Fender Design - Wheel Arch Challenge

WHEEL ARCH –FENDER DESIGN REGULATIONS

AIM

To study and understand the different fender arch regulations in various regions and to check and validate the given design of a wheel-fender arc following the European regulations.

Introduction

A fender is the curved portion of the car's body that sits over and houses the wheels. As mentioned, a fender is merely a housing for the wheels that prevents road debris from being thrown up by the rotating tires and protect the pedestrians on the road. fenders are also able to absorb impact from minor collisions.

Japan regulations

Clearance value from the outermost edge of wheel to the fender wheel arc should be 5mm or more at a line 30degree forward to the vehicle (left side) and 50degree rearward to the vehicle (right side) from the central vertical axis of wheel.

European regulations

For all the five sections from the central vertical axis of wheel clearance between the outermost edge of wheel to the fender wheel arc should be greater than or equal to 10mm.

The first two points are at a line 30degree forward to the vehicle (left side) and 50degree rearward to the vehicle (right side) from the central vertical axis of wheel and the fourth point will be at a distance 150mm character from zero line (base line) and the bisecting line between the point at 150mm and 50degree will be the last point.

USA regulations

Make clearance check on every 10degree from the outermost edge of wheel to the fender wheel arc details on all positions from -20 to 190 degree from the central vertical axis of wheel.

More than 5mm clearance should be there for every 10degree from -20to 190 degree (ie from 20 to zero and zero to 190 degree) from the central vertical axis of wheel.

Input cad received

Data to be consider while calculating the fender wheel arch design

In the part formed by radial planes at an angle of 30° towards the front and 50° towards the rear of the centre of the wheels, the overall width (q) of the wheel guard shall be at least sufficient to cover the total tyre width (b) taking into account the tyre envelope as well as the extremes of the tyre/wheel combination(s) as specified by the manufacturer. In the case of twin wheels, the tyre envelopes and total width over the two tyres (t) shall be taken into account.

Fender wheel arch with all five position drawn on sketch with the required angle as per european regulations

Distance between the outermost edge of wheel to the fender wheel arc of the design at position A

 

Distance between the outermost edge of wheel to the fender wheel arc of the design at position B

Distance between the outermost edge of wheel to the fender wheel arc of the design at position C

Distance between the outermost edge of wheel to the fender wheel arc of the design at position D

Distance between the outermost edge of wheel to the fender wheel arc of the design at position E

Distance between the outermost edge of wheel to the fender wheel arc of the design for all the five positions

Observations from the input design based on European standards

Position	A	B	C	D	E
Clearance	10mm	9.95mm	-0.114mm	-2.88mm	-5.99mm
Result	Pass	fail	fail	fail	fail

Where,

A- at 30degree forward to the vehicle (left side) from the central vertical axis of wheel.

B- Perpendicular line to the central horizontal axis (ground line) of wheel base line.

C- at 50degree rearward to the vehicle (right side) from the central vertical axis of wheel.

D- will be at a distance 150mm character from zero (base line).

E-bisecting line between C and D.

Clearance- Distance between the outermost edge of wheel to the fender wheel arc of the vehicle.

Conclusion

From the above table we can clearly understand that the given design maintained 10mm clearance only on one point (A) and fails on all other points and this will be rejected as per the Europe regulations. Thus it is highly recommended to change the curvature of fender wheel arch by following 10mm clearance between the outermost edge of wheel to the fender wheel arc of the vehicle.