Fender Design Challenge
DESIGN OF THE FRONT FENDER OF A CAR USING SIEMENS NX
AIM
To design a front fender from the given skin data and the master section provided with Drip mounting, A-pillar, Sill, Bumper and Baffle mountings.
DESCRIPTION
Fenders are the complex sheet of metal covering the front and the rear wheels of your car. Fenders on a car are panels that extend from the front bumper to the car’s doors. Car fenders not just add style to your car but also act as a protective shield for the body of the car.
Fender designs mainly uses steel, aluminum, PP/EPDM, PC/PBT and PPO/PA . The steel design has advantages in terms of lower energy consumption during production. However, when the utilization phase of the fenders is considered, the overall energy consumption of the PP/EPDM fender is smaller due to the light weight of the this polymer design.
Types of Bumpers
- Full Bumper type
- Half bumper type
For most of the present automobiles, they use half bumper type to avoid material wastage thus reducing the blank price thereby reducing weight and boosting the performance, all at a lower cost to the customer.
DESIGN CONSIDERATIONS
The major mounting sections that a design engineer need to consider includes
- Drip mounting
- A-pillar mounting
- Sill mounting
- Bumper mounting
- Baffle mountings
Fig.1. Fender design with mounting points
The Drip mounting region is one of the most important mounting section while considering the fender design, as it is attached to the engine compartment. Here, the gap from the rear end (for the cowl mounting) as well as the front end of the fender (for the headlight housing) is taken as 150mm which is well within the standard specifications.
The design is generally done in accordance with the master section prepared. For manufacturing processes like drawing, various angles are given to the drawing parts to facilitate easy tool movement and to ease the production process.
Fig.2. Fender master section data
For this design, mounting holes where of diameter 5mm with a circular reference of 10mm. Appropriate embosses along with ribs of 45 degree angles were provided at places around the holes for structural rigidity. Also, all the sharp corners where avoided for producibility purposes.
Fig.3. Drip area mounting
The A-pillar mounting region is designed with a semicircular emboss and a fastener hole of 5mm with a circular reference of 10mm. The emboss was given with 3mm depth. Smooth curvature was provided at sheet extension areas as well as along the corners for a smooth transition for ease of production.
Fig.4. A-pillar mounting
The Sill mounting region is designed with a rectangular emboss with two fastener holes of 5mm with a circular reference of 10mm. The emboss was given with 3mm depth . Smooth curvature was provided at sheet extension areas as well as along the corners for a smooth transition for ease of production. Reliefs where give at areas where different sheets joined to avoid corners.
Fig.5. Sill region mounting
The Bumper mounting region is designed with reference directly taken from the bumper itself. Here,a rectangular emboss with two fastener holes of 5mm with a circular reference of 10mm. The emboss was given with 3mm depth . Smooth curvature was provided at sheet extension areas as well as along the corners for a smooth transition for ease of production. Reliefs where give at areas where different sheets joined to avoid corners.
Fig.6. Bumper mounting region
The Baffle mounting region is designed to cover the entire wheel arc area with three mounting sections each with a rectangular emboss with fastener holes of 5mm with a circular reference of 10mm. The emboss was given with 3mm depth . Smooth curvature was provided at sheet extension areas as well as along the corners for a smooth transition for ease of production. Reliefs where give at areas where different sheets joined to avoid corners. These regions are relatively given to a automobile largely for the effectiveness of NVH, thereby providing passenger comfort.
Fig.7. Baffle mounting region
RESULTS AND CONCLUSION
The Part was created in accordance with the design data by integrating all the mounting regions at relevant points with NVH considerations. Modelling of the fender also provided with a deeper understanding on the designer's approach to the same. Also, the manufacturability of the design was taken into account by providing necessary reliefs and draft angles at required parts.
NX file: