A transversely isotropic viscohyperelastic-damage model for the brain tissue with strain rate sensitivity

Area of Science:

• Biomechanics
• Computational Mechanics
• Neuroscience

Background:

• Understanding brain tissue mechanics is vital for traumatic brain injury (TBI) research.
• TBI involves high strain rates and large deformations, necessitating advanced constitutive models.
• Existing models may not fully capture the rate-dependent and damage behaviors of brain tissue.

Purpose of the Study:

• To develop a novel 3D large strain viscohyperelastic-damage model for brain tissue.
• To accurately reproduce experimentally observed rate-sensitive elastic and stress softening behaviors.
• To provide a tool for uncovering TBI mechanisms through improved mechanical characterization.

Main Methods:

• Development of a fully three-dimensional large strain viscohyperelastic-damage constitutive model.
• Parameter identification using experimental data from uniaxial tension, compression, and simple shear tests.
• Validation of the model by comparing its predictions against experimental data.

Main Results:

• The proposed model successfully reproduces rate-sensitive elastic behavior.
• The model captures damage-induced stress softening observed in brain tissue.
• Good agreement was achieved between the model's predictions and experimental results.

Conclusions:

• The developed model effectively characterizes the mechanical behavior of brain tissue under large deformations and high strain rates.
• The model's ability to incorporate rate dependence and damage effects offers significant potential for TBI research.
• This work provides a valuable computational tool for further investigation into the mechanisms of traumatic brain injury.