Fender Design - Wheel Arch Challenge

WHEEL ARC CALCULATION

The aim of this calculation is to find out the radius of the wheel arc with the help of few parameters from various parts of the world. The wheel arch radius is calculated for the given model using NX CAD 12.0 with the given parameters. This calculation helps in finding out the distance between the fender and the tyre so that the tyre will have sufficient space according to the parameters and not damage the vehicle during turnings or any pot holes.

The wheel arc radius is calculated with the help of few standards around from different counties, here are the list of standards:

1. Japan standard

According to Japan standards, the three points taken from the center of the wheel at a particular angle and the points are placed on the side of the wheel. The gap between the points and wheel should be 5mm or more.

2. European standards

According to European standards, a distance of 150 mm vertical line is taken from the center line and the necessary angles are taken from that point. These points are places on the outside of the fender. The points should be 10 mm or more from the tire.

3. US Standards

As per US standards, the points are taken at every 15 degrees. There should a gap of 10mm on every point of the angle.

Now let us calculate the wheel arc distance for the given model,

1. Create a face on the outer wheel and sketch the following.
2. A center line is drawn namely SA and made to meet with the outer edge of the fender.
3. A line is drawn at 30 degrees from the centre namely SB and another line is drawn at 50 degrees from the center namely SC.
4. An angle bisector is drawn from the center point of the circle at an vertical distance of 150mm.
5. Lines are drawn where the angle bisector crosses the curve on the wheel namely SD and SE.
6. Now exit the sketch and go to Analysis > Simple distance and select the lines to be measured.
7. The line and the outer edge of the fender is taken as references and measured.
8. The measured distances are:
   1. Line SB = 10 mm (PASS)
   2. Line SA = 9.9727 mm (FAIL)
   3. Line SC = 2.9654 mm (FAIL)
   4. Line SD = 1.6656 mm (FAIL)
   5. Line SE = 0.2899 mm (FAIL)

LINE SB LINE SA LINE SC

LINE SD LINE SE

CONCLUSION

Only line SB passsed the standard for European Wheel arc calculation of 10mm distance between the wheel and the fneder. Hence we must discuss with the styling team and give our inputs to satisfy the European standards. Hence the given model doesnt pass the European standards.