Fender Design - Wheel Arch Challenge

Challenge: To calculate the wheel arc area and decide whether the car will pass the European standards or not.

Fender:

• Fender is the US English term for the part of an automobile (vehicle body) that frames a wheel well (the fender underside).
• Its primary purpose is to prevent sand, mud, rocks, liquids, and other road spray from being thrown into the air by the rotating tire.
• When vehicle is moving, tyres pick up stones and others and hurl them in all directions. Fenders are basically present to prevent any injuries to pedestrians and contain the motion of these particles
• Most passenger automobiles have four fenders, one over each wheel. For vehicles with a narrow car body that exposes the tire, the fender is an exposed curve over the top of the tire. For wide-body vehicles that cover the tire, the fender forms the wheel well surrounding the tire and is not directly visible from above the car body.
• Wheel wells tend to be much larger than the diameter of the tire because they do not move with the tire suspension and consequently must be large enough to allow the full range of tire motion on the suspension without touching the interior of the wheel well.
• More elaborate designs include fender skirts for enclosing the outside edge of the wheel well and stylized pontoon fenders for exposed fenders.

Types of Fender:

1. Full bumper type

2. Half Bumper type

Wheel Arch:

• Wheel Arch is the semicircular curve on the fender just above the wheels of the car
• It has some standard specifications
• For a vehicle to has its use permit in different countries, the wheel arch of the fender must compliant with the standards set by the respective countries

Fender Regulations:

There are regulations based on three standards which is decided based on the road conditions of different conutries.

1. Japanese

2. European

3. US

Indians follow European standards, as shown below image,

Wheel Arch Calculations:

Drawing the sketch as per European standards and regulations and projecting the sections on the fender to obtain the measurements for 'L' AND 'a' .

Measurement of the Clearance values at all sections:

Measuring 'L' at SB:

Measuring 'L' at SA:

Measuring 'L' at SC:

Measuring 'L' at SD:

Measuring 'L' at SE:

Results Table:

Section	Clearance L(mm)	Result
SA	10.00	Pass
SB	9.949	Pass
SC	-0.1139	Fail
SD	-4.479	Fail
SE	-9.615	Fail

From above table, the given fender doesn't pass the European standards for wheel arch area at sections SC, SD, and SE.

Note: Here the value is negative because the wheel arch line comes outside the fender

Measuring the values of clearance "a" Wheel Guard requirement:

Measuring the value of 'a' at line 30° forward from the central vertical axis of the wheel:

Measuring the value of 'a' at line 50° forward from the central vertical axis of the wheel:

Result Table:

Section	Clearance a(mm)	Result
SB	44.7757	Pass
SC	38.3599	Pass

Conclusion:

From the above results obtained, we can conclude that the given fender doesn't pass the European Standards for the Wheel Arch area. With this result, the styling team is required to modify the surface of the fender such that the clearance "L" at sections SC, SD, and SE is equal to or greater than 10 mm by increasing the curvature at those sections towards the outside.