A non-linear homogeneous model for bone-like materials under compressive load.

Area of Science:

• Biomaterials Science
• Computational Mechanics
• Materials Science

Background:

• Accurate finite element (FE) models of bone require detailed microstructural data, leading to high computational costs.
• Simulating non-linear behavior in bone is computationally intensive with current FE models.
• Linking local morphology to apparent mechanical behavior allows for coarser, more efficient FE models.

Purpose of the Study:

• To implement and validate a novel constitutive law for bone-like materials.
• To capture non-linear structural behavior and irreversible strains in FE models.
• To reduce computational expense in simulating the mechanical response of bone.

Main Methods:

• Developed a constitutive law based on anisotropic continuum damage theory and isotropic elastoplasticity within a finite strain framework.
• Incorporated fabric tensors to describe material anisotropy and an elastoplastic model with hardening for irreversible strains.
• Implemented the material model into non-linear FE software (metafor) and validated it against experimental compression data.

Main Results:

• The implemented constitutive law successfully captured the non-linear mechanical behavior of bone-like materials.
• Validation against experimental data for aluminum foams, polylactic acid foam, and deer antler cancellous bone showed good agreement.
• The model demonstrated the ability to predict irreversible strains and anisotropic responses.

Conclusions:

• The developed constitutive law provides an efficient and accurate method for simulating the non-linear mechanical response of bone-like materials.
• This approach enables the use of coarser finite element models, significantly reducing computational costs.
• The validated model has broad applicability in biomechanics and biomaterials research.