Week 5 Sphere pressing on a plate
OBJECTIVE
perform the analysis to simulate a sphere pressing on a plate.
Use Structural steel for both sphere and plate but the material of the plate must be Non Linear.
Press the sphere onto plate 4mm downwards and retract it. The plastic deformation must be captured by you.
CASE SETUP
- open ansys workbench and drop down the static structure onto the project window.
- Select structural steel and structural steel NL material from Engineering data sources with required properties.
- Import the geometry.
- Open the mechanical module.
- Rename the components as SPHERE and PLATE
- Assign structural steel for sphere and structural steel NL for plate.
Properties of structural steel and structural steel NL
SYMMETRY
- As a CAE/FEA engineer our main intension is to reduce computational time, to acheive this simplify the geometry.
- In this challenge we have a sphere with plate, it is a symmetrical component so take 1/4th of the model and symmetry it to the other directions.
- we created two symmetries about Z - axis & X- axis
CONNECTIONS
- Delete the all default contacts generated by ansys workbench.
- Create a new contacts manually , contacts - insert- manual contact region.
- create a frictional contact between sphere and plate with a frictional coefficient of 0.74
MESH
- The generated dfault mesh is fine, so go with default mesh itself.
BOUNDARY CONDITIONS
Anaysis settings :- this analysis setup for 6 steps, this doesn't control time step, but it is only indication of points where boundary conditions change. the time step is auto controlled by minimum ,initial maximum and time steps.
- Fix the bottom surface of plate using fixed support option
- Insert displacement load in y-axis direction in a tabular form, we given 4mm displacement for sphere
- output requests
RESULTS
- Directional deformation in Y- axis for both sphere and plate
Equvilent stree on plate alone
Equvilent strain on sphere alone
Equvilent strain on plate alone
Equvilent plastic strain on plate alone
CONCLUSION
- By observing the results we can see the plastic deformation occured on the plate after removing the sphere displacement load, by pressing the sphere on to the plate by 4mm downwards and after retracting it plastic deformation obtained is 1.6417mm.
- Max stress and strain occured at the contact between plate and sphere.