Fender Design - Wheel Arch Challenge

Wheel Arc- In Fender Design:-

The wheel arch is an arch-shaped cavity in the body of a vehicle, which houses a wheel. It has two important functions. It serves for the safety of pedestrians and other cars because the wheel is situated in the body of a vehicle. The second function is to protect the car from the sticky materials, such as mud, may adhere to the smooth outer tire surface, while smooth loose objects, such as stones, can become temporarily embedded in the tread grooves as the tire rolls over the ground. These materials can be ejected from the surface of the tire at high velocity as the tire imparts kinetic energy to the attached objects. For a vehicle moving forward, the top of the tire is rotating upward and forward and can throw objects into the air at other vehicles or pedestrians in front of the vehicle.

Types of wheel arc regulations:-

• JAPAN REGULATIONS:-
• Measure clearance L of tire ,hub, cap & fender in three different positions within area K and produce clearance check chart to validate.
• Clearance must be greater than 5 mm in all the three positions.
• Wheel guard requirement: The value of a shall be more than 5 mm at a line 30" forward and 50 rearward from the central vertical axis of axis of wheel

• US REGULATIONS:-
• Make clearance check details on all positions from -100* to 100* & make the clearance check table.
• All values should be greater than 5 mm to satisfy the regulations. The value of 'a' shall be more than 5 mm at a line 30* forward and 50*.
• rearward from the central vertical axis of axis of wheel.

• EUROPEAN REGULATIONS:-
• Measure CL L at sections SA-SA SB-SB SC-SC SD-SD SE-SE and produce CL check chart to validate.
• At all five sections the CL L value should be greater than 10 mm to satisfy the European regulations.
• Wheel guard requirement: The value of 'a shall be more than 5 mm at a line 30* forward and 50* rearward from the central vertical axis of axis of wheel

Wheel arc analysis:-

• There are different regulations in this regard based on different regions. This analysis has been done according to European Regulations.
• The part file was opened using NX CAD and the points were plotted on the wheel arch after taking the required measurements from the wheel center.

• The clearance value 'L' was measured and found to be as follows:-

SECTION	REQUIRED DISTANCE	CALCULATED DISTANCE	RESULT
SA	10 mm	9.949 mm	FAIL
SB	10 mm	10.000 mm	PASS
SC	10 mm	0.098 mm	FAIL
SD	10 mm	2.859 mm	FAIL
SE	10 mm	5.997 mm	FAIL

Conclusion:-

• As per the above observations the positions SA SC SD SE are less than 10mm which is necessary to pass the European standards. Hence, the front fender wheel arch does not pass the European standard.
• The styling team is required to modify the styling surface of the fender such that the clearance "L" at sections SA, SC, SD and SE is equal to or greater than 10 mm by increasing the curvature at those sections towards outside.