Roof Design and Optimization
CAR ROOF
An automobile roof or car top is the portion of an automobile that sits above the passenger compartment, protecting the vehicle occupants from sun, wind, rain, and other external elements.Because the earliest automobiles were designed in an era of horse-drawn carriages, early automobile roofs used similar materials and designs.A high-quality roof offers assurances that a low-quality roof won’t provide. Weather is the principal challenge as far as roofs go, and our climate has become increasingly intense in many parts of the country. High winds, heavy rain, hail storms, and heavy snowfall all took their toll. A lesser-quality roof may not stand up to the rigors of your regional weather.
Firstly, with the help of the roof outer surface (given) A roof ditch area was created with a tool opening angle of 3o.
After that, front and the back-roof rails were created and centre reinforcement along with two bow roofs were created accordingly by considering the curvature of the outer roof.
Section modulus of the Master sections
- Front roof rail
- Bow roof 1
- Reinforcement Roof Centre
- Bow roof 2
- Rear roof rail
Calculations to determine the Position of the Bow-roof (Heat Distortion Criteria)
The heat distortion study will play an important role in sheet metal usage. Heat distortion temperature is a temperature limit above which the material cannot be used for structural applications. This study is used to predict heat distortion temperatures at where the materials start to \"soften\" when exposed to a fixed load at elevated temperatures. In order to avoid bending/damages on roof, based on heat distortion temperature, this study will predict the bow roof position on the roof to strengthen the roof.
Prediction Formula: W = (1.73 x 10-3 x L) + [1.85 x 10-8 x R2 / t] + (1.10 x 10-3 x l - 2.68)
Judgement Conditions: OK < 2.7 < NG
Were,
L = Roof Length in X-Direction[mm](Roof dimension in 0-Y)
R = Roof curvature
R = 2 (Rx x Ry) / (Rx + Ry)
Rx = X - curvature
Ry = Y - curvature
t = Roof plate thickness [mm]
l = Bow Roof Span [mm]
Y - curvature
Bow Roof Span [mm]
| Heat Distortion Critetia | ||||||||
| Rx | Ry | R | I | L | t | R2/t | W | OK/NG |
| 5710 | 2758 | 3719 | 322 | 2037.8 | 0.75 | 18441281 | 1.5407 | OK |
| 4866 | 6554 | 5585 | 322 | 2037.8 | 0.75 | 41589633 | 1.969 | OK |
| 4085 | 10416 | 5868 | 200 | 2037.8 | 0.75 | 45911232 | 1.9147 | OK |
| 3337 | 15852 | 5513 | 482 | 2037.8 | 0.75 | 40524225 | 2.1253 | OK |
https://drive.google.com/file/d/1l0Y6U2sBLhEdeaaB8qeMc7miRDYcwfQG/view?usp=sharing