Dynamic short crack growth in cortical bone

摘要: It is well known for almost half a century that bones contain microcracks. Very little about the crack growth behaviour of very small cracks, e.g. stage before they become macroscopically long. The aim this work was to investigate dynamic sub-millimetre microcracks in cortical bone. found slow stable occurs specimens subjected static loading conditions. Crack direction dominated by local fibre orientation bones. angles varied between 10 and 36 degrees long axis Short cracks were show periods rapid followed intervals temporary arrest. Histological analysis showed arrest occurred due vascular canals During these arrest, opening displacements increased until strain sufficient overcome features. These observations indicate mechanism bone at constant stress, involving microstructural barriers, time-dependent deformation material near tip strain-controlled propagation.