How to design and perform calculations on Roof designed using CATIA V5

Objective: To design and calculate the performance criteria for the given roof and rail reinforcement designing.

Introduction:

Roof of an automobile is that commodity which sits above the passenger compartment. Roof houses the vehicle as shielding part which safeguards the occupants from sunlight, heat, rain, wind, dust, etc.

In the past roof was introduced as cover for passenger compartment but later on, it also used as a luggage carrier, sunroof and in recent past years with the introduction of the solar panelled electric vehicle got a major boost in the automotive industry.

Roof has the following functions:

• protects from external damage
• prevents passenger and vehicle from accidents
• luggage carrier
• design of the roof also affects in giving aerodynamic shape to vehicle
• sunroof
• solar panelled roof in EV

Roof is connected to the car with the pillars and also holds the 2 windshields of the car which are connected and joined through a sealant which will hold 3-4mm thick glass.

Things required to complete the challenge:

For the give Roof styling, develop the essential flanges and reinforcements, Provide appropriate dimension and check for Draft analysis and also submit your section modulus report on 0-Y section.

1. Start with the creation of roof ditch area the tool opening angle is only 3 degree.
2. Do a curvature study on the roof and perform calculations to determine the position of the Bow-roof.
3. Bow – roof prediction Formula : W = 1.73x10^-3 x L+1.85x10^-8 x (R^2)/t + 1.10x10^-3 x l-2.68
4. Judgement Condition : OK<2.7mm<NG

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]

• I have done the calculations and provided the output I gained in the below tabular format in excel sheet.

As per the standards the W value should lie between 2.7 to 3.5 but not more than 3.5. But it can be less than 2.7.

• Section Modulus values of each part I have designed are as below:

1. S(Front Roof Railing) = 101.67
2. S(Rear Roof Railing) = 254.91
3. S(Bow Roof Rail-1(Hollow)) = 1255.47
4. S(Bow Roof Rail-2(Hollow)) = 1123.368
5. S(Central Bow Roof Rail) = 2558.89

Below are the images of the parts that I have designed using CATIA V5

• 

All Roof Rails, Bow roofs attached to Roof Ditch Area

All Roof Rails and Bow roofs

Section view for Bow Roof Rail-1

Section view for Bow Roof Rail-2

Section view for Central Bow Roof Rail

Front Roof Rail

Rear Roof Rail

Roof Ditch Area

Conclusion: This is how a Roof is created and Bow roofs are added to strengthen it as per the industrial standard.

I am attaching the files on which I have performed the calculations.