Fender Design - Wheel Arch Challenge

FENDER

Fender is a part of an automobile, motorcycle or other vehicle body that frames a wheel well ( the fender underside). Its primary purpose is to prevent sand, mud, rocks, liquids, and other road spray from being thrown into the air by the rotating tire. Fenders are typically and can be damaged by contact with road surface.

The main purpose of fenders on cars is that they shield the wheels and they protect the passengers, the pedestrians, and the other vehicles from stones, mud, liquid, and other debris that can fly in the air because of the speeding rotating wheels the car is running.

Wheel Arch

• It is a curved part of the fender positioned right above the wheel.
• The wheel Arch is designed such that it protects both the pedestrian and car cabin from mud, water, rocks, and other road spray.
• Different countries have different wheel arch regulations in place, and the wheel arch design has to comply with them to be deemed usable in that country.
• For avoiding design alterations of the same vehicle to meet the different regulations in different countries, the maximum values of the concerned regulation parameters are taken into consideration for design consideration. And given data of fender and wheel is shown in following figure.

Fender Wheel Arch Regulations :

Japan Regulations :

• The clearance 'L' for tire, cap, and fender is to be measured within area K and create clearance and 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 30⁰ forward and 50⁰ rearwards from the central vertical axis of the wheel.

US Regulations :

• Clearance 'L' is to be checked at all positions from -100⁰ to 100⁰ 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 30⁰ forward and 50⁰ rearwards from the central vertical axis of the wheel.

European Regulations :

• 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 30⁰ forward and 50⁰ rearwards from the central vertical axis of the wheel.

Calculation of wheel arch area using European Regulations

For Calculation of clearance between Wheel Arch and Wheel we have to create a sketch on the outer most face of the wheel. The procedure of which is given below.

• A Datum plane is created at the outermost face of the wheel.
• The sketch is created on the new Datum Plane.
• A Horizontal line is drawn across the centre of the wheel.
• A perpendicular line SA is dropped at the centre of the wheel.
• Two lines SB and SC are created at 30⁰ forward of SA and 50⁰ rearward of SA respectively.
• A point is created 150mm vertically above the centre line.
• A line SE is drawn from the wheel centre and passes from the point created.
• Another line SD is drawn from the centre of the wheel and in the middle of lines SC and SE.

Obtained Results

1. Obtaining the value of clearance "L"

a) Measuring "L" for the given wheel and fender at SB:

The value of 'L' at SB = 10mm

b) Measuring "L" for the given wheel and fender at SA:

The value of 'L' at SA = 9.9489mm

c) Measuring "L" for the given wheel and fender at SC:

The value of 'L' at SC = -0.1137mm

d) Measuring "L" for the given wheel and fender at SD:

The value of 'L' at SD = -2.631mm

e) Measuring "L" for the given wheel and fender at SE:

The value of 'L' at SE = -5.427mm

Table 1 Clearance "L" obtained at sections SA,SB,SC,SD and SE.

Section	Clearance "L" (in mm)	pass or fail
SA	9.9489< 10	Fail
SB	10.000 < 10	Pass
SC	-0.1137< 10	Fail
SD	-2.631< 10	Fail
SE	-5.427< 10	Fail

2. Obtained values of clearance 'a' for wheel guard requirement:

a) Finding the value of 'a' at line 30⁰ forward from centre vertical axis of the wheel.

The value of 'a' at line 30⁰ forward from centre vertical axis of the wheel = 48.6263mm

b) Finding the value of 'a' at line 50⁰ rearward from centre vertical axis of the wheel.

The value of 'a' at line 50⁰ rearward from centre vertical axis of the wheel =43.3597mm

Table 2 Clearance "a" at section SB and SC.

Section	Clearance "a" (in mm)	pass or fail
SB	48.6263> 5	pass
SC	43.3597> 5	pass

3. Wheel Arch Area of the given Fender

Wheel arch area = 24432.9334 mm^2

CONCLUSION :

From the above results we can conclude that the Fender does not pass the European Regulations, as this design does not meet the requirement that is minimum clearance L between the Fender Wheel Arch and Wheel for vehicle and pedestrian safety is 10mm.