Hyper-elastic modelling of intervertebral disc polyurethane implant

Area of Science:

• Biomedical engineering
• Materials science
• Biomechanics

Background:

• Polyurethane nanocomposites are increasingly used in biomedical applications.
• Lumbar intervertebral disc prostheses require advanced materials for improved functionality.
• Understanding material behavior is crucial for designing effective prostheses.

Purpose of the Study:

• To develop a constitutive equation for a hyper-elastic polyurethane nanocomposite.
• To model the material's behavior for lumbar intervertebral disc prosthesis applications.
• To validate the constitutive model using finite element analysis.

Main Methods:

• Formulation of a constitutive equation using mathematical models.
• Consideration of four hyper-elastic potential functions: Ogden, Neo-Hookean, Yeoh, and Mooney-Rivlin.
• Calibration of hyper-elastic constants based on monotonic compression tests.
• Validation of the constitutive model through finite element (FE) analysis.

Main Results:

• A hyper-elastic constitutive model was successfully created for the polyurethane nanocomposite.
• The optimal hyper-elastic model and its constants were identified through experimental testing.
• FE analysis confirmed the validity of the developed constitutive model.

Conclusions:

• The developed constitutive equation accurately represents the hyper-elastic behavior of the polyurethane nanocomposite.
• The validated model is suitable for simulating the performance of lumbar intervertebral disc prostheses.
• Further research will focus on refining the constitutive equation and its application in advanced computer simulations.