Past Event: Oden Institute Seminar

Analysis and Modeling of Inelasticity in Tendon: Viscoelasticity, Damage, and Plastic Deformation - Note Different Day/time and location

Babak Naghizadehsafa Safa, Elliott Lab, University of Delaware

Abstract

Tendons are soft connective tissues that connect the muscular system to the skeleton. Tendons are abundant in the human body and their primary function is to enable transmission of mechanical power. These tissues are prone to overuse and disease. To understand the relationships between tendon's function and disease, one needs to clearly understand the mechanical behaviors in a physiological context. Despite decades of studies on tendon, a comprehensive framework for studying tendon mechanics that addresses its inelastic mechanical response in relationship to its structure is missing. The objective of this research was to analyze and model the inelastic mechanical behaviors of tendon that are viscoelasticity, damage, and plastic deformation. We did that through four main aims: (1) developing a comprehensive and unifying modeling framework, reactive inelasticity (RIE), for modeling the major inelastic mechanical behaviors of tendon using kinetics of molecular bonds; (2) evaluating damage and plastic deformation as the potential mechanisms of tendon softening behavior during axial loading by using micro-mechanical experiments on tail tendon and RIE modeling; (3) evaluating the poroelastic parameters of tendon, particularly hydraulic permeability, using lateral osmotic loading and biphasic mixture finite element modeling; (4) visualizing and quantifying the 3D microstructure of tendon using serial block-face SEM (SBF-SEM), which showed several helical fibrillar structure, and providing a load-transfer model for interfibrillar load transfer. This study is innovative in comprehensively addressing the mechanisms of inelasticity in tendon by separately identifying and modeling inelastic behaviors, providing a unifying theoretical explanation for the underlying mechanisms, elucidating novel structure-mechanics relationships, and calculating the inelastic mechanical properties. The outcomes of this study provide a novel understanding of tendon mechanics and its relationships to tendon's multiscale structure. BIO Babak Naghizadehsafa Safa received his PhD from U. Delaware in 2019. He received his BS in Mechanical Engineering at Sharif University of Technology in Tehran, Iran. He has developed software, ReactiveBond,” An implementation of Reactive Inelasticity model for uniaxial deformations in Matlab (https://github.com/BabakNSafa/ReactiveBond). His current research interests include: Experimental Tissue Mechanics, Tissue Damage Mechanics, Multi-scale Mechanics, Collagen Mechanics, Theoretical and Computational Inelasticity Mixture Theory, and 3D Electron Microscopy.