Hello,
I am looking for some input regarding element types for linear static analysis. Everything I learned in undergraduate and graduate FEA courses, and have read in one or two articles on this subject lead to the fact that 4-node tetrahedron elements are not as accurate as an 8-node brick (cube) element for linear static FEA of a solid object. Therefore, should be avoided for this type of analysis. Over the years I've run a few simple models that can easily be verified with hand calculations and brick element always produced more accurate results than tetrahedron elements. I typically use the default setting of mixed brick and tetrahedron elements in my FEA linear static models.
My question is this, I have a model made up of lofted spline formed cross sections, which, in itself is not friendly for FEA, and regardless of mesh settings it's difficult to use brick elements without resulting in several singularities. For situations like this is it an accepted practice to use tetrahedron elements instead? The tetrahedron elements visually look like they conform to the geometry better but I question the accuracy of their results. I've tried bricks with mid side nodes but the results are no more favorable than without. Any thoughts on this topic are appreciated.
Best Regards,
Mike
If the mesh is fine enough, the results of TET element is not bad, espcially with mid-side nodes.
TET element type can make meshing easier for some difficult cases.
-Shoubing