  Mechanical characterization of brain tissue has been investigated extensively
by various research groups over the past fifty years. These properties are
particularly important for modelling Traumatic Brain Injury (TBI). In this
research, we present the design and calibration of a High Rate Tension Device
(HRTD) capable of performing tests up to a maximum strain rate of 90/s. We use
experimental and numerical methods to investigate the effects of inhomogeneous
deformation of porcine brain tissue during tension at different specimen
thicknesses (4.0-14.0 mm), by performing tension tests at a strain rate of
30/s. One-term Ogden material parameters (mu = 4395.0 Pa, alpha = -2.8) were
derived by performing an inverse finite element analysis to model all
experimental data. A similar procedure was adopted to determine Young's modulus
(E= 11200 Pa) of the linear elastic regime. Based on this analysis, brain
specimens of aspect ratio (diameter/thickness) S < 1.0 are required to minimise
the effects of inhomogeneous deformation during tension tests.
