Numerical approach to simulate the mechanical behavior of biodegradable structures considering degradation time and heterogeneous stress field

Abstract

AbstractBiodegradable polymers are widely used to manufacture biodegradable devices, such as those used in regenerative medicine. In many cases, nonuniform degradation can arise from nonuniform stress fields. The developed numerical methodology can simulate the mechanical behavior of three‐dimensional structures subjected to loads during degradation after a given degradation time, thus providing a valuable tool for pre validation of biodegradable devices. Degradation rate was assumed as linear function of the local von Mises stress. Material model parameters change as degradation proceeds and hydrolytic damage increases. Hence, shear modulus of the neo‐Hookean constitutive model was assumed as linear function of hydrolytic damage. The methodology was developed in a finite elements' framework using ABAQUS/Standard. The local hydrolytic damage and the consequent shear modulus evolutions were calculated by means of a user material subroutine. The stress field affects locally the kinetics of degradation and the evolution of hydrolytic damage. Thus, local hydrolytic damage and the material parameter are updated at each time step to recalculate stress and strain fields at the inputted degradation time. The aim of this work was to allow the simulation of biodegradable devices subjected to both mechanical and chemical environments.