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Element Issues

Posted: Wed Jul 10, 2019 9:00 am
by ScarlettM.
I create a model in STKO using the Hinged Beam element, to model beam end releases. If I mesh the Edge with a single finite element everything is ok. However when I try to refine the mesh (multiple elements for an Edge) I have numerical issues due to singularities. Does anyone know what the problem is?

Re: Element Issues

Posted: Wed Jul 10, 2019 1:50 pm
by WeiSun
The Hinged Beam element in STKO is an automatism that creates (for each element of the mesh) 1 internal element and 2 hinges at the element ends.
If you are modeling beam-end releases it means that the hinges at the beam ends have zero rotational stiffness;
when you mesh the edge with more than 1 element, every interior node of the mesh has rotational hinges at both sides, thus rendering the stiffness matrix at that interior node singular!

What I can tell you is that when you assign a Hinged Beam to a geometrical Edge, mesh that edge with just 1 element :)