Analysis of the effect of mechanical properties on stress induced in tibia

Abstract

In this research, a 3D model of tibia was created with the exact geometry of the real bone by using spiral scan images of the human left leg. It was materialized by MIMIX and devel-oped in ABAQUS software by considering other in-vivo condi-tions, and also by loading a transversal impact which repre-sents the collision of a vehicle and pedestrian. Three different mechanical properties, i.e. elastic isotropic; elastic but trans-aversely isotropic; and finally viscoelastic were considered for the bone tissue to see and compare its behavior under the impact. Results showed that the stresses were at the same level as the ultimate stress of long bones. Interestingly, the maximum stress resulted from the impact loading, was seen in the viscoe-lastic model of tibia and the minimum was found to be when an elastic and transversely isotropic material property was considered. Moreover, because of the viscoelastic property of tibia, it has the capability to differ the rate of fracture propa-gation and also there will be an increase in the amount of stress as time goes on during the impact cycle but once loading period is over, stress relaxation was observed in which stress decreased. This was verified by checking the amounts of stress for each increment of the impact cycle. The maximum stress was seen in the last increment of the impact cycle when tibia's viscoelasticity was taken into account, while for the purely elastic, it happened when the maximum load was applied. © 2011 Springer-Verlag.