Nonlinear fiber-bundle-cells-based phenomenological modeling of human tissue samples.

Area of Science:

• Materials Science
• Biophysics
• Computational Mechanics

Background:

• Fiber bundles are key to the macroscale properties of fibrous materials.
• Previous models (FiberSpace) used linear elastic fibers, suitable for textiles but not biological tissues.
• Biological tissues are hierarchical structures requiring nonlinear fiber models.

Purpose of the Study:

• To develop a nonlinear Fiber Bundle Cell (FBC) model for simulating biological tissues.
• To enhance the FiberSpace software with nonlinear mechanical behavior.
• To analyze damage and failure mechanisms in fibrous biological structures.

Main Methods:

• Introduced nonlinear mechanical behavior for model fibers within FBCs.
• Derived mathematical formulas for tensile force calculations in nonlinear FBCs.
• Developed a new version of FiberSpace incorporating nonlinear FBCs for phenomenological modeling.

Main Results:

• The nonlinear FBC model decomposes stress-strain curves, providing insights into tissue structure and failure.
• A product-function series expansion of stress-strain curves offers alternative failure process descriptions.
• Fitted models generate damage and failure maps from tensile test data.

Conclusions:

• The nonlinear FBC-based modeling method is effective for analyzing fibrous biological tissues.
• The method provides detailed information on damage and failure sub-processes.
• Demonstrated applicability using tensile test data from human and animal tissues (nerves, tendons).