Design of the car roof using CATIA V5

A

DESIGN REPORT

ON

CAR ROOF DESIGN USING CATIA V5

By

ABHISHEK GANGURDE

Guided By

KUSHAGRA KASHYAP

ROOF DESIGN USING CATIA

Introduction

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.

Material Used For Roof: Aluminium, Steel ,Composite Plastics etc.

Types Of Roof:

• Convertible roofs

• Hardtops

• Sunroofs

• T-tops

• Targa tops

• Vinyl roofs

Problem Description:

To provide lighter weight components for vehicles. In order to minimize energy consumption, lightweight has become a critical issue because weight is a key factor for fuel consumption. The lighter the vehicle more will be the fuel efficiency.

But along with these advantages of light weight, corrosion resistance and more fuel efficiency, safety is a very important criteria for vehicle manufacturers. As vehicle rollover crashes are frequent accidents worldwide. Vehicle rollover crashes are the cause of many fatalities and severe head, neck and spine trauma around the world.

Objective:

Select proper material Which reduce weight, cost & increase efficacy

Measure the section modulus of the inertia to know the performance of it in running condition

The roof to be compliant with the relevant standards in Automotive Engineering

To measure strain and deformation at critical locations in the vehicle roof support structure and provide strengthening solutions in critical areas.

Design Of Roof Includes:

1. Front roof rail
2. Rear roof rail
3. Reinforcement roof
4. Bow roof 1
5. Bow roof 2
6. Ditch Area

Thickness of the roof = 0.75mm

Draft Angle = >7

There is three types of criteria to design roof of the car which as follows

1. Heat distortion criteria
2. Snowed criteria
3. Roof crush criteria (But this criteria done only after production of roof or on actual product)

Why do we need to calculate heat distortion criteria?

This is nothing but the curvature study and bow roof position justification.

At certain temperature material start softening when exposed to fixed load at elevated temperature above this temperature material not stable it can be deformed or loses its strength and this is unsafe to the passenger.

In order to know whether the material or roof is in a safer zone according to the position of the bow roof (Whether its position is right or wrong) we need to perform some formulae criteria as shown above.

Heat Distortion Criteria

SRNO	Comp	Rx	Ry	R	I	L	Lx	W	OK/NG
1.	FRR & 1BR	1757.193	2514.184	2068.61	325.615	2030.797	1143.856	1.4396	OK
2.	1BR & RRC	5074.615	5990.342	5494.586	395.168	2030.797	1090.771	1.5314	OK
3.	RRC & 2BR	3933.59	12016.3	5926.962	345.308	2030.797	1062.936	1.5796	OK
4.	2BR & RRR	3251.691	14151.02	5288.227	383.553	2030.797	1048.647	1.6043	OK

SNOWED CRITERIA

Why do we need to calculate snowed criteria?

In North INDIA there is continuous snowfall and it causes a door jam in the car to optimise this problem. We need to justify the snowed criteria theoretically.

To know whether the bow roof position is correct or not according to snowed load condition.

L- Length of roof in the X-Direction

SR. NO.	Comp	ly	Lx	Ly	Y	My	Alfa	s	Rx	Ry	Qr	Det.
1.	FRR & 1BR	771.5	1143.856	1731.336	455.2415	580931.1743	0.76	477.7237	1757.193	2514.184	104.822	OK
	1BR & RRC	1613	1090.771	1731.336	500.206	615818.6128	0.7327	475.5935	5074.615	5990.342	34.026	OK
3.	RRC & 2BR	546.3	1062.936	1731.336	450.981	577415.7783	0.6514	468.6440	3933.59	12016.3	6.3309	OK
4.	2BR & RRR		1048.647	1731.336	486.307	605466.3179	0.6658		3251.691	14151.02		NG

NOTE: Green region snows this value to satisfy the condition and the red value shows its NG.

Summary:

From the above calculation we summaries that this roof satisfies the theoretical heat distortion criteria as well as snowed criteria by maintaining W value in heat distortion criteria & Qr value in snowed criteria.

Here is the drive link of detail report and model:

https://drive.google.com/open?id=14ELuZPcgaa1sSCU6kxvtNH8SIUmLDGI5