【新文速递】2024年10月20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 3 篇，Mechanics of Materials 2 篇，Thin-Walled Structures 6 篇

International Journal of Solids and Structures

Three-dimensional buckling analysis of stiffened plates with complex geometries using energy element method

Zhao Jing, Yanjie Liu, Lei Duan, Siqi Wang

doi:10.1016/j.ijsolstr.2024.113105

用能量元法分析复杂几何形状加筋板的三维屈曲

A novel numerical method, energy element method (EEM), is proposed for the three-dimensional (3D) buckling analysis of stiffened plates with complex geometries. The problem is formulated in a cuboidal domain, and any complex geometric stiffened plate is modeled by assigning cutouts within the cuboidal domain. The stiffened plate is considered as an energy body and is discretized using Gauss points with variable stiffness properties to simulate its energy distribution. Incorporating the extended interval integration, Gauss quadrature, variable stiffness properties, and Chebyshev polynomials, the strain energy of stiffened plates with complex geometries can be numerically simulated by putting the stiffness and thickness of Gauss points in the cutouts to zero in the cuboidal domain. Using the principle of minimum potential energy and Ritz solution procedure, the deformation and buckling behaviors of stiffened plates with complex geometries can be captured. As a result of the new formulations in EEM, new standard energy functionals and solving procedures have been developed. In addition, Gauss points are generated within the energy elements accounting for the geometric boundaries of the stiffened plate, which are characterized by level set functions. EEM is employed to investigate complex-shaped stiffened plates with straight or curvilinear stiffeners, and the results are compared to those obtained using FEM or mesh-free method. The precision, generalization, and stability of EEM are demonstrated.

提出了一种新的用于复杂几何形状加筋板三维屈曲分析的数值方法——能量元法。该问题是在一个立方体域中表述的，任何复杂的几何加筋板都是通过在立方体域中分配切口来建模的。将加筋板视为一个能量体，采用变刚度高斯点对其进行离散，模拟其能量分布。将扩展区间积分、高斯正交、变刚度特性和切比雪夫多项式相结合，在立方体域中将切口处的高斯点的刚度和厚度设为零，可以对具有复杂几何形状的加筋板的应变能进行数值模拟。利用最小势能原理和Ritz解法，可以捕捉复杂几何形状加筋板的变形和屈曲行为。由于EEM中的新公式，开发了新的标准能量泛函和求解方法。此外，在占加筋板几何边界的能量元内生成高斯点，这些点具有水平集函数的特征。采用有限元法和无网格法对具有直线加筋和曲线加筋的复杂形状加筋板进行了分析，并将结果与有限元法和无网格法进行了比较。验证了EEM的精度、通用性和稳定性。

Journal of the Mechanics and Physics of Solids

ViscoNet: a lightweight FEA surrogate model for polymer nanocomposites viscoelastic response prediction

Anqi Lin, Richard J. Sheridan, Bingyin Hu, L. Catherine Brinson

doi:10.1016/j.jmps.2024.105915

ViscoNet：用于聚合物纳米复合材料粘弹性响应预测的轻量级有限元模拟模型

Polymer-based nanocomposites (PNCs) are formed by dispersing nanoparticles (NPs) within a polymer matrix, which creates polymer interphase regions that drive property enhancement. However, data-driven PNC design is challenging due to limited data. To address the challenge, we present ViscoNet, a surrogate model for finite element analysis (FEA) simulations of PNC viscoelastic (VE) response. ViscoNet leverages pre-training and finetuning to accelerate predicting VE response of a new PNC system. By predicting the entire VE response, ViscoNet surpasses previous scalar-based surrogate models for FEA simulation, offering better fidelity and efficiency. We explore ViscoNet's effectiveness through generalization tasks, both within thermoplastics and from thermoplastics to thermosets, reporting a mean absolute percentage error (MAPE) of < 5% for rubbery modulus and < 1% for glassy modulus in all cases and 1.22% on tan δ peak height prediction. With only 500 FEA simulations for finetuning, ViscoNet can generate over 20k VE responses within 2 minutes with 1 CPU, compared to 97 days with 4 CPUs via FEA simulations.

聚合物基纳米复合材料（pnc）是通过将纳米颗粒（NPs）分散在聚合物基体中形成的，从而形成聚合物相间区域，从而提高性能。然而，由于数据有限，数据驱动的PNC设计具有挑战性。为了应对这一挑战，我们提出了ViscoNet，这是一种用于PNC粘弹性（VE）响应有限元分析（FEA）模拟的替代模型。ViscoNet利用预训练和微调来加速预测新的PNC系统的VE响应。通过预测整个VE响应，ViscoNet超越了以前基于标量的有限元模拟代理模型，提供了更好的保真度和效率。我们通过在热塑性塑料和从热塑性塑料到热固性塑料的泛化任务来探索ViscoNet的有效性，报告了在所有情况下，橡胶模量的平均绝对百分比误差(MAPE) < 5%，玻璃模量< 1%，tan δ峰高预测的平均绝对百分比误差（MAPE）为1.22%。只有500个FEA模拟进行微调，ViscoNet可以在1个CPU的情况下在2分钟内生成超过20k的VE响应，而通过FEA模拟，4个CPU需要97天。

Understanding of topological mode and skin mode morphing in 1D and 2D non-Hermitian resonance-based meta-lattices

Qian Wu, Shaoyun Wang, Honghua Qian, Yanzheng Wang, Guoliang Huang

doi:10.1016/j.jmps.2024.105907

一维和二维非厄米共振元晶格中拓扑模式和蒙皮模式变形的理解

Recent advances have demonstrated that the non-Hermitian skin effect (NHSE), induced by system non-Hermiticity, can manipulate the localization of in-gap topological edge modes (TEMs) within mechanical topological insulators. This study introduces a straightforward analytical framework to elucidate the competition between NHSE and TEM localization in a classical mechanical meta-lattice, highlighting its impact on the dynamic behavior of TEMs within separate Bragg scattering band gaps (BSBGs). We propose a 1D non-Hermitian meta-lattice featuring a locally resonant system with active feedback control, characterized by a real-valued transfer function. This local resonance creates two separate BSBGs, each hosting a TEM defined by non-Hermitian bulk-edge correspondence. Our theoretical and numerical analyses reveal that the NHSE, with its asymmetric localization within the two BSBGs, can shift the localization of TEMs in distinct ways. This leads to an asymmetric phase transition, wherein one TEM can be delocalized and relocalized by tuning the transfer function, while the other maintains its initial localization. Moreover, we extend the mechanism of 1D asymmetric TEM delocalization to the non-Hermitian morphing of TEMs, showcasing notable examples such as temporal and spatial topological wave pumping with space- and time-dependent transfer functions in 1D time-varying and 2D stacked meta-lattices. This research bridges a gap between non-Hermitian mechanical constructs and their potential applications in classical mechanics, reinterpreting known topological wave control in 1D and uncovering new mechanisms in 2D.

最近的研究表明，由系统非厄米性引起的非厄米集肤效应（non- hermite skin effect， NHSE）可以操纵机械拓扑绝缘体内隙内拓扑边缘模式（tem）的局域化。本研究引入了一个简单的分析框架来阐明经典力学元晶格中NHSE和TEM局域化之间的竞争，强调了其对单独Bragg散射带隙（BSBGs）内TEM动态行为的影响。我们提出了一个具有主动反馈控制的局部共振系统的一维非厄米元晶格，其特征为实值传递函数。这种局部共振创建了两个独立的BSBGs，每个BSBGs都承载一个由非厄米体边对应定义的TEM。我们的理论和数值分析表明，由于NHSE在两个BSBGs中的不对称定位，可以以不同的方式改变tem的定位。这导致了不对称相变，其中一个TEM可以通过调整传递函数来脱域和重新定位，而另一个则保持其初始定位。此外，我们将一维非对称瞬变电磁法的离域机制扩展到瞬变电磁法的非厄米变形，展示了一维时变和二维堆叠元晶格中具有时空相关传递函数的时空拓扑波抽运等显著例子。这项研究填补了非厄米力学结构及其在经典力学中的潜在应用之间的空白，重新解释了已知的一维拓扑波控制，并揭示了二维的新机制。

Traction-based microplane model for charactering the progressive failure of rock-like material

Lingwei Kong, Heping Xie, Cunbao Li

doi:10.1016/j.jmps.2024.105910

基于牵引力的类岩材料渐进破坏微平面模型

Accurately understanding and predicting the progressive failure behavior of rock is crucial in rock engineering. In this study, a new microplane prediction model characterized by the intrinsic properties of the traction vector is proposed to describe the rock's multi-scale behavior, anisotropy, and the microscopic tensile and compressive-shear failure effects based on a physical foundation. Under the thermodynamic consistency framework, the microplane's free energy and state equations are derived to determine the elastic, plastic, and damage properties of a single microplane. Damage and plastic yield criteria are innovatively established according to the traction's tensile and compressive-shear effects on the rock's failure behavior. A novel efficient implicit return mapping algorithm is proposed. A nonlinear constitutive equation at the macroscopic scale is derived. The proposed theoretical model is developed to obtain the stress-strain curves and anisotropic damage evolutions of rock under tensile, compressive, and shear stress. The microplane configurations are visualized to analyze the relationship between the anisotropic microscopic damage mechanism and the macroscopic failure characteristics. The simulated and experimental results are in good agreement, indicating that the model accurately describes the multi-scale failure of the rock specimen under different stress paths.

准确地认识和预测岩石的渐进破坏行为在岩石工程中是至关重要的。在物理基础上，提出了一种以牵引矢量固有特性为特征的微平面预测模型，用于描述岩石的多尺度行为、各向异性以及微观拉伸和压剪破坏效应。在热力学一致性框架下，推导了微平面的自由能方程和状态方程，确定了单个微平面的弹性、塑性和损伤特性。根据牵引对岩石破坏行为的拉伸和压剪效应，创新性地建立了损伤和塑性屈服准则。提出了一种新的高效隐式返回映射算法。导出了宏观尺度下的非线性本构方程。建立了岩石在拉、压、剪三种应力作用下的应力-应变曲线和各向异性损伤演化模型。将微平面形态可视化，分析各向异性细观损伤机制与宏观破坏特征之间的关系。模拟结果与试验结果吻合较好，表明该模型较准确地描述了不同应力路径下岩样的多尺度破坏。

Mechanics of Materials

Electromechanical properties of different phases in ferroelectric crystals regulated by variously oriented electric fields

Zhanpeng Zhang, Dongliang Shan, Jinlin Peng, Yunya Liu, Chihou Lei

doi:10.1016/j.mechmat.2024.105183

不同取向电场调控铁电晶体中不同相的机电性能

Electric fields offer a convenient and tunable way to induce phase transitions for regulating the electromechanical properties of ferroelectrics. However, regulating the electromechanical properties by using electric fields in various directions for different ferroelectric phases has yet to be systematically investigated, especially for lead-free material KNbO3. Based on the nonlinear thermodynamics analysis, the electric field-temperature phase diagrams of KNbO3 single crystals under different electric field directions (E[001], E[011], E[111]) have been constructed, along with the electric-field-induced electromechanical responses. The results show that the phase diagrams are markedly different under different electric field directions. Specifically, the electric field-temperature phase diagram appears as a "line"-shaped phase boundary under E[001], while it appears as a "U"-shaped phase boundary under E[011], and an arrowhead-shaped phase boundary under E[111]. It is also found that there are excellent electromechanical responses near both "U"-shaped and arrowhead-shaped phase boundaries due to the significant alterations in polarization slopes near the phase boundaries, offering an alternative pathway to regulate and enhance the electromechanical properties in ferroelectrics.

电场为诱导相变以调节铁电体的机电特性提供了方便且可调节的方法。然而，针对不同铁电相位使用不同方向的电场来调节机电特性还有待系统研究，特别是对无铅材料KNbO3。基于非线性热力学分析，构建了KNbO3单晶在不同电场方向（E[001]，E[011]，E[111]）下的电场-温度相图，以及电场诱导的机电响应。结果表明，在不同电场方向下，相图明显不同。具体来说，在E[001]下，电场-温度相图呈现“线”形相界，而在E[011]下呈现“U”形相界，在E[111]下呈现箭头形相界。我们还发现，由于相边界附近的极化斜率发生了显著变化，在“U”形和箭头形相边界附近存在极佳的机电响应，这为调节和增强铁电体的机电特性提供了另一种途径。

A novel approach for accurate development of the incremental plastic multiplier and consistent tangent operator in thermo-elasto-plastic modeling of materials

Morteza Sadeghifar, Rene Billardon, Denis Delagnes, Henri Champliaud, Antoine Tahan, Mohammad Jahazi

doi:10.1016/j.mechmat.2024.105184

材料热弹塑性建模中增量塑性乘数和一致切线算子精确开发的新方法

In the present research, new and accurate equations were developed for the incremental plastic multiplier (IPM) and the consistent tangent operator (CTO) to solve numerical problems in thermo-elasto-plastic (TEP) processes using the finite element method (FEM). To ensure accuracy, all material hardening coefficients were treated as temperature-dependent, and no terms and their derivatives in the analytical-mathematical solution were ignored. Two UMAT (User MATerial) subroutines with temperature-independent and temperature-dependent parameters were programmed for the EP and TEP behavior, respectively. Finite element models were created using both the Abaqus® built-in material models and the newly developed UMAT subroutines, designated as the reference and new models, respectively. In the reference model, flow stress was implemented using tabulated plastic strain and temperature data available in Abaqus®, while in the new model, the flow stress (yield function) was derived and numerically calculated based on the developed formulation. The new equations were successfully validated by comparing the results from the new model with those from the reference model. The developed IPM and CTO can be used for accurate predictions of strains, stresses, and temperatures in TEP problems, making them well-suited for industrial applications.

本文建立了增量塑性乘数（IPM）和一致切线算子（CTO）的新的精确方程，用于用有限元法求解热弹塑性（TEP）过程的数值问题。为了确保准确性，所有材料硬化系数都被视为温度相关，并且在解析数学解中没有项及其导数被忽略。分别为EP和TEP行为编写了具有温度无关和温度相关参数的两个UMAT （User MATerial）子程序。使用Abaqus®内置材料模型和新开发的UMAT子程序创建有限元模型，分别指定为参考模型和新模型。在参考模型中，流动应力是使用Abaqus®提供的塑性应变和温度数据表来实现的，而在新模型中，流动应力（屈服函数）是基于所开发的公式推导和数值计算的。通过将新模型与参考模型的结果进行比较，验证了新方程的正确性。开发的IPM和CTO可用于准确预测TEP问题中的应变，应力和温度，使其非常适合工业应用。

Thin-Walled Structures

Uniaxial compression performance of anti-tetrachiral structures considering the effects of cell size and boundary conditions

Jinwen Xia, Youjiang Cui, Baolin Wang, Kaifa Wang

doi:10.1016/j.tws.2024.112580

考虑细胞大小和边界条件影响的反四手结构的单轴压缩性能

Anti-tetrachiral structures (AS) are typical metamaterials known for their negative Poisson's ratio. The existing analysis of the mechanical properties of AS is conducted by applying the energy method to a unit cell with periodic boundary conditions (PBC). In available works, the shear force at the structure's boundaries is neglected. But is it permissible to disregard the impact of shear forces at the boundaries on the structure's equivalent mechanical properties? By examining the deformation relationship between the ribs and the nodal rings, we developed a uniaxial compression model for AS under both free and constrained boundary conditions, which accurately predicts the mechanical properties of the AS structure. This model was validated through numerical simulations and experiments. The findings reveal that the equivalent mechanical properties of AS exhibit a size dependence related to the cell size. For example, for AS with equivalent density and identical overall dimensions, the equivalent Young's modulus of an AS with 2×2 cells will be twice that of an AS with 4×4 cells. Furthermore, the size effect of the structure can be neglected when the number of cells larger than 8×8. Moreover, it is found that the present model considering boundary conditions exhibits an equivalent Young's modulus 25% higher than the model neglecting boundary conditions. The study's findings indicate that the presence of boundary conditions can disrupt PBC, leading to significant discrepancies between theoretical derivations and practical applications.

反四手性结构（AS）是典型的以负泊松比著称的超材料。现有的对AS力学性能的分析是将能量法应用于具有周期边界条件（PBC）的单胞。在现有的工程中，忽略了结构边界处的剪力。但是，是否允许忽略边界处剪力对结构等效力学性能的影响？通过研究肋和节环之间的变形关系，建立了自由和约束边界条件下AS的单轴压缩模型，该模型准确地预测了AS结构的力学性能。通过数值模拟和实验验证了该模型的有效性。研究结果表明，AS的等效力学性能表现出与电池尺寸相关的尺寸依赖性。例如，对于具有相同密度和相同整体尺寸的AS，具有2×2单元的AS的等效杨氏模量将是具有4×4单元的AS的两倍。此外，当单元数大于8×8时，结构的尺寸效应可以忽略不计。此外，还发现考虑边界条件的模型比不考虑边界条件的模型等效杨氏模量高25%。研究结果表明，边界条件的存在会破坏PBC，导致理论推导与实际应用之间存在显著差异。

Explainable machine learning models for predicting the ultimate bending capacity of slotted perforated cold-formed steel beams under distortional buckling

L. Simwanda, P. Gatheeshgar, F.M. Ilunga, B.D. Ikotun, S.M. Mojtabaei, E.K. Onyari

doi:10.1016/j.tws.2024.112587

用于预测开槽冷弯型钢梁在扭曲屈曲下的极限弯曲能力的可解释机器学习模型

This study develops explainable machine learning (ML) models to predict the ultimate bending capacity of cold-formed steel (CFS) beams with staggered slotted perforations, focusing on distortional buckling behavior. Utilizing a dataset from 432 non-linear finite element analysis simulations of CFS Lipped channels, ten ML algorithms, including four basic and six ensemble models, were evaluated. Ensemble models, specifically CatBoost and XGBoost, demonstrated superior accuracy, with test-set performances reaching a coefficient of determination ( R 2 ) of 99.9%, outperforming traditional analytical methods such as the Direct Strength Method (DSM). SHapley Additive Explanations (SHAP) were applied to highlight how features like plate thickness and root radius critically influence predictions. The findings underscore the enhanced predictive capabilities of ML models for structural performance, suggesting a significant potential to refine traditional design methodologies and optimize CFS beam designs.

本研究开发了可解释的机器学习（ML）模型，以预测具有交错开槽穿孔的冷弯型钢（CFS）梁的极限弯曲能力，重点关注扭曲屈曲行为。利用432个CFS唇形通道非线性有限元模拟数据集，对10种ML算法（包括4种基本模型和6种集成模型）进行了评估。集成模型，特别是CatBoost和XGBoost，显示出卓越的准确性，测试集性能达到99.9%的决定系数（r2），优于传统的分析方法，如直接强度方法（DSM）。SHapley加性解释（SHAP）被用于强调板厚和根半径等特征如何对预测产生重大影响。研究结果强调了ML模型对结构性能的增强预测能力，表明了改进传统设计方法和优化CFS梁设计的巨大潜力。

Thin-Layer Ultra-High-Strength Engineered Cementitious Composites (UHS-ECC) Reinforced with Small-Diameter FRP Bars for Structural Strengthening

Ji-Xiang Zhu, Ke-Fan Weng, Wei-He Liu, Bo-Tao Huang, Kai-Di Peng, Ji-Hua Zhu, Jian-Guo Dai

doi:10.1016/j.tws.2024.112592

薄层超高强度工程胶凝复合材料（UHS-ECC）与小直径FRP筋增强结构

This study proposed a novel strengthening system for reinforced concrete (RC) structures using a thin layer of Ultra-High-Strength Engineered Cementitious Composites (UHS-ECC) reinforced with small-diameter Fiber-Reinforced Polymer (FRP) bars. Experimental investigation, digital image correlation analysis, and numerical simulation were conducted to evaluate the flexural performance and failure mechanism of RC beams strengthened with 20-mm UHS-ECC layers and 3-mm FRP bars. It was found that the 20-mm UHS-ECC layer alone improved the load capacity of RC beams by 8.3%, though with reduced deflection, whereas incorporating two 3-mm FRP bars increased load capacity by up to 40.4%, without sacrificing deflection. Failure in all specimens was caused by concrete crushing; however, FRP-reinforced UHS-ECC layers mitigated early crack localization, significantly enhancing both strength and ductility. This study also revealed that compared to epoxy-bonded prefabricated layers, cast-in-place FRP-reinforced UHS-ECC layers exhibited higher load capacity and could avoid ECC/concrete interfacial cracks. A three-dimensional finite element model was proposed for the strengthening system and successfully predicted the flexural behavior. It is revealed that the FRP-to-UHS-ECC bond had marginal influence on performance, while the bond at the UHS-ECC-to-concrete interface significantly impacted flexural behavior. Remarkably, the small-diameter FRP bar achieved 75% of its tensile strength at the ultimate stage. These findings underscore the potential of FRP-reinforced UHS-ECC layers as an effective solution for enhancing the mechanical and durability performance of RC structures.

本研究提出了一种新型的钢筋混凝土（RC）结构加固体系，该体系使用薄层超高强度工程胶凝复合材料（UHS-ECC）和小直径纤维增强聚合物（FRP）棒进行加固。通过试验研究、数字图像相关分析和数值模拟，对采用20mm UHS-ECC层和3mm FRP筋加固的RC梁的抗弯性能和破坏机制进行了评价。研究发现，仅20mm的UHS-ECC层就能使RC梁的承载能力提高8.3%，尽管挠度有所减少，而结合两根3mm FRP筋则能在不牺牲挠度的情况下将承载能力提高40.4%。所有试件的破坏均由混凝土破碎引起；然而，frp增强的UHS-ECC层缓解了早期裂纹局部化，显著提高了强度和延性。研究还发现，与环氧树脂粘结预制层相比，现浇frp增强UHS-ECC层具有更高的承载能力，并且可以避免ECC/混凝土界面裂缝。提出了加固体系的三维有限元模型，并成功地预测了其抗弯性能。结果表明，frp - uhs - ecc粘结对混凝土抗弯性能影响较小，而uhs - ecc -混凝土界面粘结对抗弯性能影响较大。值得注意的是，小直径FRP筋在极限阶段达到了其抗拉强度的75%。这些发现强调了frp增强UHS-ECC层作为提高RC结构力学和耐久性的有效解决方案的潜力。

Machine learning based multi-objective optimization on shear behavior of the inter-module connection

En-Feng Deng, You-Peng Du, Xun Zhang, Jun-Yi Lian, Zhe Zhang, Jun-Feng Zhang

doi:10.1016/j.tws.2024.112596

基于机器学习的模块间连接剪切性能多目标优化

Prefabricated prefinished volumetric construction (PPVC) has become a research hotspot in recent years. Inter-module connections have a crucial influence on the mechanical behavior of PPVC. However, current studies on shear behavior and optimization design method of the inter-module connection are insufficient. This paper investigated shear behavior and machine learning based optimization method of an innovative fully bolted liftable connection (FBLC) for PPVC. The failure mode, force transferring mechanism, and ultimate load bearing capacity of the FBLC under shear force were revealed by the shear behavior tests. Four specimens were tested and the design parameters included the strength and number of the long stay bolts. Subsequently, a refined finite element model (FEM) of the FBLC was established and validated with the ratios of the shear bearing capacity between the FEA and test results ranging from 0.99 to 1.10. Then, six mainstream machine learning algorithms were utilized to predict shear behavior of the FBLC. The Genetic Algorithm Optimized Neural Network (GANN) provided better prediction accuracy on the shear bearing capacity, with an improvement on R2 by 0.1% to 3% compared with other algorithms. Similarly, the Support Vector Regression (SVR) showed higher prediction accuracy on the ultimate displacement, improving R2 by 0.4% to 12.9% compared with other algorithms. A stacking algorithm combing the GANN and SVR was developed as the proxy model between the input variables and optimization metrics. In addition, the NSGA-II algorithm was linked to establish a multi-objective optimization method on shear behavior of the FBLC. The yield load, ultimate load and steel consumption were selected as the optimization objectives and the stacking algorithm was used as the proxy model. The Pareto optimal solution sets on the optimization objectives were explored by the NSGA-II algorithm and the optimization design method of the FBLC was established. Compared with the unoptimized specimen, the yield and ultimate shear bearing capacity of the optimized specimen were increased by 113.5% and 123.6%, respectively, with the steel consumption reduced by 26.3%. Finally, a four-story PPVC was established, and the static analysis was carried out under vertical load and wind load. The shear behavior of the FBLC and inter-story drift ratio of the PPVC before and after optimization were compared to verify the reliability of the optimization method.

近年来，预制预成型体积结构（PPVC）已成为研究热点。模块间连接对PPVC的力学行为有重要影响。然而，目前对模块间连接的剪切行为和优化设计方法的研究还不够。本文研究了PPVC的创新全螺栓可升降连接（FBLC）的剪切行为和基于机器学习的优化方法。通过剪切行为测试揭示了FBLC在剪切力作用下的失效模式、力传递机制和极限承载能力。测试了四个试样，设计参数包括长留置螺栓的强度和数量。随后，建立了FBLC的精细有限元模型（FEM），并通过FEA和测试结果之间的剪切承载力比值（从0.99到1.10）进行了验证。然后，利用六种主流机器学习算法来预测FBLC的剪切行为。遗传算法优化神经网络（GANN）在剪切承载力方面的预测精度更高，与其他算法相比，R2值提高了0.1%至3%。同样，支持向量回归（SVR）在最终位移方面的预测精度更高，与其他算法相比，R2值提高了0.4%至12.9%。将GANN和SVR相结合的堆叠算法被开发为输入变量和优化指标之间的代理模型。此外，NSGA-II算法被用于建立FBLC剪切行为的多目标优化方法。屈服荷载、极限荷载和钢材消耗被选为优化目标，堆叠算法被用作代理模型。通过NSGA-II算法对优化目标上的帕累托最优解集进行了探索，建立了FBLC的优化设计方法。与未优化的试件相比，优化后的试件的屈服承载力和极限抗剪承载力分别提高了113.5%和123.6%，钢材消耗量减少了26.3%。最后，建立了一个四层PPVC，并在垂直荷载和风荷载作用下进行了静力分析。为了验证优化方法的可靠性，对优化前后的FBLC的抗剪性能和PPVC的层间位移比进行了比较。

Uncertainty sensitivity analysis for vibration properties of composite doubly-curved shallow shells using Kriging method

Yaoye Wang, Rui Zhong, Qingshan Wang, Liming Chen, Bin Qin

doi:10.1016/j.tws.2024.112600

用Kriging法分析复合材料双弯曲浅壳振动特性的不确定性敏感性

This paper presents a Kriging based global sensitivity analysis (GSA) method for the frequency response of displacements of composite doubly-curved shallow shells. A unified solution is utilized to develop the dynamic vibration formulation using the First-order Shear Deformation Theory (FSDT) and the Rayleigh-Ritz method. Kriging surrogate model is employed to substitute the frequency response function (FRF) of displacements. Ten parameters including materials and geometrical dimension are considered as input uncertain variables. A variance-based GSA method for dynamic model is employed to quantify the influence of each uncertain parameter. In addition, to avoid the computational burden of Monte Carlo simulation method (MCS), the presented sensitivity indices are computed analytically based on the Kriging mode, which further improves computational efficiency. Based on the convergence studies and comparison with traditional methods, the accuracy and efficiency of the present method are validated. The results shows that the frequency response of displacements exhibits greater sensitivity to changes in width, and thickness is more influential than others in the example from this article. Finally, the presented numerical results demonstrate vibration characteristics of different types of shells and observation points, which can also serve as a reference for further study on uncertainty-propagation analysis.

提出了一种基于Kriging的复合材料双弯曲浅壳位移频率响应全局灵敏度分析方法。利用一阶剪切变形理论（FSDT）和瑞利-里兹方法建立了统一的动态振动公式。采用Kriging替代模型代替位移频响函数。将材料、几何尺寸等10个参数作为输入不确定变量。采用基于方差的动态模型GSA方法量化各不确定参数的影响。此外，为了避免蒙特卡罗模拟方法（MCS）的计算负担，本文提出的灵敏度指标基于克里格模式进行解析计算，进一步提高了计算效率。通过收敛性研究和与传统方法的比较，验证了该方法的准确性和有效性。结果表明，在本文的算例中，位移的频率响应对宽度的变化表现出更大的敏感性，而厚度的影响比其他因素更大。最后，给出的数值结果展示了不同类型壳体和不同观测点的振动特性，为不确定性传播分析的进一步研究提供了参考。

Propagation of leaky surface acoustic wave in a layered piezoelectric semiconductor structure

Yuyang Zou, Qingguo Xia, Menghui Xu, Jia Lou, Minghua Zhang, Jianke Du

doi:10.1016/j.tws.2024.112601

泄漏表面声波在层状压电半导体结构中的传播

Some piezoelectric materials, such as ZnO and AlN, have not only piezoelectric properties but also semiconductor property. In this paper, an analytical solution of the leaky surface acoustic wave (LSAW) is developed for the structure composed of piezoelectric substrate boned with piezoelectric semiconductor (PSC) film using the partial wave method. Furthermore, the dispersion, loss, and attenuation curves of the LSAW in the composite structure have been obtained by combining the boundary conditions at the top of the film and the continuity conditions on the interface between the film and the substrate. Numerical examples illustrate the effects of PSC film thickness-to-wavelength ratio, steady-state carrier concentration, and biasing electric field on the dispersion, loss, and attenuation curves of LSAW in AlN film/LiNbO3 substrate. In addition, we conducted simulation by means of the PDE module in COMSOL. The theoretical results are consistent with the simulations, which could be helpful for the design of surface acoustic wave devices based on PSC materials.

一些压电材料，如ZnO和AlN，不仅具有压电性质，而且具有半导体性质。本文利用部分波方法，建立了压电衬底与压电半导体（PSC）薄膜结合结构的漏声表面波的解析解。结合薄膜顶部的边界条件和薄膜与衬底界面的连续性条件，得到了LSAW在复合结构中的色散、损耗和衰减曲线。数值算例说明了PSC薄膜厚度波长比、稳态载流子浓度和偏置电场对LSAW在AlN薄膜/LiNbO3衬底中的色散、损耗和衰减曲线的影响。此外，我们利用COMSOL中的PDE模块进行了仿真。理论结果与仿真结果吻合较好，为基于PSC材料的表面声波器件的设计提供了理论依据。