Fender Design - Wheel Arch Challenge

Wheel Arch

Wheel arch is the semi - circular part of the vehicle is position on the top of the wheel. Wheel arch claddings are there to stop water and dirt ingress from getting into tight spots around the wings of the car to prevent corrosion.

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 purpose.

There are different regulations in this regard based on different regions. This case study has been done according to European regulations. As explained in the diagram below, the minimum clearance 'L' recommended at all the 5 points on the wheel arch shown here should be 10mm, the points being SB, SA, SC, SD, SE.

Fender Wheel Arch Regulations

• US Regulations

Clearance ‘L’ is to be checked at all positions from -100° to 100° and create clearance check chart to validate

• Japan 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

• European Regulations

Calculation of wheel arch area according to European Regulations

For calculation of clearance between Wheel Arch and Wheel we have to create a sketch on the outer most face of the wheel. The procedure of which is given below.

• A Datum Plane is created at the outermost face of the wheel
• The sketch is created on the new Datum Plane
• A Horizontal line is drawn across the centre of the wheel
• A perpendicular line SA is dropped at the centre of the wheel
• Two lines SB and SC are created at 30° forward of SA and 50° rearward of SA respectively
• A point is created 150mm vertically above the centre line
• A line SE is drawn from the wheel centre and passes from the point created
• Another line SD is drawn from the centre of the wheel and in the middle of lines SC and SE

Sketch:-

Applying European standards to given Fender & wheel data:

After creating the sketch, you will use the law extension feature in NX Cad. Then Finding the Clearance value between the Fender edge to law of extension edge

Let, find the value pf “L” at the sections SA-SA, SB-SB, SC-SC, SD-SD, SE-SE.

• Measuring "L" for the given Wheel and Fender at SA

The value of "L" at SA - 9.9492mm

• Measuring "L" for the given wheel and fender at SB

The value of "L" at SB = 10mm

• Measuring "L" for the given wheel and fender at SC

The value of "L" at SC = 0.113667mm

• Measuring "L" for the given wheel and fender at SD

The value of "L" at SD = 3.3759 mm

• Measuring "L" for the given wheel and fender at SE

The Value of "L" at SE = 7.184mm

RESULTS :-

Conclusion:-

The given fender is Fail the European Regulation for Wheel Arch Area. Because of clearance value is varies between the section to section. Due to the Tire is Go outside direction. So, it is danger for pedestrian safety as well as aesthetic look of the car also bad.