Event

Welcome to join Erik Brynskog’s dissertation with the title “Advancing Pelvis Computational Models for Automotive Safety Assessment”!

Erik is a Doctoral student at the Division of Vehicle Safety at the Department of Mechanics and Maritime Sciences at Chalmers University of technology. Erik Brynskog is a PhD student at the Injury Prevention Group within the Division of Vehicle Safety. Erik’s research is focused on human body computational modelling to enable injury predictions from car crashes. The research is mainly carried out using computer simulations with vehicle and human body models where the models are calibrated and validated towards experimental data. The goal of the research is to produce human body models which can predict the effect of new countermeasures, in terms of saved lives/reduced harm, before the system is on the market. Erik has been working in various SAFER HBM projects, e.g. Future Occupant Safety for Crashes in Cars (OSCCAR).

Opponent will be Senior Scientist Bronislaw Gepner, Center for Applied Biomechanics at University of Virginia in Charlottesville, USA. 

Examiner is Professor Robert Thomson, Department of Mechanics and Maritime Sciences, Chalmers University.

Supervisors are Johan Davidsson, Johan Iraeus and Bengt Pipkorn. 

For online participation -use the online here with password: Hc72nm6g

Link to the thesis here.

Abstract

The pelvis is a key load bearer in vehicle safety due to its relatively high load tolerance and shape, which is utilized to control occupant kinematics in accidents by engaging with vehicle restraint systems. However, epidemiological studies have shown that the pelvis is also a highly exposed structure, as pelvic fractures are common outcomes due to interactions with the vehicle interior and restraint systems during a crash. Furthermore, fracture risk is not equally distributed over the population and vulnerable sub-populations have been identified depending on the load scenario. In addition, future autonomous vehicles are expected to allow for a more relaxed occupant posture by reclining the seatback, which increases the risk, in frontal impacts, of the pelvis sliding under the lap belt, i.e. submarining. Together, this motivates a deeper understanding of the potential of the pelvis as a load bearing structure as well as its interaction with the vehicle restraint systems across the entire population, in various crash scenarios.

While vehicle manufacturers try to minimize variability in product development, human individual variability is an intrinsic property that must be considered to capture the vulnerable population and maximize the efficiency of vehicle safety systems. Finite element human body models (FE-HBMs) are the most advanced tool available to use in the virtual design of restraint systems and provide the opportunity to include both geometrical and material variability through population based models and assessments.

In this thesis, methods enabling inclusion of population variance in FE-HBMs were implemented for the pelvis. Key findings include that sex, age, stature, and BMI, only cover a limited part of the population variance in pelvic shape, which is relevant for state-of-the-art FE-HBM development, population based simulation studies, and post-mortem human subject (PMHS) experiments. In addition, pelvic shape was shown to be an influential factor for both pelvis response in side impacts and belt-to-pelvis interaction in frontal impacts, which warrants consideration in future safety assessments. 

To conclude, this thesis advances the field of pelvis computational models for automotive safety assessment and enables a population based evaluation for future vehicle safety systems, which can result in more robust systems, reducing the risk of injuries in real-life accidents.

Welcome!