Verification Process for Finite Element Modeling Techniques Used in Biological Hard Tissue

An approach is presented for calculation verification of geometry-based and voxel-based finite element modeling techniques used for biological hard tissue. The purpose of this study is to offer a controlled comparison of geometry- and voxel-based finite element modeling in terms of the convergence (i.e., discretization based on mesh size and/or element order), accuracy, and computational speed in modeling biological hard tissues. All of the geometry-based numerical test models have hp-converged at an acceptable mesh seed length of 0.6mm, while not all voxel-based models exhibited convergence and no voxel models p-converged. Converged geometry-based meshes were found to offer accurate solutions of the deformed model shape and equivalent vertebral stiffness, while voxel-based models were 6.35%±0.84% less stiff (p<0.0001) and deformed 6.79%±0.96% more (p<0.0001). Based on the controlled verification study results, the voxel-based models must be confirmed with local values and validation of quantities of interest to ensure accurate finite element model predictions.