Week 5 Sphere pressing on a plate

Objective:

Ther aim of this challenge is to simulate the pressing of a sphere in a plate and find out the plastic strain in the plate.

Case setup and execution:

First the static structural was opened. The structural steel NL was added to the library. Then the geomtery was imported.

In the Ansys Mechanical, the model was opened. First the parts were renamed. The plate was assigned the structural steel NL material.

In the contacts, the existing contact was deleted and a new manual contact region was inserted to define the contact between the sphere and the plate. The contact was made frictional with coefficient of friction of 0.74. The Augmeted Lagrange formulation was used.

Then the symmetry had to be defined. By right-clicking on "model" from model tree, Insert-symmetry option was selected. Two symmetries were defined by choosing faces of the sphere and the plate and X and Z axes as respective symmetry normals.

The mesh was generated using the default mesh size.

In the analysis settings, 4 loadsteps were chosen and large deflection was turned on. The "Direct" solver was chosen. Everything else was kept program controlled.

The fixed support was provided to the bottom face of the plate. The top plate of the sphere was given the displacement in negative Y-direction as shown below:

For the output, equivalent stress, strain, total deformation in Y direction and the equivalent plastic strain for the plate were requested. The results are shown below:

Results:

Animation:

Equivalent stress:

Equivalent elastic strain:

Equivalent plastic strain:

Y-directional deformation:

The following table summarises the maximum values of the results:

Equivalent stress (MPa)	3310.3
Equivalent elastic strain	0.016564
Equivalent plastic strain	1.8224
Y-directional deformation (mm)	3.3813

Conclusion:

Thus, the table indicates that the elastic strain of the sphere is very small as expected, and the plate shows the plastic deformation after the retraction of the sphere. Thus the simulation can be called a success. The zip file is attached with the report.