Fender Design - Wheel Arch Challenge

Aim - Analysis wheel arc with europeon standards

Objective -

• Calculate the wheel arc for given Fender model, by means of the European standards regulations.

Why wheel arc calculation is necessary

• Wheel arc calculation is necessary for the fender design to pass the local regulation which are based on the local road conditions.
• Wheel arch is a semi-circular area in fender, which houses the wheel well. It should have a sufficient clearance between tyre and wheel arch. So, that it doesn’t touch the wheel arch area during suspension.
• The clearance value differ from region to region, here are few regulations.

There is three regulation about fender design lets understand one by one

Japan Standard regulations

The clearance value will be more than the 5mm at 30 degree at forward and 50 degree at backward from the central vertical line according to europeon standard regualtion all five sections should SA, SB,SC,SD and SE should be greater than 10mm.

Europeon Standards regulations

The clearance value will be more than 10mm at 30 degrees at forward and 50 degree at backward and line 150mm above X-axis and Mid-point between 50 degree and line above 150mm

United States regulations

Make clearance check details on all position from -10 to 180 degrees. All values must be greater than 5mm.The Clearance Value will more than 5mm at line 30 degree forward and 50 degree backward from central vertical axis.

We take Europeon standard regulation for analysis because it is meet the criteria with Indian Roads.

Procedure

Opn Nx cad and load the skin data

If we see from rear side We see that tyre is coming outside the fender area

Now lets see from from side,

Now we an see that tyre is completely inside the fender

As per europeon standard regulation wheel should be completely inside the fender

In India the clearance should be greater than 10mm. Clearanace is depend on road conditions.

from above diagram we can see that there are five angles, our wheel arc angles should match this condition so lets check it.

We need to measure distance between wheel outer and fender outer

Initially we need some reference where we can sketch, so lets create datum plane on most outer face of tyre for sketch

Go to datum plane - select most outer face on wheel - select offset at 0 mm - ok

Now we have to sketch on it

Go to sketch - select datum plane - reference horizontal - method should be work part - ok

Now we have to mark line on the center

Click on point - select center point method - select any circle of wheel - ok

Now draw one horizontal and one vertical line using line command

Now apply diamnesions

Select rapid diamension and apply diamensions as per requirements

Distance between vertiacal line and center of wheel should be 0

Similarly distance between horizontal line and center of circle should be 0

Convert both lines into reference line

Right click on line - select Convert to reference

Now create 3 lines after that give them diamensions

Now apply the angles

Angle between the vertical referene line and first line is 30 degree

Anle between vertical reference line and second line is 50 degree

Now we need to apply vertical diamension between the point where line intersects the fender and horizontal reference line

for this we need to create a point, but we cant create a point over there os make a projective curve and then make a point

click on 2d project curve - select tangent curves - select fenders arc - ok

Now create a intersection point

select a point - select intersection point method - select lines and ok

Similarly create other points

We have four intersection points

Now mark the diamension between horizonatal reference line and third line intersection point. Distance should be 150

Now we have to get a line in between the two lines.

Select derived line - select second and third line - ok

Create a intersection point on it

We only need the intersection points so simply right click on lines makes it to reference geometry

Now we marked points on wheel, we need to measure the distance between wheel and fender so we need some reference point on fender as well

We see some gap we have to measure it

Now finish the sketch

We need to project the points on fender

go to project cureve - select points - select fender as object - select along vector - ok

Now some point are projected and some points are not projected

Now all points are created

Now measure the distance between these points

Go to analysis click on distance - select points

Lets tabulate all values

Sections	Clearance (L)	Status Criteria
SA	9.97 mm	FAIL
SB	10 mm	PASS
SC	6.43 mm	FAIL
SD	1.59 mm	FAIL
SE	5.44 mm	FAIL

Conclusion -

As per europeon standards all values of SA, SB,SC,SD, SE should be greater than 10mm but in our case only SB value matches the criteria. So this fender design fails to meet the europeon standards regulations.