Roof challenge
REPORT
ON
ROOF
UNDER THE GUIDANCE
OF
SKILL LYNCE
OBJECTIVE:-
1.To perform the section modulus study for the master section and creat for the front roof rail ,rear roof rail, bow roof rails.
2.To creat the Ditch Area and to perform the draft analysis.
DESIGN CONSIDERATION :
- VISIBILITY CRITERIA
- HEAD CLEARANCE
- CURVATURE STUDY
- HEAT DISTORTION AND SNOW LOAD CRITERIA
- MATERIAL THICKNESS
INTRODUCTION:-
ROOF:
An automobile roof or car top is the portion of an automobile that site above the passenger compartment,protecting the vehicle occupants from sun wind, rain and other external elements.becouse the earliest automobile were designed in an era of horse-drawn carriages ,early automobile roofs used similar material and designs.
MAIN COMPONENETS OF ROOF :
FRONT ROOF RAIL:
Front roof rail are used in the assembly of a roof in which it provide mounting provisions to wind shield glass and the changes in the front roof rail influence the frontal visibility of the passenger .the front roof rail also provides provisions for mounting the inside rear view mirror.
DRAFT ANALYSIS
BOW ROOF1& 2:-
BOW -Roof center 1 is an additional stiffness member used in the roof assmbly for the localised strength improvement and it is join directly to roof itself with several spot welding or even with the mastic sealant .
BOW RAIL-1 BOW RAIL-2
CENTER ROOF RAIL(REINFORCEMENT) CENTER:
Similar to other rail design we have to take into consideration the headroom clearance and the visiblity criteria while desiging the centre roof rail and bow roof but unlike.Insted mastic sealant are introduced at both the ends since centre .roof increasing the strength of the rail,embossing is done .to reduce the weigth of the matrial used . a different has been followed with a thickness of 1.5(reinforcement).
CENTER RAIL ROOF WITH RAIENFORCEMENT DRAFT ANALYSIS
REAR ROOF RAIL:-
The rear roof rail is the one of the important component of assembly which is used for the back door mouting to front roof rail important design consideration include rear visibility of the vehicle.
DRAFT ANALYSIS
ROOF WITH DITCH AREA
Heat Distortion curvature study:-
The heat distortion study play an important role in sheetmetal usage .heat distorsion temperature is a temperature limit above which the material cannot be used for structural applications.
This study is used to predict the heat distortion temperature at where the material start to soften when expossed to a fixed load at elevated temperature . in order to avoid bending /damage on roof .bassed on heat distortion temperature ,this study will predict the bow roof position to strengthen the roof.
Bow -roof prediction fromula:
W=1.73*10^-3*L+1.85*10^-8*(R^2)/t+1.10*10^3*1-1.26
L-Roof Length in X-Direction(mm)(Roof Dimension in O-Y)
R-Roof curvature
R=2(Rx*Ry)/(Rx+Ry)
Rx-xCurvature
Ry-yCurvature
t-Roof Plate Thickness(mm)
l-Bow roof spam(mm)
judgement condition : ok<2.7mm
where NG-NOT GOOD
SNOW LOAD CRITRIA :
This evalution is performed in cold region where snow occurs.roof design must pass through these calculation it has sufficent stiffness to withstand the load due to accomalation over the roof .
SNOWED CRITERIA:-
Predected formula:-
Inertia of Rear Roof Rail:-
Inertia of Front roof rail:-
Inertia of Centre Roof Rail :-
Complete inertia of Roof:-
DIFFERENT TYPE OF VIEWS :-
Conclusion:-
We were succesfully able to design the roof with all the roof for better support and strength. We designed it so as to satisfy the norms and regulations by calculating the heat distortion criteria and snow load critera . while doing this we also understood about the methodology behind designing the roof of the car and what all we take into consideration while designing .