Fender Design - Wheel Arch Challenge

Fender

A 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 roads 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, pedestrians, and 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.

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 purposes.

  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 a clearance check chart to validate
  • In 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 a 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 outermost 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 center of the wheel
  • A perpendicular line SA is dropped at the center 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 center line
  • A line SE is drawn from the wheel center and passes from the point created
  • Another line SD is drawn from the center of the wheel and in the middle of lines SC and SE

Download the file from the website

It is the fender arch model

Draw the sketch:

Create a sketch like the European standard pattern

draw lines with a given angle

Offset bottom line 150 mm for make bisecting point for SE line

create points intersections of two lines.

Created SE line and created the derived line in between SC and SE for SD line.

create points in the intersection of the al meeting area of the two lines

then project the point on the fender

then measure the distance between the two points

the clearance should be above 10mm that is correct.

Measure SA point

the clearance value SA is 9.95mm, it is not passed.

then measure the SB point

The clearance value of SB is 10mm, it is passed.

then measure the SC point

the clearance value of SC is 0.11mm, it is not pass

measure SD point

the clearance value of SD is -2.88 mm, it is not passed.

and measure SE point

The clearance value of SE is -5.97mm, it is not passed.

finally, one point only above 10mm

Measuring the clearance value 'a' for Wheel Guard Requirement

i.) Clearance 'a' at 30°-line SB

a = 52.22mm

ii.) Clearance 'a' at 50°-line SC

a= 43.35mm

Conclusion

SECTION	L (> 10mm)	Result	a (> 5mm)		Result
SA-SA	9.95mm	FAIL	52.22		PASS
SB-SB	10.00mm	PASS
SC-SC	0.11mm	FAIL	43.35mm		PASS
SD-SD	-2.88 mm	FAIL
SE-SE	-5.97mm	FAIL

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