Micromechanics and constitutive modeling of connective soft tissues

Fallah, A ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jmbbm.2015.12.029
  3. Publisher: Elsevier Ltd
  4. Abstract:
  5. In this paper, a micromechanical model for connective soft tissues based on the available histological evidences is developed. The proposed model constituents i.e. collagen fibers and ground matrix are considered as hyperelastic materials. The matrix material is assumed to be isotropic Neo-Hookean while the collagen fibers are considered to be transversely isotropic hyperelastic. In order to take into account the effects of tissue structure in lower scales on the macroscopic behavior of tissue, a strain energy density function (SEDF) is developed for collagen fibers based on tissue hierarchical structure. Macroscopic response and properties of tissue are obtained using the numerical homogenization method with the help of ABAQUS software. The periodic boundary conditions and the proposed constitutive models are implemented into ABAQUS using the DISP and the UMAT subroutines, respectively. The existence of the solution and stable material behavior of proposed constitutive model for collagen fibers are investigated based on the poly-convexity condition. Results of the presented micromechanics model for connective tissues are compared and validated with available experimental data. Effects of geometrical and material parameters variation at microscale on macroscopic mechanical behavior of tissues are investigated. The results show that decrease in collagen content of the connective tissues like the tendon due to diseases leads 20% more stretch than healthy tissue under the same load which can results in connective tissue malfunction and hypermobility in joints
  6. Keywords:
  7. Connective soft tissue ; Constitutive modeling ; Micromechanical model ; Periodic boundary condition ; ABAQUS ; Boundary conditions ; Composite micromechanics ; Constitutive models ; Fibers ; Histology ; Homogenization method ; Micromechanics ; Musculoskeletal system ; Numerical methods ; Strain energy ; Collagen fiber ; Hierarchical structures ; Numerical homogenization ; Strain energy density functions ; Transversely isotropic ; Tissue ; Collagen ; Elastomer ; Tropocollagen ; Anisotropy ; Article ; Biomechanics ; Cell density ; Comparative study ; Computer program ; Connective tissue ; Controlled study ; Elasticity ; Extracellular matrix ; Human ; Muscle mass ; Nonhuman ; Plasticity ; Priority journal ; Soft tissue ; Tendon ; Tension ; Tissue reaction ; Validation process
  8. Source: Journal of the Mechanical Behavior of Biomedical Materials ; Volume 60 , 2016 , Pages 157-176 ; 17516161 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S1751616115005032