A fully nonlinear viscohyperelastic model for the brain tissue applicable to dynamic rates

Area of Science:

• Biomechanics
• Materials Science
• Neuroscience

Background:

• Understanding brain mechanical response to injury is vital for pathological condition investigation.
• High-rate loadings from accidents necessitate constitutive modeling for injury mechanism analysis and protective device design.

Purpose of the Study:

• To critically investigate the physical background of viscohyperelastic modeling for brain tissue.
• To develop a fully nonlinear multimode Maxwell model for large, time-dependent deformations.
• To provide a model calibratable with simple uniaxial tests, avoiding complex relaxation or creep experiments.

Main Methods:

• Critical investigation of physical principles for viscohyperelastic modeling.
• Development of a nonlinear multimode Maxwell model.
• Calibration using uniaxial deformation data.
• Validation against experimental results from two independent studies.

Main Results:

• A fully nonlinear multimode Maxwell model for brain tissue was developed.
• The model accurately describes large, time-dependent deformations.
• Calibration requires only simple uniaxial deformation data.
• Model performance showed desirable agreement with experimental data.

Conclusions:

• The proposed viscohyperelastic model offers a viable approach for simulating brain tissue mechanics under high-rate loading.
• The model's simplicity in calibration enhances its practical applicability in injury research and protective design.
• Further research should explore model limitations and potential future developments for broader applications.