CCDC Army Research Laboratory Aberdeen Proving Ground United States
A shear-punch test SPT experimental method was developed to address the lack of shear deformation and failure response data for the human skull as a function of local bone microarchitecture. Shear-punch specimens were extracted from right-parietal and frontal bones of three fresh-frozen-thawed human skulls. The specimens were kept as full through-thickness or segmented into the three skull constituent layers the inner and outer cortical tables and the middle porous diplo. Micro-computed X-ray tomography CT before and after SPT provided the bone volume fraction BVF as a function of depth for correlation to shear response for the punched volumes. Five full-thickness specimens were subjected to partial indentations to investigate damage development as a function of BVF and depth. BVF dominates the shear yield and ultimate strength of human skull bone, but the equivalent uniaxial loading rate 0.001 and 0.1 s1 did not test significant p 0.1810.806 0.05 for the shear yield and ultimate strength of the skull bone layer specimens. Shear yield and ultimate strength data were represented as a function of BVF with power law and exponential relationships with a high correlation R2 0.9170.956. Full-thickness and partial indentation SPT experiments indicate the diplo primarily dictates the shear strength of the intact structure.