- #1

Hassan2

- 426

- 5

Dear all,

I have written a code for structural analysis using the finite element method. For some reason, I directly started with 3D elements ( hexahedron). I used to believe that the code was fine but recently i realized that the results ( deformation, natural frequency,..) strongly depend on the mesh size even for very small meshes. I have been trying for several days to find the problem in the code in vain. The problem might be in matrix assembling but before that, I need to make sure that my elemental stiffness matrix is correct. Does anyone have a reference with a numerical example of 8-node 3D elemental stiffness matrix?

The figure shows the matrix construed by the code. Perhaps you can judge the correctness by of the matrix by looking at the entries.

Your help would be appreciated.

Thanks

I have written a code for structural analysis using the finite element method. For some reason, I directly started with 3D elements ( hexahedron). I used to believe that the code was fine but recently i realized that the results ( deformation, natural frequency,..) strongly depend on the mesh size even for very small meshes. I have been trying for several days to find the problem in the code in vain. The problem might be in matrix assembling but before that, I need to make sure that my elemental stiffness matrix is correct. Does anyone have a reference with a numerical example of 8-node 3D elemental stiffness matrix?

The figure shows the matrix construed by the code. Perhaps you can judge the correctness by of the matrix by looking at the entries.

Your help would be appreciated.

Thanks