Fender Design Challenge

Introduction

A fender is the curved portion of the car’s body that sits over and houses the wheels. The purpose of a fender is pretty simple. Its purpose is to keep mud, rocks, and other road debris from being thrown around by the tires. In other words, the fender is a housing for the wheels that keeps road debris contained. However, fenders are also able to absorb impact from minor collisions. In this way, the fender can act as an extension of the bumper in terms of its ability to absorb the energy from a collision.

Image showing car font fender (top) and back fender (bottom)

Types of fender

Full bumper type: This type of bumper was used in old cars. This type of fender require more material compared to half bumper type. In other words two half bumper type fenders can be manufactured from one full bumper type fender

Half bumper type: This is the new convention model fender used in the current era among the car manufacturers since it reduces waste and cost to greater extent.

Fender design

The front fender is manufactured as separate part, which is then mounted on to the car body. For this purpose front fender has five mounting points. These mounting points may differ from OEM to OEM. Following image shows the different mounting points on fender.

Drip area

Drip area mounting is the important part in the fender. This mounting is attached to the engine compartment of the car. Fender drip area is mounted via weld nuts to the engine compartment.

Design considerations

• A minimum of 150 mm is kept from the front side
• A distance of 300 mm or less is kept from rear side
• Total length of fender drip area varies from OEM to OEM.
• The total height of the drip area from the top of the fender should be less than 40 mm.
• The edge of the mounting should be at least 10 mm away from the engine compartment.
• Mounting area
  • Emboss dimensions – 3.5 mm depth and 2.5 mm blend on all corners
  • Suitable distance must be provided between mounting points
  • Minimum 3 mm distance from all corners
• Darts to strengthen flange
  • 45⁰ Inclined and 3 mm width
• Minimum 7⁰ draft on all surfaces

Baffle mounting

This helps to mount the fender lining on fender. For improvement of NVH in car usually fender lining is mounted on the fender of the car. It is mounted on wheel arch area.

• Holes are created on flanges where the fender lining is mounted using the push clips.

Sill area

It is the bottom portion of the car fender and is mounted using bolts and nuts.

A Pillar mounting

Bumper side mount

Conclusion

Drip area on the fender is designed according to the given master section and other mounting areas are designed according to the design standards.