Material property influences on the modelling of child brain injuries

Abstract

Finite element simulations of a human head are often used to enhance our knowledge of injury mechanisms, assist in injury prediction and to develop preventative devices such as helmets and seatbelts. While many adult models have been developed and validated, few child models have been developed due to a lack of material data and experimental studies of which to validate the model. Therefore, many child head injuries are investigated via dimensionally scaled adult head models without the replacement of the adult material properties by the child material properties. This study aims to evaluate whether applying the child material properties to a dimensionally scaled adult head significantly influences the predicted risk of brain injury of a child head due to impact accidents. The adult model of Horgan & Gilchrist (2003) was scaled to the size of a 6-month old child’s head and then this model was compared to the one with child material properties appended. Frontal, lateral and occipital impacts were simulated, and the use of the child material properties was found to decrease the peak von Mises stress in the brain by up to 58.2%. Applying this result to the University Louis Pasteur criterion (Marjoux et al, 2008) yielded a maximum decrease of 90% in the relative risks of severe brain injury. Therefore, when analysing child brain injuries with a scaled adult model, the child material properties should be applied in order to more accurately predict the extent of brain injury. Our further numerical study explored the sensitivity of the skull and brain material properties on head injuries. The results showed that the impact force is mainly affected by the skull material properties and the brain material properties have negligible influence on the impact force. However, the maximum von Mises stress in the brain is mainly affected by the brain material properties.

Keywords:

• Brain injury
• finite element modeling
• injury biomechanics

Additional information

Notes on contributors

W Yan

Dr Wenyi Yan is a senior lecturer with Department of Mechanical and Aerospace Engineering at Monash University, Australia. He received his education in China and obtained his PhD from Tsinghua University, Beijing, in 1995. After that, he spent over five years as a research fellow in Europe, including over three years at University of Leoben, Austria, and two years at Imperial College London, UK. Wenyi moved to Australia at the end of 2000. He first worked as a research fellow at the University of Sydney and then lectured at University of Southern Queensland and Deakin University. Wenyi joined Monash University as a senior lecturer in 2007. He is interested in the research of deformation and failure of materials and structures. He has been working on different projects related to biomechanics, mechanical behaviours of functional materials and biomaterials, numerical modelling, fracture and fatigue, contact mechanics and wear. He has published about 60 journal papers from his research.

R Fittock

Robert John Fittock is a Project Engineer for Northern Victoria Irrigation Renewal Project (NVIRP) based in Shepparton. NVIRP is responsible for planning, designing and delivering Australia’s largest irrigation modernisation project, which involves upgrading infrastructure the Goulburn Murray Irrigation District, Australia’s most extensive irrigation network. Robert assists in the capital works delivery of the Connections Program and Strategic Connections Projects which involve reconnecting irrigators to a modernised main system of irrigation channels or “backbone”. This is both a capital works infrastructure project as well as a regional development project which will secure Victoria’s food bowl for the next 50 years. Robert graduated from Monash University in 2008 with a Bachelor of Science and a Bachelor of Engineering (with Honours) in the field of Mechanical Engineering. Majoring in Applied Mathematics and having an interest in many engineering aspects, Robert continues to expand his practical experience through diverse roles and training opportunities in both Civil and Mechanical Engineering disciplines. While not currently working within a research field, Robert is keen to pursue future research opportunities after gaining practical working experience in the field. His research interests include renewable and sustainable energy and water projects, fracture mechanics, and biomechanical engineering.