Transient Structural Analysis of Long Piston With Cam using Ansys
Objective - To perform a transient analysis on a piston and cam mechanism model.
Run the analysis for a total of 3 cases.
Case 1 - Frictionless contact.
Case 2 - Frictional with 0.1 as the frictional contact.
Case 3 - Frictional with 0.2 as the frictional contact.
Procedure -
Create Transient structural analysis and in engineering data select the material structural steel.
Structural Steel.
Import the geometry and check in SpaceClaim for any irregularities.
Then open Ansys mechanical and rename the geometry as BARREL, BARREL_CAM AND CAM_FOLLOWER then assign the structural steel material.
Contacts - two contacts created in the whole setup with frictionless or frictional type with friction coefficient of 0.1 and 0.2 and interface treatment is set to Add offset, Ramped effects.
Case 1 - Frictionless contact.
Case 2 - Frictional with 0.1 as the frictional contact.
Case 3 - Frictional with 0.2 as the frictional contact.
Contact - CAM_FOLLOWER to BARREL
Contact - CAM_FOLLOWER to BARREL_CAM
Joints - Three joints created in whole geometry.
Fixed - Ground to BARREL
Revolute - Ground to BARREL_CAM
Translational - BARREL to CAM_FOLLOWER
Mesh - Face Sizing option use for meshing 3mm element size.
Analysis Settings - The simulation runs for 9 steps. So, the number of steps is set as 9.
In the first step large deflection set to on and defined by time. Initial time step set to 0.1s, Minimum time step set to 5e-2s and Maximum time step set to 0.2s and stabilization set to constant, method to energy and energy dissipation ratio to 0.1, activation for first step to yes. In Output control set all output to yes except Contact miscellaneous.
The second step to nine step large deflection set to on and defined by time. Carry over time set to on, Initial time step set to 0.1s, Minimum time step set to 5e-2s and Maximum time step set to 0.3s and stabilization set to constant, method to energy and energy dissipation ratio to 0.1, activation for first step to yes. In Output control set all output to yes except Contact miscellaneous.
Joint - Rotation - cam is provided a rotation of 270 degrees.
Run the simulation and results obtained.
Result - The analysis runs successfully and results obtained.
Case 1 - Frictionless contact.
Equivalent Stress Max - 1756.6 Mpa
Total Deformation Max - 35.921 mm
Directional Deformation Max - 11.096 mm
Equivalent Elastic Strain Max - 0.0088296 mm/mm
Case 2 - Frictional with 0.1 as the frictional contact.
Equivalent Stress Max - 1849.1 Mpa
Total Deformation Max - 35.921 mm
Directional Deformation Max - 11.134 mm
Equivalent Elastic Strain Max - 0.0095993 mm/mm
Case 3 - Frictional with 0.2 as the frictional contact.
Equivalent Stress Max - 2339.1 Mpa
Total Deformation Max - 35.921 mm
Directional Deformation Max - 11.235 mm
Equivalent Elastic Strain Max - 0.012101 mm/mm
Conclusion -
Inference
- Equivalent Stress - Stress keeps on increasing as we increase the friction coefficient values. As the friction coefficient value increases it resists more the movement of the follower and thus the stress develops at the stem of the follower.
- Directional Deformation - It is increasing slightly with increasing friction coefficient value.
- Equivalent Elastic Strain - Also because of the same reason as equivalent stress, Equivalent Strain also increases due to more resistance offered.
- Total Deformation - same in all three cases.
Google drive link - https://drive.google.com/file/d/1UYYyO56cnq7XlbtJgiHcdTiMWO-Nl4Gn/view?usp=sharing