Type

Conference Proceedings

Authors

Michael D. Gilchrist
Michel Destrade

Subjects

Psychiatry

Topics
finite element viscoelastic properties brain tissue brain tension mechanical properties traumatic brain injury tbi biological tissues

Hyperelastic and viscoelastic properties of brain tissue in tension (2012)

Abstract Mechanical characterization of brain tissue at high loading velocities is particularly important for modelling Traumatic Brain Injury (TBI). During severe impact conditions, brain tissue experiences a mixture of compression, tension and shear. Diffuse axonal injury (DAI) occurs in animals and humans when the strains and strain rates exceed 10% and 10/s, respectively. Knowing the mechanical properties of brain tissue at these strains and strain rates is thus of particular importance, as they can be used in finite element simulations to predict the occurrence of brain injuries under different impact conditions.  In this research, uniaxial tensile tests at strain rates of 30, 60 and 90/s up to 30% strain and stress relaxation tests in tension at various strain magnitudes (10% - 60%) with an average rise time of 24 ms were performed. The brain tissue showed a stiffer response with increasing strain rates, showing that hyperelastic models are not adequate and that viscoelastic models are required. Specifically, the tensile engineering stress at 30% strain was 3.1 ± 0.49 kPa, 4.3 ± 0.86 kPa, 6.5 ± 0.76 kPa (mean ± SD) at strain rates of 30, 60 and 90/s, respectively. The Prony parameters were estimated from the relaxation data. Numerical simulations were performed using a one-term Ogden model to analyze hyperelastic and viscoelastic behavior of brain tissue up to 30% strain. The material parameters obtained in this study will help to develop biofidelic human brain finite element models, which subsequently can be used to predict brain injuries under impact conditions. 
Collections Ireland -> National University of Ireland Galway -> Mathematics
Ireland -> National University of Ireland Galway -> School of Mathematics, Statistics and Applied Mathematics
Ireland -> National University of Ireland Galway -> Mathematics (Conference Papers)
Ireland -> National University of Ireland Galway -> College of Science

Full list of authors on original publication

Michael D. Gilchrist, Michel Destrade

Experts in our system

1
M. D. Gilchrist
University College Dublin
Total Publications: 172
 
2
Michel Destrade
National University of Ireland Galway
Total Publications: 106