Progressive Post-Yield Behavior of Human Cortical Bone in Shear

Post-yield behavior is important for bone fragility since it accounts for the major part of energy dissipation of bone. Therefore, it is essential to study the post-yield behavior of bone to understand the different pathways for energy dissipation [1]. The post-yield behavior of bone may depend on the different loading modes. Previous studies have utilized a novel progressive loading scheme to study the post-yield behavior of cortical bone at tension [2] and compression [3]. However, few studies have reported post-yield behaviors of cortical bone in shear [4]. One of major challenges in shear tests of cortical bone is to achieve a uniform stress field over a test region. For example, the notches of the Iosipescu test may cause non-constant stress fields and locally high stresses when small amounts of bending are present [5]. The objective of this study was to develop the progressive loading scheme of shear in bone using an inclined double notch shear test, in which homogeneous shear stress fields were produced [5].