Fender Design - Wheel Arch Challenge

FENDER DESIGN - WHEEL ARCH

Aim:

To calculate the Wheel Arch gap at required points and check whether the car passes the European standard.

Theory:

Fender:

• The fender is the US English term for the part of an automobile that frames a wheel well (the fender undeside).
• Its primary purpose is to prevent sand, mud, rocks, liquids and other road spray from being thrown into the air by the rotating tire.
• When vehicle is moving, tyres pick up stones and others and hurt them in all directions. Fenders are basically present to prevent any injuries to pedestrians and contain the motion of these particles.
• More elaborate designs include fender skirts for enclosing the outside edge of the wheel well and stylized pontoon fenders for exposed fenders.

Mounting:

There are 5 mounting points in a fender. They are

• Body
• A Pillar
• Sill
• Cowl
• Drip

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 :

Measure CL L at sections SA-SA SB-SB SC-SC SD-SD SE-SE and produce CL check chart to validate.

• At all five sections the CL L value should be greater than 10 mm to satisfy the European regulations.
• Wheel guard requirement: The value of 'a' shall be more than 5mm at aline 30* forwrd and 50* rearward from the central vertical axis of wheel axis.

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 Catia V5 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.

From the central line(SA) which passing through the wheel center, we have to create the SB line and SC line at the angle of 30* and 50* respectively from SA. And then from the line passing through the wheel center(horizantal axis), we have to create the point of 150mm from it, that is said to be SE which lies on the wheel arch.

After we have to create the intermediate central line which should be exactly lies between SE and SC point and the point we create is said to be SD lies on the wheel arch projected on the datum created on the surface of the wheel.

Create the datum plane on the fender wheel arch, and follow the same procedure to create the SB, SC, SD and SE. Calculate the distance between the points created on both the datum plane and check whether it maintains minimum clearance of 10mm with the respective points.

Section	Required clearance value	Measured clearance value	Remarks
SA	10mm	10mm	Pass
SB	10mm	9.949mm	Fail
SC	10mm	0.114mm	Fail
SD	10mm	2.879mm	Fail
SE	10mm	5.976mm	Fail

Hence, we found that the Clearance value L=10mm does not maintain in all the sections and the given Fender wheel arch not accepts the Europeon standards.