RESUMO
BACKGROUND: Cortical bone crack caused by accident or other external factors is one of the main causes of fracture, so the mechanism of crack formation and propagation for cortical bone under different loads should be understood primarily to avoid fracture. Bone specimens may be destructed in experiments, which can lead to a difficulty to observe the interior mechanical state of bone structure before and after fracture. Therefore, it is important to find a finite element method that can accurately simulate the processes of cortical bone crack formation, propagation, and fracture. Current simulations mainly use the principal strain or the equivalent strain to determine the mechanical state of the element in the finite element model and to perform fracture simulation, but there are few studies on the simulation accuracy when using these two types of strains. OBJECTIVE: To testify the simulation accuracy of cortical bone fracture with the principal strain and the equivalent strain. METHODS: The principal strain and the equivalent strain were applied to perform the three-point bending simulation, and the simulation results were compared with the experimental results to determine which strain was more accurate. RESULTS AND CONCLUSION: (1) The failure time of the cortical bone simulated by the principal strain was significantly later than that obtained by the equivalent strain. (2) Compared with the experimental results, it was found that the simulation results obtained by equivalent strain were closer to the experimental results. (3) Therefore, simulating cortical bone crack and fracture using the equivalent strain is accurate.