Fender Design - Wheel Arch Challenge

Challenge is to check Wheel Arch according to European standard

Wheel Arch is the semicircular area of the Fender portion of the cars.

The major consideration in designing of a Half bumper Front Fender after receiving the skin are the points below

Once the Skin design is received from the car designers,

1.First and important criteria is saftey of pedestrains outside and passenger inside.

Pedestrains saftey consideration is by giving importance to the spilling things from rotating wheel. This fender with baffle covers the spill of stone, mud and water from the tyre from spreading to the engine area and aslo avoid from spilling outside on pedestrains. The fender should cover the wheel sufficiently to cater the spilling of mud and stone from the rotating tyre and see that no materials fly away from the tyre. By taking care of this point pedestrain saftey is covered.

2.Wheel Arch area.

Wheel Arch area has some standards stipulated by Automibile governing bodies. These are to be strickly followed. The standards varies from different regions according to thier own safety. So a fender designer has to check wether the standards is covered from the skin input received if not feed back of the dimension data to be given to skin designers mentioning the points and ask them to redesign to cover the standards.

The standards are

Japanese standards, American standards, European standards. These are explained in detail below.

3.Drip Area

Drip area is the area of fender which comes towards engine side below the hood assembly. The main consideration while desiging Drip area is that sufficient gap to be provided for cowl part and head lamp housing. There is no specific size but has other specification as mentioned in master section. The drip area is the fender fixing portion in the engine compartment area so due consideration for screw fastening and sufficient gap of 10mm from engine other parts has to be considered. The drip area also prevents direct visibility of the engine areas through the gap of hood and fender matching line.

4. Baffle mounting
Sufficient room to be given and fixing provisions to be considered for baffle while designing the fendor. Baffle is the plastic part which avoids and prevents mud, water and stones from the rotating tyre. These things flying from rotating tyre hits the baffle and falls down, there by restrict these things from flying away towards pedestrain and other areas of car.

5. other parameters are fender fixing provisions with main body, pillar, sill.

Draw depth with respect to tool manufacturing and production point of view, corner reliefs for manufacturing consideration.

Gap and flusing with mating parts like bumper, hood and body,

slot provision for side indicators,

provision for rear view mirror mounting,

provide mounting emboss.

Aesthetic look of the fender.

Some of the automibile standards for wheel arch is explained below.

Japanese standards is as below

Here the main stress is given as in the picture above, the angle marked from the central axis of the wheel 50deg on the right and 30deg on the left a gap of 5mm to be maintened (L). The gap of 5mm between the wheel and fender has to be in the area A, B, C. A is the point of centre axis at 90deg. B is point of 30deg on the left and C is the piint 50deg on the right. The gap can be more than 5mm but minimum has to be 5mm. Less than 5mm means fail in standard norms.

American standard is similar but more points is given as below

Here there are more points of measurement starting from 30deg to horizantal axis of wheel clearence has to be measured along the points at 45deg, 60deg, 90deg, 120deg, 135deg, 150deg. The gap here is also 5mm at all the specified points.

Now we consider the European standard.

In this standard it is mentioned that dimensions must be checked along the section given SB-SB which is at an angle 30deg front or forward with respect to 90deg of wheel axis, section SA-SA which is centre of the wheel axis exactly at 90deg, section SC-SC which is 50 deg rearside or right side of centre axis or 40deg from 0deg horizantal, section SD-SD which is mid point of SC and SE, section SE-SE which is 150mm from the horizantal that is from 0deg horizantal axis of the wheel axis.

The standard mentions 10mm gap all along the given section.

Now the challenge to measure gap for the given model and see if it passes European standard.

Below you find the results of different section

Section SB-SB

Section SA-SA

Section SC-SC

Section SD-SD

Section SE-SE

Below there is also one more dimension to be measured "a"

This is the gap between tyre and fender arch in the front view at section point SB-SB and SC-SC.

Gap at section SB-SB

Gap at Section SC-SC

From the above section details we get dimension of gap between tyre side surface and fender outer edge. Based on the result we prepare a report as below.

Conclusion:

The fender design do not match with European standard. Report says fender do not pass european norms of wheel arch.