Roof challenge

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.

There are at least three types of roofs commonly installed on cars, namely sunroofs, moonroofs, and also panoramic roofs.

An automobile roof consisits of 5 parts,

• Outer panel
• Front roof rail
• Rear roof rail
• Bow roof rail
• Center roof rail

FRONT ROOF RAIL:

It is created at the front side of the roof to provide strength to the roof.while designing the front roof rail,we should consider two major factor…one is driver visibility criteria and head room clearance.it is connected with outer panel with the help of mastic sealen.

REAR ROOF RAIL:

It was created at the end of the rear roof,while designing the front roof rail we also consider that backdooe design.

BOW ROOF RAIL:

It Is used to give strength at the particular area.it created between center roof rail and front roof rail,also created between center roof rail and rear roof rail.

CENTER ROOF RAIL:

It were created at the center of the roof.

ROOF IMG:

FRONT ROOF RAIL

BOW ROOFS:

CENTER ROOF RAIL:

REAR ROOF RAIL:

HEAT DISTORSION CRITERIA:

The Heat Deflection Temperature (HDT), or Heat Distortion Temperature, is a measure of a polymer's resistance to alteration under a given load at an elevated temperature.The calculation is mainly used to find the diflection is have or not? and the position of bow roof are correct or not?

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

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]

Judgment Condition

OK< 2.7

TO MEASURE L:

TO MEASURE Rx AND Ry:

TO MEASURE I(BOW ROOF SPAN):

Here,all the judgement condition are satisfied except CR-BR1.that's why i make a emboss over the roof panel for strengthning purpose.

SNOW LOAD CREATRIA:

Still, you might have wondered whether it was safe not to remove the snow immediately after a snowfall. Our snow load calculator helps you to make the decision when to remove the snow from your roof by comparing the weight of snow with the load-carrying capacity of the roof.

Snow Load Prediction Formula:

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)

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]

The width of the roof panel is 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

Judgment condition

Qr ≥ 3.1

250 ≤ s ≤ 380

TO MEASURE Ly:

TO MEASURE Lx:

TO MEASURE RX AND RY:

TO MEASURE S:

S=(L1+L2)/2

TO MEASURE Iy:

it is observed that all the three are not satisfied the judgement condition.so we use emboss to strengthen that roof.

DRAFT ANALYSIS:

With draft analysis, you can verify draft angles, examine angle changes within a face, as well as locate parting lines, injection, and ejection surfaces in parts.

we check that have manufacturing have or not?