Dynamic fracture response of a synthetic cortical bone simulant

Abstract

This work characterizes the fracture response of a composite material designed to mimic the response of human cortical bone. We have identified additive manufacturing, more generally known as 3-D printing, as a means of reproducing the curvature, variation in thickness, and gradient in porosity characteristic of the human bone between the cortical and trabecular regions. As the base material for developing bone surrogates via additive manufacturing, we evaluate a photocurable polymer with a high loading of ceramic particulate reinforcement that is compatible with stereolithographic additive (SLA) manufacturing. Specimens were printed in two orientations to measure fracture response perpendicular and parallel to the direction of deposition of the layer-by-layer manufacturing process. Mode I fracture behavior of the material was measured in four point bending configuration at high rate via modified split Hopkinson pressure bar for both orientations. In this paper, the fracture behavior of the bone simulant are presented and are compared to the mode I fracture behavior of human cortical bone perpendicular to the long axis of the human femur characterized under the same conditions.