Fender Design - Wheel Arch Challenge

WHEEL ARC CALCULATION

AIM:

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

OBJECTIVE:

• To calculate the clearance (L) at sections of SA-SA, SB-SB, SC-SC, SD-SD and SE-SE as per the European Regulations Requirement and tabulate them.
• To measure the wheel guard requirement, the value of ‘a’ from a line 30 degree forward and 50-degree rearward from the central vertical axis of axis of wheel.

Given part file of Wheel Arch:-

INTRODUCTION:

• The wheel arch is an arch-shaped cavity in the body of a vehicle, which houses a wheel. It has two important functions. It serves for the safety of pedestrians and other cars because the wheel is situated in the body of a vehicle. The second function is to protect the car from the sticky materials, such as mud, may adhere to the smooth outer tire surface, while smooth loose objects, such as stones, can become temporarily embedded in the tread grooves as the tire rolls over the ground. These materials can be ejected from the surface of the tire at high velocity as the tire imparts kinetic energy to the attached objects. For a vehicle moving forward, the top of the tire is rotating upward and forward and can throw objects into the air at other vehicles or pedestrians in front of the vehicle.

Wheel Arch-

• It is a semicircular profile above wheels designed for enclosing tire within the fender The wheel arch is designed considering all possible motions the tire undergoes while the vehicle is in motion.

• The most important body change was that the front wheel arch was cut higher into the fender.Corrosion had occurred around the splash plate at the back of the wheel arch.The car has big, high-definition headlights that extend to the wheel arch.

Fig:- (1) Wheel Arch

Using the Europian Standards Discussed:-

Fig:- (2) Europian Standards

Wheel Arc Verification Using European Standards:-

• The important parameter which is considered in the designing of wheel arch or wheel is the clearance between wheel and fender during the vehicle bump conditions.
• Requirements have been proposed by vehicle and road safety community to the minimum requirement of wheel arc distance
  from the wheel for safety.
  Rules –
  1. Measure of CL L is done on sections SA, SB , SC, SD, SE.
  2. At all sections the value of CL L should be greater that 10mm.
  3. Wheel guard requirement -: The value of a shall be more that 5mm at 30 Deg forward and 50 Deg rearward from the central axis of wheel.

The below fig shown the sketch is drawn on the wheel face as per the European Standards-

Fig:- (3) Wheel Arch

• In the above fig- we have open the given file on Siemens NX CAD 12. Firstly create the point on the center of wheel and then create the center reference line. project the on the wheel arch at section SA, SB , SC, SD and SE to measure the distance / clearance 'L', 'a' and the wheel arch area.

Calculation of the clearence value"L" as following:-

1] The Measuring 'L' for the given wheel and fender at SB- The value of 'L' at SB= 10.0000 mm.

2] The Measuring 'L' for the given wheel and fender at SA- The value of 'L' at SA= 9.9490 mm.

3] The Measuring 'L' for the given wheel and fender at SC- The value of 'L' at SC= 0.11449 mm.

4] The Measuring 'L' for the given wheel and fender at SD- The value of 'L' at SD= 2.90575 mm.

5] The Measuring 'L' for the given wheel and fender at SE- The value of 'L' at SE= 6.03373 mm.

RESULT

From the comparing above four section (like SA, SC, SD and SE) the fender doesn't pass the European standards for the wheel arch.

From the below fig- the Obtaining the value of clearance 'a' from the wheel guard requirement.

CONCLUSION,

• Negative sign indicates that the wheel arc is behind the wheel
• All the section don\'t have the CL L value at least 10mm, only SA is seen to have value 10mm
• I have study from the above results, We have conclusion that the fender does not pass the European Regulations, as the Minimum Clearence value of 'L' between the fender wheel arch and wheel for vehicle and Safety is 10 mm and this design does't meet the requirement.