今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 2 篇,Mechanics of Materials 2 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 5 篇
Re-straining induced triggering of Portevin-Le Chatelier effect in recrystallized 2198 T3 and T8 aluminium alloy: Experimental observations and FE simulations for s mooth and notched samples
S.C. Ren, T.F. Morgeneyer, G. Rousselier, M. Mazière, S. Forest
doi:10.1016/j.ijsolstr.2025.113636
再结晶2198 T3和T8铝合金中波蒂文-勒夏特列效应的再应变触发:光滑和缺口样品的实验观察和有限元模拟
The susceptibility of 2198 Al-Cu-Li alloys to the Portevin-Le Chatelier (PLC) effect was investigated under various testing conditions, including constant strain rate, relaxation, and strain rate jump tests on tensile specimens. The localisation behaviour in the naturally aged state (T3R) was compared with that in the artificially aged state (T8R) using digital image correlation (DIC). Additionally, the triggering of the PLC effect following a change in the strain path was observed. The T8R grade, which contains various precipitates, exhibits no localisation across temperatures from -50 to 80 °C. In contrast, localisations are observed in the T3R grade, which lacks precipitates, suggesting that Dynamic Strain ageing (DSA) is still the dominant mechanis m responsible for serrated yielding, rather than precipitate shearing. A McCormick-type macroscopic elastoviscoplastic model, implemented in a finite element solver, was calibrated with experimental data to simulate the effects of different loading conditions on tensile specimens. The triggering effect and spatio-temporal patterns were well captured compared to DIC results for both T3R and T8R grades. The model was also employed to simulate the early plasticity during tearing tests of flat compact-tension-like samples in order to make a direct comparison with laminography-DVC (Digital Volume Correlation) experiments. Slant localisation patterns ahead of the notch are predicted by these models but are more mobile than those observed in laminography-DVC experiments of previous studies. The differences between constant strain rate and interruptive loading conditions are evidenced. Interestingly, even for the material in artificially aged T8 condition, strain bands were predicted ahead of the notch after restraining.
研究了2198 Al-Cu-Li合金在恒应变速率、松弛和应变速率跳跃试验条件下对波特文-勒夏特列(PLC)效应的敏感性。利用数字图像相关技术(DIC)比较了自然老化状态(T3R)和人工老化状态(T8R)下的定位行为。此外,观察到应变路径变化后触发PLC效应。T8R级含有各种沉淀,在-50至80°C的温度范围内没有局部化。相比之下,在T3R级中观察到局域化,缺乏沉淀,这表明动态应变老化(DSA)仍然是导致锯齿状屈服的主要机制,而不是沉淀剪切。在有限元求解器中建立mccormick型宏观弹粘塑性模型,并用实验数据进行标定,模拟不同加载条件对拉伸试件的影响。与DIC结果相比,T3R和T8R等级的触发效应和时空格局都得到了很好的捕捉。利用该模型模拟了平面类压紧拉伸试样撕裂试验的早期塑性,并与层析-数字体积相关(dvc)实验进行了直接比较。这些模型预测了缺口前的倾斜定位模式,但比以前研究的层析成像- dvc实验中观察到的模式更具流动性。证明了恒定应变速率和中断加载条件之间的差异。有趣的是,即使是人工时效T8条件下的材料,抑制后的应变带也能提前 预测到缺口。
Harmonizing Continuum and Discrete Theories for Monatomic Graphene: Uncertainties and Challenges
Jian Wei Yan, Ling Hui He, C.W. Lim, Wei Zhang
doi:10.1016/j.jmps.2025.106361
协调单原子石墨烯的连续统和离散理论:不确定性和挑战
Any nanomaterials with periodic, discrete structure exhibit scale effects, thus a common belief is that direct application of classical continuum theories is skeptical. Many studies reveal that there is significant difference between the classical continuum model and discrete model and thus a variety of modified continuum models have been proposed. Is it really impossible to harmonize the classical continuum and discrete theories? Here we show that there exist two distinct aspects for the concept of material thickness: intrinsic thickness and structural thickness, which correspond to the occupied space by physical particles and non-particle physical effect such as long-range force. For a suspended stacked-layer graphene, the most representative nanomaterial, the structural thickness produced by long-range force becomes a quantity that has a similar order with intrinsic thickness in terms of physical effects. While for monolayer graphene, the structural thickness does not exist because any long-range force vanishes. This discontinuity from mono- to multi-layer graphene leads to a highly controversial issue of applicability for the classical continuum theories. We thus reexamine the feasibility with respect to monolayer graphene and carbon nanotube, and devote to harmonize a missing bridge between the classical continuum mechanics and discrete mechanics models.
任何具有周期性、离散结构的纳米材料都表现出尺度效应,因此人们普遍认为经典连续介质理论的直接应用是值得怀疑的。许多研究表明经典连续统模型与离散模型存在显著差异,因此提出了各种修正的连续统模型。难道真的不可能调和经典的连续和离散理论吗?在这里,我们证明了材料厚度的概念存在两个不同的方面:内在厚度和结构厚度,它们对应于物理粒子和非粒子物理效应(如远程力)所占据的空间。对于最具代表性的悬浮叠层石墨烯纳米材料而言,远程力产生的结构厚度在物理效应上与固有厚度具有相似的数量级。而对于单层石墨烯,结构厚度不存在,因为任何远程力都消失了。这种从单层到多层石墨烯的不连续导致了经典连续介质理论的适用性问题。因此,我们重新审视单层石墨烯和碳纳米管的可行性,并致力于协调经典连续介质力学和离散力学模型之间缺失的桥梁。
A multi-physics model for dislocation driven spontaneous grain nucleation and microstructure evolution in polycrystals
I.T. Tandogan, M. Budnitzki, S. Sandfeld
doi:10.1016/j.jmps.2025.106325
位错驱动的多晶自发晶粒成核和微观结构演化的多物理场模型
The granular microstructure of metals evolves significantly during thermomechanical processing through viscoplastic deformation and recrystallization. Microstructural features such as grain boundaries, subgrains, localized deformation bands, and non-uniform dislocation distributions critically influence grain nucleation and growth during recrystallization. Traditionally, modeling this coupled evolution involves separate, specialized frameworks for mechanical deformation and microstructural kinetics, typically used in a staggered manner. Nucleation is often introduced ad hoc, with nuclei seeded at predefined sites based on criteria like critical dislocation density, stress, or strain. This is a consequence of the inherent limitations of the staggered approach, where newly formed grain boundaries or grains have to be incorporated with additional processing. In this work, we propose a unified, thermodynamically consistent field theory that enables spontaneous nucleation driven by stored dislocations at grain boundaries. The model integrates Cosserat crystal plasticity with the Henry–Mellenthin–Plapp orientation phase field approach, allowing the simulation of key microstructural defects, as well as curvature- and stored energy-driven grain boundary migration. The unified approach enables seamless identification of grain boundaries that emerge from deformation and nucleation. Nucleation is activated through a coupling function that links dislocation-related free energy contributions to the phase field. Dislocation recovery occurs both at newly formed nuclei and behind migrating grain boundaries. The model’s capabilities are demonstrated using periodic bicrystal and polycrystal simulations, where mechanis ms such as strain-induced boundary migration, subgrain growth, and coalescence are captured. The proposed spontaneous nucleation mechanis m offers a novel addition to the capabilities of phase field models for recrystallization simulation.
在热机械加工过程中,金属的颗粒组织通过粘塑性变形和再结晶发生了显著的变化。在再结晶过程中,晶界、亚晶、局部变形带和不均匀位错分布等微观组织特征对晶粒的形核和生长有重要影响。传统上,这种耦合演化的建模涉及单独的、专门的机械变形和微观结构动力学框架,通常以交错的方式使用。成核通常是特别引入的,根据诸如临界位错密度、应力或应变等标准,在预定义的位置播种核。这是交错方法固有局限性的结果,其中新形成的晶界或晶粒必须与额外的处理相结合。在这项工作中,我们提出了一个统一的,热力学一致的场理论,使晶界储存的位错驱动的自发成核。该模型将Cosserat晶体塑性与henry - mellenlin - plapp取向相场方法相结合,可以模拟关键的微观结构缺陷,以及曲率和存储能量驱动的晶界迁移。统一的方法可以无缝识别变形和成核产生的晶界。成核是通过一个耦合函数激活的,该耦合函数将位错相关的自由能贡献到相场中。位错恢复发生在新形成的晶核和迁移晶界后面。该模型的功能通过周期性双晶和多晶模拟得到验证,其中捕获了应变诱导的边界迁移、亚晶生长和聚结等机制。提出的自发成核机制为相场模型的再结晶模拟能力提供了新的补充。
Atomistic insights into the effect of bacterial cellulose and water content on the mechanical properties of the bacterial cellulose/polyvinyl alcohol (BC/PVA) composite hydrogel
Zhaohui Li, Qiangqiang Zhang, Jinming Zhu, Wei Xu, Bo Gong, Ji Lin
doi:10.1016/j.mechmat.2025.105494
细菌纤维素和水含量对细菌纤维素/聚乙烯醇(BC/PVA)复合水凝胶力学性能影响的原子观察
The mechanical properties of bacterial cellulose/polyvinyl alcohol (BC/PVA) composite hydrogels, including tensile strength and extensibility, are significantly influenced by the composition of BC and the water molecules. However, the atomic-level mechanis m by which BC and water content regulate the mechanical behaviors of the BC/PVA composite hydrogel is not yet fully understood. This work employed a large-scale molecular dynamics simulation to systematically investigate the mechanical behavior of BC/PVA composite hydrogels, utilizing the Monte Carlo self-avoiding random walk method for model construction. Key findings demonstrate that BC content critically governs mechanical performance through hydrogen bond-mediated network reconfiguration. The elevation of BC content promotes hydrogen bonding between BC and PVA chains, culminating in a densely cross-linked hydrogel network that enhances tensile strength while reducing fracture strain owing to diminished polymer chain mobility. In contrast, higher water content expands the interchain distance and disrupts hydrogen bonds present at lower hydration levels. The resulting increase in free volume reduces constraints on polymer chain mobility, leading to decreased strength but enhanced ductility. These atomic-scale insights establish quantitative structure-property relationships for BC/PVA hydrogels, providing a fundamental framework for rationally designing hydrogel materials with tailored mechanical performance for biomedical and engineering applications.
细菌纤维素/聚乙烯醇(BC/PVA)复合水凝胶的力学性能,包括抗拉强度和拉伸性能,受到BC和水分子组成的显著影响。然而,BC和水含量调控BC/PVA复合水凝胶力学行为的原子水平机制尚不完全清楚。本研究采用大尺度分子动力学模拟,系统研究了BC/PVA复合水凝胶的力学行为,利用蒙特卡罗自避免随机游走法构建模型。主要研究结果表明,BC含量通过氢键介导的网络重构对机械性能起关键作用。BC含量的提高促进了BC和PVA链之间的氢键,最终形成一个紧密交联的水凝胶网络,提高了拉伸强度,同时由于聚合物链迁移率降低而降低了断裂应变。相反,较高的含水量扩大了链间距离,破坏了在较低水化水平下存在的氢键。由此产生的自由体积的增加减少了对聚合物链迁移率的限制,导致强度下降,但延展性增强。这些原子尺度的见解建立了BC/PVA水凝胶的定量结构-性能关系,为合理设计具有定制机械性能的水凝胶材料提供了基本框架,用于生物医学和工程应用。
Out-of-plane fracture in plane strain conditions: A novel criterion with an alytical and experimental evaluation in thick PUR foam
Mohammad Mahdi Touiserkani, Mahdi Heydari-Meybodi
doi:10.1016/j.mechmat.2025.105499
平面应变条件下的面外断裂:一种具有分析和实验评价的新判据
The brittle fracture of thick polyurethane (PUR) foam is investigated in this study through both experimental and theoretical approaches under out-of-plane, Mixed-Mode I/III, loading conditions. Experimental tests are conducted on Edge-Notched Disc Bend (ENDB) samples to collect some new fracture data for predicting the Mixed-Mode I/III fracture behavior of rigid PUR foam. Additionally, the fracture toughness values are determined using finite element an alysis. Theoretical predictions are then made using a new modification of the Maximum Principal Stress (MPS) criterion, termed ECD-MPS. Indeed, the Effective Critical Distance (ECD) concept is incorporated into the conventional MPS criterion in plane strain conditions, highlighting that the critical distance is influenced by both the material properties and fracture modes. A comparative ana lysis of experimental and theoretical results demonstrates that the ECD-MPS criterion provides high accuracy in predicting out-of-plane fracture. To further validate the findings, the results of ECD-MPS criterion are compared with those from two other fracture criteria: the classical MPS and Strain Energy Density (SED). Moreover, the validity of new criterion is further supported by its alignment with experimental findings from previous research.
本文采用实验和理论相结合的方法研究了厚聚氨酯(PUR)泡沫在面外、I/III混合模式加载条件下的脆性断裂。通过对边缘缺口盘弯曲(ENDB)试样进行实验测试,为预测硬质聚氨酯泡沫的I/III混合模式断裂行为收集新的断裂数据。此外,采用有限元分析确定了断裂韧性值。然后使用最大主应力(MPS)标准的新修正,称为ECD-MPS,进行理论预测。事实上,在平面应变条件下,有效临界距离(ECD)概念被纳入了传统的MPS准则,强调了临界距离受到材料特性和断裂模式的影响。实验结果与理论结果的对比分析表明,ECD-MPS准则在预测面外裂缝方面具有较高的精度。为了进一步验证研究结果,将ECD-MPS标准的结果与其他两种断裂标准的结果进行了比较:经典MPS和应变能密度(SED)。此外,新标准与以往研究的实验结果一致,进一步支持了新标准的有效性。
Mechanistic insights into stress localization and crack precursors during dwell fatigue: dislocation evolution from basal slip in near-α titanium alloys
Runchen Jia, Weidong Zeng, Heng Li, Zibo Zhao, Yujing Liu, Meng Qi, Boning Wang, Jiaxi Zhu, Jianwei Xu, Qingjiang Wang
doi:10.1016/j.ijplas.2025.104477
居住疲劳过程中应力局部化和裂纹前兆的机理研究:近α钛合金基底滑移的位错演化
Basal slips govern the onset of dwell-fatigue damage in near-α titanium alloys, yet the mechanis ms by which they rapidly evolve into crack nucleation under dwell loading remain insufficiently understood. To address this gap, we apply a multiscale framework combining in-situ dwell-fatigue testing, high-resolution dislocation microscopy, and atomistic simulations to directly uncover how basal dislocation structures develop into crack precursors. Notably, for the first time under dwell-fatigue conditions, we demonstrate that the concurrent activation of multiple basal slips on a single plane induces marked intragranular lattice rotations and strain localization, thereby accelerating damage accumulation. Conversely, co-activation of pris matic and pyramidal slip systems fragments these bands, redistributes strain, and markedly improves dwell-fatigue resistance. Furthermore, a critical slip-transfer mechanis m is clarified, wherein basal dislocation trans mission across grain boundaries is strongly governed by misorientation: low-angle boundaries permit near-continuous trans mission, promoting dislocation pile-ups and local stress amplification, while high-angle boundaries impede slip and facilitate <c+a> dislocation nucleation via interfacial shear to restore compatibility. Moreover, molecular dynamics simulations validate the broader and higher-amplitude strain fields of basal bands under dwell loading and further uncover a previously unrecognized stress-assisted edge-to-screw dislocation transformation that sustains localized shear, intensifies strain gradients, and predisposes the slip band to premature crack initiation. Collectively, these findings establish a unified failure pathway for basal slip–induced damage, offering new mechanistic insights into how slip-band evolution and dislocation interactions give rise to crack precursors, and informing alloy-design strategies to mitigate dwell fatigue in near-α titanium alloys.
在近α钛合金中,基滑移控制了久居疲劳损伤的发生,但它们在久居载荷下迅速演变成裂纹形核的机制仍未得到充分的了解。为了解决这一差距,我们应用了多尺度框架,结合原位疲劳测试,高分辨率位错显微镜和原子模拟,直接揭示了基底位错结构如何发展成裂纹前体。值得注意的是,我们首次在持久疲劳条件下证明,在单个平面上同时激活多个基底滑移会引起显著的晶内晶格旋转和应变局部化,从而加速损伤积累。相反,棱柱形和锥体滑移系统的共激活使这些条带断裂,重新分配应变,并显着提高耐疲劳性能。此外,还阐明了一个关键的滑移传递机制,其中基底位错跨越晶界的传递受到取向错误的强烈控制:低角度晶界允许近乎连续的传递,促进位错堆积和局部应力放大,而高角度晶界阻碍滑移,并通过界面剪切促进<c+a>位错成核,以恢复相容性。此外,分子动力学模拟验证了在静载作用下基带更宽、更高振幅的应变场,并进一步揭示了以前未被认识到的应力辅助边到螺旋位错转变,这种转变维持了局部剪切,加剧了应变梯度,并使滑移带易于过早萌生裂纹。总的来说,这些发现为基础滑移损伤建立了统一的失效途径,为滑移带演化和位错相互作用如何产生裂纹前体提供了新的机制见解,并为合金设计策略提供了信息,以减轻近α钛合金的居住疲劳。
An effective method for the buckling a nalysis of composite cylindrical shells under nonuniform external pressure
Fanglin Cong, Benxin Wang, Guocai Yu, Yang Jin, Zixu Zhu, Chengyang Wang, Xiao He, Xi Zhu, Linzhi Wu
doi:10.1016/j.tws.2025.113961
非均匀外压作用下复合材料圆柱壳屈曲分析的有效方法
Nonuniform external pressure significantly impacts the load-bearing capacity of cylindrical shell structures. This study introduces an effective method for an alyzing the buckling behavior of composite cylindrical shells subjected to such pressure. This method employs nonuniform load coefficients (kd) to capture the effects of varying external pressure distributions, from hydrostatic to nonuniform, on performance of the shell. The findings show that as the kd value increases, the critical buckling pressure of composite shells decreases under different nonuniform pressures. Additionally, this method facilitates parameter an alysis and optimization. The study identifies the optimal layup configuration ([90_2/70]) for composite cylindrical shells, resulting in a 72% increase in critical buckling pressure. Overall, this work enhances the understanding of nonuniform buckling behavior, offering valuable insights for the effective design of composite cylindrical shells in engineering applications.
非均匀外部压力显著影响圆柱壳结构的承载能力。本研究介绍了一种分析承受此类压力的复合材料圆柱壳屈曲行为的有效方法。该方法采用非均匀载荷系数(kd)来捕捉从静水压力到非均匀压力分布变化对壳体性能的影响。研究结果表明,在不同的非均匀压力下,随着kd值的增加,复合材料壳体的临界屈曲压力降低。此外,该方法有助于参数分析和优化。研究确定了复合材料圆柱壳的最优铺层配置([90_2/70]),使临界屈曲压力提高了72%。总体而言,这项工作加深了对非均匀屈曲行为的理解,为工程应用中复合材料圆柱壳的有效设计提供了有价值的见解。
Programmable quasi-zero stiffness triaxial low-frequency isolator empowered by inverse design of Fourier-series beams and metastructure customization
Xingyu Chen, Liye Zhao, Jiawen Xu, Luxiang Xu, Ning Guo
doi:10.1016/j.tws.2025.113964
基于傅立叶级数梁反设计和元结构定制的可编程准零刚度三轴低频隔离器
In modern precision manufacturing and metrology systems, low-frequency vibration isolation is a critical component. Compared to linear isolators, quasi-zero stiffness (QZS) nonlinear isolators offer the advantages of high static stiffness and low dynamic stiffness. In this study, a metastructure-based triaxial low-frequency isolator is developed based on the QZS principle. Specifically, an intuitively interpretable Fourier-series (FS) curved beam is first proposed as a monolithic QZS compliant mechanis m. Importantly, a deep learning (DL)-based inverse design method is introduced to directly map the desired force-displacement responses to structural design parameters, enabling rapid design of QZS FS beams. Next, building blocks A and B are then designed based on the inverse-designed QZS FS beam to create metastructure unit cells. Two orthogonally stacked unit cells constitute the minimal configuration of the QZS triaxial isolator. A static model of the FS beam and a dynamic model of the isolator are developed to investigate the QZS features and vibration isolation performance. The triaxial metastructure isolator achieves QZS programmability and high integration while retaining the advantages of miniaturization and compactness. Finally, an isolator prototype through QZS programming (FS beam tailoring and unit cell matrix arrangement) is fabricated for triaxial vibration isolation testing. The results show that the proposed QZS triaxial isolator exhibits effective isolation performance against low-frequency disturbances along the x-, y-, and z-baxes.
在现代精密制造和计量系统中,低频振动隔离是一个关键组成部分。与线性隔振器相比,准零刚度(QZS)非线性隔振器具有高静态刚度和低动态刚度的优势。在本研究中,基于 QZS 原理开发了一种基于超结构的三轴低频隔振器。首先,提出了一种直观易懂的傅里叶级数(FS)曲线梁作为单片 QZS 柔性机构。重要的是,引入了一种基于深度学习(DL)的逆向设计方法,可直接将所需的力 - 位移响应映射到结构设计参数,从而能够快速设计 QZS FS 梁。接下来,基于逆向设计的 QZS FS 梁设计了构建模块 A 和 B,以创建超结构单元。两个正交堆叠的单元构成了 QZS 三轴隔振器的最小配置。开发了 FS 梁的静态模型和隔振器的动态模型,以研究 QZS 特征和隔振性能。三轴元结构隔振器实现了 QZS 可编程性和高集成度,同时保留了小型化和紧凑性的优势。最后,通过 QZS 编程(FS 波束整形和单元矩阵排列)制造了一个隔振器原型,用于三轴振动隔振测试。结果表明,所提出的 QZS 三轴隔振器对沿 x、y 和 z 轴的低频扰动具有有效的隔振性能。
Experimental and numerical studies on the effect of sandwich structures on the dynamic response of ship sections subjected to underwater explosions
Zhiyuan Wang, Shijie Yang, Lihong Yang, Weizheng Xu, Yalun Dong, Dian Li, Jia Qu, Linzhi Wu
doi:10.1016/j.tws.2025.113969
水下爆炸作用下夹层结构对船体动力响应影响的实验与数值研究
The enhancement of underwater explosions resistance is of great significance for improving the survivability of warships. Experimental and numerical studies were conducted on the dynamic response of a ship section equipped with the corrugated sandwich protective structures, under underwater explosion loading. Three configurations of corrugated sandwich protective structures were designed and the acceleration, spectral velocity and stress response of ship section measuring points are systematically an alyzed. The results show that compared with the ship section without sandwich protection structure, equipping sandwich structure can significantly reduce the peak acceleration and stress at each measuring point of the ship section, attenuate the dynamic response faster, and lower the platform value of the velocity response spectrum. The multi-layer double-corrugated sandwich structure has superior energy absorption and plastic deformation capabilities, thereby enhancing the protection of the ship section. The findings provide practical insights for the structural optimization of naval protective systems under underwater explosion conditions.
提高水下抗爆性能对提高军舰的生存能力具有重要意义。对装有波纹夹层结构的船体截面在水下爆炸荷载作用下的动力响应进行了试验和数值研究。设计了三种波纹夹层防护结构构型,系统分析了船体截面测点的加速度、速度谱和应力响应。结果表明,与未安装夹层结构的船体截面相比,安装夹层结构可以显著降低船体截面各测点的峰值加速度和应力,更快地衰减动力响应,降低速度响应谱的平台值。多层双波纹夹层结构具有优越的吸能和塑性变形能力,从而增强了对船截面的保护。研究结果为水下爆炸条件下舰船防护系统的结构优化提供了实用见解。
Stiffness modelling and dynamics a nalysis of a deployable tubular structure inspired by Yoshimura origami
Boyan Chang, Jiahao Cui, Shuai Mo, Dong Liang, Guoguang Jin, Yuhan Gao
doi:10.1016/j.tws.2025.113966
受吉村折纸启发的可展开管状结构的刚度建模和动力学分析
Origami has been utilized to build deployable structures through folding and unfolding along the creases. These structures are usually flexible during the deploying process, leading to an unstable state that can not maintain its deployed state under loading. In this paper, a tubular truss inspired by Yoshimura origami is extracted and stiffness model is established to reveal the relationship between the load and the deformation. The an alytical predictions show good agreement with ANSYS simulations and a set of optimal geometric parameters are obtained for designing the deployable tubular structure, which can be collapsed along two different paths from the supporting state. One path with high stiffness is selected to bear heavy load and another path with zero stiffness is chosen to achieve the function of deployable motion. The selective deployability and collapsibility are an alyzed and demonstrated by experiments and dynamic simulations based on Lagrange equation. Both theoretical and experimental results demonstrate that the proposed structure not only significantly enhances the load-bearing capacity in the supporting state without dedicated locking devices but also reduces the driving force required for deployment. The principle in this work can be utilized to create versatile origami-inspired deployable structures that can find many applications.
折纸已被用来建立可展开的结构,通过折叠和展开沿折痕。这些结构在部署过程中通常是灵活的,导致不稳定状态,无法在加载下保持其部署状态。本文提取了一种受吉村折纸启发的管状桁架,建立了刚度模型,揭示了载荷与变形之间的关系。分析预测结果与ANSYS仿真结果吻合较好,为设计可展开管状结构提供了一组最优几何参数,该结构可从支承状态沿两种不同路径塌陷。选择一条高刚度路径承载重物,选择另一条零刚度路径实现可展开运动功能。通过实验和基于拉格朗日方程的动态仿真,分析论证了该结构的可选择性展开性和可折叠性。理论和实验结果均表明,该结构在无专用锁紧装置的支撑状态下,不仅显著提高了承载能力,而且减小了展开所需的驱动力。这项工作的原理可以用来创建多功能的折纸式可展开结构,可以找到许多应用。
Dynamic Modelling and Vibration Behavior of Axially Moving Honeycomb Sandwich Plates Immersed in Fluid
Tianhao Yang, Kai Zhou, Yake Li, Dao Gong, Jinsong Zhou, Leibin Wen
doi:10.1016/j.tws.2025.113967
浸入流体中轴向移动蜂窝夹层板的动力学建模与振动特性
An energy-based an alytical method is proposed to describe the vibration and stability behaviors of axially moving HSTP immersed in fluid under general boundary conditions. General boundary conditions, such as simply supported, clamped and free constraints, can be considered by different penalty parameter values. The proposed method systematically accounts for the influence of the geometric parameters of the honeycomb core and the fluid on the model. By integrating first-order shear deformation theory (FSDT) with linear potential flow theory, the energy functional formulations for the structure considered are meticulously derived. The Hamilton’s principle is applied to formulate the governing equations for the axially moving HSTP immersed in fluid, and a unified an alytical solution for the cases with general boundary conditions is derived. The accuracy of the presented method is validated through comparisons with commercial software results and published reference data. Furthermore, parametric a nalyses are carried out to evaluate how key parameters including axially moving velocity, fluid density, face sheet thickness, core wall dimensions, core height, unit cell geometry and structural damping coefficient influence the dynamic behavior of the HSTP. Numerical results demonstrate that these parameters significantly affect the stability and vibration behavior of the HSTP in fluid environments. The findings of this research can serve as a theoretical foundation for the dynamic optimization design of HSTP structures immersed in fluid environments.
提出了一种基于能量的解析方法来描述在一般边界条件下轴向移动的HSTP浸入流体中的振动和稳定行为。一般的边界条件,如简支约束、夹紧约束和自由约束,可以用不同的罚参数值来考虑。该方法系统地考虑了蜂窝芯的几何参数和流体对模型的影响。将一阶剪切变形理论(FSDT)与线性势流理论相结合,导出了所考虑结构的能量泛函表达式。应用Hamilton原理建立了浸入流体中轴向运动HSTP的控制方程,导出了具有一般边界条件情况下的统一解析解。通过与商业软件结果和已发表的参考数据的比较,验证了该方法的准确性。此外,还进行了参数分析,以评估轴向移动速度、流体密度、面板厚度、岩心壁尺寸、岩心高度、单元几何形状和结构阻尼系数等关键参数对HSTP动力性能的影响。数值计算结果表明,这些参数对HSTP在流体环境中的稳定性和振动特性有显著影响。研究结果可为浸没在流体环境中的HSTP结构的动态优化设计提供理论依据。