A hybrid potential of mean force approach for simulation of fracture in heterogeneous media
A hybrid potential of mean force approach for simulation of fracture in heterogeneous media
复制标题
DOI：
10.1016/j.cma.2021.114084
复制
发表时间：
2021-12
影响因子：
7.2
通讯作者：
Xuejing Wang;Meshkat Botshekan;Franz-Josef Ulm;M. Tootkaboni;A. Louhghalam
中科院分区：
文献类型：
--
作者：
Xuejing Wang;Meshkat Botshekan;Franz-Josef Ulm;M. Tootkaboni;A. Louhghalam
小尺度下的材料异质性是材料有效宏观性能和断裂响应的关键驱动因素。我们提出了一种基于混合能量的方法，该方法基于晶格元方法的平均力公式的潜力，用于对异质材料中的断裂和裂纹扩展进行可靠且有效的建模。所提出的框架依赖于格里菲斯断裂准则的直接应用，并去除材料点以在能量有利的方向上创建断裂表面。计算效率是通过探测高能键和准静态弛豫来实现的，从而导致几乎全局性地施加基于能量的裂纹路径解析标准。我们根据文献中的结果验证了所提出的混合方法，并用它来检查有缺陷和分层材料的断裂响应。对于断裂能不均匀的层状材料，有效韧性是层的断裂能的最大值，与层的体积分数和裂纹扩展方向无关。对于具有弹性模量异质性的层状材料，当裂纹从柔顺相内接近柔顺-刚性界面时，会出现最大能量释放率。我们研究了断裂韧性与模量对比的比例、与层体积分数的联系以及韧性各向异性和弹性模量异质性梯度之间的关系，为断裂材料的设计提供了潜在的见解。
Material heterogeneity at small scales is a key driver of material’s effective macroscopic properties and fracture response. We present a hybrid energy-based approach based on a potential of mean force formulation of lattice element method for reliable and efficient modeling of fracture and crack propagation in heterogeneous materials. The proposed framework rests on direct application of the Griffith fracture criteria and removes material points to create fracture surfaces in energetically favorable directions. Computational efficiency is achieved through a probing of high energy bonds and quasi-static relaxation leading to near global imposition of the energy-based criteria for crack path resolution. We validate the proposed hybrid approach against results in literature and use it to examine fracture response of defective and layered materials. For layered materials with fracture energy heterogeneity, the effective toughness is shown to be the maximum of fracture energies of layers irrespective of their volume fraction and the direction of crack propagation. For layered materials with elastic modulus heterogeneity, the maximum energy release rate occurs when the crack approaches the compliant-stiff interface from within the compliant phase. We examine the scaling of fracture toughness with modulus contrast, the link to volume fraction of the layers and the relationship between toughness anisotropy and the gradient of elastic modulus heterogeneity, offering insights with potential to inform the design of materials for fracture.