Rotation constraint

[jpee1]

Hi guys,

I have the following problem in Abaqus:

I have modeled a rectangular window frame (image below) which only consists out of one part. This thus means that the horizontal and vertical members (beam sections) are rigidly connected to each other. The frame is pin supported (to the structural backup) at the four corners.

Now the following problem in Abaqus occurs: When I load the vertical members in bending along the x-axis, the rotation at the top and bottom of these members is not ‘passed on’ to the horizontal members. With this I mean that due to the rotation of the vertical beams, the horizontal members have to (torsionally) rotate along their longitudinal (x) axis. I have tried to illustrate this in the images below.

So my question is: how can I make sure in Abaqus that the horizontal and vertical members have the same rotation?

Thanks.