Microcrack growth parameters for compact bone deduced from stiffness variations

This paper shows how information on the fatigue behaviour of microcracks can be obtained by the analysis of stiffness changes measured during cyclic loading. Relationships between crack length, growth rate and cyclic stress intensity were deduced, and compared with previous empirical equations. Results show that the crack growth rate decreases rapidly with increasing length; this behaviour is typical of short-crack fatigue in many materials and is interpreted in terms of microstructural barriers to growth. Implications for the role of microcracks in remodelling and adaptation phenomena are discussed.