Fender Design - Wheel Arch Challenge

FENDER:

• A fender is the part of a car, truck, motorcycle, or other vehicles that frames or covers a wheel well.
• Its main purpose is to prevent debris, rocks, mud, liquids, sand, and other road debris from the tyre from being entered into the engine bay or stopping

WHEEL ARCH

• Wheel arch of the car is portion which houses the wheels of the car.
• It’s the semi-circular region of the fender.
• Wheel arch of a car will be having some standard specification.
• The wheel cannot be outside the fender as it will lead to more chipping from the tyre.
• This is not good for the car and the pedestrians.
• So, by keeping this the pedestrian’s safety in mind, the tyre position should be inside the fender.
• This regulation changes according to the region.
• So, it is important to keep those regulations in mind while designing the fender and its wheel arch.

Types of fender:

The type of fender is based upon the area covered.

1. Full bumper type
2. Half bumper type

1.Full bumper type

• In this type more material is needed for the design the fender, hence more wastage of material.
• This design will also add on to the weight of the car as there is more sheet metal is used in this design.

2.Half bumper type

• In this type less material is used to design the part hence less wastage of material that leads to less cost.
• This design will allow to use more plastic on the bumper so the weight of the car can be reduced to a certain extend.
• This type of fenders is now widely used in the industry.

WHEEL ARCH REGUALTIONS

• According to the regions there are 3 main standards to the wheel arch design.
• This regulation is fixed by the road safety authorities of that particular regions. Those standards are:

1. Japanese standards.
2. European standards.
3. US standards.

1.Japanese standards:

• Here as shown in the picture, from the wheel centre vertical axis point.
• Two lines should be created and should be having 30 degrees to the left and 50 degrees to the right from the centre axis.
• Then on projecting the line on to the wheel arch, the distance between the intersecting points on the wheel and the wheel arch is allowed to have a minimum of 5mm distance at all three points(A, B and C).
• This is the Japanese standard.

2.European standards:

• Here as shown in the picture, from the wheel centre vertical axis point.
• Three lines SB, SA and SC should be created and should be having 30 degrees to the left for SB, SA passing 90 degrees through the centre axis and 50 degrees to the right from the centre axis for SC.
• Then after creating those three lines, a 150 mm point should be marked on the wheel arch reference and a line should be created from the centre point passing through the point on the wheel arch reference. That line is called SE.
• Then another line should be created intersecting SC line and SE line.
• Then on projecting the line on to the wheel arch, the distance between the intersecting points on the wheel and the wheel arch is allowed to have a minimum of 10mm distance at all the points.
• This is the European standard.
• 

3.US standards:

• For united state regulation, the concept is the same but the point should be taken on every 10 degrees from -20 degree to 0 and a minimum gap between the wheel and wheel arch should be 5 mm at all of those points.
• This is the United States requirement.

If the same car design is done for different markets for example Japan, Europe and US, the we are allowed to consider the maximum clearance value which will cover most of the regional requirements are we cannot make different designs for a same car as it will be inefficient.

PROCESS:

• Select the skin data and calculate the Actual value of clearance between tire and wheel arch.
• Create the datum plane on the wheel
• Create the sketch on that plane.
• Consider vertical 90 degrees line as SA. Draw a line 30 degrees forward line SB and 50 degrees backward line SC from SA.
• Now create the offset line at a distance of 150 mm from the horizontal line of the wheel center and make an intersection point with fender reference.
• Draw a line from the center of the wheel to this point and name it as SE.
• Now create the exact center point between the SC and SE on fender reference.
• Draw a line from the wheel center to this point and name this as SD.
• Then measure the clearance.

SA=9.9490

SB=10

SC=0.1126

SD=2.1685

SE=4.4116

Table shows the Actual value of clearance between tire and wheel arch

Measurement of point	SA	SB	SC	SD	SE
Required length	10	10	10	10	10
Actual Length	9.9490	10	0.1126	2.1685	4.4116
Remark	FAIL	PASS	FAIL	FAIL	FAIL

Conclusion:

• AS per European regulation requirements the clearance at give point should be minimum 10mm, more than 10mm can be accepted but at only one point there is 10mm clearance and other point clearance value is less than 10mm so the car will not pass the standards.
• The design of fender needs to modify