Element Types Comparison 02-29-16

VMH

Just a quick comparison if interested. Linear Hex8 and Quadratic Hex20 solid elements have 4 layers thru the thickness and Quadratic Tet10 solid elements have 1 layer thru the thickness. See the outline tree for descriptions.

Victor

Great example of how terrible the linear elements are for bending. Here's the same mesh but with a tensile load instead. Now they're all about the same.

davefo

so which element gives the right answer and how do i work out what to use and when?

Victor

All solid elements are correct as long as you refine the mesh until the solution stops changing much. The differences between the elements determine how fine the mesh needs to be to reach that good-enough condition.

Generally, quadratic elements (hex20, wedge15, pyr13, tet10) are better than their linear equivalents (hex8, wedge6, pyr5, tet4) in this regard, and hex is better than tet. So overall hex20 is typically the best choice for optimizing mesh size and solution time.