考虑生长与重构的生物软组织非局部损伤本构参数反演

IDENTIFICATION OF CONSTITUTIVE PARAMETER FOR NON-LOCAL DAMAGE OF BIOLOGICAL SOFT TISSUES CONSIDERING GROWTH AND REMODELING

  • 摘要: 在生物软组织力学研究中,采用非局部损伤本构模型具有能够考虑内尺度变量和避免有限元网格依赖性的优点。现有文献报道中还很少有软组织非局部损伤本构参数反演的相关工作。该文提出一个求解非局部损伤反问题的数值模型,其主要优点在于:通过数值求解反问题能够反演内尺度变量和生长重构相关的本构参数;采用一种考虑损伤-生长-重构耦合的非局部统一本构模型,能够在正问题分析中方便地建立损伤和修复变量的演化方程,同时避免有限元计算中的网格依赖性;采用了代理模型来替代非线性有限元正问题计算能够显著降低反问题求解的计算量。通过实施牛心脏主动脉软组织的离体拉伸实验和有限元模拟提供测量信息。数值算例的计算结果显示所提方法具有较好的反演精度和抗噪性,各项同性和各项异性的回代计算的曲线拟合参数分别为0.9879和0.9754。该文工作为软组织损伤本构参数识别提供了一种有效的数值模型。

     

    Abstract: The use of a non-local damage constitutive model in biomechanics of soft biological soft tissues has significant advantages in considering internal scale variables and in avoiding mesh-dependence in finite element simulations. There are very few researches on the inverse problems of non-local constitutive models in literatures. A numerical model for solving the non-local damage inverse problem is proposed, the advantages of which are: The constitutive parameters can be effectively identified by solving an inverse problem; The non-local unified damage-growth-healing coupled constitutive model is employed to conveniently considering the effect of internal length scale and establish governing equations of healing parameters; A surrogate model is used to replace the nonlinear finite element method based direct analysis to reduce the computational cost. The measurement information is provided by conducting in vitro tensile experiments and finite element simulations of bovine aortic soft tissue. The results of the numerical examples show that the method proposed has good computational accuracy and noise resistance. The curve fitting indicator with identified parameters for isotropic and anisotropic backpropagation calculations are 0.9879 and 0.9754, respectively. This article provides an effective numerical model for identifying damage constitutive parameters of soft tissue.

     

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