Assessment of madymo active human body model kinematics and dynamics by means of human volunteer response at low-speed frontal impacts

Abstract

The aim of this study was to evaluate the capability of the Madymo active HBM to predict the human response by comparing the predictions from the model with the response from human volunteers in frontal-impact tests at 9kmh. The Madymo active HBM correspond to a 50th percentile male model population (standing height=176cm; weight=75.3kg) and the 13 volunteers were selected to have a similar anthropometry (standing height=173.0±4.3cm; weight=79.1±9.5kg). The influence of a number of important parameters on the Madymo active HBM predictions was evaluated. Those parameters were friction between model and seat pan, reaction time delay and level of co-contraction of neck muscles. The friction was varied between 0.15 and 0.5; the reaction time delay from 0ms to 100ms and the level of co-contraction of neck muscles between a null and full activation. The benchmark considered the displacements of the head, vertebra (C4, T1, T4, T8, T12) and hip, the belt loads, and the estimated upper neck loads in the sagittal plane. It was found that while variations in the RT and CCR levels could cause similar forward excursions, this could also result in an overprediction of the downward excursions; and therefore, the neck muscle controller optimization should always consider both. Two configurations could be implemented in the model to represent the large variation between the volunteers’ downward excursion, the first with the closest behaviour to the volunteers’ mean and the second closer to the volunteers which showed larger head excursion.