Effects of a pore size and a pore location on the stress at the crack tip of fatigue bone specimen during one cycle- Finite element Simulation

摘要

The structure of bone cement is porous on both the macroscopic and microscopic scales. Thus, there are two types of pores in fully polymerized cement: macropores (pore diameter >1 mm) and micro pores (pore diameter≈0.1-1 mm). Pores would act as stress risers and crack nucleation sites for micro cracks, leading to early cement failure. However, they may also act as crack decelerators. Thereby, prolonging the life of the implant. In this study, a computational method based on the procedure described in the ASTM-E-647-05, was used to investigate the effects of a pore size and a pore location on the stress at the crack tip of fatigue bone specimen during one cycle. Pores exerted an effect when located in the neighbourhood of the crack tip. They may increase or decrease the stress at the crack tip, thus accelerating or decelerating the crack propagation.