HAVERSIAN CORTICAL BONE WITH A RADIAL MICROCRACK

The plane problem for the Haversian cortical bone with a radial microcrack in the interstitial bone under biaxial tension loading is considered. A two-dimensional coated fiber composite model of the Haversian cortical bone is developed correspondingly. By using the solution for the edge dislocation as Green’s functions, the problem of a radial microcrack located in the interstitial bone in the vicinity of the osteon is formulated into a system of singular integral equations with Cauchy kernels. And the interaction effect of various material and geometric parameters of the Haversian cortical bone upon the microcrack tip’s stress intensity factors is studied. The numerical analysis indicates that the stress intensity factor of the microcrack is dominated by the shear modulus ratio among the Haversian canal, the osteon and the interstitial bone, the distance of the left tip of the microcrack from cement line, the length of the microcrack. The numerical results suggest that when the osteon is softer than the interstitial bone the osteon prompts the microcrack propagation while the osteon is stiffer than the interstitial bone the osteon repels microcrack propagation. However, this interaction effect is limited near the osteon. Some of the numerical results are in accordance with the results obtained. And additional predicted numerical results are given, which need to be confirmed via experiment or computer simulation.