Types of fenders:

Full Bumper Type:

The full bumper type is the traditional type of fender where more material consumption is observed. This type is used in the old designs of automobiles where it increases the overall weight and thus reduces performance. The maintenance also relatively more due to more surface.

Half Bumper Type:

Half bumper type is the modern design where less material consumption is observed, so productivity increases by reducing the size of the blank and thus providing more performance. The maintenance also relatively low compared to the full bumper type.

 

We are changed from full bumper type to half bumper type to reduce the scrap rate per blank. In the full bumper, we can only produce one Fender per blank, whereas as a half bumper type we can produce 2 fenders per blank.

 

Steps involved while designing the fender mountings of the car:

Step1:

Designing the drip area of car with the help of the mastersection provided

Step 02:

Creating the mounting for the A pillar assembling 

Step 03:

Designing the sill mounting 

Step 04:

Designing the bumper mounting

Step 05:

Designin the splash and the baffle mounting 

Step 06:

Creatingf the slot for the fender side lamplight

Step 07:

Thicken the surface

The commands used for designing is 

commans in Curve toolbar:

1. Curve on surface 
2. Offset curve on face
3. Bridge curve
4. Project curve 
5. Intersection on curve

Commands in Surface tool bar:

1. Law extension 
2. Face blend
3. EDge blend
4. Trim sheet 
5. Sew 
6. Thicken
7. Emboss 
8. Dart

The fender class A surface provided is 

Class A surface:

Class A surface is the most aesthetic surface and the surface which is visible to the customer designed the class A surface designer in Alias software

      

Step 01:

Designing the drip area of the fender 

For the drip area design teh master section is provided for designing the master section given is 

For designing the drip area we need to trim the flange with sufficient lenth such that it will have an offset distance of 200mm from the A pillar mounting and 150mm from the bumper mounting for this we need the arrangements of creating a plane with offset distances from the both mounting positions and create the intersection curve on the flange with the plane and trim the unnecessary portion 

First of all use the offset curve in face to offset the curve of the top layer of the flange to a value of 5 mm so the width of the flange is suffiicient for mounting the drip area

Trim the sheet and the sufficient flange is obtained to create the drip area mounting 

Now analyze the mastersection for the drip area we can find a lot of calculations need to be find out fropm the section of the drip area provided trhe calculation made are

.

 

Based on the calculations create the drip area using the features like the law extension , extend sheet , face blend , edge blend nad the drip area thus we create is 

Once all the sheets for the drip area is created then apply trhe proper blends of the value as mentioned in then master section

Now start wiorking on the mounting embosses wherre the screw fasterners arecomein contact for assembling the fender with rthe car

For creating the emboisses we need to create a proper datum plane and a proper sketch with fully defined 

once all the sketcjhes are created then we need to develop the embossses of a value of 3.5mm with respect to the datum plane which is used for creating the sketches

Then create the slot for the hole for assembling the scew fasteners as assembly components the diameter of the hole is 6 mm and we need to keep in mind that there should be a10mm surfcaev area near the hole which we create so that the cleareance is enough for toooling the hole 

Along side apply the edge blend of 2.5mm radius over the mounting embosses

So three 3 embosses sare enough to fit the drip area without any failure in the vibration or any impact crash cashes in the car

In order to increase the strengh on the drip area we need to prtovide (darts) anyway called as the ribs to provide the additional strength to the drip

Now the drip area mounting is complete

 

Step 02:

Create teh mounting for the A pillar assembly

For the A pillar we need to be more concentrate on teh curve surfcae we obtain while we law extend the sheet it will create more problem while creating the emboss for the mounting

we any how manage to trim the curvy surfaces around the law extended sheet to make it more looklike a plane surface . create a datum plane on the  law extended surfcae with 3 points datum plane and continue with the designing of the emboss mounting

 

 

TRy to project the sketch along teh curve surface for creation of the proper emboss

The obtained projection is good enough to create an emboss Now continue with creation of the emboss

Now apply the proper blends along side the mounting emboss

Now create the holes for the fasteners of 6 mm diameter

Now trim the sheet to get the final mounting part for the A pillar.

Basically the curvature flow along the side of the mounting should be continous and sholud follow the tangent continuity if any break occurs there the position fails due to stree concentration for such surfaces we need to create the relief areas 

Relief area : 

The area where the excess stree concentrated area is removed nand make the curvature good and continous flow as  the tangent continuity

so , create a curve on the surfcae and place the points with trhe tangent continuity of G 1 and trim the curved surface to provide the relief so as to eliminate the stress concentration at that region

     

the final mounting for the A pillar is 

 

Step 03:

Designing the sill mounting :

Sill mounting place at the bottoim of teh fender and the design is simple for this fender which I consider just law extend the trimmed sheet and create the sketch for the emboss and create the holes and provide the relief areas for the non curved surfcaes.

The creted sketches should need to have a safe cleareance of 5 to  10mm from the outer edge corners

Once the emboss is cfreated use the bridge curve option to remove the sharp corners edges on both sides

once the sharp corners are removed provide the relief areas for the mounting for the reduction of the stress concentration

This is the final sill mounting emboss with proper continous curvature and the relief areas 

Step 04:

 Designing the bumper mounting:

While designing the Bumper mounting try to law extent the sheet and create the sketch for the emboss and for the screw fastener

After creating all the embosses , apply the required edge blends to the emboss mountings and create the sketch for the holes for fitting the fasteners and create the dart for providing the strength to the bracket and create the relief area around the sharp corners to reduce the stress concentration 

The final mopunting of the bumper of the fender will be like

Step 05:

Designing the splash and the baffle mountings :

In order to stop all the debris entering into the engine room and other components splash protector mountings is been introduced. It just reqiure a area to hold the splash protector, so holes or slots are provided as per requirement.

1. The procedure is create the falnge of the specified dimesions at the 3 locations for providing the splash and the baffle mountings 
2. Then create a plane on each mounting and create a hole of diameter 6 mm as required for mounting with the screw fasteners 
3. Trim the sketch with respect to the sheet to create the perfect holes
4. Use the bridge curve option to remove the sharp edges at the corners 

Step 06:

Creating the hole for the side lamp light :

For most of the cars there will be a side lamp light on the fender and the design for the slot changes from car to car so I made a design based on teh maruthi car model

Trim teh sketch with the sheet to get the slot for the side lamp light

Step 07:

Thicken the component

Finally thicken the entire surface by selecting the body faces and to a value of 0.75 mm 

So finally the mounting are

1.Drip area 

2.A pillar mounting:

3.Sill mounting:

4.Bumper mounting:

 

5.Splash and baffle mountings:

 

Final fender design with mountings is 

 

CONCLUSION:

                 At the end, front fender is Designed from the givenClass A data and the master section provided for Drip mounting, A-pillar, Sill, Bumper and Splash mountings using NX as CAD tool.