# Verification & Validation – Lesson 8

Recall from pre-analysis, the equivalent stiffness of the bone model is:

## $E_{equiv}=\frac{64.658/(4.947\times10^{-3})^2}{0.5/4.947}=26.14 \hspace{2mm} MPa$

Ansys gives a stiffness of 26.14 MPa for the bone model. According to Professor Hernandez, the stiffness for this model is about 24MPa. There is a 8.9% error between the simulation and the reported value. The difference may be attributed to several factors including but not limited to the accuracy of the specified Young’s modulus, errors in the mesh representation of the actual bone specimen, inaccuracies in the experimental measurement such as load cell calibration, or even differences in the roller and displacement boundary condition versus the actual experimental boundary conditions.