Speaker
Description
Biological processes, e.g., growth, repair, and remodeling generate residual stresses that significantly alter the biomechanical response of biomedical materials. The present work develops the constitutive relations for residually stressed Arruda–Boyce materials through a numerical inverse analysis. The model is validated using Treloar’s uniaxial tension data, mapped to initially stressed reference states, and analytical solutions for boundary value problems. The developed model is implemented for finite element analysis through Abaqus using UMAT subroutine. This framework studies the buckling of residually stressed thick cylinders under external pressure. A significant influence of residual stress fields and the chain-stiffening parameter (N) is investigated on the onset of surface instabilities. Based on the distribution of the residual stress fields, circumferential wrinkles develop on the inner or outer surfaces. Increasing the chain-stiffening parameter reduces stability. We further investigate the post-buckling evolution of surface instabilities for smaller and larger values of N. Residual stress appears to interfere and influence the post-buckling evolution of instability modes, both driven by residual stress and external mechanical load. The same method can examine several pattern formation and biological materials under residual stress.
