EXPERIMENTAL AND NUMERICAL FRACTURE TOUGHNESS OF HUMAN BONE IN LINEAR ELASTIC AND ELASTIC-PLASTIC FRACTURE MECHANICS IN VITRO

Abstract

In this search, study and investigate is done on the fracture toughness in linear elastic and elastic-plastic fracture mechanics LEFM and EPFM for each cadaveric bovine cortical bone and human cortical bone. Fresh and frozen human cadaveric cut as a compact tension CT specimen from the tibia for five males are prepared from the forensic medicine department ages (25, 31, 39, 45 and 51) years and (18) months for bovine cortical bone are examined, where no known skeletal pathologies. The crack length is measured without removed the specimen from the grips by using ZBL F101 technique. The experimental results are compared with numerical analysis by ABAQUS program. Roughness of fracture surface for each bovine and human specimen is examined by scanning electron microscope SEM. The appropriate method for cutting the bone has been studied. The results showed that the fracture toughness of bovine is greater than by 111% of human cortical bone and vice in the strain energy release rate for human is greater than by 124% of bovine cortical bone. So, the fracture toughness in elastic-plastic fracture mechanics showed that the for bovine is 108% greater than human cortical bone,but gets the opposite in crack tip opening displacement toughness where is larger in human approximately 106% as compared with bovine cortical bone. The numerical results are showed agree with experimental results. From this work, the elastic- plastic fracture toughness (and for human cortical bone is larger than the bovine cortical bone that due to prevent the catastrophic failure when exposed to loads. The fracture surface of bovine cortical bone specimens is rougher than the fracture surface of human bone specimens.The appropriate method for cutting the bone by using the hand saw.