【新文速递】2023年10月26日复合材料SCI期刊最新文章

今日更新：International Journal of Solids and Structures 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresA physically based strength prediction model for glassRudshaug Jonas, Aasen Karoline Osnes, Hopperstad Odd Sture, Børvik Toredoi:10.1016/j.ijsolstr.2023.112548基于物理的玻璃强度预测模型The strength of glass has been a subject of great interest for more than one hundred years. Due to the stochastic nature of glass, governed by microscopical surface flaws, glass plates exhibit large variations in fracture strength. The aim of this work is to propose a new strength prediction model for glass, named the Glass Strength Prediction Model (GSPM) that captures the nature of fracture initiation in glass, spanning from rate dependence to size effects. We aim for the presented model to be applicable in modern design processes and provide a procedure to facilitate input parameter calibration for glass plates from different suppliers. GSPM is a Monte-Carlo based model that combines the theories of linear elastic fracture mechanics (LEFM) and sub-critical crack growth (SCG) to generate virtual tests on a representative sample of glass plates. The stress evolution in the glass plates is obtained from finite element (FE) simulations. The model results in representative fracture strength distributions that span the probable fracture initiation instances with respect to time, location and stress level. We also demonstrate how the GSPM can be used to trigger fracture in constitutive models applied in FE simulations. This feature provides the option to investigate scenarios including multiple glass plates with interdependent fracture initiation behavior. The GSPM displays great promise in terms of usability and prediction capacity. It is able to capture the fracture initiation behavior of glass plates of varying geometries exposed to load cases spanning from, e.g., quasi-static four-point bending to blast pressure. The model has the potential to reduce the number of physical experiments and numerical FE simulations in modern development processes of glass structures.一百多年来，玻璃的强度一直是人们非常感兴趣的话题。由于玻璃具有随机性，受微观表面缺陷的影响，玻璃板的断裂强度变化很大。这项工作的目的是为玻璃提出一个新的强度预测模型，命名为玻璃强度预测模型（GSPM），该模型能捕捉玻璃断裂起始的性质，包括速率依赖性和尺寸效应。我们希望所提出的模型适用于现代设计流程，并提供一个程序，方便对来自不同供应商的玻璃板进行输入参数校准。GSPM 是一种基于蒙特卡洛的模型，它结合了线性弹性断裂力学（LEFM）和亚临界裂纹生长（SCG）理论，对玻璃板的代表性样本进行虚拟测试。玻璃板中的应力演变是通过有限元（FE）模拟获得的。该模型得出了具有代表性的断裂强度分布，这些分布在时间、位置和应力水平方面跨越了可能的断裂起始实例。我们还演示了如何利用 GSPM 在有限元模拟中应用的构成模型中触发断裂。该功能可用于研究包括具有相互依赖断裂起始行为的多块玻璃板在内的各种情况。就可用性和预测能力而言，GSPM 前景广阔。它能够捕捉不同几何形状的玻璃板在从准静态四点弯曲到爆炸压力等各种载荷情况下的断裂起始行为。在玻璃结构的现代开发过程中，该模型有望减少物理实验和数值 FE 模拟的数量。Mechanics of MaterialsUse of hardness, PIP and tensile testing to obtain stress-strain relationships for metalsSouthern T.J.F., Campbell J.E., Fang C., Nemcova A., Bannister A., Clyne T.W.doi:10.1016/j.mechmat.2023.104846使用硬度、PIP 和拉伸测试获得金属的应力-应变关系Both hardness testing and Profilometry-based Indentation Plastometry (PIP) can be used to obtain features of (tensile) stress-strain curves. The two tests are superficially similar, involving penetration (under a known load) of an indenter into the flat surface of a sample, followed by measurement of dimensional characteristics of the residual indent. The associated data handling procedures, however, are very different in the two types of test. Hardness numbers, which are commonly based on measurement of the lateral extent or depth of the indent, essentially give a semi-quantitative indication of the resistance to plastic deformation: going beyond this to infer features of the (nominal) stress-strain curve – notably the yield stress (YS) and Ultimate Tensile Stress (UTS) – can only be done via empirical correlations (often restricted to certain types of alloy). PIP testing, on the other hand, involves measurement of the complete indent profile, followed by (automated) iterative FEM modelling of the indentation, allowing the complete (true) stress-strain curve to be obtained. This paper covers application of both approaches to 12 different alloys, with inferred stress-strain characteristics being compared with those from tensile testing. Insights are provided relating to the very different levels of detail and reliability offered by the two procedures.硬度测试和基于轮廓仪的压入塑性测量法（PIP）都可用于获取（拉伸）应力-应变曲线的特征。这两种测试表面上相似，都是将压头（在已知载荷下）插入样品的平面，然后测量残留压痕的尺寸特征。然而，这两种测试的相关数据处理程序却大相径庭。硬度值通常以测量压痕的横向范围或深度为基础，基本上是对塑性变形阻力的半定量指示：除此之外，要推断（标称）应力-应变曲线的特征，特别是屈服应力（YS）和极限拉伸应力（UTS），只能通过经验相关性来实现（通常仅限于某些类型的合金）。另一方面，PIP 测试涉及测量完整的压痕轮廓，然后对压痕进行（自动）迭代有限元建模，从而获得完整的（真实的）应力-应变曲线。本文介绍了这两种方法在 12 种不同合金中的应用，并将推断出的应力应变特性与拉伸试验得出的应力应变特性进行了比较。这两种方法所提供的详细程度和可靠性截然不同，本文对此进行了深入分析。International Journal of PlasticityCapturing the transition from diffuse to localised failure in constitutive modelling of partially saturated soilsPhan Dat Gia, Nguyen Giang D., Bui Ha H., Bennett Terrydoi:10.1016/j.ijplas.2023.103783在部分饱和土壤的结构建模中捕捉从扩散到局部破坏的过渡过程Localised failures in the form of shear band induce localised deformation and saturation within partially saturated soils. Inelastic responses mainly take place inside the shear band, while the zone outside it usually undergoes unloading processes with much smaller changes in deformation and saturation, as observed in several triaxial tests. The interaction between responses inside and outside shear bands governs the macro behaviour under effects of the hydromechanical coupling. This mechanism, along with properties of shear band (inclination, thickness) and the specimen size, are usually missing in existing classical models based on homogenous assumption. They are incorporated into our approach to correctly capture the post-localisation behaviour of partially saturated soils. In our proposed approach, enrichment terms for kinematics are used in the thermodynamics-based formulation to account for strong variations of hydromechanical responses (stress-strain, suction-saturation) outside and inside the shear band. The proposed formulation results in a size-dependent constitutive structure capable of describing the transition of behaviour from homogeneous to localised stages. The promising features of the proposed formulation are illustrated using data from drained triaxial tests.在部分饱和的土壤中，剪切带形式的局部破坏会引起局部变形和饱和。非弹性反应主要发生在剪切带内部，而剪切带外部区域通常会经历卸载过程，变形和饱和度的变化要小得多，这在一些三轴试验中也能观察到。在水力机械耦合作用下，剪切带内外反应的相互作用决定了宏观行为。这种机制以及剪切带的特性（倾斜度、厚度）和试样尺寸，通常是现有基于同质假设的经典模型所缺乏的。我们的方法中加入了这些因素，以正确捕捉部分饱和土壤的后定位行为。在我们提出的方法中，基于热力学的公式中使用了运动学增量项，以考虑剪切带内外水力学响应（应力-应变、吸力-饱和度）的强烈变化。所提出的公式产生了一种与尺寸有关的构成结构，能够描述从均质阶段到局部阶段的行为转变。利用排水三轴试验的数据说明了所提公式的优点。Thin-Walled StructuresNegative Stiffness Metamaterial with Directional Stability in Uniform FieldsZhu Shaowei, Wang Jingzhe, Chen Liming, Liu Tao, Li Weiguodoi:10.1016/j.tws.2023.111302在均匀场中具有方向稳定性的负刚度超材料Negative stiffness metamaterials have been widely studied due to their unusual properties and potential applications in shape reconfiguration, shock isolation, and reusable energy absorption, but their stability in fields has been less studied. In this work, a theoretical framework for determining the stability of negative stiffness metamaterials in a uniform field is established. More importantly, the concepts of directional stability and semi-directional stability are proposed for the metamaterials that have different stability in different field directions; metamaterials with different physical feature distributions are designed and prepared to achieve such ability, and the finite element simulation is used for theory verification and parameter study. The proposed metamaterial has the potential to be applied as field direction detectors and field-sensitive electrical relays.负刚度超材料因其不同寻常的特性以及在形状重构、冲击隔离和可重复使用的能量吸收方面的潜在应用而被广泛研究，但对其在场内的稳定性研究较少。本研究建立了一个理论框架，用于确定负刚度超材料在均匀场中的稳定性。更重要的是，针对在不同场方向上具有不同稳定性的超材料，提出了定向稳定性和半定向稳定性的概念；设计并制备了具有不同物理特征分布的超材料来实现这种能力，并利用有限元模拟进行了理论验证和参数研究。所提出的超材料有望用作场方向探测器和场敏感电继电器。来源：复合材料力学仿真Composites FEM