今日更新：International Journal of Solids and Structures 1 篇，Journal of the Mechanics and Physics of Solids 2 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 7 篇International Journal of Solids and StructuresAn investigation of PLLA hybrid stent design to overcome thick strut problemsHakan Burcin Erdogus, Doruk Erdem Yunusdoi:10.1016/j.ijsolstr.2024.113025PLLA混合式支架设计研究，克服支架粗大问题Biodegradable polymer-based stents simultaneously provide scaffolding, drug release, and biodegradation to eliminate chronic inflammation. The most important factors hindering the wide use of these stents are thick struts, low radial strength, and large footprints formed on the inner wall of the artery as a result of stent expansion. Negative Poisson’s Ratio (NPR), also known as the Auxetic design, has shown great potential to provide radial strength with less strut thickness. However, a detailed mechanical evaluation proving improvement in stent performance parameters is not available in the literature. In this study, the performance parameters of two stent designs based on the Auxetic geometry with PLLA were analyzed under in-vivo conditions using an in-silico model consisting of the artery, crimper, and expander FE model. For this purpose, one design utilizes Auxetic unit cell, which is already available in the literature, while the other uses a newly proposed Hybrid design combining Auxetic and Chevron type geometries. Additionally, a specially heated coaxial balloon-catheter system was considered as a deployment tool between glass transition and body temperature, and carried out for thin-strut stent simulations. The Hybrid design is shown to resolve the foreshortening problem of Auxetic design and collapse pressure of commercial PLLA stents. In this present study validates the potential of Hybrid design to overcome problems for polymer-based biodegradable stents.可生物降解聚合物支架同时提供支架、药物释放和生物降解，以消除慢性炎症。阻碍这类支架广泛应用的最重要因素是支柱粗大，径向强度低，以及支架扩张在动脉内壁上形成的大足迹。负泊松比(NPR)，也被称为辅助设计，已经显示出巨大的潜力，以更少的支撑厚度提供径向强度。然而，文献中没有详细的力学评估证明支架性能参数的改善。在本研究中，使用由动脉、卷曲器和扩张器组成的计算机模型，在体内条件下分析了基于PLLA的Auxetic几何结构的两种支架设计的性能参数。为此，一种设计利用了文献中已有的Auxetic单元格，而另一种则采用了一种新提出的混合设计，结合了Auxetic和Chevron型几何形状。此外，一个特殊加热的同轴球囊导管系统被认为是玻璃化转变和体温之间的部署工具，并进行了薄支架模拟。混合设计解决了商用PLLA支架的辅助设计缩短和崩溃压力问题。在本研究中，验证了混合设计的潜力，以克服聚合物基生物可降解支架的问题。Journal of the Mechanics and Physics of SolidsHyperinelasticity, Part II: A stretch-based formulationAfshin Anssari-Benamdoi:10.1016/j.jmps.2024.105825超弹性，第二部分:基于拉伸的配方A generalisation of the hyperinelasticity modelling framework devised in Part I of this sequel is formulated here, by presenting a (principal) stretches-based hyperinelastic deformation energy function W F . This generalisation is based on the premise that the (principal) stretches λ j may assume any arbitrary real-valued exponents, rather than being restricted to the prescriptive powers 2 and −2, as in principal invariants-based models. The motivation behind this extension is to reduce the overall number of model parameters and thereby increase the versatility of the application of the hyperinelasticity framework, as well as to provide a more universal model. The ensuing hyperinelastic model is then applied to a wide range of extant experimental datasets encompassing foams, glassy and semi-crystalline polymers, hydrogels and liquid crystal elastomers, over both elastic and inelastic deformation ranges including yield, softening and plateau, and hardening behaviours, under tensile and compressive deformations. Upon demonstrating the favourable simulation of the foregoing behaviours by the model, its application is then extended to account for other nuanced aspects of inelasticity such as the effects of rate of deformation, crystallinity volume and angle of printing in 3D printed lattice structures. This augmentation is done via devising a generalised modelling framework which allows for the incorporation of a generic tensorial (including rank zero scalar) field of inelasticity-inducing factors into the core model, resulting in the model parameters to evolve with an appropriate measure of the factor of interest; e.g., deformation rate, crystallinity volume ratio etc. The proposed modelling framework will be shown to capture these effects proficiently. Given the simplicity of this modelling approach, as essentially an extension in the application of hyperelasticity, its versatility of implementation, and the favourable capturing of both elastic and inelastic behaviours, the devised hyperinelasticity framework is presented for application to the large elastic and inelastic deformation of polymers and elastomers.本文通过提出一个(主要的)基于拉伸的超非弹性变形能量函数wf，概括了本续作第一部分中设计的超非弹性建模框架。这种推广是基于这样一个前提，即(主)拉伸λ j可以假设任意实值指数，而不是像基于主不变量的模型那样局限于规定性幂2和- 2。此扩展背后的动机是减少模型参数的总数，从而增加超非弹性框架应用程序的多功能性，以及提供更通用的模型。随后的超非弹性模型被广泛应用于现有的实验数据集，包括泡沫、玻璃状和半晶体聚合物、水凝胶和液晶弹性体，在弹性和非弹性变形范围内，包括屈服、软化、平台和硬化行为，在拉伸和压缩变形下。在通过模型演示上述行为的有利模拟后，其应用程序随后扩展到考虑非弹性的其他细微方面，例如3D打印晶格结构中变形率，结晶度体积和打印角度的影响。这种增强是通过设计一个广义的建模框架来完成的，该框架允许将非弹性诱导因素的一般张量(包括零阶标量)场合并到核心模型中，从而导致模型参数随着感兴趣因素的适当度量而演变;例如:变形速率、结晶度、体积比等。所提出的建模框架将被证明能够熟练地捕捉这些效果。鉴于这种建模方法的简单性，本质上是超弹性应用的扩展，其实现的多功能性，以及对弹性和非弹性行为的有利捕获，所设计的超非弹性框架被用于应用于聚合物和弹性体的大弹性和非弹性变形。On the cyclic elastoplastic shakedown behavior of an auxetic metamaterial: An experimental, numerical, and analytical studyShen Wang, Michael Peigney, Natasha Vermaakdoi:10.1016/j.jmps.2024.105822 一种增减超材料的循环弹塑性安定行为:实验、数值和分析研究This article presents the first experimental, numerical, and analytical study of the elastoplastic shakedown response of an auxetic metamaterial structure that elucidates interactions between auxeticity and maximum shakedown loading capacity. The study aims to determine the safe elastoplastic shakedown limit of perforated auxetic aluminum sheet structures (AA5083-TO) with fixed void fraction (16.4%) under ambient cyclic asymmetric uniaxial loading conditions. The motivation is that shakedown-based designs can be used to expand the feasible design space under cyclic loading conditions compared to conventional yield-limited designs. Finite element analyses with calibrated hardening models are used to develop Bree load-interaction diagrams that are experimentally validated. It is found that shakedown occurs at stress levels up to almost four times the elastic limit of the structure for a fixed allowable equivalent strain level near three percent. This shakedown multiplier is also sensitive to the extent of auxeticity in the structure and a parametric study and analytical model are used to identify underlying mechanisms and a potential maximum condition.本文首次通过实验、数值和分析方法研究了一种失活超材料结构的弹塑性安定响应，阐明了失活性和最大安定载荷能力之间的相互作用。本研究旨在确定固定孔隙率(16.4%)的多孔铝板结构(AA5083-TO)在环境单轴非对称循环加载条件下的安全弹塑性安定极限。其动机是，与传统的屈服限制设计相比，基于试验的设计可用于扩大循环加载条件下的可行设计空间。使用校准硬化模型的有限元分析来开发经实验验证的Bree载荷-相互作用图。研究发现，在接近3%的固定允许等效应变水平下，安定发生在应力水平几乎是结构弹性极限的四倍的情况下。这种安定乘数对结构的不稳定性程度也很敏感，并使用参数研究和分析模型来确定潜在的机制和潜在的最大条件。International Journal of PlasticityCrystal plasticity-phase–field based analyses of interfacial microstructural evolution during dynamic recrystallization in a dual phase titanium alloyRitam Chatterjee, Aayush Trivedi, S.V.S. Narayana Murty, Alankar Alankardoi:10.1016/j.ijplas.2024.104087晶体塑性-基于相场的双相钛合金动态再结晶界面显微组织演变分析In this study, an integrated crystal plasticity finite element–phase–field (CPFE–PF) model is developed to examine dynamic recrystallization (DRX) in a dual phase Ti alloy. The CP framework is coupled with PF by updating the free energy density with energy contributions due to plasticity. The evolution of grain boundaries through evolving non–conserved order parameters in the PF model is tracked using the Allen-Cahn equation. Nucleation is allowed to occur if the dislocation density exceeds a critical value. DRX is studied in various Ti morphologies such as an α−Ti single crystal containing a stiff elastoplastic particle, α-Ti bicrystals with low and high misorientation between grains, an α−β bicrystal and a globular α−β Ti structure with β phase at α−α interfaces. For an α−Ti bicrystal, a high misorientation facilitates the onset of DRX at the α−α interface at a significantly lower strain than the bicrystal with low misorientation. In an α−β bicrystal, DRX is only observed at the α−β interface. For the globular morphology, nucleation is observed at both α−β interfaces and inside α grains, which is consistent with previous experimental observations for a similar morphology. Nucleation inside α grains is explained by the correlation between SSD density and misorientation indicators such as KAM and GROD at the nucleus site. To correlate slip activity with nucleation propensity immediately prior to different nucleation events, the dislocation density, shear rate and Schmid factors on different slip systems are evaluated at nucleation sites.本研究开发了一种集成晶体塑性有限元-相场（CPFE-PF）模型，用于研究双相钛合金中的动态再结晶（DRX）。CP 框架与 PF 相耦合，通过更新自由能密度与塑性导致的能量贡献来实现。使用 Allen-Cahn 方程跟踪 PF 模型中通过非保留阶次参数演变的晶界演化。如果位错密度超过临界值，则允许发生成核。DRX 在不同的钛形态中进行了研究，如含有刚性弹塑性颗粒的 α-Ti 单晶、晶粒间具有低和高错位取向的 α-Ti 双晶、α-β 双晶和在α-α 接口处具有 β 相的球状 α-β Ti 结构。对于α-Ti 双晶，高取向错位有助于在α-α界面上发生 DRX，其应变明显低于低取向错位的双晶。在 α-β 双晶中，只有在 α-β 界面才能观察到 DRX。对于球状形态，在 α-β 界面和 α 晶粒内部都能观察到成核现象，这与之前对类似形态的实验观察结果一致。α晶粒内部的成核可通过核部位的SSD密度与KAM和GROD等错取向指标之间的相关性来解释。为了将不同成核事件发生前的滑移活动与成核倾向相关联，在成核点评估了不同滑移系统上的位错密度、剪切速率和施密德因子。Thin-Walled StructuresTearing behaviors of coated fabric inflatable tubeFu Zhang, Ningrui Wang, Ruiquan Zhou, Mingyi Zhang, Minger Wudoi:10.1016/j.tws.2024.112331涂层织物充气管的撕裂行为In this paper, the tearing properties of the inflatable tube with coated fabrics were investigated. Firstly, uniaxial tensile, shear, and single-edge notched tests were conducted to obtain the material properties. Then, considering the modified stress field model and bulge effect, a theoretical calculation formula for the critical tearing pressure was proposed. Next, based on finite element method, the macroscopic orthotropic elastic continuum models of the single-edge notched test and pressurized cylinder test were established. In numerical model, when the average stress in the critical distance at the crack tip reached the tensile strength, the tearing began. Then, the critical distance was determined when the critical tearing load of the numerical model was closest to the single-edge notched tests’ result. Based on the numerical simulation of pressurized cylinder test, the critical tearing pressure of inflatable tube was obtained. Finally, the pressurized cylinder test and puncturing test were designed and conducted. In the pressurized cylinder test, when the first yarn at the crack tip broke, the critical tearing pressure and configuration around the crack were obtained. Moreover, the correctness of the critical tearing pressure in theoretical calculation formula and numerical model was verified through pressurized cylinder test. In puncturing test of inflatable tube, there were obvious crack expansion and explosion. Based on the theoretical calculation formula for the critical tearing pressure, the predicted results were consistent with puncturing test's results.研究了涂层织物对充气管撕裂性能的影响。首先，进行了单轴拉伸、剪切和单刃缺口试验，获得了材料的性能。然后，考虑修正的应力场模型和凸起效应，提出了临界撕裂压力的理论计算公式。其次，基于有限元方法，建立了单边缺口试验和受压圆筒试验的宏观正交各向异性弹性连续体模型;在数值模型中，当裂纹尖端临界距离处的平均应力达到拉伸强度时，开始撕裂。然后，当数值模型的临界撕裂载荷与单刃缺口试验结果最接近时，确定临界距离。通过增压缸试验的数值模拟，得到了充气管的临界撕裂压力。最后，设计并进行了增压缸试验和穿刺试验。在加压圆筒试验中，当裂纹尖端的第一根纱断裂时，得到了裂纹周围的临界撕裂压力和形态。通过增压缸试验，验证了理论计算公式和数值模型中临界撕裂压力的正确性。在充气管穿刺试验中，出现了明显的裂纹扩展和爆炸现象。根据临界撕裂压力理论计算公式，预测结果与穿刺试验结果吻合较好。DSM-Based Failure Load Prediction of CFS Pin-Ended Singly Symmetric Columns Buckling in Flexural-Torsional ModesElisa Cerqueira, Carlos Oliveira, Alexandre Landesmann, Dinar Camotim, Pedro B. Dinis, André D. Martinsdoi:10.1016/j.tws.2024.112334基于dsm的CFS销端单对称柱弯扭屈曲破坏荷载预测Recently, the authors investigated the post-buckling behaviour, strength and Direct Strength Method (DSM) design of cold-formed steel (CFS) fixed-ended singly symmetric columns buckling in major-axis flexural-torsional modes (FMT), some of which were shown to experience interaction with minor-axis flexural (Fm) buckling − FMT-Fm (global-global) interaction. The main fruit of this investigation was the development of an efficient DSM-based design approach capable of predicting the failure loads of such columns, regardless of their failure mode nature (pure FMT or FMT-Fm interactive). This work extends the scope of the above study to singly symmetric columns with three types of pin-ended support conditions, all fixed with respect to torsion and having warping fully prevented. Columns with seven cross-section shapes are considered, having their wall dimensions, lengths and yield stresses selected to ensure covering wide FMT slenderness ranges and various ratios between the Fm and FMT buckling loads. Following an investigation on the elastic and elastic-plastic post-buckling behaviours of the selected pin-ended columns, paying attention to the possible occurrence of FMT-Fm interaction, parametric studies are carried out to gather extensive pin-ended column failure load data, including some potentially associated with FMT-Fm interactive collapses. Then, the assembled numerical failure loads are used to show that (i) the available DSM-based strength curves are only able to predict adequately part of them and, thus, (ii) novel DSM-based design curves are needed to estimate the failure loads of the remaining pin-ended singly symmetric columns buckling in FMT modes. After developing such curves and assessing their merits (safety and reliability), it is concluded that different DSM-based design curves/approaches must be employed for columns with each type of pin-ended support conditions.最近，作者研究了冷弯型钢(CFS)固定端单对称柱在主轴弯曲-扭转模式(FMT)下屈曲后的行为、强度和直接强度法(DSM)设计，其中一些被证明与小轴弯曲(Fm)屈曲相互作用 − FMT-Fm(全局-全局)相互作用。这项研究的主要成果是开发了一种有效的基于dsm的设计方法，能够预测此类柱的失效载荷，而不管它们的失效模式性质(纯FMT或FMT- fm交互)。这项工作将上述研究的范围扩展到具有三种类型的销端支撑条件的单对称柱，这些柱都是相对于扭转和完全防止翘曲而固定的。考虑了七种截面形状的柱，其壁尺寸，长度和屈服应力的选择，以确保覆盖宽的FMT长细范围和Fm和FMT屈曲载荷之间的不同比例。在对选定的销端柱的弹性和弹塑性后屈曲行为进行研究之后，注意到可能发生的FMT-Fm相互作用，进行了参数化研究，以收集大量的销端柱破坏载荷数据，包括一些可能与FMT-Fm相互作用破坏相关的数据。然后，使用组合的数值破坏荷载表明:(i)现有的基于dsm的强度曲线只能充分预测其中的一部分，因此(ii)需要新的基于dsm的设计曲线来估计剩余的销端单对称柱在FMT模式下屈曲的破坏荷载。在开发了这些曲线并评估了它们的优点(安全性和可靠性)之后，得出结论，对于每种类型的销端支撑条件的柱，必须采用不同的基于dsm的设计曲线/方法。Predicting delamination in composite laminates through semi-analytical dynamic analysis and vibration-based quantitative assessmentJianfei Wang, Zhaolin Chang, Gan Cao, Siu-Kai Laidoi:10.1016/j.tws.2024.112346通过半解析动力学分析和基于振动的定量评价预测复合材料层合板的分层Delamination is a frequent failure mode in laminated fiber-reinforced polymer (FRP) composites structure, leading to changes in vibration characteristics. Vibration-based monitoring techniques of such defects avoid the data acquisition of multiple locations and also guarantee the frequency measurement of reliability and repeatability. Previous studies typically concentrate on using finite element method to obtain vibration characteristics and enhance the database for intelligent algorithms. This paper presents a semi-analytical result using the Chebyshev−Ritz method to expand delamination prediction. Vibration frequency serves as a global damage indicator, and multi-order frequency characteristics are utilized to identify the delamination length and location of FRP composite plates. A database of natural frequencies corresponding to damage parameters for FRP laminated plates is generated based on the established model using the region approach. An intelligent approach, known as a genetic algorithm optimization-based back-propagation (GA-BP) artificial neural network, is utilized for system identification. The network model is subjected to a sensitivity analysis, where artificial noise is added to vibration frequency to distinguish between the actual structure and the numerical model. The results indicate that the GA-BP algorithm shows good accuracy and stable performance against the standard neural networks for delamination analysis.分层是层合纤维增强聚合物(FRP)复合材料结构中一种常见的破坏模式，它会导致结构振动特性的改变。基于振动的缺陷监测技术避免了多位置的数据采集，也保证了频率测量的可靠性和可重复性。以往的研究主要集中在利用有限元方法获取振动特性和增强智能算法数据库。本文给出了用切比雪夫-里兹方法扩展分层预测的半解析结果。振动频率作为全局损伤指标，利用多阶频率特性识别FRP复合材料板的分层长度和分层位置。在此基础上，采用区域法建立了玻璃钢叠合板损伤参数对应的固有频率数据库。一种被称为基于遗传算法优化的反向传播(GA-BP)人工神经网络的智能方法用于系统识别。对网络模型进行敏感性分析，在振动频率中加入人工噪声，以区分实际结构和数值模型。结果表明，与标准神经网络相比，GA-BP算法具有良好的准确率和稳定的性能。Stability and design of high-strength aluminium alloy RHS members under eccentric compressionBeibei Li, Pengcheng He, Shuai Mo, Jingfeng Wang, Yuanqing Wang, Wanqian Wangdoi:10.1016/j.tws.2024.112325高强铝合金RHS构件偏心受压稳定性及设计The structural behaviour of the 7A04-T6 high-strength aluminium alloy rectangular hollow section (RHS) members was investigated through an eccentric compression test programme presented in this paper. The programme encompassed eight RHS members with profiles of 60 × 30 × 3 (in mm), and cross-sections of Class 2∼4 were considered, involving initial geometric imperfection measurements and pin-ended beam-column tests. Finite element (FE) models were developed and validated with respect to the load - lateral deflection curve and failure mode. These models were then employed in a series of parametric studies designed to investigate the effects of member slenderness ratios, cross-section dimensions and loading combinations. An assessment of the Chinese, European and American design codes against the experimental and simulated dataset revealed that the Chinese and European codes typically yielded conservative predictions for the buckling load-carrying capacity, whereas the American code yielded slightly unsafe predictions. A set of modification strategies shown to improve the design accuracy and simplify effective section calculation were proposed accordingly, including the addition of interaction buckling factors to the three codes as well as the extension of the direct strength method (DSM) and continuous strength method (CSM) within the framework of Chinese code. The predictions corrected by these strategies showed improved agreement with the test and FE results, exhibiting an acceptable level of reliability and dispersion.采用提出的偏心压缩试验方案，对7A04-T6高强铝合金矩形空心截面构件的结构性能进行了研究。该方案包括8个RHS成员，其剖面为60 × 30 × 3 (mm)，并考虑了2 ~ 4类截面，包括初始几何缺陷测量和销端梁柱测试。建立了基于荷载-侧向挠度曲线和破坏模式的有限元模型并进行了验证。然后将这些模型用于一系列参数研究，旨在研究构件长细比、截面尺寸和加载组合的影响。根据试验和模拟数据集对中国、欧洲和美国设计规范的评估表明，中国和欧洲规范通常对屈曲承载能力给出保守的预测，而美国规范给出的预测略有不安全。为了提高设计精度和简化有效截面计算，提出了一套修改策略，包括在三个规范中加入相互作用屈曲因素，以及在中国规范框架内扩展直接强度法(DSM)和连续强度法(CSM)。通过这些策略修正的预测与试验和FE结果的一致性有所提高，显示出可接受的可靠性和分散性水平。Design and numerical analysis of perforated plate lattice structuresYifan Zhu, Jingbang Pan, Efstratios Polyzos, Jie Wang, Lincy Pyldoi:10.1016/j.tws.2024.112339多孔板格结构的设计与数值分析The plate lattice structure, a novel mechanical metamaterial, surpasses traditional truss lattice structures in stiffness and strength. However, its closed-walled topology poses challenges for manufacturing using powder or liquid-based additive manufacturing methods. This study addresses this issue by focusing on designing manufacturable plate lattice structures with various perforations. Through numerical simulations, we conducted a parametric study to investigate how different perforations influence the stiffness, isotropy, strength, and buckling resistance of the plate lattice structures. The results demonstrate that perforated plate lattice structures maintain higher stiffness compared to the traditional stretching-dominated octet truss lattice. The degree of stiffness deterioration is dependent on the geometry of the perforations. While plate lattice structures exhibit high stiffness at an extremely low relative density of 0.009, their strength is limited by premature elastic buckling. In contrast, at this relative density, the octet truss lattice demonstrates much greater strength. Interestingly, the introduction of perforations improves the plate lattices’ buckling resistance as compared to the unperforated design. With an increase in relative density, the plate lattices’ yielding mechanism shifts from elastic buckling-dominated to material plasticity-dominated. Moreover, when compared to other lattice structures in literature, it becomes evident that perforated plate lattice structures exhibit superior stiffness and strength, underscoring their considerable potential. The perforated lattices designed in this study contribute to the advancement of infill structures applicable in additive manufacturing and expanding the current state of the art in this field.板晶格结构是一种新型的机械超材料，在刚度和强度上超越了传统的桁架晶格结构。然而，它的封闭壁拓扑结构为使用粉末或液体增材制造方法制造带来了挑战。本研究通过设计具有不同穿孔的可制造板晶格结构来解决这一问题。通过数值模拟，我们进行了参数化研究，以研究不同穿孔对板晶格结构的刚度、各向同性、强度和抗屈曲性能的影响。结果表明，与传统的以拉伸为主的八边形桁架晶格结构相比，多孔板晶格结构具有更高的刚度。刚度恶化的程度取决于孔眼的几何形状。虽然板晶格结构在相对密度极低(0.009)时具有很高的刚度，但其强度受到过早弹性屈曲的限制。相比之下，在这种相对密度下，八元桁架晶格表现出更大的强度。有趣的是，与未穿孔的设计相比，穿孔的引入提高了板格的抗屈曲能力。随着相对密度的增加，板格屈服机制由弹性屈曲为主转变为材料塑性为主。此外，与文献中的其他晶格结构相比，穿孔板晶格结构显然具有优越的刚度和强度，强调了它们的巨大潜力。本研究设计的多孔晶格有助于推进适用于增材制造的填充结构，并扩展该领域的当前技术水平。Symmetric and asymmetric vibration and buckling of a thermal rotating annular-plate with Pasternak foundationZhongbiao PU, Qi XU, Yukang YANG, Qing LUO, Yinghui LIdoi:10.1016/j.tws.2024.112342 巴斯捷尔纳克地基热旋转环形板的对称与非对称振动与屈曲This paper studies the symmetric and asymmetric vibration and buckling modes of a rotating thermal annular plate resting on a Pasternak foundation. With considering the von Kármán geometric nonlinearity and the first-order shear deformation theory, the governing equations of the system are established via Hamilton's principle, and then solved by using the differential quadrature method. With both inner and outer boundaries constrained, the modes of the rotating system vary differently depending on the mode symmetry. The symmetric modes are mainly affected by the generated centrifugal force, while the asymmetric ones are affected by both centrifugal and Coriolis forces. The additional Coriolis, with mainly two directions, strengthens the forward travelling parts of the asymmetric modes, but makes the backward counterparts buckled more easily. Also, the thermal effect, as well as boundary elasticity and foundation coefficients, are also investigated from the viewpoint of mode symmetry. Results show that the temperature rise can shift the fundamental vibration mode from the symmetric one to the asymmetric one and backward travelling waves for rotation, which also adds to the complexity of mode variation with joint parameters. For the joint effect of the temperature rise and rotating, the annular plate tends to buckle more readily while the effects of the two factors are linearly superimposed.本文研究了基于帕斯捷尔纳克地基的旋转热环形板的对称和非对称振动和屈曲模态。在考虑von Kármán几何非线性和一阶剪切变形理论的基础上，利用Hamilton原理建立了系统的控制方程，并用微分正交法求解。在内外边界均有约束的情况下，旋转系统的模态随模态对称性的不同而变化。对称模态主要受离心力的影响，而非对称模态同时受离心力和科里奥利力的影响。额外的科里奥利，主要是两个方向，加强了非对称模式的向前行进部分，但使向后的对应部分更容易弯曲。同时，从模态对称的角度对热效应、边界弹性和地基系数进行了研究。结果表明，温度升高会使基振模态从对称模态转变为非对称模态，并导致旋转的反向行波，这也增加了模态随关节参数变化的复杂性。在温升和旋转的共同作用下，两种因素线性叠加时，环形板更易发生屈曲。Evaluation of surface corrosion damage in thin plates by Zero-Group Velocity Lamb waves based on PVDF comb transducersShuai Guo, Shenxin Yin, Mingxi Dengdoi:10.1016/j.tws.2024.112345基于PVDF梳状换能器的零群速度Lamb波评价薄板表面腐蚀损伤This paper introduces a novel method for assessing surface corrosion damage in thin plates by leveraging the high sensitivity of Zero-Group Velocity (ZGV) Lamb waves and the versatility of polyvinylidene fluoride (PVDF) comb transducers. Theoretical analyses of ZGV Lamb wave modes and their differentiation from thickness vibration modes were conducted. The functionality and utility of the PVDF comb transducer tailored for the specific S1-ZGV mode were assessed. Experimental findings demonstrate that the PVDF comb transducer efficiently excites and captures the S1-ZGV mode, enabling effective assessment of surface corrosion damage in thin aluminum plates. Compared to the variations in wave velocity of surface acoustic waves (SAW) and the S1-ZGV frequency, the spectral amplitude at the initial S1-ZGV frequency exhibits a monotonically decreasing trend with increasing corrosion levels, proving to be more sensitive and reliable for evaluating surface corrosion damage. This research offers theoretical underpinnings and experimental validation for damage assessment using ZGV Lamb waves with the PVDF comb transducer, showcasing significant potential for practical engineering applications.本文介绍了一种利用零群速度(ZGV)兰姆波的高灵敏度和聚偏氟乙烯(PVDF)梳状传感器的通用性来评估薄板表面腐蚀损伤的新方法。对ZGV兰姆波模态及其与厚度振动模态的区别进行了理论分析。评估了为特定S1-ZGV模式量身定制的PVDF梳状换能器的功能和效用。实验结果表明，PVDF梳状换能器能够有效地激发和捕获S1-ZGV模式，能够有效地评估薄铝板的表面腐蚀损伤。与表面声波波速和S1-ZGV频率的变化相比，S1-ZGV起始频率的谱幅值随腐蚀程度的增加呈现单调减小的趋势，证明了对表面腐蚀损伤的评价更为敏感和可靠。该研究为使用ZGV Lamb波与PVDF梳状换能器进行损伤评估提供了理论基础和实验验证，展示了实际工程应用的巨大潜力。来源：复合材料力学仿真Composites FEM
