Week 3 Verification of Weld Joints
Aim : To verify weld joints using static structural analysis
Conclusion :
1) To simulate three different types of welding using three different weld materials
2) To fine out the directional deformation and equivalent strain experienced 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. Recent years we have accomplished mngreat advancement in welding technology, it has secured a prominent place in manufacturing machine components. Compared to other type of joints, the welded joint has higher efficiency. An efficiency > 95 % is easily possible. Since the added material is minimum, the joint has 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 structures.
2. Flanges welded to shafts and axles.
3. Crank shafts
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 static structural tool in the analysis system tool box 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 its properties are shown below.
Case 1 :
In this case, the material of the plates must stainless steel. 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", 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 naming them.
4) In connection, we have to define the contact faces of the weld geometry by selecting and deselecting as contact or target bodies. In contacts under connection tab we define the type of contact as frictional contact with coefficient of friction as 0.3 for connection between ribs and plates. Connection between the plates and weld joints are kept as bonded.
5) By opening the modelling the tab, we mesh the geometry with element size as default. Generating the mesh thereafter by right clicking on the Mesh icon. Body sizing under mesh tab is used to refine the mesh to 7mm for two plates where contacts are present.
Body sizing of 7mm mesh
Meshing done for whole geometry
6) We open 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 12000N
7) Setting up the solution
For Case 1 :
Directional deformation (Y-axis)
Equivalent strain for all weld joints
Equivalent strain for two Ribs
Equivalent stress for whole geometry
Status
Pressure
Safety Factor
For Case 2 :
Directional deformation (Y-axis)
Equivalent strain for all weld joints
Equivalent strain for two Ribs
Equivalent stress for whole geometry
Status
Pressure
Safety Factor
For Case 3 :
Directional deformation (Y-axis)
Equivalent strain for all weld joints
Equivalent strain for two Ribs
Equivalent stress for whole geometry
Status
Pressure
Safety Factor
Results :
| Sr. No | Directional Deformation | Equivalent strain | Equivalent stress |
| Case 1 | 0.28065 | 0.0012291 | 273.62 |
| Case 2 | 0.35951 | 0.0012847 | 283.39 |
| Case 3 | 0.32684 | 0.0027016 | 281.62 |
Conclusion :
We can conclude that from the above results stress on the bronze cast material used for brazing weld joint has the maximum equivalent stress among the other materials. The directional deformation in the Y axis is also high in case of bronze material.