Phase-field simulation of crack growth in cortical bone microstructure: parameter identification and comparison...

Area of Science:

• Biomechanics
• Materials Science
• Computational Modeling

Background:

• Cortical bone's fracture resistance is influenced by its microstructure.
• Phase-field models are emerging tools for simulating bone fracture.
• Experimental validation and material parameters for microstructural tissues are currently lacking for these models.

Purpose of the Study:

• To calibrate material parameters for a 2D phase-field finite element model of bovine osteonal bone microstructure.
• To validate classical phase-field methods for simulating cortical bone fracture.
• To assess the predictive performance of phase-field models against experimental data.

Main Methods:

• A design-of-experiments methodology was used to calibrate material parameters.
• Simulations were compared to single-edge notched bending experiments on bovine bone.
• Crack paths were analyzed through imaging post-experimentation.

Main Results:

• Reasonable agreement was found between model predictions and experimental data for peak load, crack initiation toughness, and crack path.
• The model successfully predicted crack initiation and propagation in specific geometries.
• Classical phase-field models failed to capture the nonlinear force response and increasing toughness observed experimentally before visible crack extension.

Conclusions:

• This study provides the first validation of classical phase-field methods for cortical bone fracture simulation.
• While promising, current phase-field models have limitations in representing the gradual damage evolution and nonlinear behavior of bone.
• Future work should explore alternative formulations to overcome these limitations and improve predictive accuracy for bone fracture.