Fender Design - Wheel Arch Challenge

A fender is a part of an automobile, motorcycle, or other vehicle body that frames a wheel well (the fender underside). Its primary purpose is to prevent sand, mud, rocks, liquids, and other road sprays from being thrown into the air by the rotating tire. Fenders are typically rigid and can be damaged by contact with the road surface.

The main purpose of fenders on cars is that they shield the wheels and they protect the passengers, pedestrians, and other vehicles from stones, mud, liquid, and other debris that can fly in the air because of the speeding rotating wheels while the car is running.

Wheel Arch

• 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 another 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.
• For avoiding design alterations of the same vehicle to meet the different regulations in different countries, the maximum values of the concerned regulation parameters are taken into consideration for design purposes.

Fender Wheel Arch Regulations

Japan Regulations

• The clearance ‘L’ for tire, hub, cap, and fender is to be measured within area K , and create clearance check chart to validate
• The value of L should be greater than 5mm at all positions
• Wheel guard requirement: The value of ‘a’ should be more than 5mm at line 30° forward and 50° rearwards from the central vertical axis of the wheel

US Regulations

European Regulations

• The Clearance ‘L’ should be measured at sections SA-SA, SB-SB, SC-SC, SD-SD and SE-SE and create clearance check chart to validate
• At all the five sections the value of L should be greater than 10mm to satisfy the European Regulations
• Wheel guard requirement: The value of ‘a’ should be more than 5mm at line 30° forward and 50° rearwards from the central vertical axis of the wheel

The given model for wheel Arch gap at required points and check whether the car passes the European standard.

The value of "L" at SA=9.95

The value of "L" at SB=10.00mm

The value of "L" at SC=0.113mm

The value of "L" at SD=2.88mm

The values of "L" at SE=5.975mm

Clearance "L" obtained at sections SA,SB, SC,SD, and SE

Section	Clearence "L" 10(in mm)	Comments
SA	9.95<10	Fail
SB	10<=10	Pass
SC	0.113<10	Fail
SD	2.88<10	Fail
SE	5.975<10	Fail

From the above results, we can conclude that the fender does not pass the European regulations, as the min clearance L between the fender wheel arch and the wheel for vehicle and pedestrians safety is 10mm and this design does not meet the requirements.