Fig. 15.

Twisting column test: mesh convergence for a hexahedral and b tetrahedral elements. Shown are displacements $u_x$, $u_y$, and $u_z$ at tip D versus time. For experiments depicted the incompressible formulation with MINI elements was chosen. At finer levels of refinement $\ell =3,4,5$ (in black) results converge to a solution for each displacement direction