Week 2 Railwheel and Track
Objective:
Perform a static structural analysis on the Railwheel and Track setup and
Case 1: Multiply the bearing load by 5 times and compare the results with the load of 100000 N. Compare the Total Deformation, Equivalent stress, and the life under both the loads
Case 2: Implement a User-defined result and calculate the Total Deformation from this result and check if it is the same as that obtained by the inbuilt result by ANSYS for a load of 100000 N.
PROCEDURE:
- Open Ansys and select Static Structural from the toolbox.
- Rename the Project to RailWheel_and_Track.
- Right Click on Engineering Data and click on edit to select the material required for the analysis.
- In this case, Structural Steel material is used for the analysis.
- Import the model and open it in SpaceClaim.
- Open the model in the Mechanical model
- Check if all the mentioned parts are assigned with the same material i.e. Structural Steel
- Under Connections, default contacts are established between the parts. Rename the contacts by definition.
- Flip the contact and target bodies by using the Flip Contact/Target option.
- Provide a frictional contact between the rail wheel and track having a frictional coefficient value of 0.3.
- Provide a frictionless contact between the solid part and the wheel.
- After assigning the respective parameters, joint loads have to be assigned to the system to run the simulation process and to evaluate the results.
- Apply a fixed Joint to the track for its non – moment and easy translation of the wheel on the track.
- A translational Joint is applied to the shaft. As observed, the shaft is attached to the wheel, and hence when the forces act on the shaft those forces will be translational to the wheel.
- Check the direction of the translation joint acting. If any need to change the direction, change the Principal Axis.
- Finally, a planar Joint is provided to the wheel.
- Generate a mesh with an overall mesh size of 50mm
- Select the faces (3 faces) that are in contact and apply a mesh sizing feature having a mesh size of 35mm.
- The generated mesh will be observed as follows
- In the analysis settings, give appropriate parameters to the setup and define joint loads that will be applied to the geometry setup.
- Switch on Force Convergence and change all the output controls to “Yes”.
- After the analysis parameters are given, Apply a Displacement joint to the shaft.
- Apply a bearing load of 100000N and 500000N accordingly.
- The setup is now complete. Solve and evaluate the necessary results.
RESULT:
Case 1: a. Bearing Load of 100KN applied.
- Total Deformation:
GIF:
Equivalent Stress:
GIF:
Equivalent Strain:
GIF:
Life of Wheel:
Life of Shaft:
Life of Track:
Contact Pressure:
User-Defined Equation result (Angle):
Case 1: b. Bearing Load of 500KN Applied.
Total Deformation:
GIF:
Equivalent Stress:
GIF:
Equivalent Strain:
GIF:
Life of Wheel:
Life of Shaft:
Life of Track:
Contact Pressure:
User-Defined Equation result (Angle):
COMPARISON:
Comparing the results for bearing the load of 100KN applied and bearing the load of 500KN applied:
| Bearing Load Applied | Total Deformation (mm) | Max. Equivalent Stress (MPa) | Max. Equivalent Strain | ||
| 100KN | 1001.5 | 139.9 | 7.932e-4 | ||
| 500KN | 1001.9 | 545.29 | 3.0006e-3 |
CONCLUSIONS from CASE - 1:
- From the above results for which the bearing load is 100kN and 500kN, we can say that the model which is subjected to a high amount of bearing load undergoes similar deformation, it has less fatigue life and produces more amount of stress and strains.
Case 2: Setup for User-Defined Equation Result for Total Deformation.
Total Deformation results can be obtained using the algebraic equations in the form of vector quantities.
a. Let's suppose,
The symbol for Total deformation is U.
Deformation along X is UX.
Deformation along Y is uy.
Deformation along Z is uz.
b. The equation for total deformation is U = `sqrt((Ux)^2+(Uy)^2+(Uz)^2`
- Enter the above equation in Expression Tab and change the output result to Displacement and solve for the Equation to get Total deformation.
RESULT:
CASE - 2: a. Bearing Load of 100KN
CASE - 2: b. Bearing Load of 500KN
COMPARISON:
| Bearing Load Applied | User-defined Total Deformation (mm) | Inbuilt Total Deformation (mm) |
| 100KN | 1001.5 | 1001.5 |
| 500KN | 1001.9 | 1001.9 |
The conclusion from CASE - 2:
As observed, the User-defined results are the same as the inbuilt results.
Conclusion:
- From the observations of comparative results, we can see the high amount of increase in Stress and Strain.
- User-Defined results are the same as inbuilt results and near the same in both cases.
- From the contact status, we can observe little change in track and little sticking due to higher pressure in the case of 500000 N loading. So it can be dangerous and leads to Derailment and power transmission loss.
- We know that the Tensile Yield Strength of Structural Steel is 250 Mpa. So in the case of 500000 N loads, Stress is going beyond the limit up to 545.29 Mpa. So there will be plastic deformation or permanent deformation can happen.
- So we should avoid higher loads for safety purposes.