Development And Validation Of Finite Element Models Of The Abdomen And Lumbar Spine Of Q6 Child Dummy

Child car crash dummy is an important tool for the research of the mechanism of child injury occurring in collision and the evaluation of vehicle protection for children. 2013, Economic Commission for Europe(ECE) began to mod ify the child safety regulations. Q series child was proposed to replace the P series child dummy in the new regulations. However, the finite element model of Q6 child dummy which is applied to the finite element simulation of car crash has not been released. It is significant to study the method of developing the finite element models of the components of Q6 child dummy.In this article, different child dummy series and the methods of developing child dummy were introduced firstly. The structural characteristics and main parameters of Q6 child dummy were also introduced. Considering of different parts of Q6 child dummy, methods of direct modeling, 3D laser scanning and CT scanning which are based on reverse engineering are applied to establish an accurate geometric model of Q6 child dummy. A new reverse method of displacement and equation was utilized to calculate the material densities of the key parts of Q6 child dummy.Based on Q6 child dummy geometric model, the detailed finite element mesh of the abdomen and lumbar spine was established. Appropriate material types and initial material parameters of the FE model were selected with reference to the published finite element models of child dummy. An inverse method which is based on optimization and utilizing of finite element simulation and designed ex periment is adopted to acquire accurate material parameters. The compression test of Q6 dummy’s abdomen was taken to obtain the target curve in the optimization. Meanwhile the finite element simulation model which simulates the abdomen compression test was established. Optimization variables were selected through sensitivity analysis by software LS-OPT. After optimization,the material parameters were acquired by using the curve matching method based on the vertical coordinate and the Hybrid Genetic Algorithm. Finally, the FE model which simulates the calibration test of Q6 child dummy’s abdomen was established. The results show that the finite element model of abdomen meet the calibration requirements and validate the effectiveness the of abdomen finite elem ent model of Q6 child dummy.For developing the finite element model of the lumbar spine of Q6 child dummy, a simulation model was established to simulate the forward calibration test of the lumbar spine. Compared with the known experimental curves, the re liability of the initial material parameters and material types of the lumbar spine was preliminarily verified. Optimization of the key material parameters of the lumbar spine was taken by the same inverse method for material parameters. After the optimiza tion, the finite element model of the lumbar spine fully meet s the calibration requirements. It verified the effectiveness of the finite element model of the lumbar spine of Q6 child dummy.