Human Body Model and Passive Safety of Vehicles: study of injuries on abdominal organs using the Peak Virtual Power method (PVP)

The Human Body Models (HBM) has opened a whole new world about the analysis of the injuries and the biomechanical results of car crashes. The level of details of these models together with the Finite Element Method (FEM), offer the possibility of getting closer to the real consequences of a car crash on the human body, in comparison with the traditional rigid dummies. The aim of this thesis work is to evaluate the “Abbreviated Injury Scale” levels (AIS, risk to life scale) of possible injuries happening to the abdominal organs of a rear passenger during a car crash using an innovative injury criterion: The Peak Virtual Power method (PVP), an energy-based engineering indicator, linearly proportional to the AIS, that applies to all body traumas and severities. In order to validate this method, an incident case from real life involving a vehicle impacting a rigid street furniture was simulated with FEM, reproducing the kinematics of the real accident. In this simulation, an accelerometer placed on the base of the C-pillar of the vehicle traced the X acceleration that was then applied to a sled model where the THUMS (Total Human Model for Safety) occupant was used, together with the seat assembly and front seat. From the sled model results on the abdominal organs under analysis, the virtual power was calculated. Through this data, the AIS 4 injury level curve was built on a plot with the PVP on the Y axis and the impact velocity on the X axis and scaled to obtain a full set of AIS corridors including the other AIS levels curves. The peak virtual power of the examined organs was then retrieved from the simulation conducted at the real case velocity and used to attain the AIS level of the injury according to the curves built before. This AIS level is finally compared with the one reported in the real-life accident report. According to the outcomes of this comparison, the PVP method shows great accuracy in the evaluation of the AIS level of traumas sustained during a vehicle impact.