Fender Design - Wheel Arch Challenge

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

Objectives:  

• 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:   

The wheel arch is the semicircular part positioned above the wheel of a vehicle. The most important body change was that the front wheel arch was cut higher into the fender. Corrosion had occurred around the splash plate at the back of the wheel arch.

                                 

       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 -100 degree to 100 degree 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.

• Import the part file into NX-CAD software.
• Create Datum Plane on the outermost face of the wheel.
• Create a sketch keeping in mind European regulations and thier angle
• Create inertsection point between line and arc or circle and finish the sketch.
• Measure distance between point to point (gives gap between wheel and wheel arch) and point to face of the arch (gives 'L' distance from the point and surface of fender.

Datum Plane creation: 

                           

Sketch: (European regulation must be followed)

            

Specify the line with thier specific name:  

            Using the text command give the proper name to the lines and the dimensions are set as per the European standard.

            

Now we need to measure the distance from the outer most wheel to the outer most wheel arch.

• Go to the analysis toolbar 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 43.6263mm and the SC line the clearance distance is 38.3597mm as shown in figure.  

        

        

Standards :

• "a" should be more than 5mm at line SB and SC.
• "L" should be greater than 10mm

Measured clearence are given below

for `a` values

                                      `SB = 43.6263 mm`

                                      `SC = 38.3597 mm`

for `L` values

                                    `SB-SB = +10.0 mm`

                                    `SA-SA = +9.9489 mm`

                                    `SC-SC = - 0.1126mm`

                                    `SD-SD = -2.8497 mm`

                                    `SE-SE = - 5.9018 mm`

And the results are tabulated which is given below

            

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 the this minimum clearance so this fender design is fail for the European Regulation standard.