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【新文速递】2024年4月23日固体力学SCI期刊最新文章

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今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Thin-Walled Structures 4 篇

International Journal of Solids and Structures

Effect of polydispersity on the transport and sound absorbing properties of three-dimensional random fibrous structures

Quang Vu Tran, Camille Perrot, Raymond Panneton, Minh Tan Hoang, Ludovic Dejaeger, Valérie Marcel, Mathieu Jouve

doi:10.1016/j.ijsolstr.2024.112840

多分散性对三维随机纤维结构输运和吸声性能的影响

A technique is proposed that uses a multi-scale approach to calculate transport properties of compressed felts using only image analysis and numerical calculations. From the image analysis fiber diameter distribution and fiber orientation are determined. From a known porosity and the latter two characteristics, two representative elementary volumes (REV) are constructed: one based on the volume-weighted average diameter and one on an inverse volume-weighted average diameter. Numerical calculations on the former showed that it correctly estimates viscous and thermal permeabilities, while the latter correctly estimates tortuosity and viscous and thermal characteristic lengths. From these calculations, micro-macro analytical expressions are developed to estimate the transport properties of polydisperse composite felts based solely on open porosity, fiber diameter polydiversity, and fiber orientation. Good agreements are obtained between analytical predictions and measurements of transport properties. The predicted transport properties are also used in the Johnson-Champoux-Allard-Lafarge (JCAL) equivalent fluid model to predict the sound absorption coefficient of the felts. Excellent agreements are obtained with impedance tube measurements.

提出了一种基于图像分析和数值计算的多尺度压缩毛毡传输特性计算方法。通过图像分析,确定了光纤的直径分布和方向。根据已知孔隙度和后两个特征,构建了两个代表性的基本体积(REV):一个基于体积加权平均直径,另一个基于逆体积加权平均直径。数值计算表明,前者能正确估计黏性和热渗透性,后者能正确估计弯曲度和黏性和热特性长度。根据这些计算,建立了微宏观分析表达式,仅根据开孔率、纤维直径多样性和纤维取向来估计多分散复合毡的输运特性。在输运性质的分析预测和测量之间得到了很好的一致性。预测的输运特性也被用于Johnson-Champoux-Allard-Lafarge (JCAL)等效流体模型来预测毡的吸声系数。阻抗管测量结果非常吻合。


Journal of the Mechanics and Physics of Solids

Continuum Strain of Point Defects

G. Gengor, O.K. Celebi, A.S.K. Mohammed, H. Sehitoglu

doi:10.1016/j.jmps.2024.105653

点缺陷的连续应变

We propose a new Regularized Green's Function Method (RGFM) derived from electron densities and captures the disturbance due to point defects, successfully extending the elastic strain determination to the lattice scales. The RGFM circumvents the use of concentrated point forces, which results in unrealistic singular fields. The objective is to determine the force variations at the atomic scales from Ab-initio calculations as Quantum Mechanical Force Density (QMFD). QMFD encodes the information regarding the electronic structure of the defect since it is related to the gradients of electron wavefunctions generated from the Density Functional Theory (DFT) calculations. Once the QMFD is calculated, RGFM solves the force equilibrium equation via Fourier transforms to compute elastic fields. Therefore, the present treatment reflects the electronic structure of the atomic positions, hence the complex elastic deformations and interactions at short range, which represents a significant advancement compared to previous studies. The RGFM can also capture the long-range fields since it calculates the decay of the force fields away from the nuclei. Previous theories, such as the elastic dipole method, face two main shortcomings: they can only handle the long-range elastic fields and contain an unphysical singularity at the center of the point defect. Our novel derivation of distributed forces addresses both challenges, i.e., it renders non-singular displacement and strain fields at the nuclei and can also describe the elastic response accurately far from the nuclei center. The application of the method to the NV (nitrogen-vacancy) center in SiC is demonstrated in comparison with the elastic dipole theory, showing the advantages of the present methodology.

我们提出了一种基于电子密度的正则化格林函数方法(RGFM),并捕获了点缺陷引起的扰动,成功地将弹性应变的测定扩展到晶格尺度。RGFM避免了集中点力的使用,这会导致不切实际的奇异场。目的是确定力在原子尺度上的变化从从头算作为量子力学力密度(QMFD)。QMFD编码了有关缺陷电子结构的信息,因为它与密度泛函理论(DFT)计算产生的电子波函数的梯度有关。一旦计算出QMFD, RGFM通过傅里叶变换求解力平衡方程来计算弹性场。因此,目前的处理方法反映了原子位置的电子结构,因此在近距离内复杂的弹性变形和相互作用,与以往的研究相比,这是一个重大的进步。RGFM还可以捕获远程场,因为它计算了远离原子核的力场的衰减。以前的理论,如弹性偶极子方法,面临两个主要缺点:它们只能处理远程弹性场,并且在点缺陷的中心包含非物理奇点。我们的分布式力的新推导解决了这两个挑战,即,它可以呈现原子核处的非奇异位移和应变场,也可以准确地描述远离原子核中心的弹性响应。将该方法应用于碳化硅中氮空位中心,并与弹性偶极子理论进行了比较,表明了该方法的优越性。


Thin-Walled Structures

Experimental research on H-section beam-square steel column joints connected by self-tapping screws

Jiahang Xu, Ting Zhou, Zhihua Chen, Xueshan Liu, Wentao Qiao

doi:10.1016/j.tws.2024.111923

自攻螺钉连接h型钢-方钢柱节点的试验研究

This paper proposes a novel thin-walled steel beam-column joint entirely using self-tapping screws. Compared to bolted and welded connections, its advantages of easy construction, low precision requirements, and fast construction are suitable for low-rise steel structures. Four full-scale H-section beam-square steel column joints connected by self-tapping screws were tested and the force transfer mechanism was investigated. Three of the specimens were loaded monotonically at the beam ends. The effects of the L-shaped connecting plate thickness and the arrangement of stiffening ribs on the bending performance of the joints are analyzed. Monotonic loading tests have demonstrated that the increased thickness and the arrangement of stiffening ribs enhance the common forces in the clusters of self-tapping screws, thereby increasing the bending stiffness of the joints. One of the specimens was tested with cyclic loads. The cyclic loading test revealed that the hysteretic curve of the self-tapping screws connection is relatively full, with high energy dissipation capacity and low degradation of strength and stiffness. Finally, the improved component method proposed the calculation method of bending resistance of self-tapping connection joints. The calculation accuracy is within 10%, which can be used as a reference for the design of bending resistance.

本文提出了一种全自攻螺钉连接的薄壁钢梁-柱节点。与螺栓连接和焊接连接相比,其施工方便、精度要求低、施工快捷等优点适用于低层钢结构。对采用自攻螺钉连接的4个全尺寸h型钢-方钢柱节点进行了试验,并对其传力机理进行了研究。其中3个试件在梁端进行单调加载。分析了l型连接板厚度和加筋肋布置对节点抗弯性能的影响。单调加载试验表明,增加厚度和加劲肋的布置增加了自攻螺钉簇中的共同力,从而增加了节点的抗弯刚度。其中一个试件进行了循环荷载试验。循环加载试验表明,自攻螺钉连接的滞回曲线较为饱满,具有较高的耗能能力和较低的强度刚度退化。最后,采用改进的构件法提出了自攻连接节点抗弯性能的计算方法。计算精度在10%以内,可为抗弯设计提供参考。


Lateral load behavior of shear connections between steel storage racks and the spine bracing with posts

Zhaoqi Huang, Xianzhong Zhao, Ken S. Sivakumaran

doi:10.1016/j.tws.2024.111924

钢储物架与带柱支撑梁剪力连接的横向荷载特性

High-rise steel storage racks are cold-formed thin-walled steel frames, which achieve their lateral strength and stiffness by the use of a spine bracing system in the down-aisle direction commonly located at a short horizontal distance away from the main rack frames. The shear connections between the main rack frame and the spine bracing system play a dominant role in the effectiveness of the spine bracing system. This paper experimentally investigates the behavior of the shear connections used in industrial practice between a steel storage rack and the spine bracing system with posts using four groups of three nominally identical connection specimens. By employing a digital image correlation (DIC) system, the tests generate comprehensive data and establish the real-time deformation fields of individual components of such shear connections. Based on the component-based approach, a linear-elastic analytical model is developed for the type of shear connections under consideration. The proposed analytical model explicitly captures the behavior of the individual connection components, including the three-dimensional flexural bending of endplates, as well as the distortions of the open sections of the upright and the bracing post. Based on the proposed model, this paper quantifies the contribution of each component towards the total deformation of the shear connections. The investigation establishes that the cross-sectional distortion of the bracing post and the out-of-plane bending of the upright web are the most flexible components of such shear connections. Recommendations associated with the shear connections under consideration are proposed for the rack designers and manufacturers.

高层钢货架是冷弯薄壁钢框架,其横向强度和刚度是通过在通道下方向使用脊柱支撑系统来实现的,通常位于距离主货架框架较短的水平距离处。主机架与脊柱支撑系统之间的剪切连接对脊柱支撑系统的有效性起着主导作用。本文试验研究了工业实践中使用的钢存储架和带有柱子的脊柱支撑系统之间的剪切连接的行为,使用四组三个名义上相同的连接试件。试验采用数字图像相关(DIC)系统,生成了全面的数据,建立了此类剪切连接各构件的实时变形场。基于基于构件的方法,建立了考虑剪切连接类型的线弹性分析模型。所提出的分析模型明确地捕捉了各个连接部件的行为,包括端板的三维弯曲,以及直立和支撑柱的开口部分的变形。基于所提出的模型,本文量化了各构件对剪切连接总变形的贡献。研究表明,支撑柱的截面变形和直立腹板的面外弯曲是这种剪切连接中最灵活的构件。对机架设计人员和制造商提出了与考虑中的剪切连接相关的建议。


Comparative Experimental Analysis of Local Buckling in Mild and High-Strength Steel (HSS) CHS Subjected to Various Galvanization Techniques

Drilon Gubetini, Martin Mensinger, Tohid Ghanbari-Ghazijahani

doi:10.1016/j.tws.2024.111925

不同镀锌工艺下低碳钢和高强钢(HSS) CHS局部屈曲的对比试验分析

This article reports on an extensive experimental study on galvanized and ungalvanized cold-formed circular hollow sections (CFCHS). All samples were produced by cold-forming thermomechanically rolled steels (TM-steels) in S355, S550, S600, S700, and S960 with high-frequency induction welding (HFI). The test specimens were examined without galvanization, with a pre-galvanization and a post-galvanization. Hardness measurements and microstructural analysis were conducted on seven samples, while the mechanical behavior was examined through 82 tensile and 78 stub-column tests with corresponding imperfection measurements. Despite being classified as prone to local elastic buckling according to international standards, the S960 samples in this study did not exhibit such failure. This suggests that the classification by the codes was conservative. The effects of pre-galvanization on CHS have not been investigated so far, and current findings from literature regarding the impact of post-galvanization on load-bearing behavior suggest a severe capacity decrease for CFCHS in high steel grades. Contrary to previous findings, the current study reveals capacity-enhancing effects resulting from galvanization. Both galvanization types enhanced the stiffness and the cross-section capacity under compression. Galvanization induces changes in material properties, including yield and tensile strength, ductility, and the characteristics of the stress-strain curve. This study serves as a validation base for less conservative yet reliable approaches for the cross-section design of high-strength steel CHS and the utilization of beneficial effects due to galvanization.

本文报道了镀锌和未镀锌冷弯圆空心型钢(CFCHS)的广泛实验研究。所有样品均由S355, S550, S600, S700和S960冷成形热机械轧制钢(tm钢)采用高频感应焊接(HFI)生产。试验样品在没有镀锌的情况下进行了检查,有预镀锌和后镀锌。对7个试样进行了硬度测量和显微组织分析,并通过82次拉伸试验和78次短柱试验进行了力学性能测试,并进行了相应的缺陷测量。尽管按照国际标准,S960样品容易发生局部弹性屈曲,但本研究中S960样品并未出现这种破坏。这表明,由代码分类是保守的。到目前为止,预镀锌对CFCHS的影响还没有被研究过,目前文献中关于后镀锌对承载行为影响的研究结果表明,在高钢等级中,CFCHS的产能严重下降。与以往的研究结果相反,目前的研究揭示了镀锌带来的能力增强效应。两种镀锌方式都提高了刚度和抗压截面能力。镀锌引起材料性能的变化,包括屈服和抗拉强度、延展性以及应力-应变曲线的特征。本研究为高强度钢CHS截面设计和利用镀锌带来的有利效应提供了不那么保守但可靠的方法验证基础。


Experimental study on the axial compression behavior of circular steel tube short columns under coastal environmental corrosion

Wanpeng Zhang, Siying Chen, Yao Zhu, ShuPing Liu, Wei Chen, Yu Chen

doi:10.1016/j.tws.2024.111929

海岸环境腐蚀下圆钢管短柱轴压性能试验研究

This study adopts experimental, numerical, and algorithmic methods to investigate the compressive behavior and failure mode of corroded circular steel tube short columns. The study establishes an equivalent relationship between electrochemical accelerated corrosion and natural coastal corrosion environments. The effects of current intensity, sodium chloride concentration, and energizing time on corrosion equivalent duration and mechanical properties of specimens are analyzed. The results demonstrate that the ultimate bearing capacity and energy absorption capacity of the specimens are significantly reduced with increasing current intensity and energized time. However, the NaCl concentration has minimal effect on the mechanical properties of the specimens. After natural corrosion in a coastal area with medium salinity for 19.2 years, the ultimate bearing capacity, ductility, initial stiffness, and energy absorption capacity of circular steel tube short columns decreased by 49.5%, 63.1%, 48.9%, and 85.6%, respectively. A novel corrosion pit generation algorithm is suggested to accurately simulate the distribution of corrosion pits and determine the ultimate bearing capacity of circular steel tube short columns. This algorithm demonstrates improved accuracy and stability compared to traditional simplified methods. Subsequently, a corrosion pit random generation model is developed using this method, and the accuracy of the finite element model is validated against experimental results. Furthermore, the impact of the diameter thickness ratio on the ultimate bearing capacity of corrosion specimens is thoroughly analyzed.

本文采用试验、数值和算法等方法对腐蚀圆钢短柱的压缩性能和破坏模式进行了研究。该研究建立了电化学加速腐蚀与自然海岸腐蚀环境的等效关系。分析了电流强度、氯化钠浓度和通电时间对试样腐蚀等效时间和力学性能的影响。结果表明:随着电流强度和通电时间的增加,试件的极限承载力和能量吸收能力显著降低;而NaCl浓度对试样力学性能的影响较小。在沿海中等盐度地区,经19.2年自然腐蚀后,圆钢管短柱的极限承载力、延性、初始刚度和吸能能力分别下降49.5%、63.1%、48.9%和85.6%。提出了一种新的腐蚀坑生成算法,以准确模拟腐蚀坑的分布,确定圆钢管短柱的极限承载力。与传统的简化方法相比,该算法具有更高的精度和稳定性。利用该方法建立了腐蚀坑随机生成模型,并与实验结果对比验证了有限元模型的准确性。进一步分析了直径厚度比对腐蚀试件极限承载力的影响。


来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemMarcDeform化学电子焊接理论材料多尺度试验螺栓
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首次发布时间:2024-11-14
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【新文速递】2024年4月26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 1 篇,Thin-Walled Structures 1 篇International Journal of Solids and StructuresExperimental studies on the interfacial separation and stiffness of rough elastic-plastic solidsXuan-Ming Liang, Meng-Rui Wang, Chun-Yun Jiang, Si-He Wang, Cheng-Ya Li, Gang-Feng Wangdoi:10.1016/j.ijsolstr.2024.112846粗糙弹塑性固体界面分离与刚度的实验研究7The direct measurement of interfacial separation between rough solids is hitherto one of the most challenging tasks in contact mechanics. This paper develops an optical interferometric technique for in-situ measuring interfacial separation with nanoscale precision. For the contact of metallic samples, the evolutions of interfacial separation and stiffness with load are measured. In the loading process, the dependence of interfacial stiffness on load can be described by a power law with the exponent smaller than unity at low loads and larger than unity at large loads. Similar relations have been found for unloading but interrupted with a linear relation at intermediate loads. These characteristics are significantly different from those known for rough elastic solids, and provide new insights in tribology.迄今为止,直接测量粗糙固体之间的界面分离是接触力学中最具挑战性的任务之一。本文提出了一种纳米级精度的原位测量界面分离的光学干涉技术。对于金属试样的接触,测量了界面分离和刚度随载荷的变化规律。在加载过程中,界面刚度对荷载的依赖关系可以用幂律来描述,在低荷载下指数小于1,在大荷载下指数大于1。在卸载时也发现了类似的关系,但在中间荷载时中断了线性关系。这些特性与已知的粗糙弹性固体有很大不同,为摩擦学提供了新的见解。Journal of the Mechanics and Physics of SolidsModeling the improved hydrogen embrittlement tolerance of twin boundaries in face-centered cubic complex concentrated alloysAnne Marie Z. Tan, Zhi Li, Yakai Zhao, Upadrasta Ramamurty, Huajian Gaodoi:10.1016/j.jmps.2024.105657 面心立方复合浓缩合金孪晶界氢脆容限的模拟With increasing interest in hydrogen as an alternative fuel, there is a need to develop structural alloys with improved resistance to hydrogen embrittlement (HE) for application in the new hydrogen economy. Complex concentrated alloys (CCAs), which include high entropy alloys and their derivatives, medium entropy alloys, are a new class of structural materials, some of which have reported improved HE resistance. While some studies have suggested that the improved HE resistance in CCAs with the face-centered cubic (fcc) crystal structure may be due to the high density of nanotwins within them, a detailed mechanistic understanding is yet to be developed. Towards that end, following the approach of Zhou, Tehranchi and Curtin, we employ a density functional theory-informed Griffith-Rice model to predict the ductile or brittle response of a crack tip interacting with twin boundaries (TBs) in a model fcc CCA, CrCoNi, both in the absence of and presence of hydrogen. Both the model and molecular dynamics simulations predict that TBs in fcc alloys are not inherently more susceptible to HE than the bulk matrix, and could in fact improve HE resistance by retarding cracks while promoting dislocation emission along the TB. Thus, designing fcc CCAs with a high density of nanotwins or utilizing gradient nanotwinned structures could be a way forward for realizing alloys with high HE resistance.随着人们对氢作为替代燃料的兴趣与日俱增,有必要开发抗氢脆(HE)性能更强的结构合金,以应用于新的氢经济领域。包括高熵合金及其衍生物中熵合金在内的复杂浓缩合金(CCAs)是一类新型结构材料,其中一些材料的抗氢脆性已得到改善。虽然一些研究表明,面心立方(ccc)晶体结构的 CCA 具有更好的抗高热冲击性能可能是由于其内部具有高密度的纳米孪晶,但详细的机理仍有待进一步研究。为此,我们沿用 Zhou、Tehranchi 和 Curtin 的方法,采用密度泛函理论为基础的 Griffith-Rice 模型来预测在无氢和有氢的情况下,与 fcc CCA(铬钴镍)模型中的孪晶边界(TBs)相互作用的裂纹尖端的韧性或脆性响应。模型和分子动力学模拟都预测,ffc 合金中的孪晶边界并不比块状基体更容易受到氢氧化物的影响,事实上,孪晶边界可以在延缓裂纹的同时促进位错沿孪晶边界释放,从而提高抗氢氧化物的能力。因此,设计具有高密度纳米孪晶或利用梯度纳米孪晶结构的 fcc CCA 可能是实现高抗冲击性合金的一条出路。Thin-Walled StructuresEfficient mechanical modeling of sandwich panels with functionally graded lattice cores under thermal environmentsZhi-Jian Li, Hong-Liang Dai, Zi-Hao He, Peng Xiaodoi:10.1016/j.tws.2024.111935热环境下功能梯度格芯夹层板的高效力学建模3D-printed sandwich panels with functionally graded (FG) lattice cores have garnered widespread attention owing to their outstanding mechanical performance. However, the straightforward interplay between the service environment, strut structure, and their mechanical behavior has not been systematically explored. In this study, an analytical two-step prediction modeling is developed to efficiently obtain the mechanical response of 3D printed sandwich panels with FG lattice cores. Initially, the effective elastic moduli of FG lattice cores are identified based on finite element (FE) analysis. The stress and deformation of the core-homogenized sandwiches in thermal environments are predicted using the higher-order shear deformation theory. Subsequently, the de-homogenization is employed to calculate strut stresses. The prediction shows excellent agreement with the FE results in the literature. Furthermore, parametric analysis is performed to uncover the impact of crucial variables on the strut stresses within the FG lattice cores. The results show that the strut stress decreases with the increased transverse layer number and power index, while increasing with the higher ambient temperature, length-to-thickness ratio, and thermal expansion of the sandwich panels. The proposed model can serve as an efficient tool for the design and printing of high-performance lattice-core sandwich panels.具有功能梯度(FG)晶格芯的3d打印夹层板因其优异的力学性能而受到广泛关注。然而,使用环境、支撑结构及其力学行为之间的直接相互作用尚未得到系统的探讨。为了有效地获取3D打印FG格芯夹层板的力学响应,本文建立了一种解析式两步预测模型。首先,基于有限元分析,确定了FG格芯的有效弹性模量。利用高阶剪切变形理论对岩心-均质夹层在热环境下的应力和变形进行了预测。随后,采用去均质化方法计算支撑应力。预测结果与文献中的有限元结果非常吻合。此外,还进行了参数分析,以揭示关键变量对FG格芯内支撑应力的影响。结果表明:随着夹层板横向层数和功率指数的增加,支撑应力减小,而随着环境温度、长厚比和热膨胀系数的增加而增大;该模型可作为高性能格芯夹芯板设计和打印的有效工具。来源:复合材料力学仿真Composites FEM

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