【新文速递】2024年11月22日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 1 篇，Journal of the Mechanics and Physics of Solids 2 篇，Thin-Walled Structures 11 篇

International Journal of Solids and Structures

Asymptotic numerical method for dynamic buckling of shell structures with follower pressure

Anh-Khoa Chau, Michael Brun, Pascal Ventura, Hamid Zahrouni, Michel Potier-Ferry

doi:10.1016/j.ijsolstr.2024.113135

随动压力作用下壳结构动力屈曲的渐近数值方法

Asymptotic Numerical Method (ANM) is applied to non-linear dynamics of thin-shells subjected to conservative and non-conservative loads such as follower pressure. ANM is decomposed into several stages: the finite element discretization of the non-linear equations of motion of the shell dynamics, a homotopy transformation of the semi-discrete non-linear equations, a perturbation technique to expand the quantities into Taylor series according to the homotopy parameter and the time integration scheme to solve the series of linear problems resulting from the perturbation technique. ANM is applied here with the 7-parameter shell elements thanks to the Enhanced Assumed Strain (EAS) concept and implicit Newmark integration. In the case of non-conservative force, follower pressure also requires to be decomposed in either Taylor series or rational Padé approximants. The academic case of the cylindrical roof with dynamic snap-through phenomenon is investigated for the purpose of comparing ANM strategies and the classical Newton–Raphson (NR) method. Two engineering cases including an I-shaped thin-walled beam and a closed thin-shell cylinder under dynamic external follower pressure are also investigated. ANM turns out to be accurate, robust and efficient in terms of computation time, providing an alternative method to the well-established Newton–Raphson method.

将渐近数值方法（ANM）应用于薄壳在保守载荷和非保守载荷（如从动件压力）作用下的非线性动力学。将ANM分解为几个阶段：壳动力学非线性运动方程的有限元离散化，半离散非线性方程的同伦变换，根据同伦参数将量展开成泰勒级数的摄动技术，以及解决由摄动技术引起的一系列线性问题的时间积分方案。由于增强假设应变（EAS）概念和隐式Newmark积分，ANM在这里与7参数壳单元一起应用。在非保守力的情况下，从动压力也需要分解为泰勒级数或有理帕德帕尔近似。以具有动态卡通现象的圆柱顶板为研究对象，比较了人工神经网络方法与经典牛顿-拉夫森方法的优缺点。研究了工字薄壁梁和封闭薄壳圆柱在动外从动压力作用下的两种工程情况。结果表明，在计算时间方面，ANM具有准确、鲁棒和高效的特点，为公认的牛顿-拉夫森方法提供了一种替代方法。

Journal of the Mechanics and Physics of Solids

A static and dynamic theory for photo-flexoelectric liquid crystal elastomers and the coupling of light, deformation and electricity

Amir Hossein Rahmati, Kosar Mozaffari, Liping Liu, Pradeep Sharma

doi:10.1016/j.jmps.2024.105949

光电液晶弹性体的静态和动态理论及光、变形和电的耦合

Photoactive nematic liquid crystal elastomers permit generation of large mechanical deformation through impingement by suitably polarized light. The light-induced deformation in this class of soft matter allows for devices such as transducers and robots that may be triggered wirelessly. While there is no ostensible direct coupling between light and electricity in nematic liquid crystal elastomers, in this work, we take cognizance of the fact that the phenomenon of flexoelectricity is universal and present in all dielectrics. Flexoelectricity involves generation of electrical fields due to strain gradients or conversely, the production of mechanical deformation through electrical fields. Barring some specific contexts, the flexoelectric effect is in general rather weak in hard materials. However, due to the facile realization of strain gradients (e.g. flexure) in soft materials, we expect flexoelectricity to be highly relevant for liquid crystal elastomers thus, prima facie, furnishing a deformation-mediated mechanism to couple light and electricity. In this work, we develop nonlinear equilibrium and dynamical models for photo-flexoelectric nematic liquid crystal elastomers and analyze the precise conditions underpinning an appreciable coupling between light and electricity. A careful scaling analysis reveals that there is an optimal size-scale at which the flexoelectricity-mediated photo-electric effect is maximized. We find that with conservative estimates of the flexoelectric coefficients of these materials, the electrical power generation is rather modest for typical optical load. However, our proposed coupling is an appropriate modality for optical sensing. Furthermore, design of next-generation liquid crystal elastomers with high flexoelectricity as well as exploitation of size-effects could ameliorate extraction of electrical power from light illumination.

光活性向列液晶弹性体允许通过适当偏振光的撞击产生大的机械变形。这类软物质的光致变形使得传感器和机器人等设备可以无线触发。虽然在向列液晶弹性体中光和电之间没有表面上的直接耦合，但在这项工作中，我们认识到挠性电现象是普遍存在于所有电介质中的事实。柔性电涉及由于应变梯度而产生的电场，或者相反，通过电场产生的机械变形。除了某些特殊情况外，柔性电效应在硬材料中通常相当弱。然而，由于柔软材料中应变梯度（例如挠曲）的容易实现，我们预计柔性电与液晶弹性体高度相关，因此，初步提供了一种变形介导的机制来耦合光和电。在这项工作中，我们建立了光挠曲电向列液晶弹性体的非线性平衡和动力学模型，并分析了支撑光和电之间明显耦合的精确条件。仔细的尺度分析表明，存在一个最佳的尺寸尺度，在该尺寸尺度下，柔性电介导的光电效应是最大化的。我们发现，对这些材料的挠曲电系数进行保守估计，对于典型的光负载，发电量相当适中。然而，我们提出的耦合是一种合适的光学传感模式。此外，设计具有高柔性电的下一代液晶弹性体以及利用尺寸效应可以改善从光照中提取电能。

Finite strain continuum phenomenological model describing the shape-memory effects in multi-phase semi-crystalline networks

Matteo Arricca, Nicoletta Inverardi, Stefano Pandini, Maurizio Toselli, Massimo Messori, Giulia Scalet

doi:10.1016/j.jmps.2024.105955

描述多相半晶网络中形状记忆效应的有限应变连续现象模型

Thermally-driven semi-crystalline polymer networks are capable to achieve both the one-way shape-memory effect and two-way shape-memory effect under stress and stress-free conditions, therefore representing an appealing class of polymers for applications requiring autonomous reversible actuation and shape changes. In these materials, the shape-memory effects are achieved by leveraging the synergistic interaction between one or more crystalline phases and the surrounding amorphous ones that are present within the network itself. The present paper introduces a general framework for the finite strain continuum phenomenological modeling of the thermo-mechanical and shape-memory behavior of multi-phase semi-crystalline polymer networks. Model formulation, including the definition of phase and control variables, kinematic assumptions, and constitutive specifications, is introduced and thoroughly discussed. Theoretical derivations are general and easily adaptable to all cross-linked systems which include two or more crystalline domains or a single crystalline phase with a wide melting range and manifest macroscopically the one-way shape-memory effect and the two-way shape-memory effect under stress and stress-free conditions. Model capabilities are validated against experimental data for copolymer networks with two different crystalline phases characterized by well-separated melting and crystallization transitions. Results demonstrate the accuracy of the proposed model in predicting all the phenomena involved and in furnishing a useful support for future material and application design purposes.

热驱动的半晶聚合物网络能够在应力和无应力条件下实现单向形状记忆效应和双向形状记忆效应，因此，对于需要自主可逆驱动和形状变化的应用来说，这是一类有吸引力的聚合物。在这些材料中，形状记忆效应是通过利用网络中存在的一个或多个晶相与周围非晶相之间的协同相互作用来实现的。本文介绍了多相半晶聚合物网络的热力学和形状记忆行为的有限应变连续现象学建模的一般框架。模型的制定，包括相位和控制变量的定义，运动学假设，和本构规范，介绍和深入讨论。理论推导是通用的，易于适用于所有交联体系，这些交联体系包括两个或多个晶域或具有宽熔化范围的单晶相，并且在应力和无应力条件下宏观上表现出单向形状记忆效应和双向形状记忆效应。模型的能力通过实验数据验证了共聚物网络具有两种不同的结晶相，其特征是良好分离的熔融和结晶转变。结果表明，所提出的模型在预测所有涉及的现象方面是准确的，并为未来的材料和应用设计目的提供了有用的支持。

Thin-Walled Structures

Hydrogen bombardment-induced nano blisters in multilayered Mo/Si coatings

Bo Yuan, Shuai Wang, Christopher M. Harvey, Xiaofeng Guo, Simon Wang

doi:10.1016/j.tws.2024.112711

氢轰击诱导多层Mo/Si涂层中的纳米泡

Nanometer-thick multilayered Mo/Si coatings, employed as artificial Bragg structures, are essential for reflecting specific wavelengths of light in synchrotrons, space telescopes, and extreme ultraviolet optical systems. However, these coatings are prone to blistering failures when exposed to energetic fluxes, such as hydrogen bombardment and solar wind particles. The blistering mechanism is investigated through systematic analysis of experimental data and the development of a multilayered mechanical model based on pockets of energy concentration theory. Energy release rates for pure mode fracture at blister tips, the evolution of blister morphologies, and interface fracture toughness are assessed through theoretical derivations. The relationship between blister radii and heights is elucidated and quantitatively validated against experimental data. Variations in fracture toughness are correlated to hydrogen characteristics, and the influence of hydrogen species, exposure temperature, dose, energy, and strained layer thickness on blister formation is evaluated using the developed model. These findings provide crucial insights for optimizing exposure parameters to mitigate blistering and enhance the performance and reliability of multilayered Mo/Si coatings.

纳米厚的多层Mo/Si涂层作为人造布拉格结构，在同步加速器、太空望远镜和极紫外光学系统中反射特定波长的光是必不可少的。然而，当暴露于高能流体（如氢轰击和太阳风粒子）时，这些涂层容易起泡失效。通过对实验数据的系统分析，建立了基于能量集中口袋理论的多层力学模型，探讨了起泡机理。通过理论推导评估了泡泡尖端纯模式断裂的能量释放率、泡泡形态的演变以及界面断裂韧性。对水疱半径与高度之间的关系进行了阐述，并根据实验数据进行了定量验证。断裂韧性的变化与氢的特性有关，并利用所建立的模型评估了氢的种类、暴露温度、剂量、能量和应变层厚度对水泡形成的影响。这些发现为优化暴露参数提供了重要的见解，以减轻起泡，提高多层Mo/Si涂层的性能和可靠性。

Experiment and simulation of the interfacial joining mechanism for the strong polyformaldehyde-aluminum alloy hybrids

Tao Deng, Chuanhong Liu, Guo Chen, Youbing Li, Tian Xia, Yi Yang, Chaolong Yang

doi:10.1016/j.tws.2024.112712

强聚甲醛-铝合金复合材料界面连接机理的实验与仿真

Using polymer-metal hybrids offers a promising energy conservation and emission reduction approach. In this investigation, nanoporous structures with varying pore sizes were synthesized on the surface of aluminum (Al) by adjusting the oxidation duration. Then, aluminum was bonded with polyformaldehyde (POM) using a hot pressing technique. An increase in nanopore size resulted in enhanced surface roughness and wettability of the Al, thereby promoting the embedding of POM into the Al surface and subsequently improving the mechanical interlocking capability at the interface. The embedding depth of POM with varying pore sizes was analyzed using atomic force microscopy (AFM). Additionally, a flow model of POM within nanopores was developed using the finite element method, and the calculated diffusion depths were consistent with the experimental results. The embedding depth reached 2.38 μm when the pore size was approximately 100 nm, at which point the interface achieved the optimal filling ratio. Furthermore, the interface was examined using X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT), revealing the presence of an Al-O-C chemical bond. The maximum joining strength of the POM-Al hybrid reached 42.56 MPa, and the failure mode was a mixed failure mode of interfacial failure and cohesive failure. In summary, these results are crucial for further designing and optimizing polymer-metal hybrids prepared using anodic oxidation.

使用聚合物金属混合材料是一种很有前途的节能减排方法。在本研究中，通过调整氧化时间，在铝表面合成了不同孔径的纳米孔结构。然后，采用热压技术将铝与聚甲醛（POM）粘合。纳米孔尺寸的增大导致Al的表面粗糙度和润湿性增强，从而促进POM在Al表面的嵌入，从而提高界面的机械联锁能力。采用原子力显微镜（AFM）对不同孔径POM的包埋深度进行了分析。利用有限元方法建立了聚甲醛在纳米孔内的流动模型，计算得到的扩散深度与实验结果吻合较好。当孔径约为100 nm时，包埋深度达到2.38 μm，此时界面填充率达到最佳。此外，利用x射线光电子能谱（XPS）和密度泛函理论（DFT）对界面进行了检测，发现存在Al-O-C化学键。POM-Al复合材料的最大连接强度达到42.56 MPa，破坏模式为界面破坏和内聚破坏的混合破坏模式。总之，这些结果对于进一步设计和优化阳极氧化制备的聚合物金属杂化材料具有重要意义。

Condensational modelling and experimental analysis for vibration of multilayer hull section Vibration Characteristics of Multilayer Hull Section

Quan Gan, Yuehua Chen, Bin Yan, Jiahui Zheng, Yanhui Niu

doi:10.1016/j.tws.2024.112733

多层船体截面振动的凝聚建模与试验分析

A vibrational modeling approach for the free and forced vibration analysis of multilayer hull section structures with intermediate supports has been introduced, complemented by experimental investigations into the free vibration characteristics of ship hulls. To address the issue of excessively large matrix dimensions in solving large and complex coupled structures, a condensation model is employed to construct the multilayer hull section, and the collocation method is engaged for the coupled solution. To validate the convergence and accuracy of existing methods, comparisons have been made between the natural frequencies, modal shapes, and dynamic responses of the coupled structures with finite element results, and experimental tests have been conducted. The results are found to be effective and accurate, with the modeling process being more straightforward and efficient. Furthermore, the effect of the number of internal decks (layers) and partitioned plates on the structural free vibration characteristics has been studied. It is observed that both the addition of internal decks and the introduction of vertical partitioned plates significantly alter the self-vibration characteristics of the entire hull section, but the first two modal shapes of the hull section remain largely unchanged. Notably, the natural frequency of the hull initially increases and then decreases when internal decks are suddenly added; the low order modes appear on the lower plates not directly connected to the partitioned plates when vertical partitioned plates are suddenly introduced. The method allows for the arbitrary modification of the number and position of decks and partitioned plates, akin to altering material properties. The findings indicate that the presented method can be readily extended to address the vibration issues of hull section structures of arbitrary complex geometries and composite material hull section structures.

本文介绍了一种用于中间支承多层船体截面结构自由振动和强制振动分析的振动建模方法，并对船体的自由振动特性进行了实验研究。针对求解大型复杂耦合结构时矩阵维数过大的问题，采用凝结模型构建多层船体截面，并采用配点法求解耦合解。为了验证现有方法的收敛性和准确性，将耦合结构的固有频率、模态振型和动力响应与有限元结果进行了比较，并进行了实验测试。结果表明，该方法有效、准确，建模过程更加直观、高效。此外，还研究了内甲板（层数）和隔板数量对结构自由振动特性的影响。可以观察到，增加内甲板和引入垂直隔板都显著改变了整个船体截面的自振动特性，但船体截面的前两个模态振型基本保持不变。值得注意的是，当突然增加内部甲板时，船体的固有频率先增加后降低；当突然引入垂直隔板时，与隔板不直接连接的下板出现低阶模态。该方法允许任意修改甲板和隔板的数量和位置，类似于改变材料特性。结果表明，该方法可推广应用于求解任意复杂几何形状船体截面结构和复合材料船体截面结构的振动问题。

Investigation on the cyclic buckling and plastic overstrength characteristics of steel shear links utilizing corrugated panels

Sida Li, He Zhao, Xiao-Gang Liu

doi:10.1016/j.tws.2024.112734

波纹板剪力杆循环屈曲及塑性超强特性研究

This paper established and validated the finite element model (FEM) for novel steel shear links utilizing corrugated panels (CSSL), analyzed the stress and strain distributions of CSSL, and summarized the buckling characteristics and determination criteria for CSSL. Utilizing the FEM, the influence of CSSL configuration parameters on its buckling deformation capacity and plastic overstrength characteristics were analyzed. The analysis results indicated that: the decrease in the corrugated panel's sub-panel slenderness a/tw could significantly improve the buckling deformation capacity of CSSL, but had little influence on pre-buckling plastic overstrength characteristics; the decrease in sub-panel aspect ratio h/a and web aspect ratio e/h, as well as the increase in web corrugation angle θ was beneficial for the buckling deformation capacity of CSSL, but might decrease the plastic overstrength characteristics; the decrease in the equivalent links length coefficient eVp/Mp and the increase in structural steel strain-hardening value α had a slight influence on the buckling deformation capacity, but could significantly improve the plastic overstrength characteristics. Based on the analysis result, a theoretical prediction approach for the buckling deformation capacity and plastic overstrength characteristics was proposed, and the load-deformation skeleton curve model was also established, which was validated to exhibit good accuracy with compassion to experimental and finite element analysis results.

本文建立了并验证了新型钢板剪力连接件(CSSL)的有限元模型，分析了CSSL的应力和应变分布，总结了CSSL的屈曲特性和判定准则。利用有限元法分析了CSSL配置参数对其屈曲变形能力和塑性超载特性的影响。分析结果表明：减小波纹板的子板细长比a/tw可显著提高CSSL的屈曲变形能力，但对预屈曲塑性超载特性影响不大；减小子板长宽比h/a和腹板长宽比e/h，以及增大腹板波纹角度θ有利于提高CSSL的屈曲变形能力，但可能会降低其塑性超载特性；减小等效连接长度系数eVp/Mp和提高结构钢应变硬化值α对屈曲变形能力影响不大，但能显著提高塑性超载特性。根据分析结果，提出了一种预测结构屈曲变形能力和塑性超载特性的理论预测方法，并建立了载荷-变形骨架曲线模型，该模型与实验和有限元分析结果相比具有良好的准确性。

X-ray computed tomography in metal additive manufacturing: A review on prevention, diagnostic, and prediction of failure

X. Sun, L. Huang, B.G. Xiao, Q. Zhang, J.Q. Li, Y.H. Ding, Q.H. Fang, W. He, H.M. Xie

doi:10.1016/j.tws.2024.112736

金属增材制造中的x射线计算机断层扫描：失效的预防、诊断和预测综述

Improvements in metal additive manufacturing (MAM) components will require a better understanding of the complex changes in their inevitable manufacturing defects and their mechanical performance that occur in service, which can lead to failure. X-ray computed tomography (XCT) is a powerful non-destructive three-dimensional (3D) imaging technique, in conjunction with multi-dimensional data analysis incorporating spatial and temporal dimensions, which provides comprehensive insights into these defects and their associated failure mechanisms. The important role of XCT throughout the lifecycle of MAM parts, from quality assessment, failure characterization, and fatigue life prediction, is herein reviewed, with an emphasis on its preventive, diagnostic, and predictive capabilities to acquire optimal performance and durability. The current limitations and future opportunities in this emerging field are also discussed, and it is anticipated that this study would accelerate the adoption of XCT and MAM in key areas such as aerospace.

金属增材制造（MAM）部件的改进将需要更好地了解其不可避免的制造缺陷及其在使用中发生的机械性能的复杂变化，这些变化可能导致故障。x射线计算机断层扫描（XCT）是一种强大的非破坏性三维（3D）成像技术，结合空间和时间维度的多维数据分析，可以全面了解这些缺陷及其相关失效机制。本文回顾了XCT在MAM零件生命周期中的重要作用，从质量评估、故障表征和疲劳寿命预测，重点介绍了XCT的预防、诊断和预测能力，以获得最佳的性能和耐久性。本文还讨论了这一新兴领域目前的局限性和未来的机遇，并预计该研究将加速XCT和MAM在航空航天等关键领域的应用。

Enhancing Mechanical Properties of 3D-Printed Continuous Carbon Fibre-Reinforced Composites via Bio-Inspired Design

Guangshuo Feng, Chunlu Xiao, Hongxu Wang, Haitao Zhang, Bo Liu, Caizheng Wang

doi:10.1016/j.tws.2024.112737

通过仿生设计增强3d打印连续碳纤维增强复合材料的机械性能

This paper explores the mechanical properties of 3D-printed continuous carbon fibre (CCF)-reinforced helicoidal laminates inspired by the laminar structures found in crustacean exoskeletons. For comparison, conventional cross-ply layups, both with and without CCF reinforcement, were also examined. The laminate specimens were manufactured layer by layer through a 3D printer using short carbon fibre-reinforced nylon and CCFs. To evaluate their mechanical properties, both quasi-static and dynamic tests were conducted using a universal testing machine and an instrumented drop-weight impact facility. Experimental data were collected to analyse the progression of mechanical failure and energy absorption in these 3D-printed composites. Additionally, micro-computed tomography (μ-CT) scans were used to analyse internal damage, such as fibre fracture and delamination, in the tested samples. The results revealed distinct dynamic failure mechanisms in the 3D-printed composites compared to their quasi-static behaviour, indicating potential real-world applications. The inclusion of CCFs in 3D-printed composites significantly enhanced their mechanical performance. While the cross-ply laminates outperformed the bio-inspired helicoidal laminates under quasi-static bending loads, the helicoidal laminates exhibited greater stiffness and superior energy absorption during low-velocity, out-of-plane impacts, surpassing their cross-ply counterparts.

本文探讨了3d打印连续碳纤维（CCF）增强螺旋层压板的力学性能，其灵感来自于甲壳类动物外骨骼中的层压板结构。为了比较，传统的交叉铺层，包括有和没有CCF加固，也进行了检查。通过3D打印机使用短碳纤维增强尼龙和CCFs逐层制造层压试件。为了评估其力学性能，使用通用试验机和仪表式落锤冲击装置进行了准静态和动态测试。收集实验数据，分析这些3d打印复合材料的机械失效和能量吸收的进展。此外，微计算机断层扫描（μ-CT）用于分析内部损伤，如纤维断裂和分层，在测试样品。结果显示，与准静态行为相比，3d打印复合材料的动态失效机制明显不同，这表明了其潜在的现实应用。在3d打印复合材料中加入CCFs可以显著提高其机械性能。虽然交叉层合板在准静态弯曲载荷下的性能优于仿生螺旋层合板，但螺旋层合板在低速、面外碰撞时表现出更大的刚度和更好的能量吸收，优于交叉层合板。

Simultaneous acoustic and vibration isolation metamaterials based on triply periodic minimal surface

Heman Xiao, Hongqing Dai, Ning Dai, Laishui Zhou

doi:10.1016/j.tws.2024.112738

基于三周期极小面的同时隔声隔振超材料

Metamaterials have attracted widespread attention because they exhibit novel physical behaviors not found in nature. In recent years, due to the excellent properties of triply periodic minimal surface (TPMS) structures, TPMS-based architected materials have played an increasingly important role in many fields. However, most TPMS-based research has focused on single functionality. This study introduces novel TPMS-based metamaterials designed for simultaneous vibration isolation and sound insulation, providing a multifunctional solution. We constructed TPMS structures and analyzed their mechanical properties, exploring how their topology and geometric parameters influence the attenuation of vibration and sound. Through simulations and experimental validations, we demonstrate that these metamaterials can effectively attenuate sound and elastic waves within a specific frequency range. This provides an innovative design approach for materials requiring combined acoustic and vibration control. The work demonstrates the ability to dynamically tune band gaps for multiple wave types by modifying structural parameters. This paves the way for developing advanced multifunctional materials with tailored acoustic and mechanical properties. Additionally, building on this work, future research could focus on refining fabrication processes and investigating different TPMS configurations. Expanding the frequency range could further enhance the robustness and practical applicability of these multifunctional materials.

超材料由于表现出自然界中没有的新物理行为而引起了广泛的关注。近年来，由于三周期极小表面（TPMS）结构的优异性能，TPMS基建筑材料在许多领域发挥着越来越重要的作用。然而，大多数基于tpms的研究都集中在单一功能上。本研究介绍了一种新型的基于tpms的超材料，设计用于同时隔振和隔声，提供多功能解决方案。我们构建了TPMS结构并分析了其力学性能，探讨了其拓扑结构和几何参数对振动和声音衰减的影响。通过仿真和实验验证，我们证明了这些超材料可以有效地衰减特定频率范围内的声波和弹性波。这为需要结合声学和振动控制的材料提供了一种创新的设计方法。这项工作证明了通过修改结构参数来动态调整多种波类型带隙的能力。这为开发具有定制声学和机械性能的先进多功能材料铺平了道路。此外，在这项工作的基础上，未来的研究可以集中在改进制造工艺和研究不同的TPMS结构上。扩大频率范围可以进一步增强这些多功能材料的鲁棒性和实用性。

Design and photothermal coupling Analysis of Kresling Origami-based Intelligent Dynamic Shading System

Ji Zhang, Tianyu Gao, Shuai Liu, Yueying Mi, Jiatong Liu, Changguo Wang

doi:10.1016/j.tws.2024.112739

基于Kresling折纸的智能动态遮阳系统设计及光热耦合分析

This study investigates the design and mechanical analysis of Kresling origami structures for reconfigurable intelligent dynamic shading system aimed at enhancing energy efficiency and thermal management. A mechanical model was developed using the principle of minimum potential energy, followed by 4D printing of specimens tested under compression, showing strong alignment with theoretical predictions. The research highlights the system's intelligent ventilation capabilities, incorporating adjustable fan blade units into the Kresling structure. Shape Memory Polymer (SMP) enables intelligent folding, while Carbon Fiber Reinforced Polymer (CFRP) ensures structural stability. The photothermal coupling analysis reveals how the system autonomously adjusts the shade angle in response to environmental changes, improving indoor illumination and thermal comfort. This intelligent shading system outperforms conventional permanent solutions, reducing energy consumption and enhancing user comfort, ultimately providing innovative insights for future energy-saving technologies in buildings.

本文研究了可重构智能动态遮阳系统中Kresling折纸结构的设计和力学分析，旨在提高能源效率和热管理。利用最小势能原理建立了力学模型，然后对压缩下测试的样品进行了4D打印，结果与理论预测非常吻合。研究强调了系统的智能通风能力，将可调节的风扇叶片单元整合到Kresling结构中。形状记忆聚合物（SMP）实现智能折叠，而碳纤维增强聚合物（CFRP）确保结构稳定性。光热耦合分析揭示了系统如何根据环境变化自主调节遮阳角度，提高室内照度和热舒适性。这种智能遮阳系统优于传统的永久性解决方案，降低了能耗，提高了用户的舒适度，最终为未来的建筑节能技术提供了创新的见解。

Sound Radiation Suppression in a Plate-Cavity Coupling System Under Acoustic Excitation Using ABH-DVA

Hanfeng Ye, Chaoyan Wang, Chongcong Tao, Hongli Ji, Jinhao Qiu

doi:10.1016/j.tws.2024.112741

ABH-DVA抑制声激励下板腔耦合系统的声辐射

The ABH-DVA, or add-on acoustic black hole based dynamic vibration absorber, represents a novel passive technology for structural vibration suppression. By leveraging the combined strengths of DVAs and the ABH effect, the ABH-DVA demonstrates superior broadband vibration and noise control capabilities compared to an equal-weight counterpart. However, the underlying noise radiation suppression mechanisms in a coupled plate-cavity system equipped with an ABH-DVA have not been thoroughly explored. This paper investigates the noise suppression performance and mechanisms of a plate-cavity system integrated with an EABH-DVA, a circular eccentric vibration absorber based on the ABH effect, under interior acoustic excitation. The EABH-DVA achieves enhanced sound radiation suppression across a wide frequency range, outperforming its equal-weight counterpart. This suppression mechanism is primarily attributed to two factors: the enhancement of structural modal damping within the EABH-DVA substructure, and the reduced cavity-structure-radiation energy transfer capability due to the modal shape reconstruction of the host structure's panel in the EABH-DVA system. To obtain a better suppression of sound radiation at higher frequencies in the EABH-DVA system, a new design incorporating an embedded ABH plate with an ABH-DVA is proposed. This paper offers a promising direction for further applications in sound radiation suppression for plate-ABH-DVA-cavity systems.

ABH-DVA，即附加声黑洞动态减振器，代表了一种新的被动结构振动抑制技术。通过利用dva和ABH效应的综合优势，与同等重量的同类产品相比，ABH- dva具有优越的宽带振动和噪声控制能力。然而，在配备ABH-DVA的耦合板腔系统中，潜在的噪声辐射抑制机制尚未得到深入的探讨。本文研究了基于ABH效应的圆形偏心吸振器EABH-DVA集成板腔系统在内声激励下的噪声抑制性能及其机理。EABH-DVA在宽频率范围内实现了增强的声辐射抑制，优于同等重量的同类产品。这种抑制机制主要归因于两个因素：EABH-DVA子结构内部结构模态阻尼的增强，以及EABH-DVA系统中主结构面板模态振型重构导致的腔-结构-辐射能量传递能力的降低。为了在EABH-DVA系统中获得更好的高频声辐射抑制效果，提出了一种将ABH- dva嵌入ABH板的新设计。本文为板- abh - dva腔系统声辐射抑制的进一步应用提供了一个有前景的方向。

Dynamic responses of riveted fuel containers subjected to oblique impacts

Kerong Ren, Jitian Miao, Hua Qing, Wentao Xu, Yong Peng, Haobo Jia, Zongkai He, Xiangyu Li, Rong Chen, Fangyun Lu

doi:10.1016/j.tws.2024.112746

倾斜冲击下铆接燃料容器的动力响应

When a high-speed projectile impacts the fuel containers, it generates hydrodynamic ram (HRAM) with significant kinetic energy causing serious damage to structures. In this study, we performed oblique ballistic impact tests on the riveted fuel containers, testing the dynamic displacement field and velocity field of the rear plate of the fuel containers using the 3D-DIC technique. The finite element simulations were also reproduced to probe the dynamic response behavior of the fuel containers. The results revealed that the propagation velocity and amplitude of HRAM were influenced by the impact velocity, impact angle, and propagation distance. The amplitude of the pioneer wave exhibited a strong impact-angle dependence. The HRAM on the rear plate displays unique temporal and spatial distribution characteristics. The impact velocity and impact angle together determined the evolution of the deformation mode of the fuel containers. Higher impulse led to the formation of a petal hole (PH), while the impact angle resulted in the rear plate of the rivets in the boundary and the formation of a free and non-fixed boundary. These elements suggested an interesting coupled phenomenon of the petal hole with a free boundary and the deformation of the plastic hinge. In the space of hole size and the total impulse I of HRAM acting on the rear plate, there are three regions. The first is the region dominated by the circular hole formed by direct penetration for small I. The second is the region dominated by PH with 3-edges fixed for medium I. The third is the region dominated by PH with 4-edges fixed for large I.

高速弹丸撞击燃料容器时，会产生具有巨大动能的水动力冲击，对结构物造成严重破坏。在本研究中，我们对铆接的燃料容器进行了斜弹道冲击试验，利用3D-DIC技术测试了燃料容器后板的动态位移场和速度场。对燃料容器进行了有限元模拟，探讨了燃料容器的动态响应特性。结果表明，HRAM的传播速度和振幅受冲击速度、冲击角度和传播距离的影响。先锋波的振幅表现出强烈的冲击角依赖性。后板上的HRAM显示出独特的时空分布特征。冲击速度和冲击角度共同决定了燃料容器变形模式的演变。较高的冲量导致花瓣孔（PH）的形成，而冲击角导致铆钉后板在边界处形成自由非固定边界。这些因素暗示了具有自由边界的花瓣孔与塑性铰变形的有趣耦合现象。在孔尺寸和作用于后板的HRAM总冲量I的空间中，有三个区域。第一个区域为小I直接穿透形成的圆孔主导区域，第二个区域为PH主导区域，中等I固定3条边，第三个区域为PH主导区域，大I固定4条边。

On tailoring morphing mechanics of a bistable composite cylindrical shell through elastic fibre prestressing

Chenmin Zhao, Bing Wang, Xiayu Chen, Chenglong Guan, Shuncong Zhong

doi:10.1016/j.tws.2024.112747

双稳复合材料圆柱壳弹性纤维预应力裁剪变形力学研究

A bistable composite cylindrical shell is a thin-walled structure that can change shape between two stable configurations under small energy input, showing great potential to be applied to space deployable mechanics. The internal stress level within a cylindrical shell plays a vital role in determining its morphing mechanics, whilst tailoring the internal stress is tricky for traditional composite manufacturing methods. In this paper, we devise a novel biaxial elastic fibre prestressing (EFP) method to systematic design and produce prestrained carbon-based composite cylindrical shells, with tailorable bistability and morphing mechanics, as well as improved load-carrying capabilities. A biaxial fibre stretching rig was devised to apply tensions on both directions of a plain-weave carbon prepreg simultaneously; prestrained cylindrical shell samples were produced with various prestrain levels to fully evaluate the fibre prestraining effects; a finite element model was established and showed good agreement with experimental observations. The fibre prestraining mechanisms were then proposed. It is found that EFP is effective in tailoring the internal strain/stress level within a composite cylindrical shell, which in turn altering the structural morphing mechanics, and able to significantly lower the maximum tensile strain during shape-changing, thus improve the load-carrying capability. These findings are expected to facilitate structural design of the deployable composite structures and flexible mechanical hinges, by allowing further design freedoms in terms of morphing mechanics and load-carrying capability.

双稳态复合圆柱壳是一种可以在小能量输入下在两种稳定构型之间转换的薄壁结构，在空间展开力学中具有很大的应用潜力。圆柱壳内的内应力水平在决定其变形力学方面起着至关重要的作用，而内应力的调整对于传统的复合材料制造方法来说是很棘手的。在本文中，我们设计了一种新的双轴弹性纤维预应力（EFP）方法来系统地设计和生产具有可定制的双稳性和变形力学的碳基复合材料圆柱壳，并提高了承载能力。设计了一种双轴纤维拉伸装置，用于同时在平织碳预浸料的两个方向上施加张力；为了充分评价纤维的预紧效果，制作了不同预紧程度的预紧圆柱壳试样；建立的有限元模型与实验结果吻合较好。提出了纤维的预紧机理。结果表明，EFP可以有效地调整复合材料圆柱壳的内部应变/应力水平，从而改变结构的变形力学，并能显著降低变形过程中的最大拉伸应变，从而提高承载能力。这些发现有望促进可展开复合结构和柔性机械铰链的结构设计，允许在变形力学和承载能力方面进一步设计自由。