Do you ever use solid elements for FEA modeling?
Do you ever use solid elements for FEA modeling?
(OP)
I don’t think I ever have. For one thing, I think they tend to overestimate stiffness. Another problem they present is interpreting results.






RE: Do you ever use solid elements for FEA modeling?
RE: Do you ever use solid elements for FEA modeling?
RE: Do you ever use solid elements for FEA modeling?
RE: Do you ever use solid elements for FEA modeling?
RE: Do you ever use solid elements for FEA modeling?
RE: Do you ever use solid elements for FEA modeling?
RE: Do you ever use solid elements for FEA modeling?
Roarks? or where?
RE: Do you ever use solid elements for FEA modeling?
RE: Do you ever use solid elements for FEA modeling?
The apples and oranges here are the kinematic formulation. The one dimensional analogy is the beam. Say you had an easily derived analytic solution for the beam loaded with a constant traction, q. Simply supported on the two ends. It is easy to derive the Euler-Bernoulli beam bending solution, since most of us have had some kind of basic mechanics of materials or "strengths" class where we learned how to do basic shear and moment diagrams. Now analyze this with two FE models--one uses 'beam' elements, the other 2D solid elements. You get two FE solutions, which is correct? If the measure of correctness is comparison with that beam bending solution you derived, the FE model with the beam elements should always give you the best answer, because the beam elements are consistent with the beam bending solution you have derived--to derive the beam elements for the FE software, the FE software developers made the same assumptions as the Bernoulli Euler beam bending analytic solutions made, therefore the beam elements are more consistent with the beam bending analytic solutions than the 2D solids are.
I am guessing that the shear wall solution in your concrete text uses some kind of plate kinematics model (say Timoshenko's plate model), which makes some key assumptions that eliminate degrees of freedom to simplify the equations (for instance, some plate models assume there is zero normal stress in the direction perpendicular to the plate surface, while clearly a plate loaded with a constant pressure normal to the surface has to have a normal stress varying from that constant pressure on the loaded surface to zero on the opposite surface). The plate elements in the FE software might use the very same assumptions your shear wall solution used, and therefore also ignore or eliminate the same degrees of freedom as the shear wall solution. Since the shear wall solution and the FE plate elements use the same assumptions, you should be able to match the shear wall solution more easily with the FE plate elements than with the FE solid elements.
Usually though a too stiff FE solution means not enough degrees of freedom, so that if you quadrupled the number of elements, you probably will get a more compliant FE model with the solid elements. It's kinda cool to play around with different FE element types to see how the answers change.
RE: Do you ever use solid elements for FEA modeling?