Week 4 -Wire Bending Challenge
Objective:
To simulate given wire bending model for different materials in ANSYS and compare obtained results.
Case setup procedure:
- Given model is loaded in Space claim GUI. In mechanical interface, parts are renamed as per our convenience such as Wire, Wheel and Lever.
- All required materials such as Aluminium alloy NL, Copper alloy NL and Magnesium alloy NL are loaded from engineering materials library
- Wire part is selected and Copper alloy NL is assigned in material tab
- Frictional conacts are setup between wire and lever, and between wheel and wire. Auto assymetric behaviour is chosen, Augmented Lagrange formulation is used. Normal stiffness factor is updated for each iteration by a factor of 0.1. In interface treatment, add offsets ramped effects is selected
- Inner surface of hole in lever is selected and a revoulte joint is setup between ground and lever
- Tetrahedron meshes are set up using default mesh size for the model. For wire and wheel surfaces which would be in contact, element size of 2.2 mm is used.
- Elements which would be in close vicinity of contacts are further refined using a sphere of influence. A new co-ordinate system is created at the point where wire meets the wheel. Element size of 0.8 mm is used in the areas within 7 mm radius in sphere of influence
- Analysis is setup using 8 steps. In step 1, auto time stepping is switched ON and is defined by time with initial time step of 0.1s, minimum time step of 0.002s and maximum time step of 0.2s.
- For steps 2 to 8, auto time stepping and carryover time is switched ON with minimum time step of 0.002s and maximum time step of 1s.
- Direct solver type is used. Large deflections is switched ON. All output controls are set to Yes.
- Inner surface of hole in the wheel is selected and is fixed. Lever is rotated from 0 degree to 140 degree along 8 steps through the revolute joint setup between lever and ground
- Required simulation results such as Equivalent stress, Equivalent strain are selected.
- Solution is solved after completing all above mentioned steps.
- The complete simulation is repeated for different materials and results are obtained from simulation
Results Discussion:
Case 1: Wire material- Copper Alloy NL
Equivalent stress of complete model:
Maximum- 383.86 MPa
Equivalent stress of Wire:
Maximum- 334.36 MPa
Equivalent strain of Wire:
Maximum- 0.0030707
Case 2: Wire material- Aluminium Alloy NL
Equivalent stress of model:
Maximum value- 318.45 MPa
Equivalent stress of Wire:
Maximum value- 318.45 MPa
Equivalent strain of Wire:
Maximum value- 0.0045073
Case 3: Wire Material- Magnesium Alloy NL
Equivalent stress of model:
Maximum value- 231.36 MPa
Equivalent stress of Wire:
Maximum value- 231.36 MPa
Equivalent strain of Wire:
Maximum value- 0.0051677
Learnings:
In this assignment, refining the mesh using sphere of influence is understood.
Conclusion:
Since Magnesium alloy wire is subjected to minimum stress among three different wire materials analysed, it is the best suitable material for the wire according to simulation results obtained.
Simulation files:
https://drive.google.com/file/d/1dvv2Sbr5WmFMH8DGRnLpk5OX8uY05mbX/view?usp=sharing