Roof Design

Roof is the topmost part of the car which connects to A pillar, B pillar, C pillar etc. Which has some assembled part
like front roof rail, Bow roof rail, center reinforcement and rear roof rail with outer skin data as class a surface
we created the roofs supports with the guidance of master section.

Front Roof rail -

Front roof rail which connects windshield glass and A pillar by guider and support to the outer roof. emboss and cutouts

occurred for strengthen and reduced the weight of vehicle.

Bow Roof rail -

Roof rails support the outer roof which locate on flat surface which attach to outer roof by mastic material.
and two corners of bow roof were attached with outer roof by spot welding.

Center reinforcement rail -

which acts major support to the roof. same as well as mastic on the center and spot weld on
the corners were used to attach with outer roof.

Rear roof rail -

Roof rails locate rear most part of the roof which connect backdoor and the outer of the vehicle here also emboss and cutout
were held as like that front roof rail.

Calculation -

Heat Distortion criteria -

Formula - W = [1.73 x 10 ^ (-3) x L] + [1.85 x 10^ (-8) x (R^2)/t] + [ 1.10x10^ (-3) x l] - 2.68

Case 1 : -

L = 2031.75mm Rx=5753.1993mm Ry=2655.9088mm
I = 403.80mm t = 0.75mm.

R = 2(Rx*Ry)/(Rx+Ry)
= 30464332.581/8391.1081
R = 3630.549mm

W = [1.73X10^ (-3) X 2031.75] + [1.85 X 10^ (-8) X (3630.549^2/0.75] + [ 1.10X10^ (-3) X 403.80] -2.68
= 3.514 +0.325+0.4441 -2.68

W = 1.6032mm 1.6032<2.7

Condition is ok

Case 2 : -

L = 2031.75mm Rx=4985.079mm Ry=6145.94mm
I = 366.9060mm t = 0.75mm.

R =61275992.858/11,131.019
R = 5,504.976mm

W = [1.73X10^ (-3) X 2031.75] + [1.85 X 10^ (-8) X (5,504.976^2/0.75] + [ 1.10X10^ (-3) X 366.9060] -2.68

= 3.514 +0.74751+0.40359 -2.68

W = 1.9851mm 1.9851<2.7

Condition is ok

Case 3: -

L = 2031.75mm Rx=3998.942mm Ry=10472.021mm
I = 479.0186mm t = 0.75mm.

R =8,37,54,009.203/14,470.963
R = 5,787.728mm

W = [1.73X10^ (-3) X 2031.75] + [1.85 X 10^ (-8) X (5,787.728^2/0.75] + [ 1.10X10^ (-3) X 479.0186] -2.68

= 3.514 +0.8262+0.52692 -2.68

W = 2.1871mm 2.1871<2.7

Condition is ok

Case 4: -

L = 2031.75mm Rx=3282.242mm Ry=14574.718mm
I = 328.9405mm t = 0.75mm.

R =95675503.115/17,856.96
R = 5,357.8830mm

W = [1.73X10^ (-3) X 2031.75] + [1.85 X 10^ (-8) X (5,357.8830 ^2/0.75] + [ 1.10X10^ (-3) X 328.9405] -2.68

= 3.514 +0.7081+0.36183 -2.68

W = 1.90393mm 1.90393<2.7

Condition is ok

Draft analysis -

1.) Outer roof

2.) Front roof rai l

3.) Bow roof rail

4.) Center reinforcement rail

5.) Bow roof 2

6.) Rear roof rail