Learning Forum

[CheapMiao]

The exercise problem I want to solve is:

[CheapMiao]

Oh...I know, add constraint to a point in middle

[peteroznewman]

Frictionless supports are wrong. They prevent those edges from moving in the Y direction, but the material has a non-zero Poisson's Ratio, which means a strain in the X direction causes a strain in the Y direction but those supports prevent that. In the figure you show, there are no supports on the long edges, they are free.
The best way to solve this model is to go back to the geometry editor and slice the body into 4 at the center. Discard 3 pieces and bring in 1/4 of the plate.
In Mechanical, apply Symmetry regions to the horizontal edge that represents the Y axis of symmetry and the two vertical edges that represent the X axis of symmetry. That takes care of 5 DOF. The last DOF is the Z direction, so apply a Z=0 displacement to the vertex created at the center of what used to be the full plate. Apply the pressure load of 10 MPa to the half edge.

[CheapMiao]

ooooo, I forget Poisson's Ratio and spilt surface form middle, you are right!!!! No wonder I feel strange when I choose dots which are close to middle but no exactly middle.
Thanks for your correction!!!