【新文速递】2025年9月9日复合材料SCI期刊最新文章

今日更新：International Journal of Solids and Structures 2 篇，Thin-Walled Structures 12 篇International Journal of Solids and StructuresInfluence of flexure-torsion coupling on wave propagation in 2D thin-walled latticeSomraj Sen, Arindam Das, Kamal Krishna Bera, Arnab Banerjeedoi:10.1016/j.ijsolstr.2025.113641二维薄壁晶格中弯曲-扭转耦合对波传播的影响Wave propagation behavior of 2D lattices has been an alyzed using frame elements; however, the influence of flexure-torsion coupling on wave propagation in periodic lattice structures with thin-walled members remains unexplored. This study focuses on simple square lattice architectures composed of thin-walled mono-symmetric beams with varying flange widths and orientation angles of cross-sectional members. Both in-plane and out-of-plane wave responses are a nalyzed to capture a comprehensive understanding of wave dispersion. Each lattice is modeled using a unit cell approach, where individual members are represented as thin-walled beams. Spectral element method is employed to capture the wave propagation behaviour of the lattices. By applying Bloch-Floquet boundary conditions, periodicity in the structure is enforced, thereby evaluating the dispersion surfaces, isofrequency contours, group velocity maps, and directivity plots elucidate the wave propagation characteristics of the lattices. Our findings reveal that the thin-walled lattice with flexural–torsional coupling produces blind zones in wave propagation, while the simple lattice exhibits uniform directivity and group velocity distribution. The an alysis reveals critical insights into the energy flow and directionality of waves, providing a deeper understanding of the spatial and wavenumber-dependent behavior of flexure-torsion-coupled lattice structures. These findings offer significant implications for the design and optimization of advanced lattice materials and wave-based engineering applications.采用框架单元分析了二维网格的波传播特性；然而，挠曲-扭转耦合对薄壁构件周期晶格结构中波传播的影响尚未得到深入研究。本研究的重点是由具有不同翼缘宽度和截面构件取向角的薄壁单对称梁组成的简单方形点阵结构。分析了面内和面外的波响应，以全面了解波的色散。每个晶格都使用单元格方法建模，其中单个成员表示为薄壁梁。采用谱元法捕捉晶格的波传播特性。通过应用Bloch-Floquet边界条件，增强了结构的周期性，从而评估了色散面、等频轮廓、群速度图和指向性图，阐明了晶格的波传播特性。研究结果表明，具有弯扭耦合的薄壁晶格在波传播中存在盲区，而简单晶格具有均匀的指向性和群速度分布。该分析揭示了对波的能量流动和方向性的关键见解，提供了对弯曲-扭转耦合晶格结构的空间和波数依赖行为的更深入理解。这些发现对先进晶格材料的设计和优化以及基于波浪的工程应用具有重要意义。Chemical equilibrium fracture mechanics − hydrogen embrittlement of two-phase hydride forming alloysA.G. Varias, A.G. Vriasdoi:10.1016/j.ijsolstr.2025.113635化学平衡断裂力学-两相氢化物成形合金的氢脆Chemical Equilibrium Fracture Mechanics (CEFM) is a multidisciplinary approach of solid mechanics, material science, thermodynamics and mathematics, for the study of crack-tip fields and structural integrity, based on the assumption of material deterioration under chemical equilibrium. A major application has been the development of crack-tip fields in hydride and non-hydride forming alloys, subjected to mechanical loads in a hydrogen environment. According to earlier studies, in single phase alloys, the crack-tip fields, in the case of hydride precipitation, deviate significantly from the well-known fields in linear elastic and elastic–plastic materials, thus necessitating the modification / extension of linear elastic, elastic–plastic and constraint-based fracture mechanics. In the present study, CEFM is applied to two-phase hydride forming alloys, by taking into account hydride precipitation as well as hydrogen residing in both interstitial lattice sites and dislocation traps. The distributions of stress and hydrogen concentration near the tip of a plane strain mode I crack are derived and applied to widely used α/β titanium alloys. The deviations from the crack-tip fields of hydrogen-free metals are confirmed in the case of two-phase alloys as well. It is shown that the partitioning of hydrogen in solid solution in the two phases, near a crack-tip in the hydride precipitation zone, is controlled by the constant hydrostatic stress and therefore varies, depending on alloy yield stress and average hydrogen content. Alloy yield stress has also a strong effect on average hydrogen content, at which hydride precipitation and therefore embrittlement initiates化学平衡断裂力学（CEFM）是基于化学平衡下材料劣化的假设，以固体力学、材料科学、热力学和数学为基础，研究裂纹尖端场和结构完整性的多学科方法。一个主要的应用是在氢化物和非氢化物形成合金中，在氢环境中受到机械载荷的裂纹尖端领域的发展。根据早期的研究，在单相合金中，在氢化物析出的情况下，裂纹尖端场与众所周知的线弹性和弹塑性材料的场有很大的偏离，因此需要对线弹性、弹塑性和约束断裂力学进行修正/扩展。在本研究中，CEFM应用于两相氢化物形成合金，考虑了氢化物沉淀以及驻留在间隙点阵和位错陷阱中的氢。导出了平面应变型I型裂纹尖端附近的应力和氢浓度分布，并将其应用于广泛应用的α/β钛合金。无氢金属裂纹尖端场的偏差在两相合金中也得到了证实。结果表明，氢化物析出区裂纹尖端附近两相固溶体中氢的分配受恒定静水应力控制，因此随合金屈服应力和平均氢含量的变化而变化。合金屈服应力对平均含氢量也有很大影响，在平均含氢量下，合金会析出氢化物，从而开始脆化Thin-Walled StructuresDamage Evolution and Failure Mechanis m of Heterogeneous Cladding Tube under Internal Pressure: Experimental Study and Numerical ModelingChong Wei, Shuang Liang, Songbin Zhangdoi:10.1016/j.tws.2025.113932内压作用下非均质包层管的损伤演化与破坏机制：实验研究与数值模拟Refractory metal-SiCf/SiC heterogeneous composites provide a promising approach to ensuring the hermeticity of nuclear-grade SiCf/SiC composites. However, their underlying failure mechanis ms affecting their performance remain unclear. In this study, we used a combination of expansion plug testing and finite element modeling to systematically investigate the damage evolution process and failure mechanis ms of Mo-SiCf/SiC heterogeneous cladding. The established theoretical model effectively predicts the damage failure process and mechanical properties of heterogeneous composite cladding, showing good agreement with experimental results. Results indicate that the heterogeneous cladding exhibits a three-stage damage evolution characteristic: initial elastic deformation transitions into nonlinear behavior via matrix cracking, subsequent Mo layer fracturing activates unstable crack propagation, and structural failure ultimately manifests as localized damage in the SiCf/SiC layer with preserved overall structural integrity. The gradient damage evolution reveals the synergistic effect of the heterogeneous cladding system, where the Mo layer not only bears hoop stress but also ensures the hermeticity, while the SiCf/SiC layer provides structural support, effectively delaying catastrophic failure. This study offers key theoretical guidance for the design of accident-tolerant fuel cladding and provides essential insights for enhancing its mechanical performance.难熔金属-SiCf/SiC非均相复合材料为保证核级SiCf/SiC复合材料的密封性提供了一条很有前途的途径。然而，影响其性能的潜在失效机制尚不清楚。本研究采用膨胀塞试验和有限元模拟相结合的方法，系统研究了Mo-SiCf/SiC非均相熔覆层的损伤演化过程和破坏机制。建立的理论模型能有效地预测非均质复合材料包层的损伤破坏过程和力学性能，与实验结果吻合较好。结果表明，非均质熔覆层呈现出三个阶段的损伤演化特征：初始弹性变形通过基体开裂转变为非线性行为，随后Mo层破裂激活不稳定裂纹扩展，最终结构破坏表现为SiCf/SiC层局部损伤，整体结构完整性保持不变。梯度损伤演化揭示了非均质熔覆体系的协同作用，Mo层承担环向应力并保证密封，而SiCf/SiC层提供结构支撑，有效延缓了灾难性破坏。该研究为耐事故燃料包壳的设计提供了重要的理论指导，并为提高其力学性能提供了重要的见解。Shape Sensing and Damage Detection of Composite Pressure Vessels Using Inverse Finite Element Method Coupled with Physics-Based Strain Pre-ExtrapolationJacopo Bardiani, Roberto Faure Ragani, Lucio Pinello, Adnan Kefal, Andrea Manes, Claudio Sbarufattidoi:10.1016/j.tws.2025.113935基于物理应变预外推的复合材料压力容器形状感知与损伤检测This study presents an advanced strategy for shape sensing and damage detection of composite Type IV pressure vessels using the inverse finite element method (iFEM) coupled with a novel physics-based strain pre-extrapolation approach. The pre-extrapolation methodology, developed based on Kirchhoff plate bending theory, enhances the accuracy of full-field displacement and strain reconstruction by addressing the need for strain input across all structural regions. By incorporating discrete experimental measurements, this framework enables precise residual strain estimation, facilitating damage localization in composite structures. The proposed inverse model is validated through both numerical and experimental investigations, leveraging fiber optic sensor networks strategically placed along axial and circumferential segments of the pressure vessel. Quasi-static compression and low-velocity impact (LVI) tests are conducted to evaluate the model’s performance under complex loading conditions. The reconstructed displacement and strain fields demonstrate the exceptional capability of iFEM in accurately capturing structural deformations and detecting damage initiation and progression. Notably, the method effectively identifies damage induced by LVI by an alyzing residual strain distributions at critical post-impact time instances. Overall, the results underscore the robustness of the iFEM framework in capturing complex shape deformations and damage patterns that might otherwise remain undetected, highlighting its potential for real-time structural health monitoring of composite pressure vessels.本研究提出了一种利用逆有限元法（iFEM）结合一种新的基于物理的应变预外推方法对复合材料IV型压力容器进行形状传感和损伤检测的先进策略。基于Kirchhoff板弯曲理论开发的预外推方法，通过解决所有结构区域的应变输入需求，提高了全场位移和应变重建的准确性。通过结合离散实验测量，该框架能够精确估计残余应变，促进复合材料结构的损伤定位。通过数值和实验研究，利用沿压力容器轴向和周向段放置的光纤传感器网络，验证了所提出的逆模型。通过准静态压缩和低速冲击（LVI）试验，对模型在复杂载荷条件下的性能进行了评价。重建的位移场和应变场显示了有限元法在准确捕捉结构变形和检测损伤发生和发展方面的卓越能力。值得注意的是，该方法通过分析冲击后关键时刻的残余应变分布，有效识别了LVI引起的损伤。总体而言，结果强调了iffem框架在捕获复杂形状变形和损伤模式方面的稳健性，否则可能无法检测到，突出了其在复合材料压力容器的实时结构健康监测方面的潜力。Multiphysics An alysis and Optimization of Solid Oxide Electrolysis Cells with Functionally Graded Fuel ElectrodesFangzheng Liu, Zhiqi Zhao, Liusheng Xiao, Ruidong Zhou, Qi Liu, Ding Rong Ou, Jinliang Yuandoi:10.1016/j.tws.2025.113936燃料梯度电极固体氧化物电解电池的多物理场分析与优化This study presents a multiphysics CFD model to understand and an alyze hydrogen production and thermal stress in anode-supported planar solid oxide electrolysis cells (SOECs), which employ functionally graded fuel electrodes with engineered linear gradients in porosity, pore size, and Ni composition along the electrode thickness direction. Moreover, orthogonal experimental design method is also developed and applied to identify the optimal parameter ranges, and the graded porosity is found to be the dominant factor enhancing hydrogen production, while the graded Ni composition is the primary parameter governing the maximum thermal stress. Synergistic optimization of porosity and Ni composition gradients achieves a 24.9% increase in the hydrogen production with a 10.0% reduction in the maximum thermal stress, demonstrating their critical role in concurrently boosting SOEC performance and mechanical durability.本研究提出了一个多物理场CFD模型来理解和分析阳极支撑的平面固体氧化物电解电池（SOECs）的产氢和热应力，SOECs采用功能梯度燃料电极，其孔隙率、孔径和Ni成分沿电极厚度方向呈工程线性梯度。采用正交试验设计方法确定了最佳参数范围，发现分级孔隙度是提高产氢的主导因素，而分级镍成分是控制最大热应力的主要参数。孔隙度和Ni成分梯度的协同优化使产氢量增加了24.9%，最大热应力降低了10.0%，证明了它们在同时提高SOEC性能和机械耐久性方面的关键作用。A novel nonlinear stability modeling of mechanical-electro-carrier coupling piezoelectric semiconductor cylindrical shellsWei Wang, Gaofei Guan, Lide Chen, Jiabin Sun, Zhenhuan Zhou, Xinsheng Xudoi:10.1016/j.tws.2025.113937 一种新型机电载流子耦合压电半导体圆柱壳非线性稳定性模型Piezoelectric semiconductors (PS) shell-like structures have great potential for the manufacture of innovative devices, such as nano sensors. To evaluate stability of such devices, a novel mechanical-electro-carrier (MEC) coupling PS cylindrical shell (PSCS) post-buckling model is developed based on the high-order shear deformation shell theory (HSDT). By applying the Galerkin technique in conjunction with newly developed trial functions, the mode-jumping equilibrium path, post-buckling deformation, distributions of electron concentration and electric potential are determined. The effects of crucial influencing parameters, including geometrical parameters, semiconductors constants and voltages on nonlinear stability of PSCS, are explored. Numerical findings reveal that, as a consequence of the MEC coupling effect, both the bifurcation point (first buckling) and load-bearing capacity of PSCS are reduced compared to those of classical piezoelectric counterpart.压电半导体（PS）类壳结构在制造纳米传感器等创新器件方面具有巨大的潜力。为了评估此类器件的稳定性，基于高阶剪切变形壳理论（HSDT）建立了一种新的机电载流子耦合PS圆柱壳（PSCS）后屈曲模型。利用伽辽金技术结合新开发的试函数，确定了跳模平衡路径、后屈曲变形、电子浓度分布和电势分布。探讨了几何参数、半导体常数和电压等关键影响参数对PSCS非线性稳定性的影响。数值结果表明，由于MEC耦合效应，PSCS的分岔点（首次屈曲）和承载能力都比经典压电材料有所降低。Flexural properties of hollow curved-pultruded GFRP square tubes under varying boundary conditionsChenglin Liu, Feng Li, Ruijie Zhu, Yan Chendoi:10.1016/j.tws.2025.113928不同边界条件下中空弯曲拉挤GFRP方管的弯曲性能This study investigates the flexural behavior of hollow curved-pultruded GFRP (Glass Fibre Reinforced Polymer) square tubes under three-point bending with varying boundary conditions including simple support (SS), hinged support (HH), fixed support (FF), and fixed-hinged support (FH). The experimental investigation comprised 12 specimens subjected to four different boundary conditions. The failure modes, load-displacement curves, and load-strain curves are reported and discussed in this study. Results showed that the structural stiffness increased with improved constraints from the SS condition to the FF condition, the failure load under SS conditions was the lowest, and failure loads showed minimal variation among HH, FF, and FH conditions. The progressive failure of GFRP tubes was investigated using finite element modeling. Various formulas of GFRP tubes for flexure in design manuals were incorporated into the an alytical model to predict the failure load. The conventional local buckling strength equation can predict the failure load under SS conditions. A prediction equation based on the delamination failure criterion was developed to predict the failure load under HH, FF, and FH boundary conditions. The hollow curved-pultruded GFRP square tubes proposed in this study can effectively improve their structural stiffness by transforming from simply supported arch beams to arch structures without increasing the cross-sectional area or employing external prestress.本文研究了弯曲拉挤中空GFRP（玻璃纤维增强聚合物）方管在三点弯曲下的弯曲行为，不同的边界条件包括简单支撑（SS）、铰接支撑（HH）、固定支撑（FF）和固定铰接支撑（FH）。实验调查包括12个试件，受4种不同的边界条件。本研究报告并讨论了其破坏模式、荷载-位移曲线和荷载-应变曲线。结果表明：从SS工况到FF工况，结构刚度随约束条件的改善而增大，SS工况下的破坏载荷最小，HH、FF和FH工况下的破坏载荷变化最小；采用有限元方法研究了玻璃钢钢管的渐进式破坏。将设计手册中关于玻璃钢管挠曲的各种公式纳入分析模型，以预测失效载荷。传统的局部屈曲强度方程可以很好地预测SS工况下的破坏载荷。建立了基于分层破坏准则的预测方程，对HH、FF和FH边界条件下的破坏载荷进行了预测。本文提出的中空弯曲拉挤GFRP方管在不增加截面面积和不施加外预应力的情况下，由简支拱梁转变为拱结构，有效提高了其结构刚度。A novel form-finding method for cable-net structures using variable-length cable elements based on absolute nodal coordinate formulationChengbin Peng, Hui Ren, Wei Fan, Jiashuo Midoi:10.1016/j.tws.2025.113933基于绝对节点坐标公式的变长索单元索网结构寻形方法Cable-net structures rely on the pretension of the cables to provide stiffness to bear external loads and ensure stability. The shape and internal forces exhibit mutual coupling, making form-finding very challenging. A novel form-finding method for cable-net structures is proposed in this work. The cable-net structure is modeled by variable-length and constant-length absolute nodal coordinate formulation (ANCF) cable elements connected by spherical joints and sliding joints. Cable lengths and node positions undergo adaptive adjustment through feedback control. The variable-length elements facilitate the cable length adjustment to ensure uniform tension distribution. The translation velocities of nodes regulate the boundary nodes’ positions to satisfy the preset boundary conditions. The key advantage of the present method is that it is insensitive to initial conditions and can be easily applied to other cable-net structures with more complex shapes. The validity and accuracy of the present form-finding method are demonstrated through several numerical examples.索网结构依靠索的预张力提供刚度以承受外部载荷并确保稳定性。形状和内力表现出相互耦合，使得寻找形状非常具有挑战性。本文提出了一种新的索网结构寻形方法。索网结构采用变长和定长绝对节点坐标法（ANCF），通过球节点和滑动节点连接索单元。电缆长度和节点位置通过反馈控制进行自适应调整。变长元件便于调整电缆长度，保证张力分布均匀。节点的平移速度调节边界节点的位置以满足预设的边界条件。该方法的主要优点是对初始条件不敏感，可以很容易地应用于其他形状更复杂的索网结构。通过数值算例验证了该方法的有效性和准确性。Concurrent topology and path optimization of manufacturable fiber-reinforced structures following hybrid concentric printing pathsCong Wang, Jiahui Li, Baohua Jia, Dong Ruan, Xiaodong Huangdoi:10.1016/j.tws.2025.113934复合同心打印路径下可制造纤维增强结构的并行拓扑与路径优化Fiber-reinforced additive manufacturing, also known as 3D printing, has attracted growing attention in recent years for its potential to fabricate lightweight structures through a layer-by-layer building process. However, anisotropic properties of materials resulting from specified layer-by-layer printing paths, e.g., commonly used hybrid concentric printing paths, coupled with structural geometry, lead to challenges in topology optimization of fiber-reinforced composite (FRC) structures. This paper presents a new optimization algorithm that can find optimal topologies of FRC structures and layer-by-layer hybrid concentric printing paths simultaneously. First, we develop the finite element model for a given FRC structure where the orientations of FRCs within each element are determined by fabricable layer-by-layer hybrid concentric printing paths. The close agreement between numerical and experimental results confirms the simulation model’s accuracy and reliability. Then, an optimization algorithm is developed to concurrently update structural topology and printing paths iteratively until an optimal structural topology and compatible hybrid concentric printing paths are achieved. The numerical examples and three-point bending flexural test are presented to demonstrate the effectiveness of this manufacturing-oriented optimization approach and its advantages over the post-processed printing paths based on the conventional topological optimized designs. The research promises the seamless integration of optimization design and fiber-reinforced additive manufacturing.纤维增强增材制造，也被称为3D打印，近年来因其通过逐层建造过程制造轻质结构的潜力而引起了越来越多的关注。然而，由于特定的逐层打印路径（例如常用的混合同心打印路径）导致材料的各向异性，再加上结构几何形状，给纤维增强复合材料（FRC）结构的拓扑优化带来了挑战。本文提出了一种新的优化算法，可以同时找到FRC结构的最优拓扑和逐层混合同心打印路径。首先，我们开发了给定FRC结构的有限元模型，其中每个单元内FRC的方向由可逐层混合同心打印路径确定。数值结果与实验结果吻合较好，验证了仿真模型的准确性和可靠性。然后，开发了一种优化算法，迭代更新结构拓扑和打印路径，直到获得最优结构拓扑和兼容的混合同心打印路径。通过数值算例和三点弯曲试验，验证了这种面向制造的优化方法的有效性，以及它相对于传统拓扑优化设计的后处理印刷路径的优越性。该研究有望实现优化设计与纤维增强增材制造的无缝集成。Nonlinear dynamics of PFG cylindrical shells reinforced with oblique stiffeners under viscous fluid flowKamran Foroutan, Farshid Torabidoi:10.1016/j.tws.2025.113925粘性流体作用下斜加劲PFG圆柱壳的非线性动力学In this paper, the nonlinear dynamic (ND) behavior of porous functionally graded (PFG) cylindrical shells (CSs) reinforced with oblique stiffeners under viscous, compressible, and non‑isentropic internal fluid flow is comprehensively an alyzed using a semi‑an al ytical approach. Moreover, this study investigates two variations of PFG: one featuring an even porosity distribution (EPD) and the other exhibiting an uneven porosity distribution (UEPD). Lekhnitskii’s s meared stiffener approach is utilized to model the stiffeners. The nonlinear governing equations (NGEs) are formulated based on Donnel shell theory (DST) incorporating von Kármán geometric nonlinearity. Then, these equations are discretized via Galerkin’s method, and a three-term approximate solution for the deflection is established. An approach utilizing the P-T method is developed for a nalyzing the ND behavior of PFG-CSs reinforced with oblique stiffeners in the presence of fluid flow, providing a continuous semi-an alytical solution across the full-time domain with highly accurate numerical results. This method combines a piecewise-constant argument with Taylor series expansions, hence its designation as the P-T method. The study advances the state of the art by integrating oblique stiffener effects, porosity variations, and realistic fluid–structure interaction in the a nalysis of PFG-CSs, thereby capturing the influence of both material distribution and internal fluid properties on their ND responses. The results demonstrate that stiffener angles, porosity distribution, and fluid characteristics significantly affect the ND behavior, providing valuable insights and design guidelines for marine risers, heavy‑oil pipelines, and aerospace propellant tanks where fluid–structure interactions are critical to structural safety and performance.本文采用半解析方法，全面分析了斜肋加筋多孔功能梯度圆柱壳在粘性、可压缩和非等熵内部流体流动下的非线性动力学行为。此外，本研究还研究了PFG的两种变化：一种具有均匀孔隙度分布（EPD），另一种具有不均匀孔隙度分布（UEPD）。采用Lekhnitskii的涂抹加劲板方法对加劲板进行建模。基于Donnel壳理论，结合von Kármán几何非线性，建立了非线性控制方程。然后，利用伽辽金方法对这些方程进行离散化，建立了挠度的三项近似解。采用P-T法分析了斜加强PFG-CSs在流体存在下的ND行为，提供了一个跨全时域的连续半解析解，并具有高精度的数值结果。这种方法结合了分段常数参数和泰勒级数展开，因此被称为P-T方法。该研究通过在PFG-CSs分析中整合斜加劲效应、孔隙度变化和现实的流固耦合，从而捕捉材料分布和内部流体性质对其ND响应的影响，从而推进了目前的研究水平。结果表明，加强角、孔隙度分布和流体特性显著影响ND行为，为海洋立管、重油管道和航空航天推进剂储罐提供了有价值的见解和设计指南，在这些领域，流固耦合对结构安全和性能至关重要。Synergistic design of curved beam metastructures with tunable stiffness, Poisson's ratio and energy absorption abilityGai-Qin Liu, Hai-Tao Liudoi:10.1016/j.tws.2025.113938具有可调刚度、泊松比和能量吸收能力的弯曲梁元结构协同设计Mechanical metastructures have garnered widespread attention due to their superior mechanical properties. However, how mechanical metastructures achieve bidirectional mechanical responses while enabling synergistic multi-performance design remains an issue worthy of in-depth investigation. In this study, four types of curved beam metastructures (CBMs) are proposed, named CBM-I, CBM-II, CBM-III, and CBM-IV. The mechanical responses of these CBMs, including stress-strain curves, energy absorption capabilities, and deformation profiles, are studied through finite element simulations and experiments. The results show that both CBM-I and CBM-II exhibit negative stiffness characteristics along the X and Y directions, while offering customizable deformation lengths. When compressed to a densification state, the stress-strain curves of CBM-I and CBM-II demonstrate a three-stage plateau feature. CBM-III not only achieves the transformation of nonlinear properties such as positive stiffness, quasi-zero stiffness, and negative stiffness but also features a tunable Poisson’s ratio, which cannot be accomplished by conventional negative-stiffness metastructures. CBM-IV exhibits excellent capability of sign switching for Poisson's ratio. The frame-reinforced design and double curved beam design strategies not only improve the peak force of CBMs but also suppress the asymmetric buckling deformation of the curved beam and enhance structural stability. The quasi-zero stiffness and customizable length characteristics of CBM-I and CBM-II give them significant application value in morphing wings. This study provides valuable insights for the multifunctional design of novel tunable CBMs and promotes their application in aerospace engineering.力学元结构因其优越的力学性能而受到广泛关注。然而，力学元结构如何在实现协同多性能设计的同时实现双向力学响应仍然是一个值得深入研究的问题。在本研究中，提出了四种类型的弯曲梁元结构（CBMs），分别命名为CBM-I、CBM-II、CBM-III和CBM-IV。通过有限元模拟和实验研究了这些CBMs的力学响应，包括应力-应变曲线、能量吸收能力和变形曲线。结果表明，CBM-I和CBM-II在X和Y方向上均表现出负刚度特征，同时提供可定制的变形长度。压缩至致密化状态后，CBM-I和CBM-II的应力-应变曲线呈现出三阶段高原特征。CBM-III不仅实现了正刚度、准零刚度、负刚度等非线性特性的转换，而且具有常规负刚度元结构无法实现的泊松比可调特性。CBM-IV具有良好的泊松比符号转换能力。框架加筋和双弯曲梁设计策略不仅提高了cbm的峰值力，而且抑制了弯曲梁的不对称屈曲变形，提高了结构的稳定性。CBM-I和CBM-II的准零刚度和长度可定制特性使其在变形翼中具有重要的应用价值。该研究为新型可调谐CBMs的多功能设计提供了有价值的见解，并促进了其在航空航天工程中的应用。Research on shear buckling behaviour of friction stir welding 6061-T6 aluminium alloy H-section beamsBeibei Li, Yanjun Tong, Shuai Mo, Jingfeng Wang, Letian Hai, Yuanqing Wangdoi:10.1016/j.tws.2025.1139226061-T6铝合金h型梁搅拌摩擦焊接剪切屈曲行为研究This study systematically investigated the shear buckling behaviour of the friction stir welding (FSW) 6061-T6 aluminium alloy H-section beams through experimental and numerical an alysis methods. FSW is a solid-state joining process that exhibits superior retention of joint strength and markedly lower sensitivity to welding-induced defects in comparison to conventional fusion welding techniques. On the basis of experimental tests on six FSW 6061-T6 aluminium alloy H-section beams, the material properties, initial geometric imperfections, FSW-induced residual stresses, failure modes and load-deflection curves were reported. Finite element (FE) models were validated against experimental results to assess their predictive accuracy in failure modes and shear buckling resistances. A parametric a nalysis involving 708 FE models was subsequently conducted to expand the database. The results indicate that FE models incorporating FSW-induced strength reduction and residual stresses effectively enhanced the predictive accuracy and consistency of shear buckling resistances of specimens. The number/width of welds and residual stresses exhibited minimal influence on shear buckling performance, while the installation of rigid end posts could enhance the anchorage restraint on web tension field development, thereby improving the shear buckling capacity of beams. Initial geometric imperfections had a certain weakening effect on the ultimate bearing capacity of the beam, while the influence of their amplitude was limited. The experimental and FE results for FSW 6061-T6 aluminium alloy H-section beams were compared against current design requirements stipulated in Chinese, European, and American codes. The comparison results indicate that when the normalized width-to-thickness ratios of the web fell within the ranges of 0.5-1.0 and 0.6-1.2, the design resistance predictions of the Chinese and American codes were unsafe, and all predicted results were overall conservative by 24.0-34.5%, also with greater dispersion. Modifications were proposed based on Chinese and European codes, achieving a 6-18% improvement in prediction accuracy and reduced dispersion compared to current standards.通过试验和数值分析方法，系统研究了搅拌摩擦焊6061-T6铝合金h型钢梁的剪切屈曲行为。FSW是一种固态连接工艺，与传统的熔焊技术相比，它具有优越的接头强度保持能力和明显降低的焊接缺陷敏感性。在对6根FSW 6061-T6铝合金h型梁进行试验的基础上，报告了材料性能、初始几何缺陷、FSW残余应力、破坏模式和载荷-挠度曲线。通过实验验证了有限元模型在破坏模式和抗剪切屈曲方面的预测精度。随后进行了涉及708个有限元模型的参数分析，以扩大数据库。结果表明，考虑fsw强度折减和残余应力的有限元模型有效提高了试件抗剪切屈曲抗力预测的准确性和一致性。焊缝数量/宽度和残余应力对剪力屈曲性能的影响最小，而刚性端柱的安装可以增强对腹板张力场发展的锚固约束，从而提高梁的剪力屈曲能力。初始几何缺陷对梁的极限承载力有一定的削弱作用，但其幅值的影响有限。将FSW 6061-T6铝合金h型钢梁的试验和有限元结果与中国、欧洲和美国现行规范的设计要求进行了比较。对比结果表明，当归一化腹板宽厚比在0.5 ~ 1.0和0.6 ~ 1.2范围内时，中美两国规范的设计阻力预测不安全，预测结果总体保守24.0 ~ 34.5%，且离散性较大。基于中国和欧洲的规范提出了修改，与现行标准相比，预测精度提高了6-18%，并降低了离散度。Mechanical performance of Q690 high-strength steel bolted joints connecting H-section steel members to hollow spheres under bending and shear for suspend-dome structuresAilin Zhang, Bowen Jin, Xuechun Liu, Xuesen Chendoi:10.1016/j.tws.2025.113927Q690悬架穹顶结构h型钢构件与空心球连接的高强钢螺栓连接在弯曲和剪切下的力学性能Conventional suspend-dome structures typically employ upper latticed shells with extensive on-site welded components and joints, while the application of H-section steel members remains limited. This approach results in prolonged construction periods, inconsistent weld quality, and significant environmental pollution. To address these issues, a large-span fully assembled high-performance suspend-dome structure with H-section steel members was proposed, along with bolted joints connecting the H-section steel members to hollow spheres. Tests under combined bending and shear loading were conducted to investigate the out-of-plane flexural performance of the proposed joints. The failure modes, load transfer mechanis ms, moment-rotation curves, key performance indicators, and patterns of bolt preload and strain variation were obtained. The influence of the geometric parameters of joint components was studied through finite element an alysis. The joint design recommendations were proposed. Furthermore, theoretical formulations for the initial flexural stiffness and flexural capacities were proposed, and the accuracy was validated through comparison with test and finite element an alysis results.传统的悬索穹顶结构通常采用上部网架壳和大量现场焊接构件和接头，而h型钢构件的应用仍然有限。这种方法导致施工周期延长，焊接质量不一致，并造成严重的环境污染。为了解决这些问题，提出了一种采用h型钢构件的大跨度全组装高性能悬索穹顶结构，并用螺栓连接h型钢构件与空心球体。在弯曲和剪切联合荷载下进行了试验，以研究所提出的节点的面外弯曲性能。得到了锚杆的破坏模式、荷载传递机制、弯矩-旋转曲线、关键性能指标以及锚杆预紧力和应变变化规律。通过有限元分析，研究了接头构件几何参数的影响。提出了联合设计建议。提出了初始抗弯刚度和抗弯承载力的理论计算公式，并与试验结果和有限元分析结果进行了对比验证。Nonlinear Stability and Vibration Ana lysis of Fluid-Conveying Nanochannel Scroll Shells Using an Adaptive Neuro-Fuzzy Inference SystemMostafa Siavashi, Morteza Dardel, Mohammad Hadi Pashaeidoi:10.1016/j.tws.2025.113931基于自适应神经模糊推理系统的输送流体纳米通道涡旋壳非线性稳定性及振动分析This study comprehensively investigates the vibrational characteristics and nonlinear stability of nanoscale scroll channel shells during fluid conveyance. By employing the First Shear Deformation Theory (FSDT) in conjunction with the Modified Couple Stress Theory (MCST), a detailed mathematical model is developed to accurately characterize the behavior of the nano scroll channel shell. Nonlinear equations incorporating von Kármán strains are derived to refine the precision of the stability ana lysis. Additionally, the influence of van der Waals forces, which are fundamental at the nanoscale, is systematically examined. The research investigates the interactions between fluid-induced forces, geometric nonlinearities, and nanoscale phenomena through rigorous computational modeling and numerical simulations. A nonlinear modeling database is established to facilitate in-depth an alysis, integrating the geometric parameters and physical properties of nanochannels to support interpolation and extrapolation of key variables. Furthermore, machine learning frameworks, including Multilayer Perceptron Networks (MLP) and an Adaptive-Network-Based Fuzzy Inference System (ANFIS), are employed to predict natural frequencies with high accuracy, significantly enhancing predictive capabilities. This framework identifies various instability scenarios in nano scroll shell channels, including fluctuations in natural frequencies, fluid-induced instabilities, and bifurcation phenomena under diverse operational conditions. The findings contribute to a deeper understanding of the dynamic behavior and stability thresholds of nanoscale scroll shells in fluid environments, providing valuable insights for optimizing fluid transport systems and advancing research into nanoscale engineering applications.本文对纳米尺度涡旋通道壳在流体输送过程中的振动特性和非线性稳定性进行了全面研究。利用第一次剪切变形理论（FSDT）和修正耦合应力理论（MCST），建立了精确表征纳米涡旋通道壳行为的数学模型。推导了包含von Kármán应变的非线性方程，以提高稳定性分析的精度。此外，范德华力的影响，这是基本的在纳米尺度，被系统地检查。该研究通过严格的计算模型和数值模拟来研究流体诱导力、几何非线性和纳米尺度现象之间的相互作用。为了便于深入分析，建立了非线性建模数据库，整合纳米通道的几何参数和物理性质，支持关键变量的插值和外推。此外，采用多层感知器网络（MLP）和基于自适应网络的模糊推理系统（ANFIS）等机器学习框架对固有频率进行了高精度预测，显著提高了预测能力。该框架确定了纳米涡旋壳通道中的各种不稳定情况，包括固有频率波动、流体诱导的不稳定以及不同操作条件下的分岔现象。这些发现有助于更深入地了解纳米级涡旋壳在流体环境中的动态行为和稳定性阈值，为优化流体输送系统和推进纳米级工程应用研究提供有价值的见解。来源：复合材料力学仿真Composites FEM