A Novel 3D Microstructural Model for Trabecular

Abstract

A novel 3D microstructural model was proposed and validated in part I of this publication. In part IT, the model was used to identify the yield surface of a representative volume element of human trabecular bone as a function of volume fraction and degree of anisotropy. Finite element models of open and closed cells geometries were used to calculate effective yield stresses for a variety of loading cases with periodic boundary conditions. The postyield behaviour of the trabecular tissue was assumed from data available for cortical tissue. The yield stresses defined by a 0·2% offset in the global stress-strain curve were fit to an orthotropic Hill criterion and the parameters of the surface calculated.

Similarly to the previous elastic analysis, distinct but strong relationships were obtained between volume fraction, fabric and the yield surface parameters for both the open and closed cell geometries. This finding suggests that volume fraction and fabric may be used to predict the initiation of mechanical damage in human trabecular bone at the continuum level.

Keywords:

• Cellular solids
• damage
• fabric
• mechanical properties
• microstructure
• trabecular bone
• yield properties