Fender Design - Wheel Arch Challenge

What is Wheel Arc Area ? Why it is to be considered as design regulation ? How many Standards are fowolled and which one is the best among them and why?

Wheel Arch Area

The shaped part of the bodywork of a car on the fender just above the wheels . It is also defigned as the space between the wheel and the body of the car that is covered by the fender.

• It should cover the Complete profile of tyre for safety purpose.
• It protects the car from stones , debries, mud , and other particles are thrown onto the body of car while running and wheels rotating.
• When the fenders are extended outwards than the tyre profile then majority of debris are get arrested not to hit the car and its mountings.
• It also protects the pedistriants by not hitting the debris to them .
• The inner baffels or Wheel gaurds arrests the debris .
• The size and shape of the wheel arch can affect the aerodynamics of the car, along with handling and stability of it also.
• A larger wheel arch can also allow for larger wheels and tires, which can improve performance and give the car a more aggressive look.
• Different regions may have different standards for the size and shape of the wheel arch area.
• For example, some regions may require larger wheel arches to accommodate larger tires or to improve clearance.
• Majorly there are 3 standards that are considering Japan , Europian and US standards.

Different Fender Regulations:

1. Japan Requirement:

• Measure clearence L of the tyre , hub , cap & fender in three diffrent positions within area K and produce clearence .
• Clearence value must be greater than the 5mm in al the three positions.
• Wheel guard regment : the value of 'a' shall be more than 5mm at a line 30 Deg forward and 50 deg rearward from the central vertical axis of the wheel.

2. Europian Standarts:

• Measure CL L at sections SA-SA SB-SB SC-SC SD-SD SE-SE and produce CL
• At all the five sections the CL L value should be greater than 10mm to satisfy the Europian standard regulations.
• Wheel gaurd requiremnt: The value of 'a' shall be more than 5mm at a line of 30Deg forward and 50Deg rearward from the central verticle axis of the wheel.

3. US Regulations:

• Make clearence check details on all positions from -100Deg to 100 Deg make the clearnce check table .
• All the values should be greater than the 5mm to satisfy the regulations.
• The value of 'a' shall be more than the 5mm at a line of 30Deg forward and 50Deg rearward from the central vertical axis of Wheel.

In general each country and each region has their own standard base up on their road conditions . But the Automobile manufactures will have the design complications to follow the separate rules , individual regulations for each region . so they follow the maximum clearence values and that will match and satisfies the other regulation requirements as well. Here the European Regulations are the minimum of 10mm , so if we follow the European regulation requirements then then it will automatically satisfies the other standards.

Here is a design that is checked with the European standard.

Objective:

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

Input file

Procedure:

• Create a plane that is outermost edge of the wheel surface.
• Create a sketch on the plane.
• Measuring the CL L at the sections of five line are drawn on the wheel plane .
• The line of 30 forward and 50 deg rearward with the reference of central vertical axis of Wheel.
• The line of 150 mm above the Central horizantal axis and projected on the Wheel outer surface and at that point make line passing through center.
• Create a line that bisects the line of 0deg rearward line along with the 150mm projected point line through orgin.
• Project the line of wheel arch area and intersect these lines and mark the points.
• project these points on the fender surface along the vector.
• Now measure the distance between the points on the lines and the points on the fender then the distance should be larger than 10mm.
• Now project the Wheel outer most profile and intersect with the 30 Deg and 50 deg lines drawn . amd measure the distance between the points and wheel arch profile , it should be greater than the 5mm.
• The reuslts are tabulated bellow.

Sketches of lines and its constraints.

30 Deg Forward and 50 Deg Rearward lines to the central vertical axis.

curves projected

Distance at SA-SA

Distance at SB-SB

Distance at SC-SC

Distance at SD-SD

Distance at SE-SE

Wheel Gaurd Requirement at 30Deg forward with central vertical axis

Wheel Gaurd Requirement at 50Deg forward with central vertical axis

Analysis of the data

MEASURING CHART OF ‘CL L’ VALUE AT 5 SECTIONS

SL NO	SECTION	DISTANCE at ANALYSIS	REQUIRED RANGE	RESULT
1	SA-SA	+ 10 mm	>10 mm	PASS
2	SB-SB	+ 9.9490 mm	>10 mm	FAIL
3	SC-SC	+ 0.113949 mm	>10 mm	FAIL
4	SD-SD	- 2.8882 mm	>10mm	FAIL
5	SE-SE	- 5.9973mm	>10mm	FAIL

At all five section the CL L value should be greater than 10mm to satisfy the European Regulation.

• The value of CL L value is less than 10mm in section SA-SA and in section SB - SB, SC-SC, SD - SD, & SE - SE . So, these values are not acceptable and need some work on structure.
• The value of CL L value is 10mm or more than 10mm in section SA - SA So, it is considered as acceptable value and pass in result at this section.

MEASURING CHART OF ‘a’ VALUE

SL NO	LINE POSITION WITH REFERENCE TO CENTRAL VERTICAL AXIS	VALUE	REQUIRED VALUE	RESULT
1	30 DEG FORWARD	43.6263mm	>5mm	PASS
2	50 DEG REARWARD	38.3597mm	>5mm	PASS

The Wheel Gaurd requirement satisfies the both the lines so there will be no more improvements are to be done in this section at design.

Conclusion:

The sketches are drawn and the values are tabulated and compare with the requirement values and concluded that only one section satisfies the CL L value and the Tyre profile is outer than the wheel arc and the values are negative so the design should be improvised to meet the Europian standards. The Wheel gaurd requirement is completly satisfied.