Fender Design - Wheel Arch Challenge
Fender Wheel Arc Regulation
Fender wheel arch is a semi circular part of the fender part positioned above the wheel of the car.fender frames the wheel well and protects the BIW part of the car and the engine compartments from the mud water or the debris coming from the wheel.
The another function of the fender is to stop the stone pellets,water on the road that could fly outside the wheel well and hit pedestrians.
Different countries have different fendor wheel arch regulation. let us consider Japan, European and US standards for wheel arch regulation.
FENDER
WHEEL ARCH
European standards for Fender wheel arch regulation
The side view and top view of the fender wheel arch is shown in the above figure.
The clearance value L of the fender wheel arch from the wheel is found at five different points by drawing lines from the centre of the wheel.
A 30° line SB is drawn to the left of the vertical line SA and a 50° line SC is drawn to the right of the vertical line.
A line SE is drawn coinciding with the wheel arch at a point 150 mm above the horizontal line.
Another line SD is drawn bisetting the lines SC and SE.
The points on the fender should have a clearance value >10 mm for the european standards.
wheel guard requirement:
The gap between the wheel and the fender wheel arch when seen from the side view should be greater than 5mm at a line 30° forward and a 50° rareword from the central vertical axis of the wheel.
a>5mm,b>5mm.
Japan Standards for wheel arch regulation
according to the Japan standards, the clearance value is studied at three different points at SA,SB,SC.
A line is drawn 30° forward and a 50° rareword of the vertical line from the wheel axis.
For the Japanese standards the clearance value L>5mm
For the wheel guard requirement,a>5mm,b>5 mm.
US standards for wheel arch regulation
In case of US, the clearance value of the wheel arch he is a studied at many points from -20° to 180° as shown in the figure.
Clearance value L at all the points should be > 5 mm
The value of a shall be >5 mm at a line 30° forward and 50° real world from the central vertical line from the wheel axis.
Wheel Arch Analysis in Catia software
Clearance value L at SA,SB
L at SA=9.949, which is less than the required 10mm clearance value.
L at SB=10 mm,which is equal to the required clearance volume.
Clearance value at SC,SD,SE
L at SC=-0.114mm,i.e The wheel arch is protruding inside.
L at SD=-2.888mm,
L at SE=-5.997mm.
At all the three points the wheel arch instead of protruding outside is on the negative side protruding inside of the wheel.
From the above two images,a>5 mm,b>5 mm.
| POINTS | CLEARANCE VALUE | RESULT |
| SB | 10mm=REQUIRED VALUE | PASS |
| SA | 9.949mm<REQUIRED VALUE | FAIL |
| SC | -0.114mm<REQUIRED VALUE | FAIL |
| SD | -2.888mm<REQUIRED VALUE | FAIL |
| SE | -5.997mm<REQUIRED VALUE | FAIL |
| POINTS | CLEARANCE VALUE | RESULT |
| a | 43.641mm>5mm,REQUIRED VALUE | PASS |
| b | 38.36mm>5mm,REQUIRED VALUE | PASS |
Conclusion
From the above table the wheel arch is satisfying only at one point and hence the fender design and wheel arch design must be changed accordingly.