Deterministic material-based averaging theory model of collagen gel micromechanics

Area of Science:

• Biomechanics
• Materials Science
• Computational Modeling

Background:

• Tissue mechanics are governed by microscale events, posing challenges for macroscopic models.
• Existing models struggle to integrate deterministic micromechanics into continuous macroscopic simulations.
• Collagen gels exhibit complex mechanical properties influenced by fibril structure.

Purpose of the Study:

• To develop and validate an averaging-theory-based multiscale modeling framework for collagen gels.
• To incorporate micromechanical behavior into a macroscopic finite-element model.
• To simulate experimental data and an idealized wound model.

Main Methods:

• Developed an averaging-theory-based framework with micromechanical analysis at each integration point.
• Modeled collagen gel microstructure as a network of nonlinear springs in a 2D finite-element model.
• Simulated uniaxial extension experiments and an idealized wound model.

Main Results:

• The multiscale model successfully captured qualitative features of collagen gel experiments, including toe regions and fibril realignment.
• Simulations of an idealized wound model showed reduced axial strains in the wound region and rotation due to fibril alignment.
• The framework demonstrated generality, adaptable to various microstructural models.

Conclusions:

• The developed multiscale framework effectively bridges the gap between microscale and macroscale mechanics in collagen gels.
• The model provides a robust tool for simulating collagen gel behavior and understanding tissue mechanics in wound healing.
• The general nature of the framework allows for its application with diverse microstructural models for advanced simulations.