Studies on the Stress-Strain Relationship Bovine Cortical Bone Based on Ramberg-Osgood Equation

Bone is a complex material that exhibits an amount of plasticity before bone fracture takes place, where the nonlinear relationship between stress and strain is of importance to understand the mechanism behind the fracture. This brief presents our study on the examination of the stress-strain relationship of bovine femoral cortical bone and the relationship representation by employing the Ramberg-Osgood (R-O) equation. Samples were taken and prepared from different locations (upper, middle, and lower) of bone diaphysis and were then subjected to the uniaxial tensile tests under longitudinal and transverse loading conditions, respectively. The stress-strain curves obtained from tests were analyzed via linear regression analysis based on the R-O equation. Our results illustrated that the R-O equation is appropriate to describe the nonlinear stress-strain behavior of cortical bone, while the values of equation parameters vary with the sample locations (upper, middle, and lower) and loading conditions (longitudinal and transverse).