Today I got asked a question regarding the used plate theory in Femap + NX Nastran, which I couldn't answer. I can see (when selecting element type PLATE and under 'formulation' that under 'Femap structural options' the plate theory is set to 0..default.
My questions are:
-Which theory is used when selecting the default option?
-Does making a choice in theory type affect the calculation when I model flat plates with a thickness/span ration of around 1/100?
The help is greatly appreciated!
Michael van Telgen
Solved! Go to Solution.
With the default formulation, FEMAP should write out CQUAD4 elements.
From the NX Nastran Element Library PDF:
CQUAD4 and CTRIA3 Elements
The formulation of the CQUAD4 and CTRIA3 elements are based on the Mindlin-Reissner shell
theory. These elements do not provide direct elastic stiffness for the rotational degrees-of-freedom
which are normal to the surface of the element.
With the mindlin theory, transverse shear is allowed, with kirchoff, no transverse shear is allowed. For a very thin plate, which it seems like what you are modeling, the transverse shear should be negligible.