Roof challenge

ROOF DESIGN CHALLENGE

OBJECTIVE:-

TO perform the section modulus study of the master section of Front roof rail, Back roof rail, Reinforcement, Bow roof-1, Bow roof-2 and also we have to design the ditch area and also calcuate draft analysis.

DESIGN CONSIDERATION:-

• VISIBILITY CRITERIA
• HEAD CLEARANCE
• CURVATURE STUDY
• HEAT DISTORTION AND SNOW LOAD AREA CALCUALTION
• ROOF THICKENESS STUDY

ROOF:-

A roof is the top portion of an automobile that sits above the passenger compartmen. This roof is protecting the from sun,wind, and rain and from dust particle. In this roof we have also some additional features like sun roof whch is the addition part.We have use the of the 0.75mm thickness. This thickness is very from company to company like MAHINDARA thickness is more thats why its cost is more.

INPUT SURFCE:-

This is the input surface which we get from styling team and now we have check the quality of the surface.

In the below image we have to check the continuity of the surface along Y and X direaction. This axis is automotive(CAR) axis.

MAIN COMPONET OF THE ROOF:-

FRONT ROOF RAIL:-Frontroof mail is front roof mounting. In front roof rail we have also design for the windsheild glasses fitting and also keep in mind that what is head clerance. The frontroof rail also provide the mounting of the revirew mirror.

REAR ROOF RAIL:- Rear roof rail is back side mounting of the roof also proidee the strength of the roof. In this design condiseration we have to keep it mind the head clearance of the rear passenger and also backtail design fitting.

In this input section not provide all necessary dimenssion so we have design a approx reference design of roof rail .

REINFORCEMENT:-

Reinforcement providde the main strength of the roof at the center of the roof and also design like no head imapct is done.There is no eviroment and master secction dimension is available so we have adopt our design criteria and dimenssion.

BOW ROOF:-

Bow roof is the additional part of the roof which provide some additional strength to the roof.

CURVATURE STUDY OF THE ROOF:

CURVATURE STUDY OF FRONT ROOF RAIL:-

CURVATURE STUDY OF REAR ROOF RAIL:-

CURVATURE STUDY OF CENTER ROOF RAIL:-

CURVATURE STUDY OF BOW ROOF_1 RAIL:-

CURVATURE STUDY OF BOW ROOF_2 RAIL:-

HEAT DISTORTION CURVATURE STUDY:

Heat distortion temperature is the temp where we do not use the material beyound this temp. in structural application.

This study help us to decide the number of bow roof and also the position of the bow roof. This bow roof help to avoid the bending of the roof.

BOW ROOF PREDICTION FORMULA:-

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

Judgement Condition : OK< 2.7> 3.1

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]

SNOW LOAD AREA:-

Qr = [Iy x t²] / [α x s x [(Rx + Ry)/2]² x 10^-8]

Note: The Qr value given over here is correct. There was a typo error in the formula given in the video.

Where

α = My x Lx² x 10^-12 , My = Y(Ly-Y)

Judgement condition = Qr ≥ 3.1

250 ≤ s ≤ 380

t = Roof plate thickness [mm]

Ly = Distance between the front and rear roof Rails on the Vehicle along with 0Y[mm]

Length of Roof panel with the center point between Roof rail Front /Rear as the front and rear reference point.

Lx = Distance between the Left and Right end of the roof on the Roof BOW [mm]

Width of the roof panel exposed on the surface.

Y = Distance front Front Roof Rail to Roof BOW[mm]

s = Distance for which Roof BOW bears divided load [mm]

s = L1/2 + L2/2

Iy = Geometrical moment of inertia of Roof BOW (Y cross-section )[mm4]

Rx = Lateral direction curvature radius of roof panel Y cross-section on Roof BOW [mm]

Roof panel curvature Radius of the Length Lx in Front view

Ry = Longitudinal Direction curvature radius of the Roof panel X cross-section on Roof BOW [mm]

Roof panel X curvature radius of length s in Side view

FOR ADDITION STRENGTH:-

DRAFT ANALYSIS

CONCLUSION:-

The curvature study, Front roof,center roof, bow roof, rear roof rail design done and also perfrom section insertia of with the help of master section. This master section is design by own.

We have also calculate heat distrotion area, Snow load and also draft analysis.