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 rigid and can be damaged by contact with the 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 while the car is running.

Types of fender

The type of fender is based upon the area covered i.e., full fender type and half fender type.

• Full fender type:

Full fender type is traditional type of fender where more material consumption is observed. This type is used in old design of automobiles where it increases the overall weight and thus reduces performance. The maintenance also relatively more due to more surface.

• Half fender type:

Half fender type is modern design where less material consumption is observed, so productivity increases by reducing size of blank and thus providing more performance. The maintenance also relatively low compared to full bumper type.

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 purpose.

Fender Wheel Arch Regulations

Japan Regulations

• The clearance ‘L’ for tire, hub, cap and fender is to be measured within 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’ should be more than 5mm at line 30° forward and 50° 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 30° forward and 50° rearwards from the central vertical axis of the wheel

US Regulations

• Clearance ‘L’ is to be checked at all positions from -100° to 100° 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 30° forward and 50° rearwards from the central vertical axis of the wheel

Calculation of wheel arch area according to 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 30° forward of SA and 50° 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

Procedure

1)sketch:

The sketch is drawn on the wheel face as per the European Standards provided and projected on the wheel arch at sections A,B,C,D and E to measure "L","a"and wheel arch area.

Clearance value:

1) Measuring “L” for the given wheel and fender at B

The value of “L” at B=10mm

2) Measuring “L” for the given wheel and fender at A

The value of “L” at A=9.9489 mm

3) Measuring “L” for the given wheel and fender at C

The value of “L” at A=0.2908 mm

4) Measuring “L” for the given wheel and fender at D

The value of “L” at D= 2.839 mm

5) Measuring “L” for the given wheel and fender at E

The value of “L” at E=5.9435 mm

Table of "L" value:-

SECTION	CLEARANCE VALUE "L"	RESULT (L≥10=PASS,L<10=FAIL)
B	10	PASS
A	9.9489	FAIL
C	0.2908	FAIL
D	2.839	FAIL
E	5.9435	FAIL

From this data of table we can say that the Fender doesn't pass the European standard because it's fails at section A,C,D and E.

Obtaining the value of clearance "a"for wheel guard requirements:-

1)Finding the value of "a"at line 30 Degress forward from centre vertical axis of the wheel.

The value of"a"at line 30 Degress forward from centre vertical axis of the wheel=43.9117mm.

2)Finding the value of"a"at line 50 degress rearward from centre vertical axis of the wheel.

The value of "a" at reward axis of the wheel=38.4164mm.

Table for"a" value:

SECTION	ANGLE(in deg.)	CLEARANCE(mm)	RESULT (a>5=Pass,a<5=Fail)
B	30	43.9117	PASS
C	50	38.4164	PASS

The clearance value obtained at B and C it passess the european standards.

CONCLUSION:

From the above result obtained,we can say or conclude that the given fender dosen't pass the eurppean standards.The stayling team is required to modify the stayling surface of the fender such that the clearance "L"at sections must be greater or equal to 10mm by increasing the curvature at those sections towards outside.