Results :Front impact: Max. deform.=1.726 mm;Min. deform=0 mm;Max. stress=609 MPa;Min stress=25.794 Pa Side impact: Max deform=0.64 mm;Min deform.=0 mm;Max stress=661.92 MPa ;Min stress=0.069 PaRollover:Max. deform.=0.72 mm ;Min. deform=0 mm;Max stress=288.38 MPa ; Min stress= 0.386 PaTorsional :Max. deform=12.754 mm;Min deformation=0 mm;Max stress=1315.7 MPa;Min stress=0.475 Pa

SUSPENSION PARAMETER FRONT REAR

Suspension type Double Wishbones

Suspension material AISI 4130

Natural frequency 2.09 Hz 2.35 Hz

Spring Stiffness 16.11N/mm

Spring material STEEL 17-7 A313

Motion Ratio 0.491

Damper Ratio 0.35

Max. Suspension Travel 135 mm 220 mm

Bounce Frequency 1.60 Hz

Caster (deg.) 7.0 (+ve)

Camber (deg.) 0-0.5(+ ve)

Kingpin Inclination (deg.) 9.37

Toe (deg.) 0

Sprung Mass 338.879 Kg

Un –Sprung Mass 48 Kg

Toppling Speed(at min. turning radius)

20.16 Km/h

Roll Centre Height 195.834 mm 225 mm

KNUCKLE STRESS ANALYSYS

EXPLODED VIEW ASSEMBLY

HUB STRESS ANALYSYS

A-ARM STRESS ANLYSIS

Camber angle v/s Wheel Travel

Roll Centre Height v/s Wheel Travel

Camber v/s Steer S

• Hydraulically actuated disc brake on all four wheels lock simultaneously

• Tandem master cylinder

• 2POT floating calliper

• X-split braking system

• Pedal ratio = 6:1

• Pedal force = 120 N

• Brake fluid = DOT4

BRAKES

Parts SpecificationRotor(stainlessSteel)

Polaris sportsman500

O.D -- 9” I.D – 5.5”

Master cylinder(tandem)

Polaris sportsman 500

0.75”

Calliper cylinder( 2pot)

Polaris sportsman500

1”

Performance Value

Torque per wheel 93.72 Nm

Total brake force 1283.39 N

Deceleration 4.73 m/s2

Stopping distance 13.04 m

Wt. transfer 36%

Disc brake and calliper assembly

Dynamic wt. On front axel

2258.29 N

Dynamic wt. On rear axel 1062.73 N

STEERING AND WHEEL GEOMETRYPARAMETER VALUES

TYPE RACK & PINION

INSIDE WHEEL ANGLE 45 degree

OUTSIDE WHEEL ANGLE 28.48 degree

ACKERMANN ANGLE 39.75 degree

WHEEL BASE 62.243 inch.

TRACK WIDTH 52.482 inch.

TURNING RADIUS 3.31 m

RACK LENGTH 16 inch.

RACK TRAVEL(lock to lock)

6.5 inch.

End to end 390 degree

ACKERMANN PERCENTAGE

72.48 %

STEERING RATIO 8.4 : 1

TORQUE 4.05 N-m

INSIDE WHEEL ANGLE FOR 100% ACKERMANN

22.79

Item Description & Dimensions

Front tire Carlisle AT489 - 25 x 8-12

Rear tire Carlisle AT489 - 25 x 11-12

Ackermann Geometry

Steering system

Wheel assembly

RPM(Engine)

Engine Torque(Nm)

Total Gear Ratio

Torque on Wheel(Nm)

Traction(N)

Velocity(km/hr)

Resistive forces(N)

Acceleration(m/s2)

1800 18.03 39.90 633.07 1993.92 5.40 443.81 3.432000 18.71 36.69 604.10 1902.66 6.52 444.03 3.232200 18.98 33.50 559.53 1762.30 7.86 444.37 2.922400 19.32 30.30 515.15 1622.52 9.48 444.85 2.612600 19.52 27.09 465.34 1465.64 11.48 445.59 2.262800 19.67 23.94 414.40 1305.17 14.01 446.70 1.903000 19.60 20.70 357.03 1124.52 19.96 448.28 1.503200 19.38 17.50 298.50 940.01 21.89 451.61 1.083400 19.11 14.29 240.31 756.88 28.48 457.35 0.663600 18.84 11.09 183.86 579.09 38.84 469.40 0.243800 18.11 11.09 176.74 556.66 41.01 472.43 0.19

POWERTRAINEngine specificationsBriggs and Stratton 10 HP OHV IntekDisplacement : 305ccMax Power : 7.187 kW @ 3800 rpmMax Torque : 19.66 Nm @ 2810 rpm

Transmission Unit Polaris P90 belt CVT

Primary(input) : 184 mm Secondary(o/p): 241 mm Low ratio :: 3.83:1 High ratio :: 0.76:1

Reversing Mechanism Tire Size (25’’*8”*13”)

Powertrain Layout

ENGINE(Crankshaft)

Reversing mechanism

(Engaged/Disengaged)

CVT SPROCKET-1 (2:1)

SPROCKET-2 (2.625:1)

LIMITED SLIP DIFFERENTIAL (Final Drive:

3.16)

WHEELS

TABLE: VELOCITY AND ACCELERATION AT OUTPUT

COST AND WEIGHT ANALYSIS PI-CHARTParts Cost(Rs.) Weight(kg)

chassis 24,400 67.276

Front tire with rim

30,000 49.16

Rear tire with rim

38,000 50.66

Suspension system

88,000 30.196

Braking system 34,000 35.844

Steering system

20,000 10.5

engine 20,000 26.4

Transmission 1,10,000 46.064

Safety feature 11,200 17.689

electrical 52,200 5

Total 4,27,800 338.789

Cost

chasis front wheelrear wheel suspension systembraking system steering systemengine transmissionsafety feature electrical

Weight(in kg)

PROJECT PLAN

VALIDATION PLANITEM Failure Mode Failure Cause Failure Effect Preventive Action

Frame Bending and breaking of frame

Axial stress exceeds yield stress of material due to excess load and impact loading

Overall damage to roll cage. Frame breaks or bends. Driver’s safety is endangered

Material with appropriate /high factor of safety(FOS) , effective design and analysis; constant testing

CVT Tuning Improper mounting Sensitive mountingRack & Pinion Leaking of fluid,

Loosening of lug nutObstruction in movement of pinion over rack, damage to components

Steering failure;Safety of driver andothers compromised

Verification of desired specification and testing

A-arm Bending, Breakage,cracks, structuraldamage

Axial stress exceeds yielding stress of materialdue to excess load andimpact loading

Damage to suspension system and rough operation of the vehicle

Material with high FOS and according to vehicle specifications; effective design and analysis

Spring Spring fractures and fail Due to faulty choice of springs, spring fails due to loads exceeding the yield stress of the material

Damage to suspension system and rough of the vehicle

Choose springsaccording to vehicle loads and other specification

Shock Absorber Leaking of suspension oil

Cylinder damage due to foreignbody/debris

Damage to suspension system and rough of the vehicle

Verification ofspecificationsand testing

pedals Structural failure die to fatigue, bending and breaking

Excess load by driver causes axial load to exceed yield strength of material

Brake failure Choose materialwith high FOS and carefultesting should be done

Braking system Mechanical failure Not sufficientbraking force

Damage to vehiclein undesiredcircumstances

Choose materialwith high FOS and careful testing

WORKSHOP FACILITIES AND TEAM COMPOSITION

Faculty advisor Dr. Partha Pratim Dutta

Faculty advisor Dr. Santanu Sharma

Chassis design and analysis

1722702,1722707

Ergonomics 1722711, 1722710

Suspension and simulation

1722713,1722716

Brake 1722701,1722708

Steering and wheel geometry

1722706,1722714

Transmission 1722704,1722715

Electrical system 1722718,1722720

Engine fuel and exhaust system

1722709,1722712

Marketing 1722717,1722721

Material procurement 1722703,1722705