【新文速递】2024年9月24日固体力学SCI期刊最新文章

今日更新：Journal of the Mechanics and Physics of Solids 1 篇，International Journal of Plasticity 3 篇，Thin-Walled Structures 5 篇Journal of the Mechanics and Physics of SolidsThe effect of stress barriers on unconventional-singularity-driven frictional ruptureBarnaby Fryer, Mathias Lebihain, Corentin Noël, Federica Paglialunga, François Passelèguedoi:10.1016/j.jmps.2024.105876应力障碍对非常规奇点驱动摩擦破裂的影响Whether or not energy dissipation is localized in the vicinity of the rupture tip, and whether any distal energy dissipation far from the crack tip has a significant influence on rupture dynamics are key questions in the description of frictional ruptures, in particular regarding the application of Linear Elastic Fracture Mechanics (LEFM) to earthquakes. These questions are investigated experimentally using a 40-cm-long experimental frictional interface. Three independent pistons apply a normal load with a fourth piston applying a shear load, enabling the application of a heterogeneous stress state and stress barriers. After loading the frictional interface to a near-critical state, subsequent unloading of one normal-load piston leads to dynamic ruptures which propagate into the heterogeneous stress fields. The ruptures in these experiments are found to be driven by unconventional singularities, characterised by an ever-increasing breakdown work with slip, and as a result do not conform to the assumptions of LEFM. As these experimental stress barriers inhibit slip, they therefore also reduce the breakdown work occurring outside of the cohesive zone. It is shown that this distal weakening, far from the crack tip, must be considered for the accurate prediction of rupture arrest length. These experiments are performed in the context of a proposed stimulation technique for Enhanced Geothermal Systems (EGSs). It has previously been suggested, through theoretical arguments, that stress barriers could be induced through the manipulation of pore pressure such that there is reduced seismic hazard during the shear stimulation of EGSs. This stimulation technique, known as preconditioning, is demonstrated here to reduce the mechanical energy flux to the crack tip, G , while also increasing the fracture energy, G c . Preconditioning is shown to be capable of arresting seismic rupture and reducing co-seismic slip, slip velocity, and seismic moment at preconditioning stresses which are reasonably achievable in the field. Due to the fully-coupled nature of seismic rupture and fault slip, preconditioning also reduces distal weakening and its contribution to the propagation of induced seismic ruptures. In a similar vein, heterogeneous pore pressure fields associated with some seismic swarms can be used to explain changes in stress drop within the swarm without recourse to material or total-stress heterogeneity.能量耗散是否局限于破裂尖端附近，以及远离裂纹尖端的远端能量耗散是否对破裂动力学产生重大影响，是描述摩擦破裂的关键问题，特别是对于线弹性断裂力学(LEFM)在地震中的应用。利用40厘米长的实验摩擦界面对这些问题进行了实验研究。三个独立的活塞施加正常载荷，第四个活塞施加剪切载荷，从而实现非均匀应力状态和应力屏障的应用。在将摩擦界面加载到接近临界状态后，随后一个法向载荷活塞的卸载导致动态破裂，并传播到非均质应力场中。这些实验中的破裂被发现是由非常规的奇点驱动的，其特征是伴随着滑动的不断增加的击穿功，因此不符合LEFM的假设。由于这些实验应力屏障抑制滑动，因此它们也减少了发生在粘聚区之外的击穿工作。结果表明，为了准确预测断裂止裂长度，必须考虑远离裂纹尖端的远端弱化。这些实验是在增强型地热系统(EGSs)增产技术的背景下进行的。以前有理论认为，通过控制孔隙压力可以诱发应力障碍，从而降低EGSs剪切刺 激过程中的地震危险性。这种刺 激技术，被称为预处理，在这里展示了减少到裂纹尖端的机械能通量G，同时也增加断裂能G。预处理被证明能够阻止地震破裂，并在预处理应力下减少同震滑动、滑动速度和地震力矩，这在现场是可以合理实现的。由于地震破裂和断层滑动的完全耦合性质，预处理还可以减少远端弱化及其对诱发地震破裂传播的贡献。同样，与一些地震群相关的非均质孔隙压力场可以用来解释地震群内应力降的变化，而无需求助于材料或总应力非均质。International Journal of PlasticityA variational framework for Cahn–Hilliard-type diffusion coupled with Allen–Cahn-type multi-phase transformations in elastic and dissipative solidsS.G. Nagaraja, T. Antretterdoi:10.1016/j.ijplas.2024.104131弹性和耗散固体中cahn - hilliard型扩散耦合allen - cahn型多相转变的变分框架This article presents a variational framework for coupled chemo-mechanical solids undergoing irreversible micro-structural changes at infinitesimal strains. The coupled problem is characterised by phenomena such as phase transitions, micro-structure coarsening and swelling. It is an extension of our previous work on variational inelasticity for a conserved chemo-mechanical setting to a unified conserved and non-conserved setting which include multi-phase transformations. The variational framework, again governed by continuous-time, discrete-time and discrete-space–time incremental variational principles, is outlined for coupled diffusion-phase transformation phenomena in elastic and dissipative solids. For the sake of simplicity, focus is restricted to isothermal conditions. It is shown that the governing macro- and micro-balance equations of the coupled problem appear as Euler equations of these minimisation and saddle point principles. In contrast to our previous work, extended variational principles (with the gradient of the chemical potential and phase fractions) are constructed that account for diffusion-phase transformation coupling. This is achieved by Legendre transformations. Note that the local–global solution strategy is still preserved and the resulting system of symmetric non-linear algebraic equations are solved by Newton–Raphson-type iterative methods. The applicability of the proposed framework is demonstrated by numerical simulations that qualitatively characterise lower bainitic micro-structure.本文提出了在无限小应变下发生不可逆微观结构变化的耦合化学-机械固体的变分框架。耦合问题的特征是相变、微结构粗化和膨胀等现象。这是我们以前的工作的变分非弹性的保守化学-机械设置扩展到统一的保守和非保守设置，包括多相变换。变分框架，再次由连续时间，离散时间和离散-时空增量变分原则，概述了耦合扩散相变现象在弹性和耗散固体。为简单起见，重点限于等温条件。结果表明，控制耦合问题的宏观和微观平衡方程表现为这些极小化和鞍点原理的欧拉方程。与我们之前的工作相反，我们构建了扩展变分原理(具有化学势和相分数的梯度)来解释扩散-相变耦合。这是由勒让德变换实现的。注意，局部全局解策略仍然被保留，得到的对称非线性代数方程组用newton - raphson型迭代方法求解。该框架的适用性通过定性表征下贝氏体微观结构的数值模拟得到了验证。Coupled cellular automata-crystal plasticity modeling of microstructure-sensitive damage and fracture behaviors in deformation of α-titanium sheets affected by grain sizeLei Sun, Zhutian Xu, Jilai Wang, Linfa Peng, Xinmin Lai, M.W. Fudoi:10.1016/j.ijplas.2024.104138晶粒尺寸影响α-钛板变形中微结构敏感损伤与断裂行为的元胞自动机-晶体塑性耦合模拟Concerning the micro-scale deformation of titanium metal sheets, the number of grains in the sheet thickness direction decreases, and their formability exhibits a strong grain size sensitivity. Meanwhile, the twinning-induced dynamic recrystallization (TDRX) associated with grain size significantly affects the fracture behavior in the microforming of titanium sheets. Therefore, an accurate prediction of formability to improve manufacturing reliability remains challenging in the microforming of miniaturized titanium components. To address this issue, an in-depth understanding of the grain size-dependent TDRX behavior and its role in damage and fracture development in the microforming of α-titanium sheets is critical, and a coupled cellular automata-crystal plasticity (CA-CP) modeling framework was thus developed as an approach providing efficient solutions and insightful comprehensions of the issue. For the proposed modeling framework, a kinematic model for TDRX was established and integrated into the CP model by the CA algorithm. As a result, the microstructure evolution caused by TDRX was regarded as an intrinsic part of the constitutive behavior to connect heterogeneous plastic deformation and damage evolution through data transmission between the CP model and the CA algorithm. Additionally, the coupled CA-CP modeling framework was validated with the internal defect morphologies and deformation microstructures characterized by X-ray computed tomography (X-CT) and electron backscattered diffraction (EBSD). Experiment and simulation results demonstrated that the fine recrystallized (DRXed) grains were generated after the twin fragmentation when the dislocation density at twin boundaries reached a threshold of 9.2 × 1013 /m2. After TDRX, the dislocation density and the stress concentration intensity in recrystallization regions were revealed to decrease, accounting for the ductility improvement. Nevertheless, the dislocation density at twin boundaries was determined to decrease with the increase of grain size, leading to less twin fragmentation and the absence of TDRX. The uncoordinated deformation between fine DRXed grains motivated defects to grow spherically into microvoids, thereby preventing premature intergranular cracks along twins/grain boundaries. Ultimately, the deformation microstructures resulting from TDRX with the decrease of grain size were confirmed to control the brittle to ductile fracture transition of α-titanium sheets. The presented modeling framework and simulation procedure were validated to be able to predict the material integrity affected by crystalline microstructure in the deformation of titanium metal sheets.在钛金属板的微尺度变形中，沿板厚方向晶粒数量减少，其成形性表现出较强的晶粒尺寸敏感性。同时，与晶粒尺寸相关的孪生诱导动态再结晶(TDRX)显著影响钛板微成形的断裂行为。因此，在微型化钛零件的微成形中，准确预测成形性能以提高制造可靠性仍然是一个挑战。为了解决这一问题，深入了解晶粒尺寸相关的TDRX行为及其在α-钛板微成形过程中的损伤和断裂发展中的作用至关重要，因此开发了一个耦合元胞自动机-晶体塑性(CA-CP)建模框架，作为一种有效的解决方案和深刻理解这一问题的方法。针对所提出的建模框架，建立了TDRX的运动学模型，并通过CA算法将其集成到CP模型中。因此，通过CP模型与CA算法之间的数据传输，将TDRX引起的微观结构演化作为本构行为的内在组成部分，将非均质塑性变形与损伤演化联系起来。此外，通过x射线计算机断层扫描(X-CT)和电子背散射衍射(EBSD)对内部缺陷形貌和变形微观结构进行表征，验证了耦合CA-CP建模框架的有效性。实验和模拟结果表明，当孪晶界位错密度达到9.2 × 1013 /m2阈值时，孪晶破碎后产生细小的再结晶(DRXed)晶粒。经TDRX处理后，再结晶区位错密度和应力集中强度降低，塑性得到改善。然而，随着晶粒尺寸的增大，孪晶边界处的位错密度减小，导致孪晶碎裂减少和TDRX的缺失。细小DRXed晶粒之间的不协调变形促使缺陷沿孪晶/晶界生长成球形微孔洞，从而防止了沿孪晶/晶界的过早晶间裂纹。最终证实了TDRX随晶粒尺寸减小而产生的形变组织控制了α-钛板的脆性向韧性断裂转变。验证了所提出的建模框架和仿真程序能够预测钛金属板变形过程中晶体微观结构对材料完整性的影响。Tailoring multi-type nanoprecipitates in high-entropy alloys towards superior tensile properties at cryogenic temperaturesShuang Qin, Zihan Zhang, Zheng Yu, Longhui Zhang, Fuping Yuan, Xiaohu Yaodoi:10.1016/j.ijplas.2024.104132 在高熵合金中定制多类型纳米沉淀物，以获得在低温下优越的拉伸性能In this work, the quasi-static tensile properties in the face-centered cubic-based Al0.5Cr0.9FeNi2.5V0.2 HEAs containing two types of heterogeneous nanoprecipitates, i.e. dual-lamellar and spherical nanoprecipitates at ambient (293 K) and liquid nitrogen (77 K) temperatures are thoroughly investigated. The microstructure formed by aging at 873 K comprises L1 2 and body-centered cubic dual-lamellar (DL) nanoprecipitates. In contrast, aging at 773 K results in solely spherical L1 2 nanoparticles. Both nanoprecipitates enhance mechanical strength as temperatures drop to 77 K; however, the DL nanoprecipitates additionally boost the work hardening rate, whereas the spherical nanoparticles notably improve ductility. To investigate the underlying deformation mechanisms, we perform interrupted mechanical tests and microstructure characterizations at various strains. The DL nanoprecipitates are observed to go through a multistage work hardening rate response by gradually introducing new boundaries to block dislocation motion, activating the stacking fault (SF) networks, and forming Lomer-Cottrell locks. A combination of interface hardening, dislocation hardening, SF-induced hardening, and precipitation hardening in DL samples leads to stronger hetero-deformation-induced hardening at cryogenic temperatures. In comparison, while samples with only spherical nanoparticles exhibit a monotonous decrease in the work-hardening rate, the spherical nanoparticles can be sheared by dislocations, effectively alleviating strain concentration and thereby enhancing ductility at cryogenic temperatures. Overall, this work provides practical design principles of nanoprecipitates for fine-tuning the balance of strength and ductility in FCC-based HEA at cryogenic temperatures.本文研究了含有两种非均相纳米沉淀物(双片层和球形纳米沉淀物)的面心立方基Al0.5Cr0.9FeNi2.5V0.2 HEAs在室温(293 K)和液氮(77 K)下的准静态拉伸性能。873 K时效形成的微观组织包括L1 - 2和体心立方双片层(DL)纳米沉淀。相比之下，在773 K下时效得到的是纯球形L1 - 2纳米颗粒。当温度降至77 K时，两种纳米沉淀物的机械强度都有所提高;然而，DL纳米沉淀物还能提高加工硬化速率，而球形纳米颗粒则能显著提高延展性。为了研究潜在的变形机制，我们在不同应变下进行了中断的力学测试和微观结构表征。观察到DL纳米沉淀通过逐渐引入新的边界来阻止位错运动，激活层错(SF)网络并形成lomo - cottrell锁，从而经历了多阶段的加工硬化速率响应。在低温下，DL样品中的界面硬化、位错硬化、sf诱导硬化和沉淀硬化的组合导致了更强的异质变形诱导硬化。相比之下，仅含球形纳米颗粒的样品在加工硬化速率上呈现单调的下降，但球形纳米颗粒可以通过位错剪切，有效地缓解应变集中，从而提高低温下的塑性。总的来说，这项工作为在低温下微调fcc基HEA的强度和延性平衡提供了实用的纳米沉淀物设计原则。Thin-Walled StructuresStudy on the load-end shortening of FGP cylindrical shells under external pressure in a thermal environmentHabib Talati, Alireza Shaterzadehdoi:10.1016/j.tws.2024.112492热环境下外压作用下FGP圆柱壳载荷端缩短研究This paper investigates the postbuckling behavior of functionally graded porous (FGP) cylindrical shells under external pressure in a thermal environment, where the properties of the shell are assumed to be temperature-dependent using the modified rule of mixture and Touloukian formulation. The governing equations are derived from classical shell theory and von Kármán-Donnell's type of kinematic nonlinearity. The extended boundary layer theory of shell buckling, which considers the influence of nonlinear prebuckling deformations, large deflections in the postbuckling range, and initial geometric imperfections, is applied to FGP cylindrical shells. To determine the buckling loads and load-end shortening equilibrium paths, a two-step perturbation approach is utilized. In order to investigate the impact of shell geometric parameters, material properties, and temperature on the on the postbuckling behavior and load-end shortening equilibrium paths of perfect and imperfect FGP cylindrical shells, a numerical parametric analysis and an examination of three types of porosity distribution have been conducted. The results show that our current method is effective and precise in resolving the problem, which is consistent with the literature. It is noted that an increase in geometric parameters such as length, ratio of radius to thickness, porosity volume fraction, and temperature leads to a decrease in postbuckling load and load-end shortening equilibrium paths for FGP cylindrical shells. Conversely, an increase in the functionally graded volume fraction index results in an increase in these paths. Furthermore, the porosity index has a substantial impact on the postbuckling behavior and load-end shortening equilibrium paths of FGP cylindrical shells.本文研究了功能梯度多孔(FGP)圆柱壳在热环境下的外压后屈曲行为，其中使用改进的混合规则和Touloukian公式假设壳的性能与温度相关。控制方程由经典壳理论和von Kármán-Donnell的运动非线性类型推导而来。将考虑非线性屈曲前变形、屈曲后大挠度和初始几何缺陷影响的扩展边界层理论应用于FGP圆柱壳。为了确定屈曲载荷和载荷-端缩短平衡路径，采用了两步摄动法。为了研究壳体几何参数、材料性能和温度对完美和不完美FGP圆柱壳屈曲后行为和载荷端缩短平衡路径的影响，对三种类型的孔隙率分布进行了数值参数分析和检验。结果表明，我们的方法在解决问题上是有效和精确的，这与文献一致。研究发现，长度、半径厚度比、孔隙体积分数和温度等几何参数的增加会导致FGP圆柱壳屈曲后载荷的减少和载荷端平衡路径的缩短。相反，功能梯度体积分数指数的增加会导致这些路径的增加。此外，孔隙率指数对FGP圆柱壳的屈曲后行为和载荷端缩短平衡路径有重要影响。Multiscale dynamic behavior of imperfect hybrid matrix/fiber nanocomposite nested conical shells with elastic interlayerMoein A. Ghandehari, Amir R. Masoodi, Seyed Ehsan Seyedi Hosseininiadoi:10.1016/j.tws.2024.112494含弹性夹层的不完全杂化基/纤维纳米复合材料嵌套锥形壳的多尺度动力学行为This investigation delves into the free vibration characteristics of coupled nested conical shells (CNCSs) made of porous composite materials. These two conical shells are connected by a mid-layer of elastic springs. The composite materials used in the shells consist of epoxy, nanofillers, and fibers. Two types of nanofillers are considered: Graphene Nanoplatelets (GNPs) and Carbon Nanotubes (CNTs), while E-glass fiber is used as the fiber. The nanofillers are distributed in four different patterns within the shell section. Porosity is uniformly distributed along the shell section and characterized by a coefficient. The rule of mixtures is employed to ascertain the equivalent material properties of the hybrid materials, while the Chamis approach is utilized for three-phase materials. First-order shear deformation theory (FSDT) and Donnell's theory are utilized for modeling the conical shells. The governing equations of motion are established through Hamilton's principle are solved using the generalized differential quadrature method (GDQM). Seven different boundary conditions (BCs) are considered to encompass the full range of BCs for CNCSs and four type of BCs for single truncated conical shell (STCS). The solution's accuracy is verified, and the effects of various parameters on the natural frequency parameter (NFP) of the shell are investigated, such as BCs, circumferential wave number (n), nanofillers pattern, semi-vertex angle, nanofillers angle, and mid-layer stiffness. Initially, a comprehensive investigation into the vibration behavior of a STCS is presented, followed by an analysis of the NFP of the CNCSs. The results demonstrate that the stiffness of the elastic mid-layer significantly influences the NFP of the system. The orientation of the nanofillers in the shell can increase or decrease the NFP. Additionally, the relationship between mode number and n depends on the type of BCs of the shells.研究了多孔复合材料耦合嵌套锥形壳的自由振动特性。这两个圆锥形的壳由一层中间的弹性弹簧连接。外壳中使用的复合材料包括环氧树脂、纳米填料和纤维。考虑了两种类型的纳米填料:石墨烯纳米片(GNPs)和碳纳米管(CNTs)，其中e -玻璃纤维作为纤维。纳米填料在壳段内以四种不同的模式分布。孔隙率沿壳截面均匀分布，用系数表示。混合材料等效材料性能的确定采用混合规律，三相材料等效材料性能的确定采用Chamis方法。利用一阶剪切变形理论(FSDT)和Donnell理论对锥形壳进行了建模。利用哈密顿原理建立了运动控制方程，用广义微分正交法求解。七种不同的边界条件(bc)被认为涵盖了cncs的全部边界条件和单截锥壳(STCS)的四种边界条件。验证了解的准确性，并研究了bc、周向波数(n)、纳米填料模式、半顶角、纳米填料角和中间层刚度等参数对壳体固有频率参数(NFP)的影响。首先，对STCS的振动特性进行了全面的研究，然后对cncs的NFP进行了分析。结果表明，弹性中间层的刚度对系统的NFP有显著影响。纳米填充剂在壳中的取向可以增加或降低NFP。另外，模态数和n之间的关系取决于shell的bc类型。Physics-informed Neural Networks (PINN) for computational solid mechanics: Numerical frameworks and applicationsHaoteng Hu, Lehua Qi, Xujiang Chaodoi:10.1016/j.tws.2024.112495用于计算固体力学的物理信息神经网络(PINN):数值框架和应用For solving the computational solid mechanics problems, despite significant advances have been achieved through the numerical discretization of partial differential equations (PDEs) and data-driven framework, it is still hard to seamlessly integrate imperfect, limited, sparse and noisy data into existing algorithms. Besides the expensive tasks and struggling completion of mesh-based and meshless-based solutions in complex computational domain, the high-dimensional solid mechanics problems governed by parameterized PDEs cannot be tackled. Furthermore, addressing inverse solid mechanics problems, especially with incomplete descriptions of physical laws, are often prohibitively expensive and require obscure formulations and elaborate codes. Since the physics-informed neural networks (PINN) was originally introduced by Raissi et al. in 2019, it has been recognized as effective surrogate solvers for PDEs while respecting any given laws, data, initial and boundary conditions of solid mechanics. PINN has emerged as a promising approach to mitigate the shortage of available training data, enhance model generalizability, and ensure the physical plausibility of results. The prior physics information can act as a regularization agent that constrains the space of admissible solutions to a manageable size, enabling it to quickly steer itself towards the right solution. To catch up with the latest developments of PINN in computational solid mechanics, this work summarizes the recent advances in the field. We first introduce the foundational concepts of PINN, including the framework, architecture, algorithms, code and associated software packages. We then discuss the applications of PINN in constitutive modeling and its inverse problem, identification, evaluation, and prediction of damage in solid materials and structures. Finally, we address the current capabilities and limitations of PINN in computational solid mechanics, and present perspectives on emerging opportunities and open challenges of the prevailing trends.对于计算固体力学问题，尽管偏微分方程的数值离散化和数据驱动框架已经取得了重大进展，但将不完美、有限、稀疏和有噪声的数据无缝集成到现有算法中仍然很困难。在复杂的计算域中，基于网格和无网格的求解不仅任务昂贵且难以完成，而且参数化偏微分方程控制的高维固体力学问题也无法解决。此外，处理逆固体力学问题，特别是在物理定律描述不完整的情况下，通常是非常昂贵的，并且需要模糊的公式和复杂的代码。由于物理信息神经网络(PINN)最初是由Raissi等人于2019年引入的，它已被认为是PDEs的有效替代求解器，同时尊重任何给定的定律、数据、固体力学的初始和边界条件。PINN已经成为一种很有前途的方法，可以缓解可用训练数据的短缺，增强模型的泛化性，并确保结果的物理合理性。先前的物理信息可以作为一个正则化代理，将可接受的解的空间限制在一个可管理的大小，使其能够快速地转向正确的解。为了赶上PINN在计算固体力学中的最新发展，本文总结了该领域的最新进展。我们首先介绍了PINN的基本概念，包括框架、架构、算法、代码和相关软件包。然后，我们讨论了PINN在本构建模及其反问题、识别、评估和预测固体材料和结构损伤中的应用。最后，我们讨论了PINN在计算固体力学中的当前能力和局限性，并对当前趋势的新机遇和开放挑战提出了看法。Low-velocity impact behavior and damage mechanisms of honeycomb sandwich structures with elastomeric interlayers in CFRP skinsZhongyu Li, Zhe Ma, Jianfeng Wang, Bing Wang, Na Yangdoi:10.1016/j.tws.2024.112482含弹性夹层的CFRP皮蜂窝夹层结构低速冲击性能及损伤机理Elastomers help improve the toughness of lightweight high-strength materials, offering significant potential for enhancing the mechanical properties. However, introducing elastomers into CFRP interlayers as skin for composite sandwich structures has not yet been explored regarding the impact responses of such novel structures. This paper, for the first time in literature studies the low-velocity impact behavior and damage mechanisms of this novel sandwich structure using a combined experimental and numerical approach. The experimental results of sandwich structures with and without elastomer layers under different impact energies are presented. Finite element models of the two sandwich structures are built and impact behaviors were compared. The differences in internal damage and energy distribution during the impact are investigated to explain the reasons for the differing impact responses of the two sandwich structures. The results reveal that elastomeric interlayers have a significant advantage in enhancing the damage resistance of composite sandwich structures, especially under high impact energy conditions. The key contributions of this paper include the experimental characterization of the impact behavior of composite sandwich structures with elastomeric interlayers, and the explanation of the reasons for the changes in impact responses caused by the elastomers from the perspectives of damage mechanisms and energy distribution.弹性体有助于提高轻质高强度材料的韧性，为提高机械性能提供了巨大的潜力。然而，将弹性体引入CFRP夹层作为复合材料夹层结构的表皮，对于这种新型结构的冲击响应尚未进行探索。本文首次采用实验与数值相结合的方法对这种新型夹层结构的低速冲击行为和损伤机理进行了研究。给出了含弹性体层和不含弹性体层的夹层结构在不同冲击能下的实验结果。建立了两种夹层结构的有限元模型，并对其冲击性能进行了比较。研究了两种夹层结构在冲击过程中内部损伤和能量分布的差异，解释了两种夹层结构不同冲击响应的原因。结果表明，弹性体夹层在提高复合材料夹层结构的抗损伤能力方面具有显著优势，特别是在高冲击能条件下。本文的主要贡献包括实验表征了含弹性体夹层的复合材料结构的冲击行为，并从损伤机制和能量分布的角度解释了弹性体引起的冲击响应变化的原因。Passive Control of Hydro-elastic Vibrations of Plates using Shunted Piezoelectric PatchesHuong Q. Cao, Mahmoud Karimi, Paul Williams, Paul Dylejkodoi:10.1016/j.tws.2024.112493分流压电片被动控制板的水弹性振动Suppressing structural vibrations is a vital engineering requirement in many applications. In this study, an analytical model is initially developed for predicting the forced vibration response of a fluid-loaded plate with arbitrary boundary conditions attached to piezoelectric patches. Each piezoelectric patch is connected to a resonant shunt circuit consisting of a resistor and inductor. Using the analytical model, it is demonstrated that the vibration control is effective for cantilever plates immersed in water. This is demonstrated first for the vibration control at individual resonance frequencies, and then at multiple resonance frequencies simultaneously using several separate piezoelectric patches. A parametric study is then performed to investigate how the efficiency of the method varies with the plate thickness, patch thickness, and patch size. It is observed that although the vibration reduction decreases steadily with increasing plate thickness, the shunted piezoelectric patches can still effectively damp the plate vibration, and their performance can be further improved by increasing the size and/or thickness of the patches.在许多应用中，抑制结构振动是一项重要的工程要求。在这项研究中，初步建立了一个分析模型，用于预测带有任意边界条件的压电片的流体加载板的强迫振动响应。每个压电片连接到一个由电阻和电感组成的谐振分流电路。利用解析模型验证了悬臂板在水中的振动控制是有效的。首先演示了在单个共振频率下的振动控制，然后使用几个单独的压电片同时在多个共振频率下进行振动控制。然后进行参数研究，以调查该方法的效率如何随板厚度，贴片厚度和贴片大小而变化。观察到，虽然减振量随板厚的增加而逐渐减小，但分流压电片仍能有效地抑制板的振动，并且通过增加压电片的尺寸和/或厚度可以进一步提高其性能。来源：复合材料力学仿真Composites FEM