Publication

Motor Vehicle Crashes (MVC) are among the leading causes of deaths for children globally. Complementary to the fatality risk, traffic road accidents are responsible for an even larger number of severe pediatric injuries which can lead to permanent impairment. Actions towards reducing or preferably eliminating this problem are to improve the design, accessibility and regulations of child restraint systems as well as implementation of these in actual passenger vehicles. Computer Aided Engineering (CAE) has become an integrated part of the contemporary automotive industry, providing the opportunity to perform crash tests using a simulation platform as a complement to physical crash tests. Finite Element Human Body Models have the potential to become a powerful tool in the virtual assessment of injury tolerances, kinematic behavior and interaction with vehicle interior design. Although substantial efforts have been contributed to the development of male HBM:s, in particular in the 50th percentile size interval, child size models are receiving less attention. Hence, the Position and Personalize Advanced Human Body Models for Injury Prediction (PIPER) project aimed to provide an open source child HBM, scalable within the range of 1.5-6 years old as well as different percentiles within each age group. In addition a scaling and positioning tool, PIPER Framework, has been released to facilitate personizalisation of FE HBM:s. This Master's Thesis project has evaluated the sensitivity of the PIPER scalable child model by exposing the PIPER baseline model (6 year old, 50th percentile) to three different shoulder belt angles, achieved by altering the D-ring position in an LS-DYNA environment. These belt routing setups have been applied to three different cases which included a belt-positioning booster, a high-back booster and a rear seat only during frontal and frontal offset impact. Kinematic behaviour of the child HBM and the occurrence of undesirable belt performance such as sliding of the shoulder resulting in increased roll-out risk or neck-loading, has been the main evaluating feature. Head accelerations, de ection of sternum and global head injury criteria (HIC) have been estimated and additionally used for comparison between the different parameters. Conclusions were made that the PIPER scalable child model was able to capture different undesired belt interaction behaviours such as roll-out and submarining, although further evaluations are necessary. A visual comparison with data retrieved during the literature review supported the exible kinematic trajectories of the PIPER scalable child HBM when exposed to the high-severity crash pulses of the parametric study. In terms of injury criteria, the PIPER scalable child HBM appeared to overestimate HIC15 values, hence additional research concerning biofidelic injury thresholds for children is necessary.