Finite element 3D modeling of mechanical behavior of mineralized collagen microfibrils

TL;DR

This paper develops a 3D finite element model to analyze the nanomechanical behavior of mineralized collagen microfibrils, considering individual phase properties and cross-link effects, to predict overall mechanical properties.

Contribution

It introduces a homogenized 3D finite element model that accounts for phase-specific properties and cross-links to evaluate microfibril mechanics.

Findings

Young's modulus and Poisson's ratio depend on phase properties.

Model predicts microfibril behavior under tensile load.

Results align with experimental data.

Abstract

The aim of this work is to develop a 3D finite elements model to study the nanomechanical behaviour of mineralized collagen microfibrils, which consists of three phases, (i) collagen phase formed by five tropocollagen (TC) molecules linked together with cross links, (ii) a mineral phase (Hydroxyapatite) and (iii) impure mineral phase, and to investigate the important role of individual properties of every constituent. The mechanical and the geometrical properties (TC molecule diameter) of both tropocollagen and mineral were taken into consideration as well as cross-links, which was represented by spring elements with adjusted properties based on experimental data. In the present paper an equivalent homogenised model was developed to assess the whole microfibril mechanical properties (Young's modulus and Poisson's ratio) under varying mechanical properties of each phase. In this study both equivalent Young's modulus and Poisson's ratio which were expressed as functions of Young's modulus of each phase were obtained under tensile load with symmetric and periodic boundary conditions.