Week 7-Long Piston With Cam
OBJECTIVE:
CASE 1: Frictionless
PROCEDURE:
- Open Ansys Workbench and choose transient structural.
- In the Engineering data, let the material be structural steel.
- For the geometry, right-click and import the given "Long_piston_cam.x_t" and open with space claim.
- Now in the workbench goto Model -> Edit, in the model window check the Geometry for the material and assign Structural Steel to all the component and also change stiffness behaviour= Rigid for the Barrel and Barrel_Cam.
- For contacts, flip the available contacts and choose the required faces only, change the Type= frictionless for both the contacts.
- Apply joints from body to ground apply fixed to the barrel and revolute to the barrel cam.
- Apply translational joint from body to body and select the barrel as reference scope and cam follower as mobile scope.
- For mesh, apply face sizing to the area of interest and element size= 3 mm.
- Before generating the mesh in sizing turn Use Adaptive Sizing= No, generate the mesh.
- For analysis setting, the number of steps= 9, for the first step the Initial Time Step= 0.1s, Minimum Time Step= 5e-2 s, Maximum Time Step= 0.2s, Weak Spring= Program-Controlled, Large Deflection= on, Stabilization= Constant, Method= Energy, Energy dissipation ratio= 0.1, Activation for first substep= yes, in output control turn all to yes except Contact miscellaneous= No.
- For time step 2 to 9, Initial Time Step= 0.1s, Minimum Time Step= 5e-2 s, Maximum Time Step= 0.3s, Weak Spring= Program-Controlled, Large Deflection= on, Stabilization= Constant, Method= Energy, Energy dissipation ratio= 0.1, Activation for first substep= yes, in output control turn all to yes except Contact miscellaneous= No.
- To provide rotation to the Barrel cam, right-click on Transient and apply joint load, JOint= Revolute- Ground To Barrel_Cam, Type= Rotation, Magnitude= Tabular data and provide the rotation data.
- In the solution request select for the required output like directional deformation along the x-axis, Equivalent elastic strain, Equivalent Stress. Click on solve to generate the result.
CASE 2: Friction 0.1
PROCEDURE:
- All of the above settings of Case 1 are kept similar except only in Contacts change the Type= Frictional and Friction Coefficient= 0.1 for both the contacts.
CASE 3: Friction 0.2
PROCEDURE:
- All of the above settings of Case 1 are kept similar except only in Contacts change the Type= Frictional and Friction Coefficient= 0.2 for both the contacts.
RESULT
Directional Deformation in X-axis
CASE 1: Frictionless
CASE 2: Friction 0.1
CASE 3: Friction 0.2
Equivalent Elastic Strain
CASE 1: Frictionless
CASE 2: Friction 0.1
CASE 3: Friction 0.2
Equivalent Stress
CASE 1: Frictionless
CASE 2: Friction 0.1
CASE 3: Friction 0.2
| Directional Deformation Along X-axis (mm) | Equivalent Elastic Strain (mm/mm) | Equivalent Stress (MPa) | |||||||
| Min. | Max. | Average | Min. | Max. | Average | Min. | Max. | Average | |
| Frictionless | -1.3852e-010 | 11.096 | 3.8706 | 6.3589e-006 | 8.8296e-003 | 6.7073e-004 | 9.0715e-002 | 1756.6 | 111.13 |
| Friction 0.1 | -3.7908e-010 | 11.133 | 3.8854 | 6.3488e-006 | 9.586e-003 | 7.0905e-004 | 9.0693e-002 | 1846.5 | 117.72 |
| Friction 0.2 | -1.3463e-010 | 11.227 | 3.9138 | 6.3295e-006 | 1.1997e-002 | 8.224e-004 | 9.0829e-002 | 2318.9 | 137.02 |
It can be observed from the analysis and the table that as the coefficient of friction is increased from frictionless to friction 0.2 the max directional deformation, max equivalent elastic strain and max equivalent stress also increases on the cam follower. In the case of frictionless the max directional deformation is 11.096 mm, max equivalent elastic strain is 8.8296e-003 mm/mm and max equivalent stress 1756.6 MPa while in the case of friction 0.2 which experiences the highest values the max directional deformation is 11.227 mm, max equivalent elastic strain is 1.1997e-002 mm/mm and max equivalent stress 2318.9 MPa.
CONCLUSION:
So from the analysis, it can be inferred that in the case of frictionless the cam follower experiences the least directional deformation, equivalent elastic strain and equivalent stress but when the friction is increased to 0.1 and 0.2 the directional deformation, equivalent elastic strain and equivalent stress value also increases the highest values are observed in the case having friction 0.2.
Simulation File: https://drive.google.com/file/d/1Mjk_nJv_VK5nsQVBrvHk-__jVCgAfavf/view?usp=sharing