Eventos Anais de eventos
MecSol 2017
6th International Symposium on Solid Mechanics
A VARIATIONAL CONSTITUTIVE MODEL FOR THE VISCOELASTIC BEHAVIOR OF BIOLOGICAL MATERIALS UNDER AFM INDENTATION TESTS
Submission Author:
Thiago André Carniel , SC
Co-Authors:
Eduardo Fancello
Presenter: Thiago André Carniel
doi://10.26678/ABCM.MecSol2017.MSL17-0056
Abstract
Withstanding mechanical loadings is the primary function of many biological tissues, such as tendons, ligaments and cartilage. In these tissues, the mechanical responses to external loadings are highly dependent on its hierarchical microstructure, cellular organization and interactions between one another. In this context, each material phase plays a remarkable role in the biomechanical behavior. On its hierarchies inside the tissue, the microstructural materials are subjected to a complex mechanical environment, holding particular nonlinear behaviors, including viscoelastic effects. Several measurement techniques have been employed to assess the micromechanical response of biological structures, such as micropipette aspiration, magnetic and optical tweezers and atomic force microscopy (AFM) indentation, also known as nanoindentation test. Among these experimental methods, the later provides a convenient structure to finite element simulations. With these motivations in mind and aiming at numerical multiscale investigations of fibrous soft tissues, the present work proposes a finite strain phenomenological model for modeling the viscoelastic behavior of biological materials in conjunction with finite element simulations of AFM indentation tests. Concerning the material modeling, the proposed model is formulated in a thermodynamically consistent framework based on a constitutive variational approach. A couple of numerical results are shown to demonstrate the particularities of the model. Finally, the finite element simulation procedures developed in this study, seem to provide a suitable numerical tool for a better understanding of stiffness and energetic dissipation of viscoelastic materials under nanoindentation experiments.
Keywords
Variational constitutive updates, Finite viscoelasticity, AFM indentation, Biological materials
