A strain rate dependent model with decreasing Young’s Modulus for cortical human bone

Abstract

This research studies the dynamic behavior of human cortical bone specimens and investigates their mechanical properties using uniaxial tensile tests. The main experimental finding is that in the range of strain rate analyzed, there is a significant decrease in Young's modulus, which is not of viscoelastic origin. In fact, the observed behavior seems related to the findings of other researchers who observed that the microcraking damage depends on the strain rate in the same sense found in our work. This allows us to interpret the qualitative results as a consequence of the microcracking that takes place within the cortical bone, and not related to viscoelastic effects. A full and objective strain rate dependent model is proposed to explain the observed data.

In addition, a general discussion of some families of viscoelastic models is given and the caution with which they should be used when dealing with complex materials such as bone.