Uniaxial tensile tests were performed on standardised longitudinal specimens of bovine compact bone at strain rates from 5.3×10−4 to 237 s−1. After testing, the microstructure and dry density of each specimen was determined. The test results demonstrated highly significant (P<0·01) positive correlations between ultimate strength and strain rate, and between ultimate strength and density. A highly significant negative correlation between ultimate strength and the extent of secondary Haversian remodelling was also found. The modulus of elasticity showed similar correlations with the test parameters. A multiple linear-regression analysis was used to derive equations for the ultimate strength and modulus as functions of strain rate and microstructure. The regression analyses accounted for 86% of the variance in strength and 50% of the variance in modulus. The extent of secondary Haversian remodelling showed a significant (P<0·01) negative correlation with the energy-absorption capacity. Strain rate also had a significant effect on the energy-absorption capacity. Specimens tested at higher strain rates generally absorbed more energy during failure. There was no evidence of a critical velocity at which the energy absorption capacity attained a maximum. The test results correlate well with previous studies of the mechanical properties of compact bone.
Keywords:
Compact bone; Energy-absorption capacity; Microstructure; Modulus of elasticity; Nonelastic deformation; Strain rate; Ultimate tensile strength