Fender Design - Wheel Arch Challenge

Fender- Wheel Arch Calculation

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

Fender mainly are of two types

Full bumper type
It covers more area and consumes material compared to half bumper.
Scrap material is more compared to the half bumper

Half bumper type
It covers less area and consumes less material
A single sheet can be used to produce more than one bumper.

Fender wheel arch area

The wheel arch is the semicircular part positioned above the wheel of a vehicle.
The main factors to be considered while designing the wheel arch area are
The wheel should be placed inside the fender or in other words, there should be a minimum distance between the outer surface of the fender and outer surface of the wheel.



The distance ‘L’ as mentioned in the above figure should be a minimum value, which varies as per standards followed by different countries.
This helps to reduce the chance of chipping of the wheel with outer particles.
It helps in increasing pedestrian safety.
Some of the different standards followed are
Japanese standards
European standards
American standards.
Japanese standards
The clearance ‘L’ between the outer surface of the tire & fender in three different positions within area K as mentioned in the figure below must be greater than 5 mm
The value of ‘L’ shall be more than 5 mm at line 30 forward and 50 rearwards from the central vertical axis to the axis of the wheel.

European standards
The clearance ‘L’ at sections at SA, SB, SC SD AND SE should be greater than 10 mm to satisfy European regulations.

US standards
The clearance ‘L’ at all positions (every 10o) from -20o to 180o should be greater than 5 mm to satisfy US regulations.

Fender wheel arch area calculation

Aim: to calculate wheel arch area for the given fender as per European standards.

Calculations

As per European standards, respective points are marked in the fender as given below.

Wheel arch area calculation as per european standard
sr no	position	clearance value "L" in mm	minimum value required as per standard	remark
1	SA	9.94	10	will not pass the standard
2	SB	10	10	will pass the standard
3	SC	0.11	10	will not pass the standard
4	SD	2.88	10	will not pass the standard
5	SE	5.99	10	will not pass the standard

Conclusions

From the above table, it is observed that the given fender will not pass the European standards in the positions- SA, SC, SC & SD.
At position SB, the required standards are met and further modification at that position is not required.
This data will be sent to the design styling department for further modifications