Fender Design - Wheel Arch Challenge

Aim :

To calculate the wheel arch gap at required points and check whether the car passes the European standard.

Objective :

• Study about the different wheel arch gap standards.
• Draw the lines at the required angle and points for the European standard.
• Measure the distance at each angles and mention given model is pass or fail.

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 passenger the pedestrians and the other vehicles from stones, mud, liquid and other particles that can fly in the air because of the speeding rotating wheels while the car is running.

For avoiding design alterations of the same vehicle to meet the different regulations parameters are taken into consideration for design purpose.

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.

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 5 mm at all positions.
• Wheel guard requirement : The value of "a" should be more than 5 mm at line 30 degree forward and 50degree 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 10 mm to satisfy the European Regulations.
• Wheel guard requirement : The value of "a" should be more than 5 mm at line 30 degree forward and 50 degree rearwards from the central vertical axis of the wheel.

US Regulations :

• Clearance "L" is to be checked at all positions from -100 degree to 100 degree 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 5 mm at line 30 degree forward and 50 degree rearwards from the central vertical axis of the wheel.

Calculations of wheel Arch area - 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 and the procedure as follows.

From the given part file we need to open in the NX cad and from the part file they give the fender and the wheel. So, now we need to check for the European regulations standard. Now we need to create the datum plane at the outer most face of the wheel as shown in figure.

After that in that plane we sketch the lines and the give the required angle from the reference of the European standard drawing by using the Rapid dimension as shown in figure.

After that 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.

The clearance between SA line and wheel arc is +10 mm also the line SA lies inside the fender so it is positive value.

The clearance between SB line and wheel arc is -9.9490 mm also the line SB lies inside the fender so it is positive value.

The clearance between SC line and wheel arc is -0.1139 mm also the line SC lies outside the fender so it is negative value.

The clearance between SD line and wheel arc is -2.8468 mm also the line SD lies outside the fender so it is negative value.

The clearance between SE line and wheel arc is -5.9973 mm also the line SE lies outside the fender so it is negative value

For "L" measurment please find attached both images.

Standards :

"a" should be more than 5mm at line 30 degree forward and 50 degree.

"L" should be greater than 10 mm.

Tabulation:

Section	Calculated clearance (in mm)	Minimum clearance to pass (in mm)	Pass/Fail
SA	+10 mm	+10 mm	Pass
SB	+9.9490 mm	+10 mm	Fail
SC	-0.1139 mm	+10 mm	Fail
SD	-2.8468 mm	+10 mm	Fail
SE	-5.9973 mm	+10 mm	Fail

Conclusion :

From the above results we can conclude that the Fender does not pass the European Regulations as the minimum clearance between the fender arch wheel to the outer most wheel is 10 mm and this design does not meet the this minimum clearance so this fender design is fail for the European Regulation standard.