MODELLING POROUS HYDROXYAPATITE MATRIX BASED BONE MICROSTRUCTURE

Abstract

This contribution covers the prediction of the stiffness tensor for a microelastic model of the bone based on a three-step homogenization scheme. A micromechanical approach of the elastic properties of bone is being approached via a step-by-step homogenization concept developed around a more general, realistic hierarchical structure of the bone. The homogenization steps were done at: nanoscale – hydroxyapatite foam (extrafibrillar space), microscale (5-10 m) – collagen and hydroxyapatite network (fibril), microscale (5-10 mm) – bone microstructure. The stiffness tensor will be evaluated for each step of the homogenization process as function of different porosities volume fraction meaningfully from bone structure point of view. The same concept was applied for the volume fractions of the major bone constitutive, the hydroxyapatite crystals (35%) and collagen molecules (30%).