【新文速递】2024年1月2日复合材料SCI期刊最新文章_Meshing_ACT_Mechanical_System_Marc_振动_断裂_复合材料_非线性_航空_航天_汽车_电力_裂纹_参数优化_理论_化机_材料_控制

【新文速递】2023年12月24日固体力学SCI期刊最新文章

今日更新：Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 4 篇Mechanics of MaterialsTopological boundary states in micropolar gyroelastic continuaMohamed Shaat, Xin-Lin Gaodoi:10.1016/j.mechmat.2023.104902微波陀螺弹性连续体中的拓扑边界态The study of topology in elastic media has been primarily focused on achieving non-trivial topological states in discrete elastic lattices through active or chiral microscopic interactions. Realization of such topological states in continuous elastic media remains largely unexplored. In this study, a new continuum theory of micropolar gyroelasticity is developed and applied to attain non-trivial topological boundary states in elastic continua. According to the new theory, an elastic continuum is composed of elastically interacting micro-volume elements that can translate and rotate and are connected at their mass centers to gyroscopes, which contribute to the linear and orbital angular momenta but not to the spin angular momentum of the continuum. By applying this micropolar gyroelasticity theory to elastic media with both periodic and finite domains, the emergence of topological boundary states in 2D micropolar gyroelastic continua is demonstrated. Through using the Floquet–Bloch method for periodic domains, the bulk-boundary correspondence is analytically established, and the emergence of non-trivial topological bulk states characterized by Mexican-hat band structures is observed. In addition, by employing an asymptotic analytical model based on the extended Bloch theorem and performing numerical analyses of micropolar gyroelastic continua with finite domains of different geometries, it is shown that the non-trivial Mexican-hat band structure is associated with and provides protection for topological boundary states confined at the boundaries. Finally, the application of the newly developed micropolar gyroelasticity theory to Zinc-blende structured materials (including ZnTe, GaP, InP and ZnS) reveals that the emergence of the topological boundary states in an elastic continuum is not triggered solely by the gyroscopic effect but also depends on the material properties of the micropolar continuum. This study provides new insights into extending notions and methods of topology to analyze elastic continua, paving the way for the practical implementation of topological mechanical systems in various engineering applications.弹性介质拓扑学的研究主要集中在通过主动或手性微观相互作用在离散弹性晶格中实现非三维拓扑状态。在连续弹性介质中实现这种拓扑状态在很大程度上仍未得到探索。在本研究中，我们提出了一种新的微极性陀螺弹性连续理论，并将其应用于在弹性连续体中实现非三维拓扑边界态。根据新理论，弹性连续体由弹性相互作用的微体积元素组成，这些元素可以平移和旋转，并在其质心处与陀螺仪相连，陀螺仪对连续体的线性角动量和轨道角动量有贡献，但对自旋角动量没有贡献。通过将这种微陀螺弹性理论应用于具有周期性和有限域的弹性介质，证明了二维微陀螺弹性连续体中拓扑边界态的出现。通过对周期性域使用 Floquet-Bloch 方法，分析建立了体-界对应关系，并观察到以墨西哥帽带结构为特征的非三维拓扑体态的出现。此外，通过采用基于扩展布洛赫定理的渐近分析模型，并对具有不同几何形状的有限畴的微极陀螺弹性连续体进行数值分析，证明了非微观墨西哥帽带结构与限制在边界的拓扑边界态相关，并为其提供保护。最后，将新开发的微波陀螺弹性理论应用于锌蓝晶结构材料（包括 ZnTe、GaP、InP 和 ZnS），发现在弹性连续体中拓扑边界态的出现并非仅由陀螺效应引发，还取决于微波连续体的材料特性。这项研究为扩展拓扑学的概念和方法以分析弹性连续体提供了新的见解，为拓扑机械系统在各种工程应用中的实际实现铺平了道路。International Journal of PlasticityA dislocation-density-based crystal plasticity model for FCC nanocrystalline metals incorporating thermally-activated depinning from grain boundariesJonathan Cappola, Jian Wang, Lin Lidoi:10.1016/j.ijplas.2023.103863基于位错密度的面心立方纳米晶金属晶体塑性模型，其中包含晶界热激活去氧化作用A novel dislocation-density-based crystal plasticity model for nanocrystalline face-centered cubic metals is developed based on the thermally-activated mechanism of dislocations depinning from grain boundaries. Dislocations nucleated from grain boundary dislocation sources are assumed to be the primary carriers of plasticity in the nanocrystals. The evolution of the dislocation density thereby involves a competition between the nucleation of dislocations from grain boundary defect structures, such as ledges, and the absorption of dislocations into the grain boundary via diffusion processes. This model facilitates the simulation of plastic deformation in nanocrystalline metals, with consideration of the initial microstructure resulting from a particular processing method, to be computed as a direct result of dislocation-mediated plasticity only. The exclusion of grain boundary-mediated plasticity mechanisms in the formulation of the crystal plasticity model allows for the exploration of the fundamental role dislocations play in nanocrystalline plasticity. The combined effect of average grain size, grain size distribution shape, and initial dislocation density on the mechanical performance and strain-rate sensitivity are explored with the model. Further, the influence of the grain boundary diffusivity on post-yielding strain-hardening behavior is investigated to discern the impact that the choice of processing route has on the resulting deformation response of the material.基于晶界位错降解的热激活机制，为纳米晶面心立方金属建立了一种基于位错密度的新型晶体塑性模型。假定从晶界位错源成核的位错是纳米晶体塑性的主要载体。因此，位错密度的演化涉及晶界缺陷结构（如台阶）中的位错成核与通过扩散过程吸收到晶界中的位错之间的竞争。该模型有助于模拟纳米晶金属的塑性变形，考虑到特定加工方法产生的初始微观结构，只计算位错介导塑性的直接结果。在制定晶体塑性模型时排除晶界介导的塑性机制，可以探索位错在纳米晶塑性中的基本作用。该模型探讨了平均晶粒尺寸、晶粒尺寸分布形状和初始位错密度对机械性能和应变速率敏感性的综合影响。此外，还研究了晶界扩散性对屈服后应变硬化行为的影响，以了解加工路线的选择对材料变形响应的影响。Thin-Walled StructuresNonlinear Forced Vibrations of Functionally Graded Three-phase Composite Cylindrical Shell Subjected to Aerodynamic Forces, External Excitations and Hygrothermal EnvironmentT. Liu, H.Y. Zheng, W. Zhang, Y. Zheng, Y.J. Qiandoi:10.1016/j.tws.2023.111511受空气动力、外部激励和湿热环境影响的功能分级三相复合圆柱壳体的非线性受迫振动In this paper, the new functionally graded three-phase composite cylindrical shell is assumed as a common structure in the carrier rocket in the future, and we creatively study the nonlinear forced vibration of this cylindrical shell considering the interaction of different factors in the complex operating environment, including the aerodynamic forces, external excitations, and hygrothermal environment. Based on the first-order shear deformation theory, Von-Karman geometric nonlinear theory, and Hamilton's principle, we derive the nonlinear partial differential equations of motion of the functionally graded three-phase composite cylindrical shell. Considering the axisymmetry of the perfect circular shell, there is a 1:1 internal resonance between the conjugate modes of this cylindrical shell. On this basis, the nonlinear forced vibration of the cylindrical shell is investigated by a combination of Galerkin's method and the pseudo-arc length continuation method. Matcont toolbox can directly solve the ordinary differential equations to obtain the nonlinear frequency response curves. The method can effectively obtain both stable and unstable solutions, avoiding the mathematical difficulties encountered in the formulation process, and facilitating the study of the effects of parametric variables on the resonance response in complex environments. The results show that the variation of material parameters and the complex environment have important effects on the nonlinear resonance response of functionally graded three-phase composite cylindrical shell.本文将新型功能分级三相复合材料圆柱壳体假定为未来运载火箭的常用结构，考虑到复杂工作环境中不同因素的相互作用，包括空气动力、外部激励和湿热环境，创造性地研究了该圆柱壳体的非线性受迫振动。基于一阶剪切变形理论、冯-卡曼几何非线性理论和汉密尔顿原理，我们推导出了功能分级三相复合圆柱壳的非线性偏微分运动方程。考虑到完美圆壳的轴对称性，该圆柱壳的共轭模之间存在 1:1 的内部共振。在此基础上，结合 Galerkin 方法和伪弧长延续方法研究了圆柱壳的非线性受迫振动。Matcont 工具箱可以直接求解常微分方程，从而得到非线性频率响应曲线。该方法能有效地得到稳定解和不稳定解，避免了公式化过程中遇到的数学困难，便于研究参数变量对复杂环境下共振响应的影响。结果表明，材料参数的变化和复杂环境对功能分级三相复合材料圆柱壳的非线性共振响应有重要影响。The added mass of a biaxial tensioned membrane in still airShaochen Yang, Bing Zhao, Wujun Chendoi:10.1016/j.tws.2023.111531静止空气中双轴拉伸薄膜的附加质量It is well known that added mass significantly impacts the vibration of membrane structures in still air. Numerous theoretical, numerical, and experimental studies have been conducted on the added mass of axial tensioned membranes. However, the added mass of biaxial tensioned membranes subjected to different tensile forces in two directions in still air remains unclear. Therefore, this study focuses on investigating the added mass of biaxial tensioned membranes in still air. Firstly, this paper proposes a simplified theoretical model for the added mass of biaxial tensioned membranes in still air based on the energy conservation law. To validate the accuracy of the proposed model, a modal testing system for a rectangular membrane is designed to identify the frequencies of biaxial tensioned membranes in still air. In the experimental system, the utilization of a laser displacement sensor array is to obtain the time-displacement information of observation points. Then, a combination of Fast Fourier Transform (FFT) and Stochastic Subspace Identification (SSI) methods is employed for modal identification. Comparative analysis between the experimental and theoretical model results demonstrates an excellent agreement in frequencies. Additionally, the proposed added mass model is closer to the experimental added mass than other models, with a maximum deviation of only 4.77%. This research provides a reference for the study of the impact of air on the ground vibration of membranes.众所周知，附加质量对静止空气中膜结构的振动有很大影响。关于轴向拉伸膜的附加质量，已经进行了大量的理论、数值和实验研究。然而，在静止空气中受到两个方向不同拉伸力的双轴拉伸膜的附加质量仍不清楚。因此，本研究将重点放在研究静止空气中双轴拉伸膜的附加质量上。首先，本文基于能量守恒定律，提出了静止空气中双轴拉伸膜附加质量的简化理论模型。为了验证所提模型的准确性，本文设计了一个矩形膜的模态测试系统，以确定静止空气中双轴张拉膜的频率。在实验系统中，利用激光位移传感器阵列获取观测点的时间位移信息。然后，结合快速傅立叶变换（FFT）和随机子空间识别（SSI）方法进行模态识别。实验结果与理论模型结果的对比分析表明，两者在频率上非常一致。此外，与其他模型相比，所提出的附加质量模型更接近于实验附加质量，最大偏差仅为 4.77%。这项研究为研究空气对膜材地面振动的影响提供了参考。A simple SIF determination method for cracked orthotropic cylindrical shell by means of stress ratioRong Li, Shuai Bai, Meng Yang, Bin Liang, Ke-jun Hudoi:10.1016/j.tws.2023.111532利用应力比确定开裂正交圆柱壳 SIF 的简单方法A convenient and universal calculation method for stress intensity factor (SIF) in cracked orthotropic cylindrical shell under diverse loadings is described. The present expressions are derived from traditional classical numerical method and simplified by extracting and eliminating the complex but regular parameters. A simple relation between SIF and crack tip stress from finite element method (FEM) is constructed by means of reference problem and unknown problem, then a simple SIF formulation can be realized and the impact of material orthotropy is considered. The feasibility and advantages of present study are proved to be analyzed by comparing against published results.本文介绍了在不同载荷作用下，开裂的正交圆柱壳体应力强度因子（SIF）的一种方便通用的计算方法。本表达式源自传统的经典数值方法，并通过提取和消除复杂但规则的参数进行了简化。通过参考问题和未知问题，构建了有限元法（FEM）中 SIF 与裂纹尖端应力之间的简单关系，从而实现了简单的 SIF 公式，并考虑了材料正交性的影响。通过与已发表的结果进行对比分析，证明了本研究的可行性和优势。Study on stability of H-type section aluminum alloy perforated members under axial compression and eccentric compression around weak axisWenyuan Kong, Hang Yang, Liang Zhou, Zhiquan Xing, Yu Chen, Wei Chen, En Lindoi:10.1016/j.tws.2023.111533H 型截面铝合金穿孔构件在轴向压缩和围绕弱轴的偏心压缩条件下的稳定性研究Aluminum alloy components have the advantages of light weight, high strength, favorable machinability, and good acid corrosion resistance, which can greatly reduce maintenance costs and easy to make the structures with beautiful appearance. Based on the shortcomings of existing research fields, the stability of H-type section 6082-T6 aluminum alloy perforated members under axial compression and eccentric compression around weak axis is studied by combining experimental and numerical simulation methods in this paper. The test results of aluminum alloy members under axial compression and aluminum alloy members under eccentric compression around weak axis with different web opening numbers, opening diameters, slenderness ratios and eccentric distances are analyzed. The verified finite element model is used to carry out the extensive parameter analysis focusing on the key variables. Based on the test and numerical simulation results of the stability bearing capacity of 134 members, the design methods for H-type section aluminum alloy perforated members under axial compression and eccentric compression are proposed and evaluated by reference to the existing specification.铝合金构件具有重量轻、强度高、可加工性好、耐酸腐蚀性好等优点，可大大降低维护成本，且易于制作成外形美观的结构。基于现有研究领域的不足，本文采用实验和数值模拟相结合的方法，研究了 H 型截面 6082-T6 铝合金穿孔构件在轴向压缩和绕弱轴偏心压缩下的稳定性。分析了不同腹板开孔数、开孔直径、细长比和偏心距的铝合金构件在轴向压缩和绕弱轴偏心压缩下的试验结果。利用经过验证的有限元模型对关键变量进行了广泛的参数分析。根据 134 个构件的稳定承载力试验和数值模拟结果，提出了轴向压缩和偏心压缩条件下 H 型截面铝合金穿孔构件的设计方法，并参照现有规范进行了评估。来源：复合材料力学仿真Composites FEM

【新文速递】2024年1月2日复合材料SCI期刊最新文章

Composite Structures

Composites Part A: Applied Science and Manufacturing

Composites Science and Technology

【新文速递】2023年12月24日固体力学SCI期刊最新文章