【新文速递】2024年5月18日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 6 篇

International Journal of Solids and Structures

Model for predicting temperature-dependent indentation yield strength and hardness considering size effects

Yi He, Jiabin Yang, Yanli Ma, Pan Dong, Jianzuo Ma, Hui Xiong, Weiguo Li

doi:10.1016/j.ijsolstr.2024.112881

考虑尺寸效应的温度相关压痕屈服强度和硬度预测模型

The development of theoretical models to facilitate access to the mechanical properties of materials has been a long-standing pursuit of scholars. In this study, temperature-dependent yield strength models and temperature-dependent hardness models considering indentation size effects were developed under different loading modes (loading to the same displacement or the same load at different temperatures), respectively. Based on the Force-Heat Equivalence Energy Density Principle, the proposed models are free of any adjustable fitting parameters, and the quantitative relationships among temperature, yield strength/hardness, Young's modulus, and indentation load/displacement were successfully captured. All the available 36 groups of experimental data validate the accuracy of the proposed models over a wide temperature range. The yield strength and hardness of metallic materials over a wide temperature range can be easily predicted by using the developed models. Based on the parametric analysis of the models, it has been theoretically clarified for the first time that the two loading modes have opposite indentation size effects for the same material. Although the indentation size effect all decreases gradually with increasing temperature for different loading modes. The influence of loading modes should be noted in future studies where temperature-dependent indentation size effects need to be considered. This work systematically considers the effects of temperature, loading mode, indentation load/displacement, and Young's modulus on the indentation yield strength and hardness, which is important to facilitate the study of the deformation behavior of materials at different temperatures by indentation methods.

发展理论模型以方便获取材料的力学性能一直是学者们长期追求的目标。本研究分别建立了不同加载模式下(相同位移加载或不同温度下相同加载)考虑压痕尺寸效应的温度相关屈服强度模型和温度相关硬度模型。基于力-热等效能量密度原理，该模型不需要任何可调整的拟合参数，并成功捕获了温度、屈服强度/硬度、杨氏模量和压痕载荷/位移之间的定量关系。所有可用的36组实验数据在较宽的温度范围内验证了所提出模型的准确性。利用所建立的模型可以很容易地预测金属材料在较宽温度范围内的屈服强度和硬度。基于模型的参数化分析，首次从理论上阐明了两种加载模式对同一材料的压痕尺寸效应相反。在不同加载模式下，压痕尺寸效应随温度升高而逐渐减小。在未来的研究中，应注意加载模式的影响，因为需要考虑温度相关的压痕尺寸效应。本文系统地考虑了温度、加载方式、压痕载荷/位移和杨氏模量对压痕屈服强度和硬度的影响，这对于利用压痕方法研究材料在不同温度下的变形行为具有重要意义。

Mechanics of Materials

Computational study of the influence of microstructure on fracture behavior near crack-tip field in nacre-like materials

Xiaoyan Ye, Akihiro Nakatani

doi:10.1016/j.mechmat.2024.105034

类珠状材料裂纹尖端场附近显微组织对断裂行为影响的计算研究

The small-scale failure process around a plane strain mode I crack in nacre-like materials is analyzed. The displacement increments of boundary nodes are specified by the analytical solutions based on the orthotropic linear elasticity to conduct an incremental finite element analysis. We set up a structural model composed of staggered arranged brittle aragonite tablets and cohesive zones within a process window surrounding the crack tip to investigate the toughness as well as the deformation mechanism in the fracture process zone. The results obtained by the parametric studies of different geometries and mechanical properties in the microstructure of the materials show that the aspect of failure in the near-tip fields can be categorized into four distinct fracture mechanisms. These mechanisms significantly affect the fracture toughness with differences of hundreds of times. We show a failure-mechanism map in which these fracture mechanisms can be divided into regions of geometry and mechanical properties in microstructure. Findings obtained in this study about the toughening mechanisms give us the useful knowledge to design novel materials with specific microstructures to control fracture mechanisms.

分析了类珠粒材料平面应变型裂纹的小尺度破坏过程。边界节点的位移增量由基于正交各向异性线弹性的解析解指定，进行增量有限元分析。我们建立了脆性文石片与裂纹尖端周围过程窗口内的黏结带交错排列的结构模型，研究了脆性文石片在断裂过程区的韧性和变形机制。对材料微观结构中不同几何形状和力学性能的参数化研究结果表明，近尖端场的破坏可分为四种不同的断裂机制。这些机制对断裂韧性影响显著，差异达数百倍。我们展示了一个失效机制图，其中这些断裂机制可以在微观结构中划分为几何和力学性能区域。本研究的增韧机制为我们设计具有特定微观结构的新型材料来控制断裂机制提供了有用的知识。

International Journal of Plasticity

Mechanical anisotropy induced by the competition between twinning and basal slip of AZ31 magnesium alloy under biaxial tension

Yao Cheng, Hua Qiao, Yuanjie Fu, Yunchang Xin, Qiuju He, Xinde Huang, Gang Chen, Peidong Wu, Qing Liu

doi:10.1016/j.ijplas.2024.104005

双轴拉伸下AZ31镁合金孪晶与基滑移竞争引起的力学各向异性

The mechanical behavior of a hot-rolled Mg AZ31 plate was studied under biaxial tensions along two perpendicular loading axes of x and y in the ND-TD plane, with the x-axis aligned at a 45° counterclockwise angle from the TD (ND and TD refer to the normal direction and transverse direction). A complex strain partitioning in two loading axes is observed with the variation of stress ratio σxx:σyy. For σxx:σyy = 1:1 and 1:1.5, the strains along the x- and y-axes, εxx and εyy, are both positive. However, With the stress ratio of σxx:σyy = 1:3, εyy remains positive, while εxx becomes negative. Interestingly, for σxx:σyy = 1:2, εxx changes from negative during the early stage of loading to positive upon failure. Crystal plasticity simulations and theoretical calculations reveal that the observed strain transition. The reasons for the strain transition with stress ratio is related to the competition between {101¯2} twinning and basal slip. For {101¯2} twinning, the accommodated strains by most of the twins are εxx>0 and εyy>0 for all the stress ratios considered. For basal slip, most of the basal variants accommodate a positive y-axis strain, while for loading cases with low stress ratios, most of the basal variants result in a negative x-axis strain. As the stress ratio decreases, basal slip becomes more active, while the activity of {101¯2} twinning gradually decreases, leading to the observed strain transition. For σxx:σyy = 1:2, the transition from negative to positive is related to the increasing activity of {101¯2} twinning with strain. Theoretical calculations reveal that the competition of basal slip and {101¯2} twinning under biaxial tension is determined by the variation of their Schmid factors with σxx:σyy.

研究了热轧镁 AZ31 板在 ND-TD 平面上沿 x 和 y 两个垂直加载轴的双轴张力作用下的力学行为，其中 x 轴与 TD 成 45° 逆时针角（ND 和 TD 指法线方向和横向方向）。随着应力比 σxx:σyy 的变化，在两个加载轴上观察到复杂的应变分区。当 σxx:σyy = 1:1 和 1:1.5 时，沿 x 轴和 y 轴的应变 εxx 和 εyy 均为正值。然而，当应力比为 σxx:σyy = 1:3 时，εyy 仍为正值，而 εxx 则变为负值。有趣的是，当σxx:σyy = 1:2 时，εxx 从加载早期的负值变为失效时的正值。晶体塑性模拟和理论计算揭示了观察到的应变转变。应变随应力比变化的原因与{101¯2}孪晶和基底滑移之间的竞争有关。对于{101¯2}孪晶，在所有考虑的应力比下，大多数孪晶的容纳应变都是εxx>0和εyy>0。对于基底滑移，大多数基底变体都能容纳正的 y 轴应变，而对于低应力比的加载情况，大多数基底变体都能产生负的 x 轴应变。随着应力比的减小，基底滑移变得更加活跃，而{101¯2}孪晶的活跃性逐渐减小，从而导致观察到的应变转变。在σxx:σyy = 1:2 的情况下，从负应变到正应变的转变与{101¯2}孪生的活性随应变的增加而增加有关。理论计算显示，在双轴拉伸下，基底滑移和{101¯2}孪晶的竞争取决于它们的施密德因子随σxx:σyy的变化。

Thin-Walled Structures

An enhanced strain gradient model for temperature-dependent sound transmission loss in double-walled functionally graded microplates

Samaneh Soleymani, Parham Memarzadeh, Davood Toghraie

doi:10.1016/j.tws.2024.112001

双壁功能梯度微孔板中温度相关声传输损失的增强应变梯度模型

With the growing use of functionally graded (FG) microplates in structural acoustic metamaterials for aerospace and automotive applications, accurate modeling of sound transmission loss is critical for effective vibration and noise control engineering. In this study, a theoretical model is formulated based on the first-order shear deformation theory (FSDT) to estimate sound transmission loss (STL) through air-filled rectangular double-walled FG microplates with simply supported boundary conditions. The microplates are subjected to a nonlinear thermal environment, and the modified strain gradient theory (MSGT) is employed, incorporating three material length scale parameters to account for the size effect. The material properties are temperature-dependent and vary across the thickness following a power-law distribution. Size-dependent coupled vibroacoustic equations are derived utilizing the sound velocity potential, normal velocity continuity conditions, and Hamilton's principle, and are subsequently solved using the Galerkin method. Comparative analysis is performed by contrasting the results obtained from the MSGT model with those from the modified couple stress theory (MCST) and classical continuum theory (CCT) models, allowing for the assessment of the accuracy and precision of the proposed solution. Additionally, the influence of various parameters, such as gradient index, length scale parameters, temperature variation, incident angles, and acoustic cavity depth, on the STL is investigated. Key findings demonstrate that in the stiffness-controlled region, length scale parameters significantly enhance STL, while power-law index and temperature variation reduce it.

随着功能梯度(FG)微板在航空航天和汽车结构声学超材料中的应用越来越多，声传输损失的精确建模对于有效的振动和噪声控制工程至关重要。本文基于一阶剪切变形理论(FSDT)，建立了一种计算简支边界条件下充气矩形双壁FG微孔板声传输损失(STL)的理论模型。微孔板受非线性热环境影响，采用修正应变梯度理论(MSGT)，结合三个材料长度尺度参数来考虑尺寸效应。材料的性质与温度有关，并随厚度的幂律分布而变化。利用声速势、法向速度连续条件和Hamilton原理，推导了尺寸相关的耦合振动声方程，并利用伽辽金方法进行了求解。通过将MSGT模型与修正耦合应力理论(MCST)和经典连续介质理论(CCT)模型的结果进行对比分析，以评估所提出解的准确性和精密度。此外，还研究了梯度指数、长度尺度参数、温度变化、入射角和声腔深度等参数对STL的影响。研究结果表明:在刚度控制区，长度尺度参数显著提高了STL，而幂律指数和温度变化则降低了STL。

Low frequency bandgap and high stiffness of innovative auxetic metamaterial with negative thermal expansion

Qiao Zhang, Yuxin Sun

doi:10.1016/j.tws.2024.112010

新型负热膨胀消磁超材料的低频带隙和高刚度

Achieving multifunctional integration is crucial in mechanical metamaterials to meet the requirements of structures and equipment serving in complex environments across various engineering fields. In this study, we propose two novel bi-material and tri-material metamaterials based on the original edge-shared quadrangle (EQ/EQO) metamaterial, which exhibit negative thermal expansion (NTE), negative Poisson's ratio (NPR), and bandgap characteristics. The effective thermoelastic properties, including coefficient of thermal expansion (CTE), Poisson's ratio (PR), and Young's modulus, are compared and analyzed through theoretical formulation based on Timoshenko beam theory and numerical simulation using continuum elements with Abaqus. Additionally, finite element analysis is employed to calculate the energy band structures of these metamaterials based on Bloch's theorem, while the transmission characteristic curve verifies the validity of the obtained band structure. We systematically discuss the bandgap characteristics, coupling relationship between bandgaps and thermoelastic properties, as well as the influence of geometrical parameters on both bandgaps and thermoelastic properties. Our results demonstrate that the effective thermoelastic properties of these metamaterials are primarily determined by their frame structure's geometrical parameters, particularly the incline angle. Furthermore, for bi-material metamaterials, their specific stiffness closely relates to their bandgaps; however, for tri-material metamaterials, only the central local resonant unit determines their bandgap behavior. Notably, planar and 3D tri-material metamaterials can concurrently achieve a low-frequency bandgap along with high stiffness as well as NTE/NPR behavior. This work presents a new design strategy for optimizing multifunctional metamaterials' bandgaps while incorporating NTE behavior.

实现多功能集成是机械超材料满足各种工程领域复杂环境中结构和设备需求的关键。在本研究中，我们提出了两种新的双材料和三材料的超材料，基于原始的边缘共享四边形(EQ/EQO)超材料，具有负热膨胀(NTE)，负泊松比(NPR)和带隙特性。通过基于Timoshenko梁理论的理论公式和基于Abaqus的连续单元数值模拟，对比分析了热膨胀系数(CTE)、泊松比(PR)和杨氏模量等有效热弹性性能。此外，基于Bloch定理，采用有限元分析方法计算了这些超材料的能带结构，并通过透射特性曲线验证了所得能带结构的有效性。系统地讨论了带隙特性、带隙与热弹性的耦合关系以及几何参数对带隙和热弹性的影响。我们的研究结果表明，这些超材料的有效热弹性性能主要取决于其框架结构的几何参数，特别是倾角。此外，对于双材料超材料，其比刚度与其带隙密切相关;然而，对于三材料超材料，只有中心局部谐振单元决定其带隙行为。值得注意的是，平面和三维三材料超材料可以同时实现低频带隙、高刚度和NTE/NPR行为。这项工作提出了一种新的设计策略，用于优化多功能超材料的带隙，同时结合NTE行为。

Ballistic performance of UHMWPE fiber laminates with pre-formed holes

Rui Zhang, Xiao-Tong Song, Lu-Sheng Qiang, Xin Xu, Bin-Qian Zheng, Jian Deng, Yi Zhou, Xin Wang, Chang-Ye Ni

doi:10.1016/j.tws.2024.112011

超高分子量聚乙烯纤维预成型孔层压板的弹道性能

Understanding how previous ballistic impacts affect the subsequent penetration resistance of ultra-high molecular weight polyethylene (UHMWPE) fiber laminates is crucial for their application in multi-hit scenarios. In order to investigate the effect of fiber fracture, a systematic examination of the ballistic performance of UHMWPE laminates with pre-formed holes is conducted through a combined experimental and numerical approach. Penetration resistance, dynamic penetration process, and deformation/failure modes of laminates with different configurations of pre-formed holes are tested and compared. A full three-dimensional finite element model is established, and a continuum homogenized model is utilized to simulate the laminate. The effectiveness of numerical model is validated by achieving a reasonable agreement between predictions and measurements. The presence of a single pre-formed hole will change the severity of delamination and result in tear failures, while it has minimal effect on penetration resistance until the spacing distance reaches 10 mm. When spacing distance remains the same, the change in orientation of a single pre-formed hole has little influence on the velocity history. Further, an enhancement in ballistic performance is observed when the number of pre-formed holes is increased to four, due mainly to the significant pull-in at the edge of pre-formed hole and the released fiber tensile stresses. The results of this study are valuable for comprehending the ballistic performance of UHMWPE laminate when subjected to multiple projectile impacts and have practical implications for the design of advanced protective systems.

了解先前的弹道冲击如何影响超高分子量聚乙烯(UHMWPE)纤维层压板的后续抗侵彻能力，对于其在多碰撞场景中的应用至关重要。为了研究纤维断裂的影响，采用实验与数值相结合的方法对带预成形孔的超高分子量聚乙烯层合板的弹道性能进行了系统的研究。对不同预成形孔结构层合板的侵彻阻力、动态侵彻过程和变形破坏模式进行了测试和比较。建立了全三维有限元模型，采用连续均化模型对层合板进行了数值模拟。数值模型的有效性得到了验证，预测结果与实测结果基本一致。单个预成型孔的存在将改变分层的严重程度并导致撕裂失败，而在间距达到10 mm之前，它对穿透阻力的影响最小。在间距相同的情况下，单个预成型孔的方向变化对速度历史的影响不大。此外，当预成形孔的数量增加到4个时，可以观察到弹道性能的增强，这主要是由于预成形孔边缘的显着拉入和释放的纤维拉伸应力。研究结果对于理解超高分子量聚乙烯复合材料在多重弹丸冲击下的弹道性能具有重要意义，并对先进防护系统的设计具有实际意义。

Cyclic behavior of high-strength steel beam-to-column welded flange-bolted web connections

Fangxin Hu, Zhan Wang

doi:10.1016/j.tws.2024.111999

高强度钢梁-柱焊接法兰-螺栓腹板连接的循环性能

Four Q690 high-strength steel beam-to-column moment connections, which use welded joints between beam and column flanges as well as a bolted beam web to the column flange, were tested under cyclic loading. The effects of beam-to-column welding details and panel zone strength were studied. Two pairs of welded flange details were incorporated, including the Chinese code-specified complete-joint-penetration (CJP) welded connections with backing plates where the bottom backing plate is reinforced by a fillet weld, and enhanced CJP welded connections with backing plates removed, weld roots backgouged, and further reinforced by fillet welds. Three panel zone thicknesses were designed to characterize strong, intermediate and weak panel zones, respectively. The test results show that backing plates should be removed in these moment connections to prevent brittle weld fracture, but still rendering only limited plastic hinge rotations in the order of 0.01–0.02 rad in the beam end before ductile fracture of the beam flange. The panel zone, however, survived even after a plastic shear rotation of 0.03 rad, demonstrating much higher plastic deformation capacity than the beam plastic hinge. This suggests that ductility can be exploited in 690 MPa high-strength steel panel zones, but not reliably in 690 MPa steel beams.

采用4种Q690高强钢梁柱弯矩连接方式，采用梁与柱法兰的焊接连接以及梁腹板与柱法兰的螺栓连接，进行了循环荷载试验。研究了梁柱焊接细节和板区强度的影响。结合了两对焊接法兰的细节，包括中国规范规定的完全连接渗透(CJP)焊接连接与垫板，底部垫板通过角焊缝加强，增强CJP焊接连接与垫板去除，焊根反刨，并进一步加强角焊缝。三种面板区域厚度分别用于表征强、中、弱面板区域。试验结果表明，在这些弯矩连接中，为了防止焊缝脆性断裂，应拆除支承板，但在梁翼缘发生延性断裂之前，梁端仍只进行0.01 ~ 0.02 rad的有限塑性铰转动。然而，即使在0.03 rad的塑性剪切旋转后，面板区域仍然存在，显示出比梁塑性铰链更高的塑性变形能力。这表明，在690 MPa高强度钢板区域，延性可以发挥作用，但在690 MPa钢梁区域，延性不可靠。

Influence of joint types on rigidity of Chebyshev elastic gridshells: A parametric analysis

Xianheng Wang, Xinming Qiu

doi:10.1016/j.tws.2024.112008

节点类型对切比雪夫弹性网格壳刚度影响的参数分析

Elastic gridshells (EGS) have many applications in the field of architecture. Built according to Chebyshev net geometry, the Chebyshev EGS (CGES) is a famous kind of EGS; since an arbitrary three-dimensional CEGS can be transformed into a planar state without any stretching strain. Due to its tremendous potential application in novelly deployed structures, the rigidity of CEGS is an important mechanical property to be investigated.In this study, using the analytical and finite element methods, the influence of joint types and gridshell parameters on the rigidity of CEGS subjected to point loads is studied in detail. The joint types are classified as pin joints, semi-rigidity joints, and rigid joints. A robust relation between rigidity and gridshell parameters is proposed, including Young's modulus, rod diameter, size of CEGS, joint stiffness, and rod numbers. Further, the above relation is nondimensionalized. The dimensionless rigidity is only related to the two dimensionless parameters, which are dimensionless joint stiffness and rod number. The rigidities of CEGS on four types of surfaces are calculated to verify the above relation, and satisfactory agreement is obtained. Therefore, the proposed relationship of rigidity is confirmed to be accurate and efficient for a wide range of parameters.

弹性网格壳在建筑领域有着广泛的应用。根据切比雪夫网几何构造的切比雪夫EGS (CGES)是一种著名的EGS;因为任意三维CEGS可以在没有任何拉伸应变的情况下转化为平面状态。由于其在新部署结构中的巨大应用潜力，CEGS的刚度是研究的重要力学性能。本文采用解析法和有限元法，详细研究了节点类型和格壳参数对点荷载作用下CEGS刚度的影响。接头类型分为销钉接头、半刚性接头和刚性接头。提出了刚度与网格壳参数之间的鲁棒关系，包括杨氏模量、杆直径、CEGS尺寸、节点刚度和杆数。此外，上述关系是非量纲化的。无量纲刚度只与无量纲节点刚度和杆数两个参数有关。计算了四种类型表面上CEGS的刚度，验证了上述关系，得到了满意的结果。因此，所提出的刚度关系在较宽的参数范围内是准确有效的。

Cyclic Modelling of T-Joints With CHS Chord Members and Passing-Through Plates

S. Di Benedetto, M. Latour, G. Rizzano

doi:10.1016/j.tws.2024.112009

具有CHS弦杆和贯通板的t形节点的循环建模

This paper focuses on modelling the cyclic response of welded T-joints between Circular-Hollow-Section (CHS) chords and passing-through plates. Recent works have highlighted that, in practical applications, this specific joint typology can be regarded either as a standalone connection or as a component representing one of the main sources of deformability and energy dissipation capacity in more complex beam-to-column joints with CHS columns and passing-through I-beams. Currently, research efforts have primarily focused on predicting the strength and stiffness of this type of connection. However, there is a knowledge gap regarding the characterization of the cyclic response of joints with passing-through members, a crucial aspect for modelling steel structures with these connection types in seismic areas. In light of this, the paper aims to characterize the cyclic response of T-joints with CHS members and passing-through plates using a comprehensive approach that incorporates experimental, numerical, and analytical methods. Initially, the results of an experimental study examining the cyclic behaviour of T-joint specimens with passing-through plates are presented. Subsequently, models of the tested joints are implemented in Finite Element software and validated against the experimental outcomes. The validated models are used to conduct a parametric study, considering 44 different configurations to obtain their force-displacement cyclic responses. These responses are mathematically modelled using the hysteretic uniaxial material from the OpenSees library and a Genetic Algorithm based tool previously developed by the authors (MultiCal). Finally, regression analyses are performed to develop formulations for predicting the mathematical parameters of the hysteretic uniaxial material model starting directly from the geometrical and mechanical properties of the connection. This approach enables designers to model the cyclic response in structural analysis with a straightforward approach, without the need for new calibrations or tests, if the modelled joints fall within the proposed range of calibration. From the point of view of the component modelling, the approach presented aligns with the larger research strand devoted to the extension of the component method codified in Eurocode 3 part 1.8 to cyclic loading conditions.

本文主要研究了圆空心截面弦与贯通板之间焊接t形接头的循环响应模型。最近的研究强调，在实际应用中，这种特定的节点类型既可以被视为独立的连接，也可以被视为代表更复杂的具有CHS柱和穿过工字钢的梁柱节点的变形能力和耗能能力的主要来源之一的组件。目前，研究工作主要集中在预测这种连接的强度和刚度上。然而，对于具有贯通构件的连接的循环响应的表征存在知识缺口，这是在震区对具有这些连接类型的钢结构进行建模的关键方面。鉴于此，本文旨在利用综合实验，数值和分析方法来表征具有CHS成员和穿过板的t形节点的循环响应。最初，一项实验研究的结果检查循环行为的t型接头试件与通过板提出。随后，在有限元软件中建立了被试节点的模型，并与实验结果进行了验证。利用验证的模型进行参数化研究，考虑44种不同的结构，获得其力-位移循环响应。利用OpenSees库中的滞回单轴材料和作者(MultiCal)先前开发的基于遗传算法的工具，对这些响应进行了数学建模。最后，进行回归分析以开发公式，用于直接从连接的几何和力学特性开始预测滞回单轴材料模型的数学参数。这种方法使设计人员能够以直接的方法在结构分析中模拟循环响应，而不需要新的校准或测试，如果建模的关节落在建议的校准范围内。从组件建模的角度来看，所提出的方法与致力于将欧洲规范3第1.8部分中编纂的组件方法扩展到循环加载条件的更大研究链一致。