AI 中文总结
本研究提出一种统一计算框架，采用混合维度离散裂缝-基质表示，耦合弹性波传播与含摩擦等机制的裂缝变形，经验证后应用于多裂缝介质的波传播模拟。
AI 中文摘要
裂缝介质中的弹性波传播与地震波分析、材料无损表征等应用相关，理解波-裂缝相互作用产生的衰减与散射行为对解释野外及实验室尺度的观测结果十分重要。本研究提出一种基于混合维度离散裂缝-基质表示的裂缝介质弹性波传播计算框架，裂缝变形由四种复杂度递增的模型描述，涵盖从广泛使用的基于弹簧的公式到带摩擦的裂缝接触力学模型，所有模型均整合于统一计算框架内。以往诸多研究常局限于简化波场、单裂缝或部分相关的裂缝变形机制，相比之下，所提框架可实现弹性波传播与裂缝变形模型的完全耦合模拟，该模型考虑弹性法向变形、摩擦接触及裂缝的张开与闭合。弹性波方程采用单元中心有限体积法（多点应力近似，带弱对称性）进行空间离散，采用纽马克（Newmark）法进行时间离散；空间离散具有局部守恒性，适用于一般多面体网格，因此非常适合包含裂缝、材料非均质性和各向异性的介质。所提框架通过数值收敛分析得到验证，随后被应用于含多条相交裂缝的二维和三维介质中的波传播与裂缝变形研究。
英文摘要
Elastic wave propagation in fractured media is relevant to applications such as analysis of seismic waves and non-destructive characterization of materials. Understanding attenuation and scattering behavior arising from wave-fracture interaction is important for interpreting observations at both field and laboratory scales. This work presents a computational framework for elastic wave propagation in fractured media based on a mixed-dimensional discrete fracture-matrix representation. Fracture deformation is governed by four models of increasing complexity, ranging from widely used spring-based formulations to fracture contact mechanics models with friction, all incorporated within a unified computational framework. Many previous studies are often restricted to simplified wave fields, single fractures or subsets of the relevant fracture deformation mechanisms. In contrast, the proposed framework enables fully coupled simulation of elastic wave propagation with fracture deformation models that account for elastic normal deformation, frictional contact and fracture opening and closure. The elastic wave equation is discretized in space using the cell-centered finite volume method Multi-Point Stress Approximation with weak symmetry and in time using the Newmark method. The spatial discretization is locally conservative and applicable to general polyhedral grids, making it well suited for media containing fractures, material heterogeneities and anisotropy. The proposed framework is verified through numerical convergence analyses and is subsequently applied to wave propagation and fracture deformation in two- and three-dimensional media containing multiple intersecting fractures.
