Fender Design - Wheel Arch Challenge

Objective: To calculate wheel arch gap and to check whether the car passes through the European standard or not.

Introduction: The semicircular wheel arch is located above the tyre and helps to keep debris out of the engine compartment. Additionally, the wheel arch shields pedestrians and those inside the vehicle. There are different standards set for the wheel arch clearance with the car tyres and differs in different countries. 

Following are the two standards which have been explained as well:

Japan Requirement: Following image shows the requirement for the Japan standard

the distance L should be greater than 5mm at all the three positions A, B, and C as shown. These conditions are with respect to the road conditions in the Japan region. 

European Regulations Requirement: 

Following image shows the standard requirements for the European standards.

At all five sections as shown, the distance L should be greater than 10mm to meet the requirements for the European standard. And the value of wheel guard clearance, 'a' should be greater than 5mm at SB and SC which are at 30° and 50° from the central vertical axis.

US regulation requirements: 

Here the value of L should be greater than 5mm at all positions as shown in the image.

Challenge: To check for the European standard requirements for the given wheel arch

To check for distance 'L' as discussed earlier as per European standard,

1.I created skecth on the plane of outer edge of the wheel as shown below.

2.Then I projected the edge of the fender on the sketch plane and drew lines at specified angles as per European standard requirements as shown in the figure. And found intersection ponts of the same. 

3. Projected this sketch on the fender surface to get the distance between the wheel outer edge and the fender edge.

At SB-SB, L =10.000 mm

At SA-SA, L= 9.490 mm

At SC-SC, L=0.1126 mm

AT SD-SD, L= 2.8661 mm

At SE-SE, L= 5.8954 mm

At SB-SB, a= 46.1330 mm (wheel guard clearance)

At SC-SC, a= 38.3597 mm

Conclusion: 

From above analysis, it is observed that the given car doesn't have required 'L' distance at all sections as per European Standard. Only at SB-SB, L= 10.000 mm. 

However, the wheel guard clearance, 'a' is more than 5 mm at SA-SA and SC-SC, hence meeting the standards wheel guard clearance . But the overall standard requirements are not fulfilled and therefore the car doesn't pass the European standard.