2019 Volume 4 Pages 141-146
Bone fracture injury frequently occurs in various accidents. During an accident, bone may be subjected to a single load or combination of multiple loads, e.g. tension, compression and shear. In this study, we conducted tension, compression and shear tests on bone tissue specimens in order to obtain the mechanical and failure characteristics of cortical bone tissue. Bone specimens were obtained from bovine femur. Haversian bone part of the femur was utilized to manufacture three kinds of specimens for tested in tension, compression and shear tests. The tests were conducted using a table-top universal testing machine equipped with custom-made jigs under a displacement rate of 1 mm/min. From the test result, load-displacement curves and stress-strain curves could be derived. Variations in the curves were confirmed. There were also notable differences in the elastic moduli and failure points. The failure strength of bone tissue was considered to be dependent on the loading modes. Collagen fiber was considered to have a strong resistance against tension, whereas hydroxyapatite was considered to have a strong resistance against compression. In addition, the direction of load against femoral axis was also found to have influences on the elastic modulus and failure point. The orientation of collagen fibers in the specimens was considered to be a factor that caused the differences.