今日更新：International Journal of Solids and Structures 1 篇，Mechanics of Materials 1 篇，Thin-Walled Structures 9 篇International Journal of Solids and StructuresAnalysis of the Mullins effect in buckling instability of double-network hydrogel beams under swelling equilibriumPingping Zhu, Zheng Zhongdoi:10.1016/j.ijsolstr.2023.112627膨胀平衡下双网水凝胶梁屈曲不稳定性中的穆林斯效应分析Due to their outstanding physical and mechanical properties, double-network (DN) hydrogels have gained a most attention among various synthetic tough hydrogels. The Mullins effect and buckling instability are two frequent phenomena that may occur simultaneously in slender DN hydrogel structures as high load-bearing candidates. The swelling/deswelling degree of the DN hydrogel affects the coupling phenomena. It is essential to understanding the interplay between these behaviors. In this work, a physically based damage constitutive model for a DN polymer under water-diffusion equilibrium and cyclic loadings is developed. This theory of coupled swelling and load-induced deformations show good capability in capturing the Mullins effect of swollen DN hydrogels and the corresponding swelling ratio. The model parameters are determined by fitting experimental data of a freely swollen DN hydrogel under cyclic compression. Based on the constitutive model and determined parameters, the buckling instability of DN hydrogel beams is studied via the analytical formula of incremental modulus. The stability diagrams of the DN hydrogel beams under virgin loading and reloading are presented. The influences of stress softening, strain stiffening and chemical potential on buckling conditions for compressive stress and slenderness ratio are thoroughly analyzed. It demonstrates that the stress softening is dramatically against the stability of the beam, but the strain-stiffening effect would conversely help widen the stable range. Besides, it is found that a DN gel beam immersed in a sufficient low chemical potential environment has better buckling stability. These theoretical results are valuable in the preparation and structural design of DN hydrogels for repeated use purpose.双网（DN）水凝胶因其出色的物理和机械性能，在各种合成韧性水凝胶中最受关注。Mullins 效应和屈曲不稳定性是作为高承载候选材料的细长 DN 水凝胶结构中可能同时出现的两种常见现象。DN 水凝胶的膨胀/溶胀程度会影响耦合现象。了解这些行为之间的相互作用至关重要。在这项研究中，我们开发了一种基于物理的 DN 聚合物在水扩散平衡和循环负载条件下的损伤构成模型。这种溶胀和载荷诱导变形耦合理论在捕捉溶胀 DN 水凝胶的 Mullins 效应和相应的溶胀率方面表现出良好的能力。模型参数是通过拟合循环压缩下自由膨胀 DN 水凝胶的实验数据确定的。根据构成模型和确定的参数，通过增量模量解析公式研究了 DN 水凝胶梁的屈曲不稳定性。给出了 DN 水凝胶梁在原始加载和再加载条件下的稳定性图。深入分析了应力软化、应变硬化和化学势对压应力和纤度比屈曲条件的影响。结果表明，应力软化会极大地影响梁的稳定性，而应变加固效应则有助于扩大稳定范围。此外，研究还发现，浸泡在足够低的化学势环境中的 DN 凝胶梁具有更好的屈曲稳定性。这些理论结果对重复使用的 DN 水凝胶的制备和结构设计很有价值。Mechanics of MaterialsA continuum-micromechanical model for crazing in glassy polymers under cyclic loadingTobias Laschuetza, Thomas Seeligdoi:10.1016/j.mechmat.2023.104901循环加载下玻璃态聚合物开裂的连续微观力学模型A micromechanics-inspired constitutive model is developed to describe the deformation behaviour of fibrillated material within crazes in glassy polymers subjected to cyclic loading. In a finite strain setting, the model accounts for the morphology change taking place by the drawing of material from the intact bulk polymer into craze fibrils and their transition from primitive to mature fibrils. Building on previous research, fibril drawing is described as a viscoplastic process. A novel contribution of this study is the incorporation of viscoelastic deformation of existing fibrils, which is motivated by experimental observations. This new perspective allows for creep recovery, especially during the unloading phases of cyclic deformation. A parameter study which pays special attention to the role of the characteristic times scales of fibril drawing and fibril creep in relation to the imposed loading rate illustrates the performance of the model. Since the model is designed as an input to cohesive fracture simulations in glassy polymers, its response under monotonic loading is analysed and compared to existing crazing models. Of primary interest, however, is the model behaviour under cyclic loading which is investigated for different loading scenarios up to fibril failure. The study highlights the complex interplay between the two viscous mechanisms and how they influence the local deformation behaviour of the craze matter as well as the number of cycles until failure.本研究开发了一种微观力学启发的构成模型，用于描述玻璃态聚合物裂纹内纤维化材料在循环载荷作用下的变形行为。在有限应变设置下，该模型解释了材料从完整的块状聚合物拉伸成裂纹纤维以及从原始纤维过渡到成熟纤维所发生的形态变化。在以往研究的基础上，纤维拉伸被描述为一种粘塑性过程。本研究的一个新贡献是根据实验观察结果，将现有纤维的粘弹性变形纳入其中。这一新观点允许蠕变恢复，尤其是在循环变形的卸载阶段。参数研究特别关注纤维拉伸和纤维蠕变的特征时间尺度与施加的加载速率之间的关系，说明了模型的性能。由于该模型是作为玻璃态聚合物内聚断裂模拟的输入而设计的，因此对其在单调加载下的响应进行了分析，并与现有的龟裂模型进行了比较。然而，最令人感兴趣的是模型在循环加载下的行为，研究了不同加载情况下直至纤维断裂的情况。研究强调了两种粘性机制之间复杂的相互作用，以及它们如何影响裂纹物质的局部变形行为和直至失效的循环次数。Thin-Walled StructuresNonlinear vibration analysis of double curved shallow sandwich shell in which the core made of three-phase nanocomposite and the two-outer layer of electromagnetic materialsNguyen Van Huong, Pham Hong Cong, Nguyen Dinh Ducdoi:10.1016/j.tws.2023.111501以三相纳米复合材料为内核、两外层为电磁材料的双曲面浅夹层壳体的非线性振动分析This paper investigates the nonlinear vibrations of a double curved shallow sandwich shell with a three-phase nanocomposite core and two outer electromagnetic layers considering the thermal environment's influence. Relying on the Halpin-Tsai model, the core is assumed to be made of some composite plies incorporating three constituents: carbon nanotubes (CNTs) or graphene nanoplatelets (GPLs) as nanocomposites, fibers and polymeric matrix (resin). Governing equations calculating the nonlinear vibration of the double curved shallow shell were obtained by combining Reddy's first-order shear deformation theory (FSDT) and the Von Kármán geometrical nonlinearity. Later, this system of equations is transformed into the nonlinear ordinary differential expressions by utilizing the Galerkin procedure. Thus, the effects of material properties, temperature, geometrical properties, elastic foundations to the frequency of linear and nonlinear free vibration, and amplitude-frequency relations of the double curved shallow sandwich shell were discussed. The results demonstrate that the free vibration frequency of the shell increases if the magnetic field enhances, whereas that decreases when the voltage expands in both models as CNTs and GPLs. Simultaneously, the shallow shell has a better ability to force load compared to a plate with the same dimensions. These outcomes can make a profit in the design and manufacturing of new smart structures applied in energy harvesting, and medicine.考虑到热环境的影响，本文研究了具有三相纳米复合材料内核和两个电磁外层的双曲面浅夹层壳体的非线性振动。根据 Halpin-Tsai 模型，假定核心由一些复合材料层组成，其中包含三种成分：作为纳米复合材料的碳纳米管 (CNT)或石墨烯纳米片 (GPL)、纤维和聚合物基质（树脂）。通过结合 Reddy 的一阶剪切变形理论（FSDT）和 Von Kármán 几何非线性，得到了计算双曲面浅壳非线性振动的指导方程。随后，利用 Galerkin 程序将该方程系统转化为非线性常微分表达式。因此，讨论了材料特性、温度、几何特性、弹性基础对双曲面浅夹层壳的线性和非线性自由振动频率以及幅频关系的影响。结果表明，在 CNTs 和 GPLs 两种模型中，如果磁场增强，壳体的自由振动频率会增加，而当电压扩大时，自由振动频率会降低。同时，与相同尺寸的板相比，浅壳的受力能力更强。这些成果将有助于设计和制造应用于能量收集和医学领域的新型智能结构。Stress-strain state of a porous flexible rectangular FGM size-dependent plate subjected to different types of transverse loading: Analysis and numerical solution using several alternative methods.A.V. Krysko, L.A. Kalutsky, V.A. Kryskodoi:10.1016/j.tws.2023.111512多孔柔性矩形 FGM 尺寸依赖板在不同类型横向荷载作用下的应力-应变状态：使用几种替代方法进行分析和数值求解。In this study, a mathematical model of flexible porous functionally graded (PFG) Kirchhoff size-dependent plates on a rectangular plane is constructed. Hamilton's principle provides new size-dependent governing equations, taking into account geometrical nonlinearity according to the model of Theodor von Kármán, as well as boundary conditions and initial conditions for the displacement of the plates. Modified Coupled Stress Theory (MCST) is used to account for size-dependent effects. Numerical investigations analysing the stress-strain state of flexible Kirchhoff functionally graded size-dependent porous plates on a rectangular plane are based on the application of the Variational Iteration Method (VIM) or the Extended Kantorovich Method (EKM). The efficiency and high accuracy of the VIM method are demonstrated. The validity and reliability of the solutions obtained by VIM are discussed and compared with solutions obtained by other methods, such as the BGM in higher approximations, FDM of second-order accuracy and the FEM. Additionally, the solutions are compared with results obtained by other authors in the study of porous functionally graded macro, micro, and nanoplates. The solutions obtained are considered accurate. The results include an analysis of the influence of size-dependent parameters, type of material porosity, porosity index, functionally graded index, and different types of boundary conditions on the stress-strain state of plates under the action of different types of transverse loading.本研究构建了矩形平面上柔性多孔功能分层（PFG）基尔霍夫尺寸相关板的数学模型。根据 Theodor von Kármán 模型，考虑到几何非线性，以及板位移的边界条件和初始条件，汉密尔顿原理提供了新的尺寸相关控制方程。修正耦合应力理论（MCST）用于考虑尺寸效应。应用变异迭代法（VIM）或扩展 Kantorovich 法（EKM）对矩形平面上柔性基尔霍夫功能分级多孔板的应力应变状态进行了数值研究分析。结果证明了 VIM 方法的高效性和高精确度。讨论了 VIM 求解的有效性和可靠性，并将其与其他方法求解进行了比较，如更高近似的 BGM、二阶精度的 FDM 和 FEM。此外，还将求解结果与其他作者在多孔功能分级宏观、微观和纳米板研究中获得的结果进行了比较。所获得的解决方案被认为是精确的。研究结果包括分析尺寸相关参数、材料孔隙率类型、孔隙率指数、功能分级指数以及不同类型的边界条件对不同类型横向载荷作用下板材应力应变状态的影响。Energy-based efficient residual stress prediction of titanium alloys with lack-of-fusion porosity in powder bed fusionZhi-Jian Li, Hong-Liang Dai, Chong Du, Peng Xiao, Yuan Yaodoi:10.1016/j.tws.2023.111513基于能量的粉末床熔合中具有熔合孔隙率不足的钛合金的高效残余应力预测Residual stress and porosity exert adverse effects on the mechanical properties of metal parts fabricated by powder bed fusion. However, the modeling of the correlation between process parameters, process-induced porosity, and residual stress remains challenging. In this paper, a thermo-mechanical model of titanium alloy with porosity is established, where the relation between process parameters, porosity, and effective material properties is identified. The porosity is first predicted based on the power conservation principle in the process. The effective material properties of as-built titanium alloy with porosity are estimated using a homogenization method. Subsequently, the stress and distortion resulting from temperature variation are predicted using the shear deformation theory. The predicted results exhibit excellent agreement with the predictions and experimental results in the literature. Furthermore, the effect of the main process parameters on the porosity, residual stress, and distortion is investigated. The results show that excessive laser power, small laser radii, and extensive scan tracks contribute to a significant lack-of-fusion porosity. Additionally, the normal stress along the scan direction and vertical deflection are the major residual stress and distortion of titanium alloy with porosity, respectively. The proposed model can serve as a guideline for the design and fabrication of PBF-built titanium alloys.残余应力和孔隙率对通过粉末床熔融技术制造的金属零件的机械性能产生不利影响。然而，工艺参数、工艺引起的孔隙率和残余应力之间的相关性建模仍具有挑战性。本文建立了具有孔隙率的钛合金热机械模型，确定了工艺参数、孔隙率和有效材料性能之间的关系。首先根据工艺中的功率守恒原理预测孔隙率。使用均质化方法估算出带孔隙率钛合金的有效材料属性。随后，利用剪切变形理论预测温度变化产生的应力和变形。预测结果与文献中的预测和实验结果非常吻合。此外，还研究了主要工艺参数对孔隙率、残余应力和变形的影响。结果表明，过大的激光功率、过小的激光半径和过长的扫描轨迹都会造成严重的熔合孔隙率不足。此外，沿扫描方向的法向应力和垂直挠度分别是产生气孔的钛合金的主要残余应力和变形。所提出的模型可作为设计和制造 PBF 型钛合金的指南。Dynamic response of square sandwich panels with stagger-layered honeycomb cores under intensive near-field air blast loadingYing Liu, Haichao Yu, Jinda Wu, Kui Tangdoi:10.1016/j.tws.2023.111515带有交错层蜂窝芯的方形夹芯板在高强度近场空气冲击载荷下的动态响应Metallic honeycomb sandwich panels have been widely used in energy dissipation due to large plastic deformation under impact/blast loading. In this paper, the dynamic response of a honeycomb sandwich panel with stagger-layered core under intensive near-field air blast loading is investigated. Comparative experiments are conducted for stagger-layered and typical honeycomb sandwich panels with the same geometrical size and mass. Numerical simulation has been undertaken based on the experiments. Numerical results coincide well with experimental results on the deformation/failure modes and center-point deflection of back face sheet. The influence of layer number as well as the geometrical parameters on the energy absorption ability of sandwich panels is clarified. Results show that stagger-layer arrangement of honeycomb core greatly improves energy dissipation capability of sandwich panels compared to typical one with the same mass. The increase of layer number and cell size benefits this effect. These findings indicates that core stagger-layer arrangement is a well choice to improve energy dissipation ability of sandwich panels under air blast loading, especially for highly intensive near-field blast loading.金属蜂窝夹芯板在冲击/爆破载荷作用下会产生较大的塑性变形，因此被广泛应用于消能领域。本文研究了带有错层夹芯的蜂窝夹芯板在高强度近场空气冲击载荷下的动态响应。对具有相同几何尺寸和质量的交错层和典型蜂窝夹芯板进行了对比实验。在实验的基础上进行了数值模拟。数值结果与实验结果在背面板材的变形/失效模式和中心点挠度方面非常吻合。层数和几何参数对夹芯板能量吸收能力的影响也得到了澄清。结果表明，与相同质量的典型夹芯板相比，蜂窝芯的错层布置大大提高了夹芯板的能量耗散能力。层数和单元尺寸的增加对这一效果有利。这些研究结果表明，蜂窝芯错层布置是提高夹芯板在空气冲击载荷下能量耗散能力的最佳选择，尤其是在高强度近场冲击载荷下。Test on Seismic Behaviors of Stainless Steel Bolted Extended End-Plate Beam-column JointsBaofeng Zheng, Dianhan Wu, Jiachang Wang, Ganping Shudoi:10.1016/j.tws.2023.111516不锈钢螺栓加长端板梁柱连接的抗震性能测试This study conducted tests on the seismic behavior of austenitic stainless steel bolted extended end-plate beam-column joints, which have been few reported. Considering the influence of material type, end-plate thickness, bolt diameter, panel zone thickness, and loading scheme, 11 stainless steel joints and two carbon steel joints were designed and tested. Material properties, joint failure modes, moment-rotation curves, bolt load distributions, and joint component yield sequences were reported in detail. Experimental research showed that the beam-column joints in austenitic stainless steel experienced four failure modes, i.e. plastic hinge at the beam end, fracture failure of weld between the beam flange and end-plate, bolt rupture failure, and composite failure. All the tested joints had good seismic behavior, with rotation capacity greater than 0.03 rad.. The influence of joint configurations on the seismic behavior were analyzed. The results indicated that the end-plate thickness, end-plate stiffener, and bolt diameter had a substantial impact on the joint seismic behavior, while the thickness of column web in panel zone, material properties, and loading scheme had a comparatively small effect. The initial rotational stiffness and moment resistance(yield moment) of joint obtained from the experiment were compared with the predictions of the EN1993-1-8, Design Guide 16, and JGJ 82-2011. Comparisons indicated that the EN1993-1-8 overestimated the initial rotational stiffness; Both the EN1993-1-8 and JGJ 82-2011 underestimated the moment resistance, while the predictions from the Design Guide 16 were significantly higher than the moment resistance and closer to the ultimate moment.本研究对奥氏体不锈钢螺栓连接加长端板梁柱接头的抗震行为进行了测试，目前相关报道较少。考虑到材料类型、端板厚度、螺栓直径、面板区厚度和加载方案的影响，设计并测试了 11 个不锈钢接头和 2 个碳钢接头。详细报告了材料特性、连接失效模式、力矩-旋转曲线、螺栓载荷分布以及连接部件屈服序列。实验研究表明，奥氏体不锈钢梁柱接头经历了四种失效模式，即梁端塑性铰链、梁翼缘板和端板之间焊缝断裂失效、螺栓断裂失效和复合失效。所有测试接头都具有良好的抗震性能，旋转能力大于 0.03 弧度。分析了接头结构对抗震性能的影响。结果表明，端板厚度、端板加劲件和螺栓直径对接头抗震性能有很大影响，而面板区柱腹板厚度、材料特性和加载方案的影响相对较小。实验得出的连接初始旋转刚度和抗弯矩（屈服弯矩）与 EN1993-1-8、Design Guide 16 和 JGJ 82-2011 的预测值进行了比较。比较结果表明，EN1993-1-8 高估了初始旋转刚度；EN1993-1-8 和 JGJ 82-2011 低估了抗弯强度，而《设计指南 16》的预测值明显高于抗弯强度，且更接近极限弯矩。The low frequency multi-linear spectrum vibration control study of cylindrical shell through a semi-analytical methodYuan Du, Yang Tang, Yucheng Zou, Yichun Wang, Fuzhen Pang, Fuxin Jia, Yong Ma, Shijie Wangdoi:10.1016/j.tws.2023.111521通过半解析法研究圆柱形壳体的低频多线性频谱振动控制Dynamic vibration absorber is efficient in controlling low frequency vibration of cylindrical shell, which is meaningful for engineering practice. However, the efficiency of designing dynamic vibration absorber using traditional method is low. This paper demonstrates a semi-analytical method for designing dynamic vibration absorber of cylindrical shell. The convergence analysis presented in the research proves the accuracy of the current method when handling different edge constraints through limited truncation numbers. Additionaly, forced vibration and control of multi-line spectrum vibration of cylindrical shell have also been studied. The comparison between FEM and current method shows a significant improvement when handling equivalent mass, which is a key process when designing dynamic vibration absorbers. Finally, an intriguing relationship is discovered when controlling multiple resonance peaks through a single dynamic vibration absorber. The semi-analytical method described in this paper may be beneficial when controlling the vibration of cylindrical shell structures in the further research.动态吸振器能有效控制圆柱形壳体的低频振动，对工程实践很有意义。然而，使用传统方法设计动态吸振器的效率较低。本文展示了一种设计圆柱形壳体动态吸振器的半解析方法。研究中的收敛分析证明了当前方法在通过有限截断数处理不同边缘约束时的准确性。此外，还研究了圆柱形壳体的强迫振动和多线谱振动控制。在处理等效质量时，有限元与当前方法的比较显示了显著的改进，而等效质量是设计动态减震器的关键过程。最后，在通过单个动态吸振器控制多个共振峰时，发现了一种有趣的关系。本文所述的半分析方法可能会在进一步的研究中有益于控制圆柱形壳体结构的振动。A novel active hydroforming & curing process to manufacture GLARE laminates: Numerical and experimental investigationsMeng Zhang, Muhammad Saad, Hang Zheng, Marko Vilotic, Bao-sheng Liu, Zheng-ping Zou, Yong Lidoi:10.1016/j.tws.2023.111508制造 GLARE 层压板的新型主动水压成型和固化工艺：数值和实验研究Fiber Metal Laminates (FMLs) are preferable thin-walled structures in several fields for their exceptional mechanical properties. However, how to manufacture thin-walled FMLs structures with complex shapes and guarantee the high mechanical properties is still a challenge. To address these, this paper proposes an innovative hybrid forming method, referred to as active warm hydroforming and curing, to enhance the formability and performance of FMLs in GLARE form by combining the forming and curing process into a single step. The hybrid method was verified on a box-shaped part as a proof-of-concept to assess the feasibility and parameter influence. Online curing was utilized to enhance efficiency and quality. The outcomes revealed that the new method increases the ultimate tensile stress by 12.1 % and reduces curing deformation from 3.1 mm to 1.3 mm compared to the vacuum bagging method. Furthermore, the critical parameters in forming of thin-walled structures, including blank holder force (BHF), pressure rate (PR), maximum pressure (MP), and forming temperature (FT), were identified using experimental, mathematical, and numerical approaches. Four defects in the formed thin-walled structures were observed and successfully eliminated through the control of these parameters. The method and results presented in this paper also provide direct guidance for optimizing the process parameters of FMLs warm hydroforming.金属纤维层压板（FMLs）因其优异的机械性能而成为多个领域的首选薄壁结构。然而，如何制造形状复杂的薄壁 FMLs 结构并保证其较高的机械性能仍是一项挑战。为了解决这些问题，本文提出了一种创新的混合成型方法，即主动温压成型和固化，通过将成型和固化过程合并为一个步骤来提高 GLARE 形式 FML 的成型性和性能。作为概念验证，该混合方法在箱形零件上进行了验证，以评估其可行性和参数影响。在线固化被用来提高效率和质量。结果表明，与真空袋法相比，新方法的极限拉伸应力提高了 12.1%，固化变形从 3.1 mm 减小到 1.3 mm。此外，利用实验、数学和数值方法确定了薄壁结构成型的关键参数，包括坯料夹持力（BHF）、压力速率（PR）、最大压力（MP）和成型温度（FT）。通过对这些参数的控制，观察到并成功消除了成形薄壁结构中的四个缺陷。本文介绍的方法和结果也为优化 FML 温水压成形工艺参数提供了直接指导。Out-of-plane Compressive Response of Aluminum Honeycomb Sandwich Panels: Adhesive Geometry and Bonding EffectsMengqian Sun, Patrick Kendall, Diane Wowk, Christopher Mechefske, Il Yong Kimdoi:10.1016/j.tws.2023.111509铝蜂窝夹芯板的平面外压缩响应：粘合剂几何形状和粘合效果Lightweight aluminum honeycomb sandwich panels are widely used in industrial engineering, particularly in aircraft applications. Due to their thin-walled nature, the honeycomb cell walls are especially susceptible to buckling under out-of-plane compressive loading, while the adhesive fillet that secures the honeycomb to the face-sheet remains intact. This paper investigates the effect of the adhesive geometry and bonding constraints on the out-of-plane compressive response through experimental, Finite Element (FE), and mathematical methods. A hybrid method accounting for adhesive bonding between the face-sheet and the cell walls, and different adhesive fillet geometries was proposed to predict strain onset and stress-strain relationships during densification. The resulting stress-strain curves predicted the energy absorbed by the panels to within 3.5% of the experimental results. The widely used material model for honeycomb core does not account for densification and underpredicted the absorbed energy by 15.6%. These findings emphasize the need for detailed adhesive analysis in the design of lightweight, thin-walled sandwich structures.轻质铝蜂窝夹层板广泛应用于工业工程，尤其是飞机应用领域。由于其薄壁特性，蜂窝单元壁特别容易在平面外压缩载荷作用下发生屈曲，而将蜂窝固定到面板上的粘合剂丝扣却保持完好。本文通过实验、有限元（FE）和数学方法研究了粘合剂几何形状和粘合约束对平面外压缩响应的影响。我们提出了一种混合方法来预测致密化过程中的应变起始和应力-应变关系，该方法考虑到了面层和细胞壁之间的粘合以及不同的粘合剂圆角几何形状。由此得出的应力-应变曲线预测了面板吸收的能量，与实验结果的误差不超过 3.5%。广泛使用的蜂窝芯材料模型没有考虑到致密化，对吸收能量的预测低了 15.6%。这些发现强调了在设计轻质薄壁夹层结构时进行详细粘合分析的必要性。BENDING ANALYSIS OF FGSP NANOPLATE RESTING ON ELASTIC FOUNDATION BY USING NONLOCAL QUASI-3D THEORYDang Xuan Hung, Le Tien Thinh, Nguyen Văn Long, Tran Minh Tu, Dang Xuan Trungdoi:10.1016/j.tws.2023.111510利用非局部准三维理论对位于弹性地基上的 fgsp 纳米板进行弯曲分析In this paper, the bending response of a functionally graded saturated porous (FGSP) nanoplate resting on the Pasternak elastic foundation is analyzed within the framework of quasi-3D higher-order shear deformation theory (quasi-3D HSDT) for the first time. The material properties are presumed to change gradually along the thickness direction following three patterns of porosity distribution: uniform, non-uniform symmetric, and asymmetric. The theory of poroelasticity developed by Biot is utilized in modeling the stress-strain relationships for the saturated condition. Moreover, the nanoscale effects of the structures are considered by Eringen's nonlocal elasticity theory. The governing equations are derived by using the principle of minimum potential energy according to quasi-3D HSDT, which ensures transverse shear stress-free on the upper and lower surfaces of the nanoplate. Based on the obtained closed-form solution, the impacts of the porosity distribution patterns, porosity coefficient, Skempton coefficient, geometrical parameters, elastic foundation, and nonlocal parameters on the bending behavior have been explored. According to the findings, when the pores are saturated by the fluid, the plate stiffness increases. Additionally, increasing the values of the nonlocal parameter for FGSP nanoplates leads to an increase in deflection and stresses. Finally, the present study quantitatively reveals the size-dependent effects of a saturated porous medium.本文首次在准三维高阶剪切形变理论（quasi-3D HSDT）框架内分析了位于帕斯捷尔纳克弹性基础上的功能分级饱和多孔（FGSP）纳米板的弯曲响应。假定材料特性沿厚度方向按照均匀、非均匀对称和非对称三种孔隙率分布模式逐渐变化。在模拟饱和状态下的应力-应变关系时，采用了 Biot 提出的孔弹性理论。此外，Eringen 的非局部弹性理论还考虑了结构的纳米级效应。利用准三维 HSDT 的最小势能原理推导出控制方程，确保纳米板上下表面无横向剪应力。根据得到的闭式解，探讨了孔隙率分布模式、孔隙率系数、Skempton 系数、几何参数、弹性基础和非局部参数对弯曲行为的影响。研究结果表明，当孔隙被流体饱和时，板的刚度会增加。此外，增加 FGSP 纳米板的非局部参数值会导致挠度和应力增加。最后，本研究定量揭示了饱和多孔介质的尺寸效应。来源：复合材料力学仿真Composites FEM
