Research On The Modeling And Impact Injury Of Obese Children Based On Mesh Morphing Method

With the development of vehicle safety technology and the increasing attention on the issue of child occupant safety,child occupant research on the injury prevention has been significantly improved.However,obese children are more vulnerable in the car crash compared with the general size of children.Unfortunately,the existing crash test dummies,human finite element models and other injury assessment tools are not considering obesity effects.Due to the improvement of living standards and modern medical technology,the research and development of the finite element model of obese children occupants has become an important subject to be solved in the field of vehicle safety.Impact injury of obese child was studied based on the 10-year-old child finite element model.Firstly,the effect of obesity on the risk of pediatric injury and existing pediatric occupant injury evaluation tools were studied.And the anatomy structures and common injury criteria of pediatric head,neck,chest and abdomen were analyzed.Due to the complexity of modeling process of finite element model when it was used to study the impact response for injury assessment,two kinds of mesh morphing techniques for human finite element modeling were developed.The accuracy and efficiency of this two methods were compared and analyzed by a head model.Then the obese child model was obtained by mesh morphing method.An obese child body surface model was acquired on the combination of pediatric anthropometric database and generator of body data(GEBOD)where simple obese anthropometric data were obtained by entering age,height and BMI.Obese child finite element model with good mesh quality was obtained by mapping the original base model according to nodal displacements between original body surface and obese body surface calculated using mesh morphing method.The model was validated based on the experimental data of sled test and chest-abdomen impact test.Finally,both of high-speed and low-speed sled simulations and injury analysis were conducted with the obese model and the original model.It was found that radial basis function mesh morphing method can quickly and effectively generate finite element model of obese children.Compared with normal child model,head and neck injury value of obese child increased.Increased stress and strain values of ribcage and internal organs caused the chest and abdomen to be more vulnerable and the risk of rib fractures increased.At the high-speed condition,the peak time of obese child model’s shoulder belt and lap belt force were significantly delayed than non-obese child model,and obese child model showed poor belt fit.