Beam - Simply Supported - Quad8s

Example of 8-node shell elements representing a simply supported beam.  The beam can represented in two different orientations.  Both are equivalent if the plate thickness is the same as the length in this case.  The boundary conditions in the upper beam actually depend on how the beam is physically supported (whether the restraint is underneath the beam or in the middle or at the top).  In this example, I have placed the support in the middle.  Restraints have been added in the X and Y directions on one end and in the X direction on the other end.  Because I have two beams in one model, I have modelled them as 3D plates so have added restraints in the Z directions for all six end nodes.

The lower beam is loaded normal to the plate faces.  Restraints are added in the X and Y direction for the three nodes on one end and only in the Y direction for the three nodes at the other end.  The center end nodes were restrained in the Z direction as well.