Fender Design - Wheel Arch Challenge

FENDER DESIGN - WHEEL ARC CHALLENGE

INTRODUCTION :

Fender is the American English term for the part of an automobiles. 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.

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.

In British English the fender is called the Wing. (This may refer to either the front or rear fenders. However, in modern unibody vehicles, rear fenders may also be called quarter panels) The equivalent component of a bicycle or motorcycle or the "cycle wing" style of wing fitted to vintage cars, or over tires on lorries which is not integral with the bodywork, is called a Mudguard in Britain, as it guards other road users – and in the case of a bicycle or motorcycle, the rider as well – from mud, and spray, thrown up by the wheels.

In modern Indian and Sri Lankan English usage, the wing is called a mudguard.

FENDER WHEEL ARCH :

• Wheel arch is the semi circular part of the fender positioned above the wheel of the vehicle .
• The design of the wheel arch of the fender should be such that it must shield wheels and protect both passanger and padestrian from the projection of stone and mud.
• For the vehicle to has different permit in different countries , the wheel arch of fender must be compliant with the standard and regulation set by respective countries .

FENDER REGULATIONS BY DIFFERENT REGIONS/CUOUNTRIES :

EUROPEANS STANDARDS -

• The european regulation requires a pre- determined clearance or a minimum distance of 10 mmm to be maintained between the fender and respective tyre at particular points, along the tyre profile as shown below .
• Wheel guard requirement : The value of 'a' should be more than 5 mm at line 30 degree forward and 50 degree reward from the central vertical axis of the wheel .

U.S REGULATIONS :

• Clearance 'L' is to be checked at all positions from -100 to 100 degree and create clearance check chart to validate .
• The value of L should be greater than 5 mm to satisfy the regulations.
• Wheel guard requirement : The value of a should be more than 5 mm at line 30 degree forward and 50 degree reward from the central vertical axis of the wheel .

JAPAN REGULATIONS :

• The clearance 'L' for is to be measured within area K and create clearance check chart to validate.
• The value of L should be greater than 5 mm at all point.
• Wheel guard requirement : The value of a should be more than 5 mm at line 30 degree forward and 50 degree reward from the central vertical axis of the wheel.

CALCULATIONS OF WHEEL ARCH AREA ACCORDING TO EUROPEANS REGULATIONS :

• A Datom plane is created at the outermost face fo the wheel.
• Horizontal and vertical line is created from the center of wheel and make it reference.
• Create 30 degree and 50 degree line with respect to vertical line.
• Now take ofset of 150mm from the horizontal line.
• Now create 5 point on plane and project it into the fender.
• Now measure the clearance 'L'.

CALCULATION OF CLEARENCE DISTANCE AT DIFFERENT POINTS :

CLEARENCE 'L' AT SECTION - B

CLEARENCE 'L' AT SECTION - A

CLEARENCE 'L' AT SECTION - C

CLEARENCE 'L' AT SECTION - D

CLEARENCE 'L' AT SECTION - E

RESULT OF ANALYSIS :

Section	Required Minium Clearence (MM)	Measured clearence (MM)	Result Pass/Failed
SB	10	9.9490	Failed
SA	10	10	Passed
SC	10	0.113949	Failed
SD	10	-2.8875	Failed
SE	10	-5.9973	Failed

Note - Negative means tyre is protruding outsides the tyre.

CONCLUSION :

Except one point -SA- every other points failed to meet the minimum clearance requirements according to European Standards. Aslo, points 'SD' & 'SE' are outside the fender which is not allowable. So the fender must be modified to meet the standards.