Fender Design Challenge

FENDER DESIGN USING NX-CAD

Objective:

To design BIW Fender mounting using sheet metal parameter on the Class A surface with given skin data and master section, using NX CAD.

Introduction:

Fender is Body in White part of an automobile (vehicle body) which houses or frame wheels in order to prevent sand, mud, rocks, liquid, and other road debris to throw into the air when tyre is in motion, which may lead to a pedestrian accident and protect the engine compartment from damages. Apart from pedestrian safety, it serves the purpose of providing an aerodynamic shape to the car thus performing better at higher speeds and give aesthetic look to the body.

Types of car fenders:

• Full Bumper type
• Half Bumper type

Either a single full bumper type or two half bumper type fenders can be produced from a single blank. Half bumper type is widely used because of less wastage of material, which in turn reflects the car's overall price.

Fenders based on location:

• Front Fenders or Front Quarter Panels:

Front fender panels are located on the sides of each front wheel. These panels typically cover the sides of the headlights to the hinge of the driver and passenger doors on the A-pillar. A car front fender runs vertically from the hood to the wheel well.

• Rear Fenders or Rear Quarter Panels:

Rear fender panels are located on the sides of each rear wheel. They extend from the edge of the rear doors on the C-pillar all the way towards the edge of the taillights. Rear fenders also usually feature a fuel hole with a gas cap. These features can be found on either the driver or passenger rear panels, depending on the year and model of the vehicle.

Mounting regions of fender:

Fender are mounted on five important regions with car body

• Drip mounting area
• Sill mounting area
• Bumper mounting area
• A-pillar mounting area
• Splash/ Baffle mounting area

These Mountings are joined using fasteners. To Improve the NVH Factor (Noise, Vibration, harshness).

Design Methodology:

Given data:

Master Section

Drip area design constraints:

Drip area has some design constraints which can be inferred from the master sketch. This drip area is the joining piece of fender and engine compartment.

Drip area constraints

The drip area is given minimum 200 mm distance from the rear or 300mm less from the A – pillar of the car. This distance is given for wiper motor placement. Likewise a 150mm distance from front end of fender is given for the placement of head lamps housing unit. The remaining area is available for the drip design.

Given skin data:

1. Design of drip mounting area:

2. Design of Sill Mounting Area:

3. Design of Bumper Mounting Area:

4. Design of A-Pillar Mounting Area:

5. Design of Splash/Baffle Mounting Area:

Locating Side Indicator on Fender:

Indicator lights are amber in colour and can be located at the front, the rear, and sometimes at the side of the car on both the left and right-hand sides. W use our indicators to show an intended change of direction, whether turning left or right or moving out into traffic.

Use of Indicator:

Use indicators while changing lanes, overtaking, taking turns, and for other denotations as they form an integral part of road safety and keeps fellow road users informed about the driver's intents and thus, avoid accidents.

Commands used from NX CAD to model this fender are:

1. Offset in face
2. Curve on surface
3. Trim sheet
4. Law extension
5. Datum plane
6. Intersection curves
7. Face blend
8. Bridge curve
9. Sketch
10. Projected curve
11. Emboss
12. Edge blend
13. Sew
14. Dart
15. Thicken

• While designing the drip area, a 150mm clearance is maintained from the front-end for headlight fittings and 200mm clearance from the rear-end for the wiper motor assembly (Cowl top area).
• The depth of the drip area is maintained at less than 60mm so as to avoid the spring-back effect.
• Ribs are provided at the fender drip area to increase strength in that area.
• It is to be observed that no sharp corners persist so that machining can be carried out easily.
• A thickness of 0.75mm (22 gauge) is given after all the modeling is done.

Front View of Fender:

Back View of Fender:

Isometric View of Fender:

Conclusion:

Thus, all mounting areas for the fender designed by using NX-cad from the skin data and master section received from the styling team.