Hello, in PrePoMax only tetrahedral elements (2nd order element is called C3D10) can be used to mesh 3D solids. Calulix user manual says about C3D10: „ The element behaves very well and is a good general purpose element, although the C3D20R element yields still better results for the same number of degrees of freedom.“
The term „better results“ is a little vague. What is your experience concerning various analysis types for C3D20R vs. C3D10 elements with Calulix or any other solver ?
Thanks!
It’s a really broad topic considering the variety of scenarios that are analyzed with FEA. Usually, it’s advised to use hexahedral elements when possible (when a particular shape can be meshed with this type of elements in a given software) because good quality brick meshes usually give a solution of equivalent accuracy at less computational cost. But there are exceptions such as some contact analyses and simulations involving explicit solver.
It’s important to run benchmarks for various cases and compare the performance of different types of elements in a particular software. Here’s such an example involving plasticity: Elasto-plastic bending - elements, accuracy - CalculiX
For this type of behavior, hex meshes are superior because they are less stiff.
for quadratic type: may the term is change to “performances” instead of “results” i have excessive problem in multipart contact analysis and plasticity of curved object, hexahedral element perform better. linear type element with refined mesh is convergence at best.