Bone

Why it matters

The aim of the thesis is to study and implement a constitutive model for cortical bone that describes its mechanical behaviour through orthotropic elasticity, viscoplasticity and damage under small strains. Such a model stems from the need to overcome the simplifications of traditional models and to provide a more complete representation of the mechanical response of bone tissue. It will become a numerical tool to simulate bone behaviour more realistically and to support FEM applications under physiological and pathological loading conditions.

What you'll do

• Constitutive model implementation: the model will be implemented in MATLAB and FORTRAN, and its response will be checked against representative test cases (assessing its behaviour under controlled loading conditions).
• FEM implementation: integration of the numerical model into a UMAT subroutine for use in Abaqus.
• Sensitivity analysis: assessment of how the main constitutive parameters affect the mechanical response of the model, focusing on those related to viscosity, yielding and damage.
• Verification in a FEM environment: assessment of the model's behaviour inside finite element software (Abaqus), checking its numerical stability and its ability to reproduce the mechanical response of bone tissue under different loading conditions.

Prerequisites

• Basic knowledge of FEM simulations — you need the fundamentals, the model is built during the thesis.
• Basic programming skills.

Tools

• MATLAB, for the formulation, preliminary implementation and first tests of the constitutive model.
• FORTRAN, for the final implementation of the model in the UMAT subroutine.
• Abaqus, to integrate the UMAT, run the FEM simulations and analyse the results.

Supervisor

Prof. Gianluca Mazzucco · gianluca.mazzucco@unipd.it