Finite element human body models, comprising detailed anatomical descriptions, can complement anthropomorphic test devices (ATDs) in the development of new restraint systems. Human body models (HBMs) can evaluate injury on tissue level, i.e. rib strain can be used to evaluate the risk of rib fracture, although the HBM must accurately predict the rib strain distribution to be effective. Current HBMs are not validated for rib strain, and it remains unknown if any represent an average-shaped ribcage. Thus, a new generic ribcage was created, representing an average male, based on a combination of averaged geometrical and material data from in-vivo and in-vitro datasets. The ribcage was incorporated into the THUMS AM50 Version 3, resulting in the SAFER HBM Version 9. Validation of ribcage kinetic, kinematics and strain distribution was carried out at three levels of complexity: anterior-posterior rib bending tests; rigid impactor table-top test; and a 40 km/h frontal sled test. The rib strains in the single rib load case were predicted within ± one standard deviation for 91% of the measuring points. The biofidelity for the rib strains in the table-top and sled test load cases was deemed ‘fair’ using CORA analysis. This study is an important step in the development and validation process of strain-based rib fracture criteria for HBMs.
Keywords: Finite element; Human body model; Ribcage; Strain; Validation