The Finite Element Modeling And Collision Response Analysis Of6Years OLD Children Abdomen

According to the date provided by the National Highway Traffic Safety Administration, about18500children died in the traffic accidents every year in China, while only76children died in the car in Germany. In our country, the rate of fatality in Road Traffic Accident was2.6times as much as in the America and2.5times as much as in Europe. This factor was the main reason which caused children died who were under14years old. So we should pay more attention to study the damage mechanism of the children’s chest and abdomen in the collision. The abdomen of4-year-old child and over who used restraint belt in the car is the second most vulnerable part, and the head is the first. This is because the restraint belt in the car was prepared for adult rather than children. So the adult seat belt is too large to be fastened to the Child growing iliac. The belt was easy to slip from the hipbone to the abdomen and compressed the abdomen. The organs in the abdomen would be injured by the compression. Child cadaver experiments were rare because of the social ethics and the finite element model including detailed anatomical structure was used to study the damage mechanism of child in impact simulation internationally. So developing a6-year-old finite element model of detailed anatomical structure is important to study abdomen’s damage mechanism of child in this paper.In this study, all the work were based on real anatomy6-year-old children abdominal CT scan images, the abdominal geometric characteristic parameters were extracted by Mimics software, and initial geometric model was processed and divided the curved surface piece by the reverse engineering software Geomagic. The geometric models were meshed by TrueGrid and HyperMesh software. These meshes were optimized by TrueGrid and HyperMesh software. A complete abdominal model was constructed. The model includes bones, muscles and ligaments.The bones include lumbar (L1-L5) and disc. Abdominal muscle includes erector, obliquus externus abdomins, obliquus internus abdominis, transverses abdominis, rectus abdominis, diaphraqm quadratus lumborum and psoas major. Organs include liver, kidneys, stomach and spleen. The model consists of165609elements and196185nodes.(The ligaments, diaphragm, abdomins and stomach were definited by shell elements. The other tissues were definited eight-nodded six-polyhedron solid elements.) These different tissues were simulated by Elastic material, Elastic-Plastic material and linear viscoelastic material. The model of various tissues are connected with each other through the common node method and definition of contact. Based on this model, we have done some impact tests by LS-DYNA. These experiments included the analysis of load transfer by the articular surface between L4-L5and side abdominal impact tests. The results of experiments was nearly the same as the cadaver impact test. But there was some different between child and adult in the first experiment. The load transfer by the child articular surface was smaller than the adult. This result showed that the rate of the lumbago in the children is much low than the adult.To sum up, this study constructed the finite element model of6-year-old children abdomen, and provided a reliable theoretical basis for injury mechanism research of children abdomen and laid the foundation for promoting China automobile child safety regulations.