Publication

A child dies in road traffic crashes every fourth minute. Totally were 186 300 children under the age of 18 killed in vehicle accidents in 2012, even more were severely injured [1]. The World Health Organisation (WHO) could conclude that fatalities in traffic accidents are more likely to occur in low- to middle income countries compared to high income countries [1]. Finite element based human body models has enabled the increased understanding of kinematics and injury mechanisms of child occupants. These models sustain higher biofidelity than the previously used crash test dummies. The European project PIPER [6] had the aim to develop a model that, combined with a framework, would simplify positioning and also to offer a scalable HBM child model. The PIPER framework software and the scalable PIPER model offers child HBM:s within the ages 1.5-6-years old and is an useful tool for the analysis of child occupants. 

The present study evaluates the kinematics and dummy responses of the 4- and 6-year old PIPER model evaluated. The objective of this master thesis is to evaluate the PIPER model with respect to its sensitivity to seat belt geometries, child restraint system, load cases and child anthropometrics. The aim of the master thesis is to get an increased comprehension of the PIPER model and its capability to evaluate occupant kinematics relevant for safety developments, with a special focus on seat belt geometry and interaction in frontal impacts.

The PIPER model showed good sensitivity to different seatbelt geometries regarding the abdominal part of the shoulder belt and to different CRS. The PIPER framework was perceived as hard to use and with the presence of errors. The kinematic response showed good accuracy compared to other previous studies with other crash test dummies however, reoccurring error termination could not be neglectable. 

The PIPER model is limited to its ease to positioning in desired sitting postures within the PIPER framework. It is regardless of its disadvantages believed to be a suitable tool to further understand occupant kinematics, as for different belt routings, child anthropometrics and dummy responses are further studies needed to validate the outputs that the model offers and to conclude its robustness in crashworthiness tests.