Roof challenge
AIM:
Develop the essential flanges and reinforcements, Provide appropriate dimensions and check for Draft analysis, and submit your Section Inertia report on the 0-Y section.
PROCEDURE:
To extract the surface from the model
untrim the sheet 
roof creation
bow rail design
Front roof
rear roof creation
Bow–roof prediction 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
Judgment Condition
OK< 2.7
Where
L = Roof Length in X-Direction[mm](Roof dimension in 0-Y)
R = Roof curvature
R = 2(Rx*Ry)/(Rx+Ry)
Rx = X curvature
Ry = Y curvature
t = Roof plate thickness [mm]
l = Bow Roof Span [mm]
make sketch and calculate the value
| section | R | L | Rx | Ry | l | t | W | |
| 1 | 1766.6 | 1919 | 4271.3 | 3013 | 336 | 0.75 | 1.07 | |
| 2 | 2651 | 1919 | 11805 | 3420 | 425 | 0.75 | 1.2 | |
| 3 | 5855 | 1919 | 16475 | 9085 | 501 | 0.75 | 1.72 | |
| 4 | 2571 | 1919 | 14333 | 3134 | 184 | 0.75 | 0.92 |
section modulus
bow roof:
s=I/Y
=2824/40
S=70
bow rail 2
s=1393/36.5
S=38.1
roof
S=I/Y
=1.8*10^6/105
S=1742
Front roof
S=I/Y
=8.4*10^3/65
S=129
Rear rail roof
S=I/Y
=37044/93.5
S=396.5
Snow load Prediction formula
Qr = [Iy x t2] / [α x s x [(Rx + Ry)/2]2 x 10-8]
Note: The Qr value given over here is correct. There was a typo error in the formula given in the video.
Where
α = My x Lx2 x 10-12 , My = Y(Ly-Y)
Judgment condition
Qr ≥ 3.1
250 ≤ s ≤ 380
t = Roof plate thickness [mm]
Ly = Distance between the front and rear roof Rails on the Vehicle along with 0Y[mm]
Length of Roof panel with the center point between Roof rail Front /Rear as the front and rear reference point.
Lx = Distance between the Left and Right end of the roof on the Roof BOW [mm]
The width of the roof panel is exposed on the surface.
Y = Distance front Front Roof Rail to Roof BOW[mm]
s = Distance for which Roof BOW bears divided load [mm]
s = L1/2 + L2/2
Iy = Geometrical moment of inertia of Roof BOW (Y cross-section )[mm4]
Rx = Lateral direction curvature radius of roof panel Y cross-section on Roof BOW [mm]
Roof panel curvature Radius of the Length Lx in Front view
Ry = Longitudinal Direction curvature radius of the Roof panel X cross-section on Roof BOW [mm]
Roof panel X curvature radius of length s in Side view
make sketch and calculate values
| SECTION | Ly | Lx | Y | s | iy | Rx | Ry | Q | |
| 1 | 1962 | 11146 | 470 | 490 | 2820 | 2555 | 2426 | 10.4 | |
| 2 | 1962 | 1092 | 995 | 506 | 4100 | 6235 | 2887 | 35.4 | |
| 3 | 1962 | 1063 | 1584 | 374 | 1300 | 11660 | 3901 | 8.57 |
DRAFT ANALYSYS
FRONT RAIL
CENTER ROOF
BOW ROOF
Roof
rear
roof
Result:
The Section Inertia study for the Master sections you create for the Front roof rail, Rear roof rail, Bow Roof Rail, and Rear Roof Rail are done in the project.