Fender Design - Wheel Arch Challenge

Wheel Arch-

• It is a semicircular profile above wheels designed for enclosing tire within the fender The wheel arch is designed considering all possible motions the tire undergoes while the vehicle is in motion.
• It is a curved part of the Fender positioned right above the Wheel.
• The Wheel Arch is designed such that it protects both the pedestrian and car cabin from mud, water rocks and other road spray.
• Different countries have different wheel arch regulations in place, and the wheel arch design has to comply with them to be deemed usable in that country

Fender Wheel Arch Regulations

Japan Standards

• The clearance between the wheel and fender wheel arch must be greater than 5mm in all the three positions (A, B & C which is shown in the following picture).
• Wheel guard requirement: the value of ‘a’ shall be more than 5mm at a line 30º forward and 50º rearward from the central vertical axis of wheel.

European Standards

• The clearance between the wheel and fender wheel arch must be greater than 10mm in sections SA-SA, SB-SB, SC-SC, SD-SD and SE-SE to satisfy the European regulations.
• Wheel guard requirement: the value of ‘a’ shall be more than 5mm at a line 30º forward and 50º rearward from the central vertical axis of wheel.

U.S Standards

• The clearance between the wheel and fender wheel arch must be greater than 5mm in all positions.
• The value of ‘a’ shall be more than 5mm at a line 30º forward and 50º rearward from the central vertical axis of wheel.

Calculation of wheel arch area according to European Regulations for the given design is as follows:

Wheelarch gap at point SA is 9.9490mm as shown in the image below

Wheelarch gap at point SB is 10.0mm as shown in the image below

Wheelarch gap at point SC is 0.113949mm as shown in the image below

Wheelarch gap at point SD is 2.8875mm as shown in the image below

Wheelarch gap at point SE is 5.9973mm as shown in the image below

Tabulated form of the obtained results is as follows:

Region	Reuired Clearence	Obtained Clearence	Result
SA	10 mm	9.9490 mm	FAIL
SB	10 mm	10.0 mm	PASS
SC	10 mm	- 0.113949 mm	FAIL
SD	10 mm	- 2.8875 mm	FAIL
SE	10 mm	- 5.9973 mm	FAIL

Hence, from the obtained results we can conclude that the car cannot pass through the European standards as the minimum clearance 'L' between the fender wheel arch and wheel for vehicle is 10mm as per the european regulation, the given design does'nt meet the requirement.