Roof Design

 OBJECTIVE

 Main objective is to design roof of a car and also to analyses roof curvature with the help of Heat distortion and snow load condition.

 ROOF REINFORCEMENT PARTS 

1. FRONT ROOF RAIL 
2. BOWROOF 1
3. CENTRAL ROOF SUPPORT
4. BOWROOF 2
5. REAR ROOFRAIL

Mian purpose of the reinforecements is to provide better strength and support to defined region of the roof 

Also it reduces the impacts that acting on the roof outer surface 

ROOF CREATION 

Created the Roof reinforcement areas and outer panel as per the given master sections.

required images are shown below.

 

CREATION OF BOWROOF1 

•  Created the bow roof as peer the given mastersections.
•  Bow roofs are made to give support on the roof flat areas
•  It prevents the roof from the external sheet metal to buckle while applied an external force 
•  created the boow roofs with offseting method 
•  Provided a 7 degree angle for the smooth production of part 
• ends of the bows are 20mm long and cut the end flanges for mastic purposes 
• Also verified with the draft analysis with 7degree the images are shown below

CREATION OF CENTRAL ROOF SUPPORT

• Reinforcement rail ceneter is provided on the center of the external roof 
• There is a chance of buckling of the roof due to the weight to prevent from it central roof support playing a majour role.
• It gives the strength at particular area with the head room clearence

• The Central supports are also made as per the given master sections
• Designed it with offseting method
• Provided 7 degrees for better drafting 
• The flanges of the Central support given with 25mm length 
• Draft analysis of the central roof rail is also attached below 

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BOWROOF 2

•  The same design procedures of bowroof1 is used here 
•  The snapshots given below 

 

 FRONT ROOF REAIL

• Front roof rail is designed based on the master section of the front roof rail shown below considering the dimension windshield which is accommodated in front of front roof rail measuring 3.70 mm as shown in the figure.
• Dimensions shown 32mm and 80mm in the above image is based on the factors such as head room clearance and visibility criteria
• Embosses given to the front roof rail for the better strength 

REAR ROOF RAIL

• The rear roof rail primarily supports the roof of the car.
•  It also assists in the operation of the back door hinges, facilitating smooth opening and closing. 
• The reinforcement center is a crucial structural element of the roof.

BOW-ROOF PREDICTION CALCULATION

•   W = [1.73 x 10^(-3) x L] + [1.85 x 10^(-8)  x (R^2)/t] + [ 1.10x10^(-3) x l] - 2.68            

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] 

 

This is the formula for finding the bowroof prediction.

To find the Ry value using bisecting method of distance between two bowroofs are used  

 

 

 Devided the entire roof portion into 4 regions 

                          I                L            Rx                 Ry               R               W           CONDITION

FRTRF-1BR       364.83        2139      1657.4         2407.32        1963.1       1.5168          OK

1BR - RRC        409.59        2139      3135.3         2880.3          3002.3       1.6933          OK

RRC-2BR          344.58        2139      3568.75       18914.3        6004.55      2.288           OK 

2BR-RR RF       497.411       2139      2985.5         23485.4        5297.56      2.259           OK

 That is  the bow- roof prediction criteria is ok for the design