Roof challenge
ROOF
Aim:
To design the front roof rail, center bow, bow roofs and rear roof rail according to the engineering standards using Siemens NX 12.
Introduction:
Roof is a part of the automobile which protects the passengers from dust, rain, and sunlight. Roof is one of the major components in the automobile, it consists of front roof rail, center bow, rear roof rail and additional bow roofs depending upon the size of the automobile and also according to the conditions.
Roof also has a provision for sunroof which can be seen in most of the high end model automobiles and roofs are categorized as:
- Convertible roofs.
- Hardtops.
- Sunroofs.
- T-tops.
- Targa tops.
- Vinyl roofs.
Roof is a sheet metal component which is manufactured by the press operation and having a thickness of about 0.75-8mm depending on various factors.
As roof is a major component in automobile various considerations must be taken before designing the roof, they are:
- Headroom clearance.
- Visibility criteria.
Based on the above considerations master sketch was prepared and appropriate tools were used to design the roof and its components.
Front roof rail:
Front roof rail plays major role in the frontal crash analysis and this must be strong enough to withstand those forces and also should perform better and must reduce or avoid the collision of automobile and must have to save passengers who were inside the automobile, mastics will be provided and required welding will be done on the ditch area to provide the good aesthetics to the roof.
Bow Roof 1&2:
Bow roof 1&2 helps in providing strength to the roof and plays vital role in snow load condition, these add more strength to the roof and these were designed with the thickness of 0.75mm and can be increased further more to increase more strength to the roof, width is also can be adjusted to increase strength.
Center bow:
Center bow also plays key role in both heat distortion and snow load condition and adds strength to the roof, center bow will have a provision for lamp and has additional bow roof to enable strength to the roof.
Rear roof rail:
Rear roof rail is designed with thickness of 0.75mm which helps in adding strength to the roof.
Heat Distortion Condition:
Heat distortion analysis is done to predict the failure of roof because of the elevated temperatures and to position the bow roofs at appropriate location. Sheet metals components fail due to buckling because of the elevated temperature’s which softens the material and leads to failure. Heat distortion failure can be calculated using the formula.
Bow-roof prediction formula:
Condition results:
Snow-Load Condition:
In European countries and other parts of the world where snow plays vital role, snow load condition plays factor in those regions, snow starts accumulating on the roof and has tendency to flow inside the pores which makes the roof and bow roofs to bend and starts failing to creep, because of this reason snow load factor is considered and used to predict the failure due to the snow accumulation.
Snow load criteria formula:
Condition results:
Conclusion:
Roof and its components were designed according to the given standards and results were provided for both heat distortion and snow load criteria.
Here is the link for the RAR file of the roof:
https://drive.google.com/file/d/1HytLQJQz7C9CnVMfbBPM9WM2xavghOXS/view?usp=sharing