Ferreira J P S, Parente M P L, Jabareen M, Jorge R M Natal
Faculdade de Engenharia da Universidade do Porto, Rua Dr Roberto Frias, 4200, Porto, Portugal.
Faculty of Civil and Environmental Engineering Technion - Israel Institute of Technology, Haifa, 32000, Israel.
Biomech Model Mechanobiol. 2017 Aug;16(4):1119-1140. doi: 10.1007/s10237-017-0875-9. Epub 2017 Jan 25.
The highly nonlinear mechanical behaviour of soft tissues solicited within the physiological range usually involves degradation of the material properties. Mechanically, having these biostructures undergoing such stretch patterns may bring about pathological conditions related to the steady deterioration of both collagen fibres and material's ground substance. Tissue and subject variability observed in the phenomenological mechanical characterisation of soft tissues often hinder the choice of the computational constitutive model. Therefore, this contribution brings forth a detailed overview of the constitutive implementation in a computational framework of anisotropic hyperelastic materials with damage. Surmounting the challenge posed by the mesh dependency pathology requires the incorporation of an integral-type non-local averaging, which seeks to include the effects of the microstructure in order to limit the localisation phenomena of the damage variables. By adopting this approach, one can make use of multiple developed material models available in the literature, a combination of those, or even propose new models within the same numerical framework. The numerical examples of three-dimensional displacement and force-driven boundary value problems highlight the possibility of using multiple material models within the same numerical framework. Particularities concerning the considered material models and the damage effect implications to represent the Mullins effect, induced anisotropy, hysteresis, and mesh dependency are discussed.
在生理范围内受载的软组织的高度非线性力学行为通常涉及材料特性的退化。从力学角度来看，使这些生物结构经历此类拉伸模式可能会导致与胶原纤维和材料基质持续退化相关的病理状况。在软组织的唯象力学表征中观察到的组织和个体差异常常阻碍计算本构模型的选择。因此，本文详细概述了具有损伤的各向异性超弹性材料在计算框架中的本构实现。克服网格依赖性病态带来的挑战需要纳入积分型非局部平均，其旨在纳入微观结构的影响以限制损伤变量的局部化现象。通过采用这种方法，可以利用文献中已有的多个已开发材料模型、它们的组合，甚至在同一数值框架内提出新模型。三维位移和力驱动边界值问题的数值示例突出了在同一数值框架内使用多个材料模型的可能性。讨论了所考虑材料模型的特殊性以及损伤效应对于表征穆林斯效应、诱导各向异性、滞后现象和网格依赖性的影响。
