今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Thin-Walled Structures 5 篇
Non-contact electromagnetic controlled metamaterial beams for low-frequency vibration suppression
Yu Sun, Haokai Zheng, Qiang Han, Chunlei Li
doi:10.1016/j.ijsolstr.2024.112667
用于低频振动抑制的非接触式电磁控制超材料梁
To address the challenge of suppressing extremely-low frequency vibration and noise in precision instruments and equipment, a novel non-contact metamaterial beams is proposed in this paper. The resonators of the metamaterial beams integrate negative stiffness mechanism and electromagnetic damping tuning system. Based on the magnetic dipole theory and the electromagnetic induction law, the mechanical model of magnetic resonator is established. The band structure and transmission spectrum of the metamaterial beams are obtained by transfer matrix method. Besides, the results of numerical simulations are used to verify the accuracy of theoretical results. The result shows that the negative stiffness can be controlled by nonlinear magnetic force among the magnets. Based on this mechanism, the bandgap frequency can be reduced to a minimum of 50Hz. Then, the method of combining electromagnetic damping and negative impedance circuit is proposed to form a tuning system which can reduce the initial frequency of the bandgap to 4Hz. Interestingly, the proposed bandgap control mechanism achieves the extremely-low bandgap while broadens the bandwith relatively, which overcomes the deficiency of traditional quasi-zero-stiffness metamaterials that reduce the bandgap frequency while causing the bandwidth to narrow. This study is expected to provide valuable ideas for the application of metamaterials in the field of low-frequency vibration and noise reduction.
为解决精密仪器设备中极低频振动和噪声的抑制问题,提出了一种新型非接触式超材料梁。超材料梁谐振腔集成了负刚度机构和电磁阻尼调谐系统。基于磁偶极子理论和电磁感应定律,建立了磁谐振器的力学模型。利用传递矩阵法得到了超材料光束的能带结构和透射谱。此外,用数值模拟结果验证了理论结果的准确性。结果表明,磁体间的非线性磁力可以控制负刚度。基于这种机制,带隙频率可以降低到至少50Hz。然后,提出了电磁阻尼与负阻抗电路相结合的方法,形成了一个可将带隙初始频率降至4Hz的调谐系统。有趣的是,所提出的带隙控制机制实现了极低的带隙,同时相对拓宽了带宽,克服了传统准零刚度超材料在降低带隙频率的同时导致带宽变窄的缺点。该研究有望为超材料在低频振动降噪领域的应用提供有价值的思路。
Modeling storage particle delamination and electrolyte cracking in cathodes of solid state batteries
Tao Zhang, Marc Kamlah, Robert M. McMeeking
doi:10.1016/j.jmps.2024.105551
固态电池阴极中存储颗粒分层和电解液开裂的模拟
Interface delamination between storage particles and solid electrolytes contributes to greater impedance for Li transfer and capacity loss in solid-state batteries. Electrolyte cracking would cause degradation of the ionic or electronic conductivity of electrolytes. The occurrence of interface delamination and electrolyte cracking is commonly ascribed to mechanical stress, which evolves from inhomogeneous shrinkage and swelling of storage particles confined by the surrounding solid electrolytes when lithium is extracted or inserted. Here, a coupled model of Li diffusion, ionic conduction, interfacial reaction, mechanical stress and a phase field fracture approach is applied to investigate defect-initiated interface delamination and how cracks nucleate in electrolytes in a full 3D dynamical description for the first time. We find that unstable interface delamination is a very likely event during extraction. On the other hand, homogeneous delamination where the whole interface delaminates simultaneously, can happen for smaller interfacial defects with larger particle sizes and higher applied current densities. Larger interfacial defects delay the onset of delamination due to damage dependent interfacial reaction. More particle storage capacity can be utilized for smaller particle sizes and smaller interfacial defects prior to delamination. We further demonstrate electrolyte cracking can happen quite readily, and the electrolyte can break into several parts in only one insertion half cycle and even the appearance of full delamination.
在固态电池中,存储颗粒和固体电解质之间的界面分层导致锂离子转移阻抗增大和容量损失增大。电解液的开裂会导致电解液的离子或电子导电性下降。界面分层和电解质开裂的发生通常归因于机械应力,这是锂提取或插入时由周围固体电解质限制的存储颗粒的不均匀收缩和膨胀演变而来的。本文首次采用Li扩散、离子传导、界面反应、机械应力和相场断裂的耦合模型,对缺陷引发的界面分层以及裂纹如何在电解质中成核进行了完整的三维动力学描述。我们发现不稳定的界面分层是萃取过程中很可能发生的事件。另一方面,对于较小的界面缺陷,较大的颗粒尺寸和较高的施加电流密度,可以发生整个界面同时分层的均匀分层。由于损伤相关的界面反应,较大的界面缺陷延迟了分层的发生。在分层之前,更小的颗粒尺寸和更小的界面缺陷可以利用更多的颗粒存储容量。我们进一步证明了电解质的开裂是很容易发生的,电解质可以在一个插入半周期内分解成几个部分,甚至出现完全分层。
Comparison of two progressive damage models for predicting low-velocity impact behavior of woven composites
Yogesh Kumar, Mohammad Rezasefat, Sandro C. Amico, Andrea Manes, Patricia I. Dolez, James D. Hogan
doi:10.1016/j.tws.2024.111611
两种预测编织复合材料低速冲击行为的渐进损伤模型的比较
This research focuses on comparing the two progressive damage models available in the explicit nonlinear finite element software LS-Dyna. To explore the prediction capabilities in terms of mechanical response and dominating failure modes in S2 glass woven composites, low velocity impact response at four different energies ranging from 27.9 J to 109.7 J were considered in this study. A macro-homogeneous solid element formulated finite element model was simulated to understand the response and failure mechanics in the laminate under low-velocity impact. The material modeling was carried out utilizing the MAT 55 and MAT 162 material models. An effort has been made for robust calibration of the various physical and non-physical parameters in both material cards for accurate predictions. The prediction capabilities of the models were then examined by comparing them against the experimental results, which fall within the deviation of ∼ 11%. The results show that MAT 162 yields a better resemblance with the damage morphology patterns and the delamination for the accounted impact zone, due to inclusion of strain-rate effect. Overall, this paper provides insight into the limitations and advantages of both material models, which establishes the route for the selection of the appropriate material model for simulating impact behavior in woven composites.
本文主要对LS-Dyna显式非线性有限元软件中现有的两种渐进损伤模型进行了比较。为了探索S2玻璃编织复合材料力学响应和主要破坏模式的预测能力,本研究考虑了27.9 ~ 109.7 J四种不同能量下的低速冲击响应。为了解层合板在低速冲击下的响应和破坏机理,建立了宏观均质实体有限元模型。利用MAT 55和MAT 162材料模型进行材料建模。为了准确预测,已经努力对两种材料卡中的各种物理和非物理参数进行稳健校准。然后通过将模型与实验结果进行比较来检验模型的预测能力,实验结果的偏差在~ 11%之内。结果表明,由于包含应变率效应,MAT 162与计算的冲击区损伤形态和分层具有更好的相似性。总体而言,本文深入分析了两种材料模型的局限性和优势,为选择合适的材料模型来模拟机织复合材料的冲击行为奠定了基础。
Surface effects on wave propagation in piezoelectric-piezomagnetic loosely bonded bilayer system using nonlocal theory of elasticity
Sudarshan Dhua, Subrata Mondal, Arpita Maji
doi:10.1016/j.tws.2024.111612
基于非局部弹性理论的压电-压电松散键合双层体系中波传播的表面效应
This study investigates nonlocal and surface effects on the dispersion behaviors of Shear horizontal (SH) waves in piezoelectric(PE)- piezomagnetic(PM) bilayer systems. The interface between these two layers is imperfectly bonded. The general governing equations are derived from the nonlocal magnetoelectroelastic (MEE) theory by adding an inherent length. The G-M model and generalized Younge–Laplace equations have been used to incorporate surface effects into the boundary conditions of the bilayer systems. The closed-form dispersion equation is obtained analytically for electrically open and magnetically short conditions. Numerical solutions are utilized to investigate the effects of nonlocal scale parameters and surface parameters on SH surface wave propagation. Contrary to the results of classical theory, the coupling effects of nonlocal small-scale and surface piezoelectricity are more significant than individual effects. Also, it has been observed that the imperfectness parameter across the interface and the thickness ratio of the bilayer significantly affect the phase velocity. Moreover, 2D and 3D plots of the mode shapes of field variables for the propagation of SH waves are presented graphically. These results are validated by conducting analyses excluding nonlocal effects. This allows us to isolate the specific impact of surface effects in the piezoelectric-piezomagnetic bilayer system, drawing connections to existing results and enhancing the robustness of our findings. This study provides valuable insights into complex wave dynamics, helping to optimize the performance and functionality of such smart composites in various engineering applications.
本文研究了压电(PE)-压磁(PM)双层体系中剪切水平波(SH)色散行为的非局域和表面效应。这两层之间的界面是不完美结合的。一般控制方程由非局部磁电弹性(MEE)理论导出,并加入固有长度。利用G-M模型和广义young - laplace方程将表面效应纳入双层系统的边界条件。得到了电开和磁短条件下的闭式色散方程。利用数值解研究了非局部尺度参数和表面参数对SH表面波传播的影响。与经典理论的结果相反,非局部小尺度和表面压电的耦合效应比个体效应更显著。此外,还观察到界面上的缺陷参数和双层膜的厚度比对相速度有显著影响。此外,还给出了SH波传播场变量模态振型的二维和三维图形。通过进行排除非局部效应的分析,验证了这些结果。这使我们能够分离出压电-压电双分子层系统中表面效应的具体影响,将其与现有结果联系起来,并增强我们发现的稳健性。这项研究为复杂的波动动力学提供了有价值的见解,有助于优化这种智能复合材料在各种工程应用中的性能和功能。
GLARE deformation in low-restraint state: tensile and bending behavior
Yao Wang, Xiaokai Ye, Chao Yang, Junzhe Wei, Sifa Zheng, Libin Zhao, Ning Hu
doi:10.1016/j.tws.2024.111613
低约束状态下的眩光变形:拉伸和弯曲行为
Fiber metal laminates (FMLs) possess a better weight reduction effect than traditional metal materials due to the coupling properties of heterogeneous materials, showing promise in the areas of aviation and aerospace. At present, the research on FMLs mainly focuses on the deformation properties after curing while the mechanical properties in the low-restraint state, i.e. the laminates are temporarily not cured and are formed under lower constraint stresses, are not studied in detail. Herein, the low-restraint GLARE is taken as a research object and its deformation characteristics and failure mode are studied using uniaxial tensile, bending experiments and numerical simulation in this paper. Moreover, the influence of key parameters, such as temperature, laminate structure and span length, is investigated, as well as the tensile and bending deformation behavior of GLARE in a low-restraint state is obtained. In addition, based on experimental observations, it is found that the low-restraint GLARE produces the phenomenon of interlayer slip, and the interlaminar residual stress is much smaller than the cured laminate, whereas the deformation limit and performance are improved. This paper provides theoretical bases for the in-depth analysis of deformation properties and forming laws of low-restraint GLARE, guiding further applications of laminates.
由于非均质材料的耦合特性,金属纤维层压板具有比传统金属材料更好的减重效果,在航空航天领域具有广阔的应用前景。目前,对层合材料的研究主要集中在固化后的变形性能上,而对层合材料在低约束状态下,即暂时不固化,在较低约束应力下形成的力学性能研究较少。本文以低约束眩光为研究对象,通过单轴拉伸、弯曲试验和数值模拟对其变形特性和破坏模式进行了研究。此外,研究了温度、层合结构、跨长等关键参数对眩光的影响,得到了眩光在低约束状态下的拉伸和弯曲变形行为。此外,基于实验观察发现,低约束眩光会产生层间滑移现象,层间残余应力远小于固化层板,但变形极限和性能均有所提高。本文为深入分析低约束眩光的变形特性和形成规律提供了理论依据,指导了层合板的进一步应用。
Dual-functional perforated metamaterial plate for amplified energy harvesting of both acoustic and flexural waves
Tian Deng, Luke Zhao, Feng Jin
doi:10.1016/j.tws.2024.111615
双功能穿孔超材料板,用于放大声波和弯曲波的能量收集
Metamaterials with defect states are commonly utilized in energy harvesting from acoustic and elastic waves due to their remarkable ability to localize waves. In this study, a novel piezoelectric energy harvester based on a perforated double-pillars metamaterial plate with a point defect, which offers the advantage of efficiently harvesting both ambient acoustic and flexural wave energy, is proposed. The proposed structure incorporates a locally resonant mechanism that enhances the concentration of vibration energy at the defect band frequency. Then, the amplified wave energy is efficiently converted into electrical energy by attaching a piezoelectric patch at the defect position. To initiate this investigation, the differential quadrature method is employed to theoretically estimate the boundary frequencies of the first band gap. Subsequently, this study investigates how holes size, electrical boundary conditions, and electrical circuit connections affect the energy harvesting of both acoustic and flexural waves. Correspondingly, the mechanisms behind their effects are thoroughly explained. Numerical results demonstrate that the wave energy localization performance can be remarkably amplified with an increasing holes radius, and the harvesters with the 1mm holes radius generate voltages that are approximately 2.12 and 1.44 times higher than those with the 0mm holes radius from acoustic and flexural waves, respectively. Furthermore, variations in the defect band frequency and corresponding wave localization behavior depend on the specific electrical boundary conditions and circuit connection approaches, ultimately leading to distinct results in the output electrical energy. These findings present valuable insights and guidelines for the development of high-performance electronic applications in the context of acoustic and elastic wave energy harvesting.
具有缺陷态的超材料由于其出色的波局部化能力而被广泛应用于声波和弹性波的能量收集中。本文提出了一种基于带点缺陷的多孔双柱超材料板的新型压电能量收集器,该收集器具有有效收集环境声波和弯曲波能量的优点。所提出的结构包含一个局部共振机制,增强了振动能量在缺陷频带频率上的集中。然后,通过在缺陷位置粘贴压电片,将放大后的波能有效地转化为电能。为了开展这项研究,采用微分正交法从理论上估计了第一带隙的边界频率。随后,本研究探讨了孔大小、电边界条件和电路连接如何影响声波和弯曲波的能量收集。相应地,对其作用背后的机制也作了详尽的解释。数值结果表明,随着孔半径的增大,波能局域化性能显著增强,孔半径为1mm的收集器产生的声波电压和弯曲波电压分别比孔半径为0mm的收集器高约2.12倍和1.44倍。此外,缺陷频带频率的变化和相应的波局部化行为取决于特定的电边界条件和电路连接方式,最终导致输出电能的不同结果。这些发现为在声学和弹性波能收集的背景下开发高性能电子应用提供了有价值的见解和指导方针。
Aerodynamic Stability and Free Vibration of FGP-Reinforced Nano-Fillers Annular Sector Microplates Exposed to Supersonic Flow
Ehsan Arshid, Saeed Amir, Abbas Loghman, Ömer Civalek
doi:10.1016/j.tws.2024.111610
超声速流动下fgp增强纳米填料环形扇形微板的气动稳定性和自由振动
Metal foams have many different uses, but they also have some weaknesses. To address this issue, scientists are exploring the possibility of adding nano-fillers to make them stronger and more rigid. As a result, there has been increased interest in analyzing structures that are made from these materials among researchers. Here and now, the authors have conducted a new study that focuses on analyzing the aerodynamic stability and free vibrational characteristics of an annular sector microplate. This is the first time that such an analysis has been done for this type of microplate. The microplate is exposed to supersonic flow and nonlinear temperature changes. The actual properties of the microplate are determined via different introduced homogenization schemes; and four distinguished patterns for both pores and nano-fillers dispersion are considered. To evaluate the reinforcements impact, two most widely recognized nano-fillers, i.e., carbon nanotubes and graphene nanoplatelets are employed and their influence on the outcomes is observed. By utilizing Hamilton's principle and performing certain mathematical operations, the equations of motion were derived and solved numerically under different boundary conditions. A case study is conducted to examine how different parameters affect the natural frequencies, corresponding mode shapes, and critical aerodynamic pressures. Since no similar research has been found, the outcomes of this work may be accounted as reference points for upcoming investigations.
金属泡沫有许多不同的用途,但它们也有一些弱点。为了解决这个问题,科学家们正在探索添加纳米填充物的可能性,以使它们更坚固、更坚硬。因此,研究人员对分析由这些材料制成的结构越来越感兴趣。在此,作者进行了一项新的研究,重点分析了环形扇形微孔板的气动稳定性和自由振动特性。这是第一次对这种类型的微孔板进行这样的分析。微孔板暴露在超声速流动和非线性温度变化中。通过引入不同的均质方案来确定微孔板的实际性能;并考虑了孔隙和纳米填料分散的四种不同模式。为了评估增强剂的影响,采用了两种最广泛认可的纳米填料,即碳纳米管和石墨烯纳米片,并观察了它们对结果的影响。利用哈密顿原理,进行一定的数学运算,推导出不同边界条件下的运动方程,并对其进行数值求解。通过实例分析,研究了不同参数对固有频率、相应模态振型和临界气动压力的影响。由于没有发现类似的研究,这项工作的结果可以作为今后调查的参考点。