Fender Design - Wheel Arch Challenge

AIM

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

Before calculating the Wheel Arc gap using the European standard, we need to understand the different standards in fender design. There are three standard about Fender design.

JAPAN STANDARDS

The requirement of the japan standard is mentioned below ,

• 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 STANDARD

The requirement of the European standard is mentioned below ,

• 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 STANDARD

The requirement of the US standard is mentioned below ,

• 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.

Procedure for calculating the wheel arc gap in the NX CAD following the Eurpean standard

• Import the given skin data to NX CAD

• From rear side we see that tyre is coming outside the fender area.

• From Front side we see that the tyre is completely inside the fender

• Now we need to check for the European regulations standard. For that we need to create the datum plane at the outer most face of the wheel as shown in figure.

• After that in that plane we sketch the lines and the give the required angle from the reference of the European standard. Create points using the intersection point. And project the points to the fender.

• Measure the required distances as the European standard as shown in figure. From the SB line the clearence distance we measure is 43.9119mm and the 50degree SC line the clearance distance is 38.6842mm as shown in figure

• Also measure the SB-SB, SA-SA, SC-SC , SD-SD, SE-SE.

All the values and their result compare to the European standard is tabulated in below,

SECTION	L (>10mm)	RESULT	a (>5mm)	RESULT
SA-SA	9.9490	FAIL
SB-SB	10	PASS	43.9119	PASS
SC-SC	0.11395	FAIL	38.6842	PASS
SD-SD	2.8875	FAIL
SE-SE	5.9973	FAIL

CONCLUSION

From the above results we can conclude that the given Fender does not pass the European Regulations as the minimum clearance between the fender arch wheel to the outer most wheel is 10 mm and this design does not meet the this minimum clearance so this fender design is fail for the European Regulation standard.