Fender Design - Wheel Arch Challenge
AIM :Calculate the Wheel Arch gap at required points and check whether the car passes the European standard.
INTRODUCTION
1.FENDER
Most other vehicles have quarter panels at the rear or a wheel-well style fender. Whichever kind of fender your vehicle has, the rules are still the same. In most states, you cannot have the tire sticking out past the “fender.”
2.WHEEL ARCH
The wheel arch is the semicircular part positioned above the wheel of a vehicle. The most important body change was that the front wheel arch was cut higher into the fender.
The wheel arch liners can be mounted on the front and/or rear wheel arch opposite the wheel to protect the body of the car. Eventually splash shields can be integrated in the design of the part. Outer liners are used at the exterior of the car.
These wheel arch liners may reduce the noise transmission into the vehicle interior of noises generated during driving of the vehicle. These noises are mainly caused by the wheel rotating on the road surface, as well as noise from coming from water and stones thrown by the tires at the wheel house. However the wheel arch liner also serves as protection against particles highly accelerated against the wheel arch during driving, due to the rotating wheel, such as sand and gravel, and for protection against water and mud.

Fig.2. wheel arch of differnt vehicles
3. WHEEL ARC GAP

fig 3 Gap between wheel arc to tyre profile
based on the standard measure the gap between fenderwheel arc to tyre at different positions.it is illegal in most states for the tires to stick out past the fenders.because the fenders are there to do a job and as with many parts that job is to do with safety.Different countries following different regulations.The regulatios are given below.
4. FENDER WHEEL ARCH REGULATIONS
There are three Regulations
- Jappan Regulation
- European Regulation
- U.S Regulation
1. Jappan Regulation

fig.1a. Jappan Regulation
- The clearance "L" for tire, hub, cap and fender in three different position is to be measured within the 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" shall be more than 5mm at a line 30° forward and 50°rearwards from the central vertical axis of wheel.
2 . European Regulation

fig. 2b. European Regulation
- Measure "L" at sections SA-SA, SB-SB, SC-SC, SD-SD and SE-SE and produce 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" shall be more than 5mm at a line 30° forward and 50°rearwards from the central vertical axis of wheel.
3. U.S Regulation

fig.3c. U.S Regulation
- check the value of "L" at all positions from -100° to 100° and produce check chart to validate.
- All the value of "L" should be greater than 5mm to satisfy the Regulations.
- Wheel guard requirement : The value of "a" shall be more than 5mm at a line 30° forward and 50°rearwards from the central vertical axis of wheel.
5. WHEEL ARC GAP CALCULATION
Here Calculating the Wheel Arch gap of given design at required points and check whether the car passes the European standard
- Create a datum plane on the outer surface of the wheel.
- draw vertical and horizontal axis of wheel from wheel centre(SA vertical axis ).
- draw the lines line 30° forward and 50°rearwards from the central vertical axis of wheel.(SB and SC)
- draw a line (SE) below SC from the wheel centre to wheel arc ,the distance between intersection point on wheel arc and wheel horizontal axis should be 150 mm.
- Draw a line (SD)passing through the middle of the arc between SE and SC.
- create points and projected the points to wheel arc.
- measure the distance and create a clearance check chart to validate.

fig 5.a. Points created based on european standard
The required points created based on European standard fig 5.a .Then measure the distance with the help of NX cad tool as shown in fig 5.b

fig .5.b. Calculating the Wheel Arch gap of given design at required points

fig5.c. wheel arch gap at different points
Measure the distance and created a clearance check chart to validate.
|
Section |
Required value of L (European standard) mm |
Measured value of L (Given Design ) mm |
Remarks |
|
SA-SA |
The value of "L" should be greater than 10mm to satisfy the European Regulations. |
9.9490 |
Fail |
|
SB-SB |
10.00 |
Pass |
|
|
SC-SC |
-0.1139 |
Fail |
|
|
SD-SD |
-2.8875 |
Fail |
|
|
SE-SE |
-5.9973 |
Fail |
6.CONCLUSION
Wheel Arch gap at required points calculated and checked whether the car passes the European standard.From the clearence chart we can conclude that this car not passes the European standard.The minimum required gap at all points is 10 mm .The given design does not meet the this minimum clearance .