Thoracic response of the Chinese human body model in 50th percentile male size (CHUBM-M50) in blunt impacts - investigation in speed, direction and location

摘要

Thoracic injury is one of the leading causes of fatalities from automotive collisions. This paper integrated the features and conditions into numerical finite element analysis on thoracic mechanical responses with CHUBM-M50, to realise peak force, maximum compression, viscous criterion (VCmax), effective stiffness (EF) and rib fractures of the thorax, under various blunt loadings of impact speeds, locations and directions. The model was validated by test simulations via the cadaver pendulum tests. A total of 30 cases designed by two vertical alignments x five directions x three speeds were carried out. Additionally, t-test was performed in order to identify the correlation of impact direction and location. It indicated that the thoracic characteristics had significant correlation with impact location, and the mechanical responses at midsternal level were much stiffer than those at xiphoid process. It also demonstrated that the impact at xiphoid process causes more severe injuries even at low speed. The thoracic response pattern was similar between left and right side impact, which showed that the symmetrical characteristic in spite of asymmetric anatomical features of viscera. This study also figured out that the lateral EF was significantly higher than the oblique. The ribs tended to fracture most in the connection with costal cartilage in oblique impacts while the ribs were broken laterally in the costal angle position.