displacements on a straight line and thickness for a 2D

[nicolasdegand]

In the case of a 2D unit cell (for example rectangular):

1.how to impose a thickness (of 1mm for example)?

2.in applying a pressure on one side, how to impose that all the nodes of this side have a displacement as a straight line? (complete procedure)

 

[bkal]

Answering to your second question, this depend on your element type. Generally, if it is a linear element (4 noded) you just split it between the nodes on an element by element basis. If it is a quadratic element, then it is not that simple as the direction of the applied equivalent nodal load to give uniform deformation is different between the corner and the midside node (i.e. the corner node force is in the same direction as the applied pressure, while the midside node is opposite). I am talking from the top of my head but checking any book on FE or doing nuerical integration of the load vector yourself should give you the nodal forces.

Most FE pograms should be able to do it automatically, and it is not clear if you want to do it manually.