Fender Design - Wheel Arch Challenge

• OBJECTIVE:

Calculate the Wheel Arch gap at required points and check whether the car passes the European standard.

FENDER WHEEL ARCH

It is a curved part of the Fender positioned right above the Wheel. The Wheel Arch is designed such that it protects both the pedestrian and car cabin from mud, water rocks and other road spray. 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.

Wheel arch comes with some standard specifications. When viewed from the front or top side of the vehicle, if the wheel is protruding outside the fender, that would lead to more chipping while driving and compromises pedestrian as well as the vehicle safety. Taking these factors into consideration, the wheel has to be positioned inside the wheel.

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

Japan Regulations

• The clearance ‘L’ for tire, hub, cap and fender is to be measured within area K and create clearance check chart to validate
• The value of L should be greater than 5mm at all positions
• 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

• The Clearance ‘L’ should be measured at sections SA-SA, SB-SB, SC-SC, SD-SD and SE-SE and create clearance check chart to validate
• At all the five sections the value of L should be greater than 10mm to satisfy the European 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

US Regulations

• Clearance ‘L’ is to be checked at all positions from -100° to 100° and create clearance check chart to validate
• The value of L should be greater than 5mm to satisfy the 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

STEPS FOLLOWED IN CREATING THE SKETCH REQUIREMENT FOR EUROPEAN STANDARDS

1. A Horizontal and vertical axis is drawn from the centre of the wheel.
2. The vertical axis intersection point is labelled as A.
3. Similar references are drawn at 30 degrees to left and 50 degree to the right and named it as B and C respectively.
4. A line of 150mm is drawn perpendicular to the horizontal axis and normal from the normal point on fender which gives point E.
5. The midpoint of the arc cut by the sections C and E results in a new section D.
6. The value of 'L' at each section and the value of 'a 'are found out to detrmine whether the fender satisfies the european standards

Sketch

i.) Clearance 'L' at SA-SA

ii.) Clearance 'L' at SB-SB

iii.) Clearance 'L' at SC-SC

iv.) Clearance 'L' at SD-SD

v.) Clearance 'L' at SE-SE

Measuring the clearance vlaue'a' for Wheel Guard Requirement

i.) Clearance 'a' at 30° line SB

ii.) Clearance 'a' at 50° line SC

Conclusion

From the above results we can conclude that the Fender does not pass the European Regulations, as the minimum clearance L between the Fennder Wheel Arch and Wheel for vehicle and pedestrian safety is 10mm and this design does not meet the requirement.