A Study Of Knee Joint Injury Mechanism Of Automobile Passenger Base On Finite Element Method

As the development of automotive industry, there has been an increasing focus on vehicle safety. Although current restraint systems greatly reduce the risk of occupant injury, protection offered by these systems is not very effective for lower limbs as compared to that offered for the head and chest. Although injuries to the lower extremity are seldom fatal as in the case of head injury, they can result in long-term disability and impairment. The development of finite element technology greatly promotes the brain injury research.In order to further improve the finite element model of biological simulation, this study will increase in soft tissue model based on the model of the skeletal. The soft tissue model in strict accordance with the anatomical structure extraction and divided, including a total of 23 muscle as well as fat. The muscles use solid elements connected into a whole, Tendon use the methods of element transition to simulation, and complete the skin mesh division. A 50th percentile Chinese female lower limb finite element model was developed.This study is based on the lower limb bones finite element model. By improving an existed FE model of lower limb, a new knee joint FE model was developed. A validated strain rate dependent plastic material was used to describe ligament. Based on the properties of Chinese ligament, the ligament thickness was redefined. The model was impacted in anterior-posterior direction. When knee joint positioning in bending at 90°, the knee joint injury was then studied by loading in different height and in different angle. The result show that femoral fracture would be avoided when the loading of axial is less than 8kN; the PCL was not likely to be ruptured when loading angle was greater than 8°.The complete finite element model of the lower limbs was used to simulate different eversion angle of the knee injury in the real automotive environment. With the increase in the eversion angle, the femoral axial force peak gradually decreases.Not found knee injury at 95°,mainly due to the striker perpendicular to impact the axis of the femur. Impact force received will be dispersed to the femoral condyle by the pad.When the angle at 90°,100° and 105°, the increasing pressure will cause fracture of the patella and femoral condyles.This study used a new method to complete soft tissue model and a significant exploration to improve the simulation of the human finite element model. To explore the different conditions under knee injury, this work has significantly practical meaning to better understand the mechanism of lower limbs injury.