Fender Design - Wheel Arch Challenge

Fender design-Wheel Arch Challenge

Objective: To calculate the wheel arch area of the given fender and prove whether the car will pass the European Standards or not.

What is 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, tires 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:

Full fender type is traditional type of fender where more material consumption is observed. This type is used in old design of automobiles where it increases the overall weight and thus reduces performance. The maintenance also relatively more due to more surface.

2. Half Bumper Type:

Half fender type is modern design where less material consumption is observed, so productivity increases by reducing size of blank and thus providing more performance. The maintenance also relatively low compared to full bumper type.

What is Wheel Arc ?

• Wheel Arch is the shaped part of the bodywork of a car or other vehicle that allows the wheel to be accessed, and in the case of front wheels, enable them to be steered. It is the semi-circular part that is positioned above the wheel of the vehicle. It should have the sufficient clearance between the tire and the wheel arch so that it does not touch the wheel arch area.
• If the wheel arch calculation is not done then it does more chipping which causes a lot of damage to the pedestrian as well as to the car also. The clearance value differs from region to region, according to the road condition. Followings are some standards that are followed by automobile industries.

Japanese Standards For Fender Wheel Arc:

• 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 wheel.

European Standards For Fender Wheel Arc:

• At all five sections the clearance value should be greater than 10 mm.
• Wheel guard requirement: The value of ‘a’ shall be more than 10 mm at a line 30˚ forward and 50˚rearward from the central vertical axis of wheel.

US Standards For Fender Wheel Arc:

• All values should be greater than 5 mm.
• Wheel guard requirement: The value of ‘a’ shall be more than 5 mm 30˚ forward and 50˚ rearward from the central vertical axis of wheel.

Wheel Arch Calculation:

This calculation will be done using European standards as per the instruction in the challenge to be followed.

Procedure: The sketch is drawn on the wheel face and projected on the wheel arch at section SA, SB, SC, SD, and SE and then the clearance value at these sections is measured.

Obtaining the clearance value ‘L’ at section SA, SB, SC, SD and SE:

At Section SA:

At Section SB:

At Section SC:

At Section SD:

At Section SE:

Observation Table:

Note: The negative sign is used because the curvature of the fender-wheel arch is going down from the wheel surface.

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

To satisfy the European requirements the value of 'a' should be more than 5mm at a line 30° forward and 50° rearward from the central vertical axis of wheel

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

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

Observation Table:

To calculate the wheel arc area, use measure function to calculate the wheel arc length by changing the length option and click the wheel arc which is 1041.5129 mm.

Then Measure the faces of wheel arc to calculate area which is 24432.9334 mm^2.

Conclusion: The given model is analyzed according to the European Standards and from the above table it is clear that the fender does not pass the European standards at all sections except at section SB.

Suggestion: I suggest that the model should be sent to the styling team and they should modify the curvature of the fender in such a way that there should have a minimum clearance of 10 mm.