An experimentally validated continuum damage mechanics model of the micro-damage process zone during cortical bone fracture

Abstract

Bone fractures remain a significant concern worldwide especially with aging and bone damaging diseases. These fractures not only lead to a high rate of morbidity and mortality but also place a considerable burden on the economy. This burden is as a result of the unmet need for better mechanical tools for predictive and preventive measures of bone fractures. This can be traced to the fact that there is still an incomplete mechanistic understanding of how bone resists fracture, specifically not understanding what changes cause fracture resistance to decline with aging and in bone damaging diseases. In this study, a continuum damage mechanics (CDM) approach was investigated to model the microdamage process zone (MDPZ), a primary toughening mechanism in cortical bone fracture. The CDM model was then validated against experimentally generated microdamage process zones using digital image correlation. The CDM model was able to replicate MDPZ formation observed experimentally. Results demonstrate that continuum damage mechanics provides a robust means of modelling the microdamage process zone in cortical bone fracture. With further development this work could yield a useful tool to better understand the fracture process in cortical bone in terms of its MDPZ formation.