The predictive capacity of the MADYMO ellipsoid pedestrian model for pedestrian ground contact kinematics and injury evaluation

Shi Shang,Catherine Masson,Maxime Llari,Max Py,Quentin Ferrand,Pierre-Jean Arnoux,Ciaran Simms

doi:10.1016/j.aap.2020.105803

Abstract

Pedestrian injuries occur in both the primary vehicle contact and the subsequent ground contact. Currently, no ground contact countermeasures have been implemented and no pedestrian model has been validated for ground contact, though this is needed for developing future ground contact injury countermeasures. In this paper, we assess the predictive capacity of the MADYMO ellipsoid pedestrian model in reconstructing six recent pedestrian cadaver ground contact experiments. Whole-body kinematics as well as vehicle and ground contact related aHIC (approximate HIC) and BrIC scores were evaluated. Reasonable results were generally achieved for the timings of the principal collision events, and for the overall ground contact mechanisms. However, the resulting head injury predictions based on the ground contact HIC and BrIC scores showed limited capacity of the model to replicate individual experiments. Sensitivity studies showed substantial influences of the vehicle-pedestrian contact characteristic and certain initial pedestrian joint angles on the subsequent ground contact kinematics and injury predictions. Further work is needed to improve the predictive capacity of the MADYMO pedestrian model for ground contact injury predictions.

Highlights

The World Health Organization (WHO) estimates that more than 300,000 pedestrians have died in 2019 (WHO, 2020), based on its Global Status Report on Road Safety 2018 (WHO, 2018)
A recent analysis based on German real-world crash data (GIDAS) showed that 43 % of 1221 selected cases had injuries subjected to ground contact, demonstrating the importance of ground related pedestrian injuries and providing significant motivation for counter measures to prevent or moderate pedestrian injuries from ground con tact (Shang et al, 2018). (Shang et al, 2020) recently conducted six cadaver tests which recorded the whole process from vehicle contact until after the end of the ground contact
As vehicle contact has been previously validated (Coley et al, 2001; Serre et al, 2006) while there has been no previous attempt at validating the pedestrian model for ground contact, our emphasis here is on ground contact

Summary

Introduction

The World Health Organization (WHO) estimates that more than 300,000 pedestrians have died in 2019 (WHO, 2020), based on its Global Status Report on Road Safety 2018 (WHO, 2018). Pedestrian collisions usually involve a primary contact with the vehicle, followed by a secondary contact with the ground (Han et al, 2018; Shang, 2020). (Shang et al, 2020) recently conducted six cadaver tests which recorded the whole process from vehicle contact until after the end of the ground contact. They observed that peak linear accelerations in ground contact are generally higher than for the vehicle contact. They observed a high predicted risk of rotationally induced brain injury from ground contact, even for very low vehicle collision speeds

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