Normalized specimen thickness requirements of a compact sandwich test for measuring fracture toughness of bone.

AIM Fracture toughness is one of the properties that assesses bone quality. Compact sandwich (CS) test gives a better choice of bone sample size and therefore suits a wide variety of fracture toughness testing needs and constraints. This study addresses one of the important standardization aspects of CS test for fracture toughness testing of bone. The aim of this study is to establish normalized specimen thickness requirements of CS test. METHODS This study used finite element (FE) simulation of CS test in order to establish the requirements, and experimental fracture toughness tests to verify the same. Statistical analysis validated the FE and experimental results. RESULTS Validation of FE model was performed using post-hoc analysis of existing experimental data. The experimental CS tests gave statistically valid stress intensity factor and energy release rate of bone. CONCLUSIONS Reliable normalized specimen thickness requirements of CS test are established. This serves as a guideline to carry out CS test. CS test helps in meeting the fracture toughness testing requirements at macroscopic and sub-millimetre scales.