CM3332 Bus Body Design

8/12/2019 CM3332 Bus Body Design

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CDM2Name of Work Design of bus Body

ClientTamilnadu State Express Transport

corporation

Reference No. CTC/0101210801

Design Algorithm Input/Computations/Decisions

100 Description, location and overall

geometry of producta. urpose o e ve c e

Bus/Truck(t)/Cargo truck/ Refrigerated

truck ( R ) others B

b. Kind of body StrutureStiffned panel/Sandwich/grid Stiffened/grid

c. Shape of body configuration

Retagular ono box shape/two box Rectangular one box shape

d. Shape of front and rear

Flat/Curved streamlined Flat

102 Dimensions

a. Overall length L in mm 10,100

b. Overall Width B in mm 2430c. Height of side walls H above the

chassis in mm 2350

102 Internal arrangements

a. Whether separate driver's cabin

provided yes/No No

b. The lenth ldof drivers cabin in mm NA

c. Whether the passenger/ Cargo cabin is

integral with drivers cabin or separtely on

a trailer NA

d. Location, Width Wdand height hdof

driver entry door in mm 700e. Location, Width Wdand height hdof

helper entry door opposite drivers door

in mm 700

f. If driver cabin is separate, length Lc of

cargo cabin in mm NA

Design Input

Design of all composite busbody


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g. Whether the top is covered or open 30

h. If top is open height hf of the side walls NAi.. If top is open whether the side walls

can be rigity fixed or hinged for loadingand un loading NAj. Whether the bus is ordinary

(OB),Luxury bus(LB), or Air-conditioned

bus(AB)

k. No of passengers seats to be fixed 45+2

l. No. Of additional passengers allowed to

travel as standees 60

m. Cargo weight Wcto be permitted

inside in kg 1000kg

n. No . Of seats per row 4

o. Distance between successive row,lsof

seats in mm 1000p. Self weight of seats in kg 20kg

q. Method of fixing of seats

Fixed on the floor board by bolting Fixed on floor board

r Whether luggage carrier racks/ boxes to

be provided yess. Whether interior padding is to be

provided on the side walls

Yes if 1025 is LB or AB NA

t. Location width Weand height heof

passanger entry door in mm 700

u. Location width Wpc

and height hpc

ofpassanger entry door in mm

This can be same as helper entry door in

1012 if the driver cabin is integral with

passanger cabin 700

v. If the bus is AB, Temperature T in C

inside during operation NA

x.

w. If the bus is AB, location and weight of

air conditioner in kg NA

x. Type of cargo

Vegetables/Meat/ Fish /Others NA

y. Whether the cargo can exert weight onwalls during acceleration / deceleration /

storage / or while negotiating curves

No. of the cargo is firmly fixed on floor

with gap between wall and cargo NA

z. Location width W rand heighy hrof the

cargo door NA


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bb Whether metallic lining is required

inside to take local impacts NA

cc. Temperature oc cabin in C NA

dd. Whether insulated container only with

no AC or with refrigerator attached NA

ee. if with refrigerator location and weight

of refrigerator NA130. Support conditions

a.Whether to be supported in chassis

(SC) or to be an integral monocoqe

shell(SM) SCb.If 1061 is SC

No . And dimensions of longitudinal

beams in chassis over body to be

supported

Two channels

229mm x 76mm x 6.35mm

c.Spacing Wcof chassis beam in mm 840

d. Environmental temperature in C 45

e. Design temperature Dt in C

( if not given takes as 90 C for vehicles

exposed to sunlight on outside pannel 90

f. Minimum environmental temperature in

C 15 Cg. Minimum design temperature DTM in C

D TM can be minimum of

1073,1054,1037 15 C

110. Major product elements of

busbody and dimensions

120. Functional requirements

m. Expected life given in running km 3x 10^5 KM

130. Operational Static and Dynamc

loads

a. Total design pay load in kg Wp

Wp is passanger and cargo / luggage

weight 9000kg

b. Snow load Ps on roof in N/mm2

if not applicable take Ps as zero NA

c. Self weight of body in kgAssumed 50% of pay load for deign

purpose 5000kg


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d. No. of fitting with concentrated load

effect their location and weigh tin kg give

sl. No. location as distance in mm from

front and weight in kg under 3 column on

right hand side 6150N131. Aerodynamic loads

a. Pressure acting on front end on roof

and front wall rear walls pa in N/mm2 rear end

b. wind pressure Pwin N/mm2, when

vehicle, is stationery in N/mm2 Not to be consideredc. Impact factor a

a. Vertical accelerator mZSfor symmenric

load

b. Vertical accelerator mZUfor

unsymmenric load

c. Longitudinal l accelerator or load factor

mSC

d. Load factor for corning mYe.Load factor for kerbing mK

f. Load factor for turn over mR

2.5

1.3

0.7

1.01.0

1.5

d. Fatigue design load and the no. of

cycles during lie period 10^6

e. Normal operational speed Vm in km ph 60

f. Peak operational speed Vp in km ph 100

g. Frequency vibration due to traffic or

other wise in HZ 50

h. Corrosion or chemical attack nil

i. whether moisture effect can give

degradation Nil effectj. whether moisture effect can give

degradation Impact in sea coast and

places where deicing is done Negligible

k. whether thrmal stresses can arise due

to thermal expansion or thermal gradient NO

l. Whether degradation due to fire, friction

UV radation other radiations, biological

attacks or lightning to be considered NO

200. Selection of geometry in addition

to wht is alredy taken in input data

210. Manufacturing method

2. Design selections


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a. If to be designed as per any standard,

specify standard no Nob. Type body construction

Steel frame and panel (SP) / steel and

sandwich (SS)/Steel and grid (SG)/ all

sandwich with no steel (AS) / all grid with

no steel (AG)

SP for wall,Sg for floor and SS for

roof

c. If 2002 is not FP go tod. Spacing of cross steel arches lse in mm

( Normally these can be considering with

the seat spacing so that a windows can

be provided in between frame for

passangers sitting in each row to see

outside) 1000mm

e. No of frame nfin long direction

nf= (L or Lc)/ Ise+1 10100/1000+ 1=11

f. No.of lingitudinal members of steel

frame excluding bottom panel 9g. Location of lingitudinal beam

If must be such that windows can be

placed without obstruction 9h. Spacing of cross members on the floor

panel lsfin mm

Keep it same as that of the wall cross

members 1000

i. No.of lingitudinal members on the floor

panel and that spacing wsf in mm 13

j. Method of joining of steel members

Welding / Bolting Welding

k. Type of panel between steel frame onthe floor

Sandwich / Grid / stiffened panel / single

skin gridl. Tytpe of panel on roof

Sandwich / Grid / stiffenedpanel/ single

skin Sandwich

m. Type of panel on side wall

Sandwich / Grid / stiffened / single skin Single skin

n. Type of panel / or the front end for

impact resistence stiffenedo. Panel structure of single skin

Flat / corrugated Flat

p. Panel material E-glass CSM-Polyester

q. Grid material E-glass UDC-Polyester

r. Sandwich material

E-glass CSM-Polyester and

polyurethane


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s. Grade polyester resin

Isophthalic is to be used automobile

grade for ompact resistence Isophthalict. Heat distortion temperature HDT of

resin in C

HDT < 100 100

u. Gel coat resin and thickness

Normally 0.5 mm thickness 0.5

v. Whether gel coat to be pigmented

Yes if not painting is planned no

w. UV stabiliser material its grade and

percentage Tinovin 0.1%

x. Pigment grade colour and percentage NA

y. Whether filler can be added to lay up at

if so name of material and percentage

Yes 10% maximum Calcium carbonatez. Area density Wcsm of CSM in gsm 450

aa. Text of rovings for grid constrution 2400

ab. Area of density of WRM to be used 610Selection of design criteria

a. Whether to be designed by strength of

material approach only/strength of

materials for preliminary selection and

FEM for optimisation

strength of materials for each

element as Fem for final assembly

designb. Whether design for functional

requirements to be under taken

Not provided in this modle No

c. Any design for safety under non-

mechanical /environment effects to be

considered No

d. factor of safetyv 6DESIGN FOR SAFETY

a. Weight of passanger Wpin N

Wp = np 90 x 9.81

9000 x 9.81

=88290

b. Chassis weight Wc in N 37200

Weight of front axle with wheel and axle

in N 10,000

Rear axle with wheel and acceleration in

N 14,050Weight of milds / is stracture in its body

and floor in N 13000

Weight of the ghaged windows in N 4500

Weight of the 50 suels in N 7500

Weight of mi fillling in N 6150

Design of roof Phril


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a. Type of stracture Sandwich with form wire

b. Span lsin mm 1000

c. Width of panel Wsin mm 2430d. Assumed stractural behaviour

Plate if Ws < 2ls

beam if Ws > 2ls beam

Design palm load on moffing in N

25 x 90 x 9.81

= 22072.5

Design pressure Pdin N/ mm2

22072.5/10100 x 2430

=0.0008993Assumed skin thickness no of sand with t

in mm

Assumed 2 mm min / mm 2 in CSM 450 mat

Assumed core thickness C in mm 25

Moment of inertia

I = 2 t/2 + 2 (25F x t / 2 )2 t 2 x 2^3 / 12 + 2 (25+1)2 x 2

Deflection ymax in mmymax = 1/38h x Plx ls ^4 / EI

1 x 0.0008993 x 1000^4 / 384 x

6300 x 2705= 0.1374

if deflection is acceptable

yes if ymax < span / 200 Yes

Bending moment M in N-mm / mm

M = Pd . L s^2/ 8

0.0008993 x 1000^2 / 8

= 112.4125

Allowable bending moment Mal

12.5 x 2 x 27

= 675

If design acceptable

Yes if M < Mal yes

Design of bottom panel

Type of stracture Grid floor

span lb in mm 1000Width wb in mm 2430

Assumed stractural bed view Equalent or plate

Spacing a of grid beam placed in the

axial direction in mm 100

thickness tl of grid beam placed

longitudnally 10

Spacing b of grid beam placed

longitudnally in mm 100

Thickness tt of grid beamplaced 10

Depth of beam dh in load in loaded

direction in mm 50Depth dt of beam in direction 25

Dx = El t l dl ^3 / 12 a

30000 x 10 x 25 ^3 / 12 x 100

= 3906250 x 8

Dy = El t l dl ^3 / 12 a 3906250 x 8

2H = 2a (Jl / a + Jt /b 7812500 x 8


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Distributed load

(88290+ 7500 + 6150) / 10100 x

2430 =

0.0041535

Deflection Ymax in mm

ymax = 16 p d/ 3.14^2 D

16 x 0.0041535 x 10^6 / 3.14^2 x

5.34133 x 8

= 15.075 mm

Bending moment Mx in N-mm

m l = 16 p d a / 3.14 ^4 x w^4 [D]

16 x 0.00415.35 x 100 / 3.14^4 x

1000^4 x 8 x 5.3413 x 10^-6

= 1.5998 x 10 ^-9

Bending moment Mx in N-mm

m l = 16 p d a / 3.14 ^4 x w^4 [D]

16 x 0.00415.35 x 100 / 3.14^4 x

24830^4 x 8 x 5.3413 x 10^-6 =

4.5883 x 10 ^-11


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Documents

CM3332 Bus Body Design