Week 3 Verification of Weld Joints

Aim: To verify weld joints using static structural analysis.

Objective:

1. To stimulate three different types of welding using three different weld materials.
2. To find out the directional deformation and equivalent strain experience by the setup.
3. To identify the weld joint that experiences the highest equivalent stress in each case and compare the results for all three cases.

Introduction:

Welding is a very commonly used permanent joining process. In recent years we have accomplished great advancement in welding technology, it has secured a prominent place in manufacturing machine components. Compared to other types of joints, the welded joint has higher efficiency. An efficiency > 95 % is easily possible. Since the added material is minimum, the joint has a lighter weight. Welded joints have smooth appearances. Due to flexibility in the welding procedure, alteration and addition are possible. Forming a joint in difficult locations is possible through welding.

The advantages have made welding suitable for joining components in various machines and structures. Some typically welded machine components are listed below.

1. Pressure vessels, steel structure
2. Flanges welded to shafts and axles
3. Crankshafts
4. Heavy hydraulic turbine shafts
5. Large gears, pulleys, flywheels
6. Gear housing
7. Machine frames and bases
8. Housing and mill-stands

Procedure:

1) To verify welds in the setup, we use the static structural tool in the analysis system toolbox to define the geometry and other input parameters for the same.

First, we open SpaceClaim to identify and rectify the errors in the geometry. In the below geometry we can see the welds are

2) In the engineering data we input the material and its properties. In this case, we are using three different types of materials and their properties are shown below.

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".

3) Input the given weld geometry from the geometry tab and name them.

Case 1:

Case 2:

Case 3:

4) In connection, we have to define the contact faces of the weld geometry by selecting and deselecting contact or target bodies. In contacts under the connection tab, we define the type of contact as frictional contact with a coefficient of friction of 0.2 for connection between ribs and plates. The connection between the plates and weld joints is kept as bonded.

5) By opening the modelling tab, we mesh the geometry with element size as default. Generating the mesh thereafter by right-clicking on the Mesh icon. Body sizing under the mesh tab is used to refine the mesh to 4 mm for two plates where contacts are present.

Body sizing of 4 mm mesh

Meshing is done for the whole geometry

6) We open the analysis setting where we define step control settings and input the parameters as needed.

Defining Fixed support with one step by selecting the faces

Force applied in the Y-direction of 15000N

7) Setting up the solution

Case 1:

Directional Deformation in Y-axis:

Equivalent Stress for whole geometry:

Equivalent Strain for all Weld Joints:

Equivalent Strain for two Ribs:

Pressure:

Safety Factor for the whole body:

Safety Factor at weld Joints:

Case 2:

Directional Deformation in Y-axis:

Equivalent Stress for whole geometry:

Equivalent Strain for all Weld Joints:

Equivalent Strain for two Ribs:

Pressure:

Safety Factor for the whole body:

Safety Factor at weld Joints:

Case 3:

Directional Deformation in Y-axis:

Equivalent Stress for whole geometry:

Equivalent Strain for all Weld Joints:

Equivalent Strain for two Ribs:

Pressure:

Safety Factor for the whole body:

Safety Factor at Weld Joints:

Results

Materials	Case 1	Case 2	Case 3
Directional Deformation (Maximum) in mm	0.33343	0.43026	0.39158
Directional Deformation (Minimum) in mm	-3.1933e-002	-1.9806e-002	-2.4356e-002
Equivalent Stress (Maximum) in MPa	384.95	404.11	398.73
Equivalent Stress (Minimum) in MPa	2.2312e-002	3.0659e-002	2.895e-002
Equivalent Elastic Strain for Ribs (Maximum) in mm/mm	4.897e-004	9.1254e-004	7.0169e-004
Equivalent Elastic Strain for Ribs (Minimum) in mm/mm	1.9747e-005	2.8024e-005	1.4225e-005
Equivalent Elastic Strain at Weld Joints (Maximum) in mm/mm	1.6084e-003	3.8815e-003	3.5428e-003
Equivalent Elastic Strain at Weld joints (Minimum) in mm/mm	1.925e-005	4.6411e-005	3.2715e-005

Conclusion:

• From the above results strain on the Aluminium cast material used for brazing, the weld joint has the maximum equivalent elastic strain among the other materials.
• From the above results stress on the Bronze cast material used for brazing, the weld joint has the maximum equivalent stress among the other materials.
• The directional deformation in the Y-axis is also high in the case of Aluminium material.

Note: google drive link is provided below in a text file. Please check the link for the model.

Thank You...