Micro finite element analysis of vertebrae using zero-thickness cohesive elements represents post-failure fracture...

Area of Science:

• Biomechanics
• Materials Science
• Computational Modeling

Background:

• Bone tissue failure involves damage and fracture, impacting mobility and requiring interventions.
• Micro finite element (μFE) modeling is a key tool for analyzing bone mechanical properties.
• Existing μFE models use various mechanics approaches to simulate bone damage and fracture.

Purpose of the Study:

• To combine continuum damage mechanics with cohesive zone modeling for simulating bone damage and fracture.
• To model damage initiation, crack formation, and fracture propagation in rodent vertebrae.
• To validate computational predictions against experimental observations.

Main Methods:

• Generated voxel-based μFE models from micro computed tomography (μCT) scans of rat vertebrae.
• Applied axial compressive loading to failure using a μCT-compatible device.
• Integrated cohesive elements with continuum damage mechanics to simulate damage and fracture propagation.

Main Results:

• Computational models accurately predicted damage site locations and fracture patterns observed in μCT images.
• The combined modeling approach successfully simulated damage initiation and crack propagation.
• Validated the ability to model post-failure behavior, including contact between fractured bone trabeculae.

Conclusions:

• The integrated continuum damage mechanics and cohesive zone modeling approach effectively simulates vertebral bone failure.
• This method allows for detailed analysis of damage initiation, fracture propagation, and post-failure mechanics.
• The approach provides valuable insights into the biomechanics of bone fracture, despite computational demands.