今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 4 篇,Mechanics of Materials 1 篇,International Journal of Plasticity 2 篇,Thin-Walled Structures 7 篇
Vibration theory of piezoelectric plate with gradient thickness to frequency programmable design
Jialin Zuo, Peirong Zhong, Jinxin Xiao, Tianlin Jiang, Yukun Zhou, Wenhua Zhang
doi:10.1016/j.ijsolstr.2025.113381
梯度厚度压电板的振动理论到频率可编程设计
In today’s smart device applications, optimizing the properties and designing characteristics of piezoelectric materials is critical. This paper derives vibration theory of piezoelectric plate with gradient (stepped/continuous) thickness and investigates their mechanical–electrical coupling mechanism during vibration and the resonance behavior. With this theory, we have established the mapping relationship between the radius, thickness distribution, and intrinsic frequency of a piezoelectric plate with gradient thickness. It is a challenge to solve the multi-parameter inversion problem, determining the structural radius and thickness distribution through a given frequency. In this paper, a self-learning optimization loop algorithm is used to determine the frequency response ranges for variable-thickness plates with different radii, enabling rapid design for target frequencies. Subsequently, the theory is validated through a full-field scanning laser vibrometer experiment, with error for the first seven orders of the intrinsic frequency are ranges from 0.4% and 5%. This study presents a scheme for the frequency forward design of piezoelectric thin plates and demonstrate an interesting case of tone scale design. By thoroughly investigating the mechanical–electrical coupling mechanism of piezoelectric plate with gradient thickness during vibration, it is expected that this study will not only reveal its complex physical phenomena, but also provide a theoretical basis for optimal design.
在当今的智能设备应用中,优化压电材料的性能和设计特性是至关重要的。本文推导了梯度(阶梯/连续)厚度压电板的振动理论,研究了其振动过程中的机电耦合机理和共振行为。利用这一理论,我们建立了具有梯度厚度的压电板的半径、厚度分布和固有频率之间的映射关系。在给定频率下确定结构半径和厚度分布是多参数反演问题的难点。本文采用自学习优化回路算法确定不同半径变厚板的频响范围,实现了目标频率的快速设计。随后,通过全场扫描激光测振仪实验验证了该理论,其固有频率前7阶误差范围为0.4% ~ 5%。本文提出了压电薄板频率正向设计方案,并展示了一个有趣的音阶设计案例。通过深入研究梯度厚度压电板在振动过程中的机电耦合机理,不仅可以揭示其复杂的物理现象,而且可以为优化设计提供理论依据。
Effective mechanical response of biomimetic staggered composites: Closed-form estimates via a micromechanical variational formulation
Pierfrancesco Gaziano, Lorenzo Zoboli, Elisabetta Monaldo, Giuseppe Vairo
doi:10.1016/j.jmps.2025.106137
仿生交错复合材料的有效机械响应:通过微力学变分公式的封闭形式估计
Bio-inspired composite materials with staggered microstructures exhibit superior mechanical properties compared to traditional composites, paving the way for the development of advanced functional materials. The existing analytical models mainly address the macroscale constitutive response along the staggering direction using plane strain or plane stress assumptions. Consequently, a significant gap remains in the characterization of the equivalent material response in triaxial loading scenarios. This study presents a micromechanical variational formulation to derive an analytical and comprehensive characterization of the anisotropic homogenized behavior of biomimetic staggered composites. The microscale equilibrium problem, tailored to a suitable representative volume element, is tackled by applying stationary conditions to the total potential energy functional, evaluated over a class of quasi-compatible strain fields that capture the dominant microscale kinematics. A linearization technique leads to closed-form expressions that fully characterize the macroscale stiffness tensor of the material. Through a parametric case study, the obtained analytical results are compared with finite element micromechanical simulations and theoretical solutions and bounds. The results confirm the validity of the proposed formulation, demonstrating the consistency and accuracy of the obtained analytical estimates.
与传统复合材料相比,交错微结构的仿生复合材料具有优越的机械性能,为先进功能材料的发展铺平了道路。现有的分析模型主要采用平面应变或平面应力假设来求解沿交错方向的宏观尺度本构响应。因此,在等效材料在三轴加载情况下的响应表征方面仍然存在显著的差距。本研究提出了一种微力学变分公式,以推导出仿生交错复合材料各向异性均化行为的分析和综合表征。微尺度平衡问题,适合于一个合适的代表性体积单元,是通过对总势能泛函应用平稳条件来解决的,在一类准相容的应变场上进行评估,这些应变场捕获了主要的微尺度运动学。线性化技术导致封闭形式的表达式,充分表征材料的宏观刚度张量。通过参数化算例分析,将得到的解析结果与有限元细观力学模拟、理论解和边界进行了比较。结果证实了所提公式的有效性,证明了所得到的分析估计的一致性和准确性。
Force-field-induced energy-based design method for arbitrary prescribed modes in elastic metamaterials
Zhiwen Ren, Hao-Wen Dong, Mingji Chen, Haiou Yang, Yue-Sheng Wang, Li Cheng, Daining Fang
doi:10.1016/j.jmps.2025.106144
弹性超材料中任意规定模态的力场诱导能量设计方法
Elastic metamaterials possess flexible regulatory capabilities of elastodynamic field information and energy through engineering and tailoring wave amplitudes, phase, and polarization vectors. However, due to the lack of general wave quantities and dynamic mode characterization methods, it is difficult to describe and design customized elastic dispersions with prescribed eigenmodes of interest, especially under large wave vectors or high frequencies. To tackle this challenge, we propose a systematic design method based on force-field-induced energy to inversely customize arbitrary prescribed eigenmodes at required frequencies for both small and large wave vectors. We build up a dynamic mode characterization theory based on energy, which contributes to portraying eigenmode response behavior under external excitations. It theoretically reveals the distribution features of the energy, induced by external excitations, in wave vector-frequency (k−ω) domain for the solid media. A systematic inverse-design method, using responsive energy maximization, is proposed to tailor-make eigenmodes and dispersions under arbitrarily prescribed k−ω conditions. Then, a series of periodic porous structures are optimized to support orthotropic/anisotropic longitudinal, transversal and rotational modes at different k−ω points, alongside customized dispersion. Meanwhile, an inverse strategy fusing longitudinal and transversal modes is forged and used to realize broadband fluid-like mode in porous microstructure with an effective refractive index, in which a strongly suppressed transversal mode in the extremely low-frequency region of the dispersion and a single broadband longitudinal mode are supported. In addition, through inversely designing local vibration modes at three k−ω points simultaneously, a dispersion passband supporting negative group velocity is generated within an expected frequency range. Meanwhile, entire dispersion curves satisfying the prescribed k−ω relationship and supporting prescribed modes are customized. The wave behaviors of the optimized metamaterials are elucidated by phonon-band-structure experiments as well as numerical simulations. The established approach provides a universal design paradigm of wave modes that promises to pave the route for engineering extreme dispersion and functionalities.
弹性超材料通过工程设计和调整波幅、相位和极化矢量,具备对弹性动力场信息和能量进行灵活调控的能力。然而,由于缺乏通用的波量和动态模式表征方法,难以描述和设计具有特定特征模式的定制弹性色散,尤其是在 大 波矢或高频条件下。为解决这一难题,我们提出了一种基于力场诱导能量的系统设计方法,能够逆向定制任意给定频率下所需的特征模式,无论波矢大小。我们建立了一种基于能量的动态模式表征理论,有助于描绘固体介质在外部激励下的特征模式响应行为。从理论上揭示了外部激励在波矢-频率(k-ω)域中诱导的能量分布特征。提出了一种基于响应能量最大化的系统逆向设计方法,用于在任意给定的 k-ω 条件下定制特征模式和色散。然后,一系列周期性多孔结构被优化,以在不同的 k−ω 点支持各向异性/正交的纵向、横向和旋转模式,以及定制色散。同时,一种融合纵向和横向模式的逆向策略被制定并用于在具有有效折射率的多孔微结构中实现宽带流体状模式,在这种模式中,在色散的极低频区域强烈抑制横向模式,并支持单个宽带纵向模式。此外,通过同时逆向设计三个 k−ω 点的局部振动模式,在预期的频率范围内生成了支持负群速度的色散通带。同时,定制了满足规定的 k−ω 关系并支持规定模式的整个色散曲线。通过声子能带结构实验以及数值模拟阐明了优化后超材料的波行为。所建立的方法提供了一种通用的波模式设计范例,有望为工程极端色散和功能铺平道路。
Slow dynamic nonlinear elasticity during and after conditioning, a unified theory and a lock-in probe
John Y. Yoritomo, Richard L. Weaver
doi:10.1016/j.jmps.2025.106149
调节过程中和调节后的慢动态非线性弹性,统一理论和锁定探针
Of the non-classical nonlinear elastic phenomena, slow dynamics (SD) has received particular attention due to recent modeling efforts and experiments in new systems. SD is characterized by a loss of stiffness after a minor conditioning strain, followed by a slow recovery back towards the original stiffness. It is observed in many imperfectly consolidated granular materials (e.g., rocks and concrete) and unconsolidated systems (e.g., bead packs). Here we posit a simple unified phenomenological model capable of seamlessly describing modulus evolution for SD materials during steady-state conditioning, during conditioning ringdown, and during recovery. It envisions a distribution of breaking and healing bonds, with healing rates governed by the usual spectrum of relaxation times. Well after the end of conditioning, the model recovers the characteristic logarithmic-in-time relaxation. For times during conditioning ringdown, when recovery has initiated but conditioning has not fully ceased, the model predicts deviations from log(t) and a dependence on the ringdown rate. We compare these model predictions with SD measurements on four different systems. To perform the measurements, an ultrasonic digital lock-in (DLI) probe is developed. The advantages of DLI over other techniques to measure SD are a sufficiently high time resolution and an insensitivity to noise from conditioning. We find good agreement between theory and experiment. The model in conjunction with DLI also allows for estimates of the minimum relaxation time. Our measurements indicate that the minimum relaxation time is material dependent.
在非经典非线性弹性现象中,由于最近在新系统中的建模努力和实验,慢动力学(SD)受到了特别的关注。SD的特点是在轻微的调节应变后刚度损失,然后缓慢恢复到原始刚度。在许多不完全固结的颗粒材料(如岩石和混凝土)和未固结的系统(如砾石堆)中都可以观察到这种现象。在这里,我们假设了一个简单的统一现象学模型,能够无缝地描述SD材料在稳态条件下的模量演变,在条件消退期间,以及在恢复期间。它设想了一个断裂和愈合的关系分布,愈合率由通常的放松时间范围决定。在条件作用结束后,模型恢复了特征的对数时间弛豫。在调节停机期间,当恢复已经开始,但调节尚未完全停止时,该模型预测偏离log(t)和对停机率的依赖。我们将这些模型预测与四个不同系统的SD测量结果进行比较。为了进行测量,研制了一种超声数字锁相(DLI)探头。与其他测量SD的技术相比,DLI的优点是具有足够高的时间分辨率和对调节噪声不敏感。我们发现理论和实验很吻合。与DLI相结合的模型还允许估计最小松弛时间。我们的测量表明,最小弛豫时间与材料有关。
Probing Fracture Mechanics of Graphene through Heterocrack Propagation in a Moiré Superlattice
Yuan Hou, Jingzhuo Zhou, Zezhou He, Shuai Zhang, Qunyang Li, Huajian Gao, Yang Lu
doi:10.1016/j.jmps.2025.106151
通过莫尔维尔超晶格中异裂纹扩展探测石墨烯断裂力学
Understanding the fracture properties of two-dimensional (2D) materials is essential for enhancing their mechanical performance and extending the service life of 2D-based devices. A major challenge lies in examining stress singularities near crack tips at nanoscale. In this study, we show that we can obtain fracture toughness of monolayer graphene by investigating the propagation of heterocrack in twisted graphene layers. We developed an in situ mechanical measurement to monitor the heterocrack propagation under electron microscopy. The cracks propagated and deflected along the twisted graphene-graphene interfaces, accompanied by periodic stress fluctuations and distorted moiré superlattice. By further leveraging molecular dynamics simulations, we developed a moiré strain analysis method to track strain distributions during heterocrack propagation within moiré superlattice. The fracture toughness can be measured through the strain fields at the crack tip. Moreover, we examined the effect of the moiré potential on the heterocrack propagation behaviors and proposed an equivalent stress intensity factor to evaluate the fracture properties of graphene under varying twist angles. This work provides key insights into the fracture mechanics of 2D materials, and also offer a foundation for assessing the reliability and mechanical stability of 2D-material-based nanodevices.
了解二维(2D)材料的断裂特性对于提高其机械性能和延长基于2D的设备的使用寿命至关重要。一个主要的挑战在于在纳米尺度上检查裂纹尖端附近的应力奇点。在本研究中,我们发现可以通过研究异裂纹在扭曲石墨烯层中的扩展来获得单层石墨烯的断裂韧性。我们开发了一种在电子显微镜下监测异质裂纹扩展的原位力学测量方法。裂纹沿着扭曲的石墨烯-石墨烯界面扩展和偏转,伴随着周期性的应力波动和扭曲的莫尔维尔超晶格。通过进一步利用分子动力学模拟,我们开发了一种moir<s:1>应变分析方法来跟踪异裂纹在moir<s:1>超晶格内传播过程中的应变分布。断裂韧性可以通过裂纹尖端的应变场来测量。此外,我们还研究了波纹势对异裂纹扩展行为的影响,并提出了等效应力强度因子来评估石墨烯在不同扭转角度下的断裂性能。这项工作为二维材料的断裂力学提供了关键的见解,也为评估基于二维材料的纳米器件的可靠性和机械稳定性提供了基础。
The effect of microstructural inertia on plastic localization and void growth in porous solids
N. Hosseini, T. Virazels, N. Jacques, J.A. Rodríguez-Martínez
doi:10.1016/j.mechmat.2025.105339
微观结构惯性对多孔固体塑性局部化和孔洞生长的影响
This paper investigates the impact of microinertia on plastic localization, void growth, and coalescence in ductile porous materials subjected to high strain rates. For that purpose, we have performed finite element calculations on a flat double-notched specimen subjected to dynamic plane strain tension. The simulations employ three distinct approaches to model the mechanical behavior of the porous aggregate: (1) discrete voids within a matrix material governed by von Mises plasticity; (2) homogenized porosity represented using standard quasi-static Gurson-Tvergaard plasticity; and (3) homogenized porosity described with Gurson-Tvergaard plasticity extended by Molinari and Mercier (2001) to account for microinertia effects. The porous microstructures used in the simulations are representative of additive manufactured metals, featuring initial void volume fractions varying between 0.5% and 4%, and pore diameters ranging from 30 μ m to 150 μ m (Marvi-Mashhadi et al., 2021, Nieto-Fuentes et al., 2023). The applied tensile velocities ranged from 100 m / s to 1000 m / s , producing strain rates between 1 0 5 s − 1 and 1 0 6 s − 1 , and stress triaxiality values spanning from 4 to 30. The simulations with discrete voids validate the calculations performed using homogenized porosity and microinertia effects, demonstrating that higher strain rates and larger pore sizes lead to slower void growth and a delayed, regularized plastic localization. Conversely, the standard Gurson-Tvergaard model shows notable mesh sensitivity and fails to describe the influence of the loading rate on plastic localization. Ultimately, the comparison between finite element models with discrete voids and those with homogenized porosity illustrates the stabilizing effects of porous microstructure and multiscale inertia on dynamic plastic flow, while also highlighting the strengths of the constitutive model introduced by Molinari and Mercier (2001) for simulating engineering problems involving porous ductile materials subjected to high-velocity impacts.
本文研究了微惯性对高应变率下延性多孔材料塑性局部化、孔洞生长和聚结的影响。为此,我们对受动平面应变张力作用的扁平双缺口试样进行了有限元计算。模拟采用三种不同的方法来模拟多孔骨料的力学行为:(1)由von Mises塑性控制的基质材料内的离散空隙;(2)均匀孔隙率用标准准静态Gurson-Tvergaard塑性表示;(3)用Molinari和Mercier(2001)推广的Gurson-Tvergaard塑性来描述均匀孔隙度,以解释微惯性效应。模拟中使用的多孔微结构代表了添加剂制造的金属,其初始孔隙体积分数在0.5%至4%之间,孔径在30 μ m至150 μ m之间(Marvi-Mashhadi等人,2021,Nieto-Fuentes等人,2023)。施加的拉伸速度范围为100m / s至1000m / s,产生的应变速率为10.5 s−1至10.6 s−1,应力三轴性值为4至30。离散孔洞的模拟验证了均匀孔隙和微惯性效应的计算结果,表明更高的应变率和更大的孔洞尺寸导致孔洞生长更慢,并且延迟了正则化的塑性局部化。相反,标准Gurson-Tvergaard模型具有显著的网格敏感性,无法描述加载速率对塑性局部化的影响。最后,将具有离散孔洞的有限元模型与具有均匀孔洞的有限元模型进行比较,说明了多孔微观结构和多尺度惯性对动态塑性流动的稳定作用,同时也突出了Molinari和Mercier(2001)引入的本构模型在模拟涉及受高速冲击的多孔延性材料的工程问题时的优势。
Effect of Twinning on Shear Localization of Al0.1CoCrFeNi High Entropy Alloy at High Strain Rates: Experiment and Crystal Plasticity Modeling
Wen An, Jiang-Peng Yang, Chuan-Zhi Liu, Qi-Lin Xiong
doi:10.1016/j.ijplas.2025.104339
孪生对高应变速率下Al0.1CoCrFeNi高熵合金剪切局部化的影响:实验与晶体塑性模拟
As one of the most important plastic deformation mechanisms of high-entropy alloys, deformation twinning can increase the strength without losing plasticity. Nevertheless, recent studies have shown that high-density twins can form "soft spots" and promote the occurrence of shear localization failure at high strain rates. The extent to which deformation twins contribute to the formation of shear localization remains unclear. In this study, a series of dynamic uniaxial compression experiments have been performed with Al0.1CoCrFeNi HEAs under different conditions to disclose the dynamic recrystallization mechanism. Corresponding to the dynamic recrystallization and plastic dissipation mechanisms at high strain rates, a dislocation entanglement model has been established in conjunction with deformation twinning and physically based heat dissipation to capture the process of shear localization formation. The dislocation entanglement model has been integrated into the theoretical framework of crystal plasticity to perform finite element simulations of high-strain rate deformations. The results predicted by the crystal plasticity simulations are in good agreement with the experimental data, confirming the rationality of the new constitutive model. Deformation twinning can significantly improve strain hardening ability and resistance to shear localization. Interestingly, when the volume fraction of twins reaches a certain level, the mechanism of twin-assisted continuous dynamic recrystallization is triggered due to the interaction between dislocations and twins, resulting in the formation of many “soft spots” (corresponding to the twin region with high density). Upon further deformation, these “soft spots” continue to evolve and aggregate to eventually form the bands of shear localization. Our results can be used for the microstructure design of dynamic high-performance metals with high strength and plasticity to artificially control shear localization.
变形孪晶是高熵合金最重要的塑性变形机制之一,可以在不损失塑性的情况下提高合金的强度。然而,最近的研究表明,高密度孪晶在高应变速率下会形成“软点”,促进剪切局部化破坏的发生。变形孪晶在多大程度上促成了剪切局部化的形成尚不清楚。本研究对Al0.1CoCrFeNi HEAs在不同条件下进行了一系列动态单轴压缩实验,揭示了动态再结晶机理。针对高应变速率下的动态再结晶和塑性耗散机制,建立了结合变形孪晶和物理散热的位错纠缠模型,以捕捉剪切局部化形成过程。将位错纠缠模型整合到晶体塑性的理论框架中,进行高应变速率变形的有限元模拟。晶体塑性模拟预测结果与实验数据吻合较好,证实了新本构模型的合理性。变形孪晶可以显著提高材料的应变硬化能力和抗剪切局部化能力。有趣的是,当孪晶体积分数达到一定水平时,由于位错与孪晶的相互作用,触发孪晶辅助连续动态再结晶机制,导致形成许多“软点”(对应高密度孪晶区)。在进一步变形后,这些“软点”继续演化和聚集,最终形成剪切局部化带。研究结果可用于高强度、高塑性动态高性能金属的微观结构设计,人为控制剪切局部化。
Tensile Behavior of Additively Manufactured Inconel 718 and Stainless Steel 316L with Compositionally Graded Joints
Yaojie Wen, Yang Gao, Ramasubramanian Lakshmi Narayan, Wei Cai, Pei Wang, Xiaoding Wei, Baicheng Zhang, Upadrasta Ramamurty, Xuanhui Qu
doi:10.1016/j.ijplas.2025.104342
增材制造Inconel 718和不锈钢316L复合梯度接头的拉伸性能
The microstructure and tensile behavior of laser powder bed fusion (LPBF) processed 316L austenitic stainless steel (316L) and Inconel 718 Ni-based superalloy (IN718) coupons with compositionally graded joints (CGJ), spanning lengths of 0, 10 and 20 mm, in the as built and heat-treated conditions, are investigated. In the as built condition, the microstructure of pure 316L and IN718 ligaments consist of micron-sized sub-grains present within <001> textured columnar grains, whereas CGJs contain a mixture of randomly textured columnar and equiaxed grains. Heat treatment, involving solutionizing above 1040 °C with subsequent ageing at 720 and 620 °C, leads to the recrystallization of portions with > 85 wt.% IN718 of the CGJ coupons. Higher composition gradient span, in both the as built and heat-treated states, improves the yield and tensile strengths of the specimens, but compromises ductility. Tension-compression asymmetry, which also progressively increases with increasing strain and the CGJ span, is observed in all the specimens. Simulations indicate that CGJs with shallower composition gradients have lower fluctuations in the stress triaxiality, von mises equivalent stress, and the maximum shear stress compared to those with sharper gradients. These mechanical property variations and the deformation characteristics of the CGJ specimens are analyzed in detail by considering the varying degrees of plastic constraint on the 100 wt.% 316L and the degree of interactions between strain-generated dislocations and geometrically necessary dislocations. Finally, the effectiveness of CGJ in enhancing the tensile properties of the 316L/IN718 joints and the geometrical considerations for designing such joints for different alloy combinations is discussed.
研究了激光粉末床熔合(LPBF)加工316L奥氏体不锈钢(316L)和Inconel 718镍基高温合金(IN718)在预制和热处理条件下的组织和拉伸行为,并对其组成渐变接头(CGJ)的长度分别为0、10和20 mm。在实验条件下,纯316L和IN718韧带的显微组织由微米级的亚晶粒组成,这些亚晶粒存在于<001>的织构柱状晶粒中,而CGJs则由随机织构的柱状晶粒和等轴晶粒混合组成。热处理,包括1040°C以上固溶,随后在720°C和620°C时效,导致含> 85 wt.% IN718的部分再结晶。较高的成分梯度跨度,无论是在建成和热处理状态,提高屈服和抗拉强度的试样,但妥协延性。拉压不对称性随应变和CGJ跨度的增大而逐渐增大。模拟结果表明,相对于梯度较陡的复合材料,梯度较浅的复合材料在应力三轴性、von mises等效应力和最大剪切应力方面的波动较小。考虑到100wt .% 316L的塑性约束程度的不同,以及应变产生的位错与几何必要位错之间的相互作用程度,详细分析了CGJ试样的力学性能变化和变形特征。最后,讨论了CGJ提高316L/IN718接头拉伸性能的有效性,以及设计不同合金组合的接头时应考虑的几何因素。
Elastic dislocation states of full-polarization micromechanical metamaterials
Yuyang Chen, Boqing Lei, Ying Wu, Yijie Liu, Zhiwei Yu
doi:10.1016/j.tws.2025.113270
全极化微机械超材料的弹性位错态
Benefiting from the profound advancements in topological metamaterials of condensed matter physics, micromechanical metamaterials have demonstrated extensive applicability in transporting high-frequency elastic waves. However, the full-polarization elastic waves impose profound challenges on the practical applications of micromechanical metamaterials. Since most current studies remain confined to single polarization, we have engineered micromechanical metamaterials capable of eliciting a full polarization response to topological edge and corner modes. Firstly, we design a phononic crystal with C4 symmetry, which exhibits line degeneracies along the boundaries of the Brillouin zone. Line degeneracies are lifted through geometric perturbation, and a higher-order bandgap identified by modal analysis is generated. By successfully separating the high-order bandgaps for in-plane and out-of-plane modes, we achieve edge and corner states in pure in-plane, out-of-plane, and full-polarization configurations. Besides, we first incorporate topological Wannier cycles into full-polarization micromechanical metamaterials. Compared to the edge states in higher-order phases, the robust dislocation states span nearly the entire bandgap, greatly enhancing the utilization of topological protection. Inspired by the mode conversion of elastic waves, we explored the coupling phenomenon between dislocation and edge states, which enhances the energy harvesting and frequency identification capabilities of higher-order dislocation structures. The novel concept of combining helical dislocations with artificial gauge flux significantly expands the manipulation of full-polarization elastic waves, offering a powerful tool for identifying higher-order topological phases.
得益于凝聚态物理拓扑超材料的深刻进展,微机械超材料在传输高频弹性波方面表现出了广泛的适用性。然而,全极化弹性波对微机械超材料的实际应用提出了深刻的挑战。由于目前大多数研究仍然局限于单极化,我们设计了能够引发拓扑边缘和角模式的完全极化响应的微机械超材料。首先,我们设计了一个C4对称的声子晶体,沿布里渊带边界表现出线简并。通过几何扰动解除了线简并,产生了由模态分析识别的高阶带隙。通过成功分离平面内和平面外模式的高阶带隙,我们实现了纯平面内、平面外和全极化配置的边缘和角态。此外,我们首次将拓扑万尼尔循环引入到全极化微机械超材料中。与高阶相的边缘态相比,鲁棒位错态几乎覆盖了整个带隙,大大提高了拓扑保护的利用率。受弹性波模态转换的启发,我们探索了位错与边缘态之间的耦合现象,从而提高了高阶位错结构的能量收集和频率识别能力。将螺旋位错与人工规范通量相结合的新概念极大地扩展了对全极化弹性波的操作,为识别高阶拓扑相提供了有力的工具。
Multi-physical driven time-dependent reliability analysis framework for reinforced concrete floating wind turbine foundations considering climate change
Jiaxin Zhang, Hongyuan Guo, Jafar Jafari-Asl, You Dong, Emilio Bastidas-Arteaga, Hongzhi Cui
doi:10.1016/j.tws.2025.113309
考虑气候变化的钢筋混凝土浮式风力机基础多物理驱动时变可靠性分析框架
As a critical component of floating offshore wind turbines (FOWTs), reinforced concrete (RC) floating foundations are typically designed to last two to three times longer than the upper structure. However, their durability and reliability are challenged due to the coupled effects of corrosion and fatigue in harsh marine environments. This study proposes a multi-physics coupling framework to explore the deterioration mechanisms of RC-FOWT foundations under dynamic wind-wave loading and adverse environments. A cylindrical chloride diffusion model quantifies chloride transport in concrete, considering temperature, humidity, and fatigue-induced cracks. A pitting corrosion model assesses the cross-sectional loss and pitting depth of steel reinforcements, while the Paris-Erdogan fatigue crack growth model simulates corrosion-induced crack propagation under cyclic loading. Additionally, probability density function informed method-driven probabilistic analysis and various climate change scenarios predict the time-dependent failure probability of FOWT foundations. Results indicate that extreme climate change scenarios increase energy production by 12.9% compared to non-climate-change scenario. However, chloride diffusion and corrosion rates accelerate by 62%, significantly speeding up crack propagation and reducing structural lifespan by approximately 49.15%. This study highlights the trade-off between increased energy production and accelerated structural deterioration due to climate change, emphasizing the need for balanced design considerations.
作为海上浮式风力发电机的关键部件,钢筋混凝土(RC)浮式基础的使用寿命通常是上部结构的两到三倍。然而,在恶劣的海洋环境中,由于腐蚀和疲劳的耦合作用,它们的耐久性和可靠性受到了挑战。本研究提出了一个多物理场耦合框架,探讨RC-FOWT地基在动力风浪荷载和恶劣环境下的劣化机制。圆柱氯化物扩散模型量化氯化物在混凝土中的传输,考虑温度、湿度和疲劳引起的裂缝。点蚀模型评估钢筋的截面损失和点蚀深度,而Paris-Erdogan疲劳裂纹扩展模型模拟循环加载下腐蚀诱导的裂纹扩展。此外,概率密度函数指示方法驱动的概率分析和各种气候变化情景预测了FOWT基础随时间变化的破坏概率。结果表明,与非气候变化情景相比,极端气候变化情景的能源产量增加了12.9%。然而,氯化物的扩散和腐蚀速率加快了62%,显著加快了裂纹扩展,使结构寿命缩短了约49.15%。这项研究强调了由于气候变化导致的能源生产增加和结构加速恶化之间的权衡,强调了平衡设计考虑的必要性。
Lipped Channel section laminated beams with non-symmetries subjected to four-point bending
Filip Kazmierczyk, Monika Zaczynska, Tomasz Kubiak
doi:10.1016/j.tws.2025.113311
受四点弯曲的非对称唇形槽截面层合梁
Short GFRP beams with lipped cross-section beams subjected to four-point bending have been investigated. The influence of non-symmetries in the form of non-symmetric cross-section and non-symmetric laminate layer arrangement on buckling and post-buckling behavior has been investigated. It was found that also for short beams under bending the distortion or lateral distortion buckling mode could exist. These types of buckling modes may lead to lateral deflection in the post-buckling range and finally decrease the load-carrying capacity. The non-symmetrical layer arrangement characterizes the non-obvious behavior due to different types of ABD matrix couplings. Therefore, it was danalyzed how the layer arrangements impact the lateral deflection, buckling load, and/or load-carrying capacity. The finite element model has been developed and validated by the results of experimental tests. The parametric studies, i.e., checking the influence of non-symmetries on beam behavior have been performed. Discussing relations between layer arrangements, cross-section, buckling, and post-buckling behavior is presented. Where it was found that it is possible to find non-symmetrical cross-section and layer arrangements that provide the lowest lateral deflections.
对具有唇形截面的GFRP短梁进行了四点弯曲试验研究。研究了非对称截面和非对称层合层排列形式的非对称性对屈曲和后屈曲行为的影响。研究发现,在弯曲作用下,短梁也可能存在畸变或侧向畸变屈曲模式。这些类型的屈曲模式可能导致后屈曲范围内的侧向挠曲,最终降低承载能力。由于不同类型的ABD矩阵耦合,非对称层排列具有不明显的行为特征。因此,分析了层的布置对横向挠度、屈曲载荷和承载能力的影响。建立了有限元模型,并通过试验验证了模型的正确性。进行了参数化研究,即检查非对称性对梁性能的影响。讨论了层布、截面、屈曲和后屈曲行为之间的关系。发现有可能找到提供最低横向挠度的非对称截面和层排列。
Effects of center-hung scoreboard on seismic responses of suspendome structure
Zhen Lu, Xiongyan Li, Suduo Xue, Yuanqing Wang, Caibao Liu
doi:10.1016/j.tws.2025.113313
中悬记分板对悬索结构地震反应的影响
In order to investigate the effect of the center-hung scoreboard on the seismic response of the suspendome structure, a two-degree-of-freedom (2-DOF) series dynamic model was established based on the primary-secondary coupled effect. The dynamic response of the coupled system was then derived using the transfer function method. Subsequently, the MATLAB software was used to conduct a comprehensive investigation into the impact of various parameters, including the center-hung scoreboard, its lifting, and the site soil characteristic frequency, on the vertical and horizontal seismic responses of the suspendome structure. By comparing with the test results, the impact of different parameters on the dynamic response of the suspendome structure was obtained. Finally, the parametric analysis of the mass ratio and frequency ratio was carried out by using the verified stochastic seismic model of the primary-secondary coupled system. The characteristics and laws of the dynamic interaction between the center-hung scoreboard and the suspendome structure were found and summarized: the center-hung scoreboard increases the vertical seismic response of the primary structure. The center-hung scoreboard exerts a comparatively minor impact on the horizontal seismic response of the primary structure. The center-hung scoreboard lifting has little effect on the seismic response of the superstructure. From the perspective of acceleration and displacement, in order to realize the desired interactive damping of the center-hung scoreboard and suspendome structure, the frequency ratio β ≥ 4 should be guaranteed.
为了研究中心悬挂记分牌对悬架结构地震反应的影响,建立了基于主次耦合效应的两自由度串联动力模型。然后利用传递函数法推导了耦合系统的动态响应。随后,利用MATLAB软件对悬架结构的竖向和水平地震反应进行了综合研究,研究了中心悬挂记分牌、其升力、场地土体特征频率等参数对悬架结构竖向和水平地震反应的影响。通过与试验结果的比较,得到了不同参数对悬架结构动力响应的影响。最后,利用经验证的主次耦合系统随机地震模型,对质量比和频率比进行了参数化分析。发现并总结了中挂记分板与悬架结构动力相互作用的特点和规律:中挂记分板增加了主结构的竖向地震反应;中心悬挂记分牌对主结构水平地震反应的影响较小。中心悬挂记分牌提升对上部结构的地震反应影响不大。从加速度和位移角度考虑,为实现中挂记分牌与悬架结构所需的交互阻尼,应保证频率比β≥4。
Nonlinear dynamic analyses of a rotating ferromagnetic functionally graded cylindrical shell with initial geometric imperfections
Tao Yang, Yuda Hu
doi:10.1016/j.tws.2025.113264
具有初始几何缺陷的旋转铁磁功能梯度圆柱壳的非线性动力学分析
In this paper, the magneto-thermoelastic dynamic response of a rotating ferromagnetic functionally graded (FG) cylindrical shell with initial geometric imperfections is investigated. Considering the temperature dependence and spatial graded characteristics of physical properties, a combination of power-law distribution and temperature-dependent function is employed to formulate the equivalent physical parameters mathematically. Using the physical neutral surface as a reference and based on Donnell's nonlinear shell theory, constitutive equations are established for the FG cylindrical shell with initial geometric imperfections. Meanwhile, considering the effect of rotation, which induces both the centrifugal force and initial circumferential tension, expressions for kinetic energy and initial strain energy are presented. According to the electromagnetic elasticity theory, the Lorentz force generated by the eddy current effect and the nonlinear magnetization force due to spin magnetic moments are deduced. Subsequently, the nonlinear governing equations are established and discretized based on Hamilton's principle and Galerkin's method. Analytical solutions for the steady-state response are derived utilizing the multi-scale method, and stability conditions of the resonance response are determined by the Lyapunov theory. Afterward, numerical results are leveraged to perform detailed parametric studies on the vibration response of different resonance forms. Of particular interest in this process is the influence of initial geometric imperfections and external physical fields on the resonance behavior. This study offers a rigorous solution and deepens the understanding of the dynamic behavior of rotating imperfect cylindrical shells in multi-physical fields.
本文研究了具有初始几何缺陷的旋转铁磁功能梯度(FG)圆柱壳的磁热弹性动力学响应。考虑到物性的温度依赖性和空间梯度特征,采用幂律分布和温度依赖函数相结合的数学方法来表示等效物性参数。以物理中性面为参考,基于Donnell非线性壳理论,建立了具有初始几何缺陷的FG圆柱壳的本构方程。同时,考虑到旋转的影响,产生离心力和初始周向张力,给出了动能和初始应变能的表达式。根据电磁弹性理论,推导了涡流效应产生的洛伦兹力和自旋磁矩引起的非线性磁化力。然后,根据Hamilton原理和Galerkin方法建立非线性控制方程,并对其进行离散化。利用多尺度法推导了稳态响应的解析解,并利用李亚普诺夫理论确定了谐振响应的稳定条件。然后,利用数值结果对不同共振形式的振动响应进行了详细的参数化研究。在这一过程中 特别令人感兴趣的是初始几何缺陷和外部物理场对共振行为的影响。该研究提供了一个严谨的解决方案,加深了对旋转非完美圆柱壳在多物理场中的动力学行为的理解。
Stability of prestressed stayed I-section steel columns: Zones-based and intelligent design considering local buckling
Kaidong Wu, Xinyu Zhou, Cheng Huang, Zhe Xing, Ziheng Lu, Kuntao Quan
doi:10.1016/j.tws.2025.113269
预应力工字截面钢柱的稳定性:考虑局部屈曲的区域智能设计
The instability and design methods of prestressed stayed I-section steel columns are investigated with local buckling taken into accounts. Mechanical tests on this system are conducted, and a validated finite element modelling is developed. The conventional prestressing zones are revised through introducing the effective cross-section from EN 1993-1-5. It is found that the nonlinear stability and actual optimum prestress of this system are strongly linked to dominant global buckling modes, and for the cases with more significant local buckling, the buckling and post-buckling behaviour are less sensitivity to stay size, crossarm length and prestressing levels. Explicit expressions for designing the load-carrying capacity of this system are proposed based on the revised prestressing zones, and an artificial neural network (ANN) model for predicting ultimate loads is also developed. The comparison between these two design methods shows that the performance of the ANN model based design method is more robust and satisfied.
研究了考虑局部屈曲的预应力工字形截面钢柱的失稳及设计方法。对该系统进行了力学试验,并建立了有效的有限元模型。通过引入en1993 -1-5的有效截面,对传统预应力区域进行了修订。研究发现,该系统的非线性稳定性和实际最优预应力与主要的全局屈曲模式密切相关,而对于局部屈曲较为显著的情况,屈曲和后屈曲行为对横臂尺寸、横臂长度和预应力水平的敏感性较小。提出了基于修正预应力区域的系统承载力设计显式表达式,并建立了预测极限荷载的人工神经网络(ANN)模型。两种设计方法的比较表明,基于人工神经网络模型的设计方法具有更强的鲁棒性和令人满意的性能。
Experimental and Numerical Investigation of Axially Loaded Aluminium Alloy Angle Struts with Lateral Bracing on One Leg
Zhaoyu Xu, Yujia Zhang, Lei Zhang, Yafei Chen, Genshu Tong
doi:10.1016/j.tws.2025.113310
轴向载荷单腿侧撑铝合金角支撑的试验与数值研究
This study investigates the buckling behaviour and resistance of aluminium alloy angle struts with lateral bracing on one leg. Axial compressive tests were conducted on eleven simply supported angle struts, each with one leg supported by lateral bracing. The initial geometric imperfections of the specimens were carefully measured using a 3D laser scanner. Finite element models were developed to perform a comprehensive parametric study. The sensitivity to initial imperfections was analysed in detail. The ratio of the flexural buckling load about the rectangular axis Ncr,FR to the torsional buckling load Ncr,T was found to have a significant effect on the buckling behaviour. Comparison of buckling resistance indicates that existing design codes cannot be directly applied to aluminium alloy angle struts with lateral bracing on one leg. By introducing the elastic buckling load ratio Ncr,FR / Ncr,T, the proposed new design methods demonstrated good accuracy.
本研究对单侧有侧向支撑的铝合金角撑杆的屈曲行为和承载能力进行了研究。对 11 根简支角撑杆进行了轴向压缩试验,每根角撑杆的一侧均有侧向支撑。采用三维激光扫描仪对试件的初始几何缺陷进行了精确测量。建立了有限元模型以进行全面的参数研究。详细分析了初始缺陷的敏感性。发现绕矩形轴的弯曲屈曲载荷 Ncr,FR 与扭转屈曲载荷 Ncr,T 的比值对屈曲行为有显著影响。屈曲承载能力的对比表明,现有的设计规范不能直接应用于单侧有侧向支撑的铝合金角撑杆。通过引入弹性屈曲载荷比 Ncr,FR / Ncr,T,所提出的新设计方法显示出良好的准确性。