STUDIES ON RAMBERG-OSGOOD EQUATION PARAMETERS OF CORTICAL BONE.

Bone is a complex material that exhibits an amount of plasticity before bone fracture takes place, where the non-linear relationship between stress and strain is of importance to understanding the mechanism behind the fracture. This brief presents our study on the examination of the stress-stain 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 non-linear 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).