Study On Validation Method Of The 50 Percentile Chinese Lower Limb Finite Element Model Based On The Optimization

With the rapid development in the field of auto industry, pedestrian safety has become an important issue of domestic and foreign automotive safety research. Because the lower extremities first collision with the vehicle, lower limb injuries is very common in a car collision with pedestrian. Although lower limb injuries are not fatal, but the most likely to lead to long-term or permanent disability. Therefore, to explore the mechanism of lower extremity injury is important for the protection of the safety of pedestrians. Finite element can simulate the response of the lower extremities and car collision which simulate the stress and strain of human tissue accurately, it has become an effective way to study the damage mechanism of the human body. However, the existing finite element models are based on the Europe body, the response to the biomechanical between Chinese human and Europe is worth exploring. Therefore, we will build Chin ese 50 percentile lower limb geometry size using scaling method and optimization methods to carry out comprehensive model validation, for establishing finite element model of the Chinese body’s lower extremities.In order to obtain accurate lower limb geometry model, using computer tomography for skeleton, magnetic resonance imaging for soft tissue to obtain a clear picture of various parts of the lower extremities. Using medical image processing software Mimics, three-dimensional processing software Geomagic Studio and lower extremity anatomy for accurate geometric model of lower extremity. According to statistical data the lower limb model was scaled to Chinese 50 percentile body size.Using ANSYSY ICEM CFD and Hypermesh software to mesh high accuracy hexahedral of lower limb model and giving different material properties based on anatomical structure and mechanical properties of various parts of the lower extremities.Using scale method for literature data so that the biomechanical test data to meet Chinese 50 percentile body size.In order to fully verify the biofidelity of lower extremity finite element model, it was verificated though different ways in this test. In verify thigh and lower leg model.The material of the long bone cortical: elastic modulus, compressive stress-strain curve, failure strain and thigh, calf muscle bulk modulus is o ptimized using the optimization method, so that the proximal, middle, distal loading position of femur, tibia, fibula, lower leg and thigh dynamic simulation results, femur, tibia, fibula middle(A-P) and(L-M) quasi-static simulation results were in good agreement with the experimental results. In knee joint model validation, the material and failure of anterior cruciate ligament(ACL), posterior cruciate ligament(PCL), tibial collateral ligament(MCL), fibular collateral ligament(LCL), and knee four-point bending, three-point bending shear were optimized and validated. Finally, the whole lower limb model was validated.By optimizing method, the curves of simulation and experimental are fitting better, the peak time and results are in the range of the experiment. This indicates that the established finite element model of the lower extremities has higher precision and fidelity of the biological, it also can be used in lower limb biomechanical study.At the same time, it shows that the modeling and validation methods can effectively used in the finite element model of human development.