Verification of weld joints

OBJECTIVE:

To simulate three different types of welding using three different weld materials.

Weld Material to be used:

Case 1: Stainless Steel: In this case, the material of the plates must also be the same. Use Stainless steel for both weldments and plates. No need to add flux to the weldments.

Case 2: Aluminium Alloy: The material to be chosen for this case is Aluminium alloy (high strength, wrought). [Plate material to be used is stainless steel]

Case 3: Bronze: In order to simulate \"Brazing\", you should be using bronze as the weld material. Assign Stainless Steel to both plates and Copper to the \"Ribs\".

Run the simulation for a load of 15000N that is to be applied at the rectangular hole in the small plate.

For each case, find out the directional deformation and equivalent strain experienced by the setup. Identify the weld joint that experiences the highest equivalent stress in each case and compare the results for all three cases.

SOLUTION:

Step 1: Model Design

The given model has two plates, with one plate fixed perpendicular to the other and two ribs holding these plated together. 26 weld joints have been given over the corner of the plates to fix the entire body together.

Step 2: Material

The simulation has to be carried out for three different material combinations. In all the cases, the plates are made from stainless steel. Further, for each case the weld material changes, for case1 stainless steel, case2 aluminium alloy and for case 3 bronze for weldments and copper for ribs. The material was assigned for each case respectively and the properties are as given below:

Step 3: Connections

All the contacts between the plates themselves and the plates and ribs were defined as frictional and was given a coefficient of friction of 0.2.

Step 4: Meshing

The model was meshed using the ANSYS Mesher and an element size of 7mm was used.

Step 5: Analysis settings

The simulation of the model was carried out in a single step and the large deflection was turned on. The big plate was given the fixed by giving the fixed support condition to the holes provided in the plate. A directional force of 15000N was given in the negative ‘y’ direction on the rectangular hole provided in the small plate.

Step 6: Results

The equivalent strain, directional deformation and the equivalent stress experienced by the weld joints were analysed for each case and compared.

Weldment Material	Max Equivalent strain	Max Equivalent strain on ribs
Stainless steel	0.0018652	0.00078323
Aluminium alloy	0.0031717	0.0007687
Bronze	0.0030322	0.0010509 (rib material – copper)

Weldment Material	Max directional deformation
Stainless steel	0.35929
Aluminium alloy	0.37402
Bronze	0.40594

Weldment Material	Max Equivalent stress	Max Equivalent stress on weld joints
Stainless steel	340.11	281.92
Aluminium alloy	344.7	233.99
Bronze	349.2	242.57

CONCLUSIONS:

The simulations were carried out and the results were compared.

1. The maximum strain was found for the model with aluminium weld joints and minimum strain was for the one with stainless steel. Further, the copper ribs showed higher strain than stainless steel.
2. The maximum deformation was observed for the model with bronze weld joints.
3. The maximum stress was formed for the model with bronze weld joints and the front left weld joint (as shown in figure) showed the maximum stress for all the cases.