Fender Design - Wheel Arch Challenge

WHEEL ARC CHALLENGE - CALCULATIONS

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.

Theory :

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 pedestrains 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.

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

US Regulations :

• Clearance "L" is to be checked at all positions from -100degree to 100degree 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 30degree forward and 50degree 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.

And using the text give the proper name to the lines and the dimensions are set has per the European standard as shown in the figure.

And then we need to measure the distance from the outer most wheel to the outer most wheel arch for that we add the some ponits on the face and the angle line as shown in figure.

And now using the analysis tab in the NX Cad in that click simple distance to measure the required distances as the European standard as shown in figure. from the SB line the clearence distance we measure is 43.52mm and the 50degree SC line the clearance distance is 38.30mm as shown in figure.

standards :

• "a" should be more than 5mm at line 30degree forward and 50degree.
• "L" should be greater than 10mm

From the measuing for clearence are given below

for "a" values

SB=44.75 mm

SC=38.35 mm

for "L" values

SB-SB=10.00mm

SA-SA=9.94mm

SC-SC=0.11mm

SD-SD=2.88mm

SE-SE=5.99mm

And the results are tabulated which is given below

SECTION	L(>10MM)	RESULTS	a(>5mm)	RESULTS
SA-SA	9.94	FAIL
SB-SB	10	PASS	44.75	PASS
SC-SC	0.11	FAIL	38.35	PASS
SD-SD	2.88	FAIL
SE-SE	5.99	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 this minimum clearance so this fender design is fail for the European Regulation Standards.