今日更新:International Journal of Solids and Structures 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 6 篇International Journal of Solids and StructuresThe lateral confinement effect on the interfacial crack in hybrid composites under uniaxial compressionCheryala Sneha B., Yerramalli Chandra S.doi:10.1016/j.ijsolstr.2023.112589单轴压缩下混合复合材料界面裂纹的横向约束效应The effect of hybridization on the interface crack growth along the fiber is predicted from numerical and analytical modelling approaches. A three-phase hybrid composite representative volume element (RVE) with an adjustable hybrid ratio and an initial interfacial crack is modelled. The fracture parameters and composite strength are computed from finite element analysis using VCCT approach in Ansys Workbench. A fracture energy-based mathematical model with a steady state crack growth is implemented to compute the hybrid composite splitting failure strength. The results show an enhancement in the compressive splitting strength with hybridization due to lateral confinement effect on the interfacial crack.通过数值和分析建模方法预测了杂化对界面裂纹沿纤维生长的影响。对具有可调混合比和初始界面裂纹的三相混合复合材料代表体积元素(RVE)进行了建模。通过在 Ansys Workbench 中使用 VCCT 方法进行有限元分析,计算了断裂参数和复合材料强度。在计算混合复合材料的分裂破坏强度时,采用了基于断裂能量的数学模型,该模型具有稳定的裂纹生长状态。结果表明,由于界面裂纹的横向约束效应,混合后的压缩劈裂强度有所提高。International Journal of PlasticityAn extended M-K model under surface traction with adjustable gradient distributionMa Li, Zheng Lihuang, Wang Zhongjindoi:10.1016/j.ijplas.2023.103817可调节梯度分布的地表牵引力下的扩展 M-K 模型The forming limit of sheets usually corresponds to the strain accumulation before localized necking and is closely related to the loading state. In the viscous pressure forming (VPF) method, the surface traction generated by the force-transmitting medium with high-viscosity fluid-flow characteristics on the sheet exhibits the obvious gradient distribution near the necking region. However, existing necking instability theories have not factored in the surface traction gradient distribution (STGD) and can't accurately explain the inherent mechanism of the VPF method with this loading state to improve the forming limit. To deal with the issue, STGD-related ‘stress balance’ equations are established and an extended M-K model with STGD response under 3D stress state (STGD-3D-MK model) is proposed, based on the analysis of the adjustable STGD generated in the VPF method during the necking development. The proposed model is used to explore the influence and mechanism of the STGD on the forming limit, as well as to provide suggestions on how to achieve the full positive effect of tangential surface traction. This research demonstrates that the forming limit is sensitive to the STGD, which affects the ability of surface traction to improve the forming limit. The STGD changes the stress path of the groove, affecting the development of necking. In addition, the critical STGD that can increase the limit strain is also provided and its magnitude is related to the strain path. Finally, the VPF-based experimental results are provided to support the effectiveness of the analysis of the STGD-3D-MK model. This work provides a new perspective on the loading method to improve the forming limit.板材的成形极限通常对应于局部缩颈前的应变累积,与加载状态密切相关。在粘性压力成形(VPF)方法中,具有高粘度流体流动特性的传力介质在薄片上产生的表面牵引力在颈缩区域附近呈现明显的梯度分布。然而,现有的缩颈不稳定性理论并未将表面牵引梯度分布(STGD)考虑在内,无法准确解释 VPF 法在这种加载状态下提高成形极限的内在机理。为了解决这个问题,我们建立了与 STGD 相关的 "应力平衡 "方程,并根据对 VPF 方法在颈部发展过程中产生的可调节 STGD 的分析,提出了一个在三维应力状态下具有 STGD 响应的扩展 M-K 模型(STGD-3D-MK 模型)。该模型用于探讨 STGD 对成形极限的影响和机理,并就如何充分发挥切向表面牵引的积极作用提出建议。研究表明,成形极限对 STGD 非常敏感,STGD 会影响表面牵引改善成形极限的能力。STGD 会改变沟槽的应力路径,影响颈缩的发展。此外,还提供了能增加极限应变的临界 STGD,其大小与应变路径有关。最后,提供了基于 VPF 的实验结果,以支持 STGD-3D-MK 模型分析的有效性。这项工作为改善成形极限的加载方法提供了一个新的视角。Thin-Walled StructuresMechanically induced electric potential and charge redistribution in laminated composite piezoelectric semiconductor circular cylindrical thin shellsCao Yong, Guo Ziwen, Qu Yilindoi:10.1016/j.tws.2023.111372层压复合压电半导体圆柱薄壳中的机械感应电动势和电荷再分布We study electromechanical effects and piezotronic behaviors in a Kirchhoff-Love laminated composite piezoelectric semiconductor circular cylindrical thin shell, which is composed of a non-piezoelectric semiconductor core and two piezoelectric dielectric layers. A second-order assumption for electric potentials and carrier concentration perturbations is utilized to capture accurate descriptions of the electric field and charge distributions within the composite shell, where the zeroth-order, first-order, and second-order forms represent constant, antisymmetric, and symmetric distributions along the thickness, respectively. The field equations and boundary conditions are simultaneously derived through a principle of virtual work and the fundamental lemma of the calculus of variation. The new governing equations derived show a new coupling relation between mechanical deformation and charge behavior in the composite shell, where all mechanical deformations (extension, bending of the shell) and all distribution forms of electric potential (zeroth-, first-, second-order electric potentials) are coupled, which is different from piezoelectric semiconductor beams and plates. Then, the numerical results of electromechanical effects and piezotronic behaviors in static bending and forced vibration problems of the shell are conducted with the derived theoretical model. Numerical studies of static bending graphically show some fundamental coupling relations between mechanical forces and charge distributions in deformed piezoelectric semiconductor shells. The new results from the forced vibration analysis given by the current model show that the deflection amplitude and the electric potential distribution in the thin shell are frequency-dependent and can be adjusted by controlling the excitation frequency. In addition, the semiconducting properties (dependence of mechanical behavior on doping level) are studied in both static and dynamic problems. The mechanically controlled charge distribution suggests that shell-shaped piezoelectric semiconductor shells could serve as an effective means of sensing or energy harvesting by converting mechanical energy into electricity.我们研究了基尔霍夫-洛夫层压复合压电半导体圆柱薄壳中的机电效应和压电行为,该薄壳由一个非压电半导体芯和两个压电介质层组成。利用电势和载流子浓度扰动的二阶假设来捕捉复合外壳内电场和电荷分布的精确描述,其中零阶、一阶和二阶形式分别代表沿厚度方向的恒定、非对称和对称分布。场方程和边界条件是通过虚功原理和变分微积分基本定理同时导出的。推导出的新控制方程显示了复合材料壳体中机械变形和电荷行为之间的新耦合关系,即所有机械变形(壳体的延伸、弯曲)和所有电动势分布形式(零阶、一阶、二阶电动势)都是耦合的,这与压电半导体梁和板不同。然后,利用推导出的理论模型对壳体静态弯曲和受迫振动问题中的机电效应和压电行为进行了数值计算。静态弯曲的数值研究以图形方式显示了变形压电半导体壳体中机械力和电荷分布之间的一些基本耦合关系。当前模型给出的受迫振动分析的新结果表明,薄壳中的偏转振幅和电动势分布与频率有关,可通过控制激励频率进行调整。此外,还研究了静态和动态问题中的半导体特性(机械行为与掺杂水平的关系)。受机械控制的电荷分布表明,壳形压电半导体外壳可以通过将机械能转化为电能,成为传感或能量收集的有效手段。Experimental and numerical research on the analysis methods for buckling and post-buckling of inclined stiffened panel under shear loadLian Chenchen, Wang Peiyan, Chen Xin, Liu Fuchao, Yuan Kangbo, Zheng Jie, Yue Zhufengdoi:10.1016/j.tws.2023.111374剪切荷载下倾斜加劲板屈曲和后屈曲分析方法的实验和数值研究The purpose of this paper is to investigate the buckling and post-buckling behavior of inclined stiffened composite panels under shear load. Two types of stiffened composite panels were manufactured and tested. The buckling load, ultimate load and other required structural properties of the inclined stiffened composite panels were obtained. The test results show that the failure load of the two types of panels are 5.79 times and 11.2 times of the buckling load, respectively, indicating that such inclined stiffened panels have a large post-buckling capacity. The damage modes of the panel are tearing around the skin near the clamps and debonding of the stringers from the skin. The combination of Hashin failure criterion, Cohesive model and nonlinear connection of clamp was used to conduct finite element modeling, which effectively predicts the buckling, post-buckling and damage modes of the structure. The buckling and post-buckling behavior of stiffened panels with different stinger configurations were discussed based on finite element analysis. The results show that when the initial buckling occurs between the stringers, the buckling and failure load of the stiffened panel become larger as the equivalent skin thickness between the stringers become larger. The research in this paper can provide reference for aircraft structural design.本文旨在研究倾斜加劲复合板在剪切载荷作用下的屈曲和屈曲后行为。我们制造并测试了两种加劲复合板。获得了倾斜加劲复合板的屈曲载荷、极限载荷和其他所需的结构特性。试验结果表明,两种板材的破坏荷载分别是屈曲荷载的 5.79 倍和 11.2 倍,这表明这种倾斜加劲板材具有较大的屈曲后承载能力。面板的破坏模式为夹具附近表皮的撕裂和 弦杆与表皮的脱粘。采用哈申失效准则、内聚模型和夹具非线性连接相结合的方法进行有限元建模,可有效预测结构的屈曲、后屈曲和损坏模式。基于有限元分析,讨论了不同激振杆配置的加劲板的屈曲和后屈曲行为。结果表明,当初始屈曲发生在弦杆之间时,随着弦杆之间等效表皮厚度的增大,加劲板的屈曲和破坏载荷也随之增大。本文的研究可为飞机结构设计提供参考。Life-cycle Assessment and Prediction on Ultimate Capacity of Corroded Q690 Steel Columns with H-section under Bi-directional Cyclic LoadingZhang Qiang, Wen Jianian, Han Qiang, Zhuge Hanqing, Zhou Yulongdoi:10.1016/j.tws.2023.111391双向循环荷载下腐蚀的 H 型截面 Q690 钢柱的生命周期评估和极限承载力预测The structures or structural members made of high-strength steel may have time-varying mechanical properties in whole life-cycle due to the ageing effects. In particular, the corroded steel structures in high-seismicity regions could have unexpected failure modes when subjected multi-directional excitations. Therefore, in this study, the mechanical properties of Q690 steel H-section columns during the life-cycle under bi-directional cyclic loads are investigated. Firstly, a refined finite element (FE) model is built, which takes the time-varying of corrosion characteristics into consideration. Then, the degradations of mechanical property and failure mechanisms of steel columns with different design parameters at whole life-cycle are analyzed by the FE models. Finally, a quantitative calculation method of ultimate resistance and damage index of steel columns considering ageing effects is proposed. The findings demonstrate that several factors affect the ultimate strength of steel columns during the life-cycle stage, with the axial compression ratio and flange width-thickness ratio having the greatest impacts on the ultimate capacity. The ageing effect decreases the plastic flow capacity of steel columns, increases the stress concentration, and induces the failure mode transition from plastic flow to buckling failure. The ageing effect may be accurately estimated by the suggested calculation method for the ultimate capacity and damage index of steel columns at the life-cycle stage. The findings of this study highlight the significance of taking into account the ageing effects of steel columns in the seismic design.由于老化效应,由高强度钢材制成的结构或结构部件在整个生命周期内可能具有随时间变化的机械性能。特别是在高震地区的锈蚀钢结构,在受到多向激励时可能会出现意想不到的破坏模式。因此,本研究对 Q690 钢 H 型截面柱在双向循环荷载作用下全生命周期的力学性能进行了研究。首先,建立了一个考虑了腐蚀特性时变的精细有限元(FE)模型。然后,通过有限元模型分析了不同设计参数的钢柱在全寿命周期内的力学性能退化和破坏机理。最后,提出了考虑老化效应的钢柱极限抗力和损伤指数的定量计算方法。研究结果表明,钢柱在全寿命周期阶段的极限强度受多种因素影响,其中轴向压缩比和翼缘板宽厚比对极限承载力的影响最大。老化效应降低了钢柱的塑性流动能力,增加了应力集中,并导致失效模式从塑性流动过渡到屈曲失效。老化效应可通过建议的计算方法准确估算钢柱在生命周期阶段的极限承载力和损伤指数。本研究的结果凸显了在抗震设计中考虑钢柱老化效应的重要意义。Experimental and numerical investigation into hysteretic performance of orthogonal double corrugated steel plate shear wallZhu Bo-Li, Bai Wen-Hua, Wen Chen-Bao, Zuo Jia-Qi, Sun Hao-Jun, Wang Xiong, Guo Yan-Lindoi:10.1016/j.tws.2023.111392正交双波纹钢板剪力墙滞回性能的实验和数值研究The orthogonal double corrugated steel plate shear wall (ODC-SPSW) is comprised of two identical corrugated plates that are arranged orthogonally and interconnected through high-strength bolts located at the valleys of the corrugations. Due to the strong axis of one corrugated plate coinciding with the weak axis of the other corrugated plate, the flexural rigidity of each plate can be significantly enhanced in its weak axis, thereby improving its shear resistance. The ODC-SPSW has itself boundary elements in two side and connected only with frame beams at its top and bottom, leading to conveniently moving within the frame. This paper presents experimental and numerical analyses of the shear resistance and the hysteretic performance of ODC-SPSW. Two experimental specimens subjected to cyclic loading were tested, and accordingly finite element (FE) simulations were conducted, both reaching an excellent agreement. Firstly, the test results of two ODC-SPSW specimens under cyclic loading are reported and analyzed. Second, FE models are established to simulate the hysteretic energy-dissipation performance of the test specimens. The numerical results from FE Model agree well with the test results, thus validating the FE models. Moreover, a parametric study was conducted using the validated FE model through changing various geometrical parameters, such as aspect ratio, bolt number and arrangement, corrugation depth, corrugated steel plate thickness, boundary element dimensions of the ODC-SPSWs. It is found that these parameters affect significantly the ultimate shear resistance and hysteretic energy-dissipation capacity of the ODC-SPSW. The numerical result obtained indicated the dimensions of the boundary elements have little effect on the shear resistance and hysteresis performance of the ODC-SPSWs. Finally, some design recommendations are concluded which can provide valuable references for the practical design of ODC-SPSWs.正交双波纹钢板剪力墙(ODC-SPSW)由两块相同的波纹板组成,两块波纹板正交排列,并通过位于波纹谷处的高强度螺栓相互连接。由于一块波纹板的强轴线与另一块波纹板的弱轴线重合,因此每块波纹板的挠曲刚度都能在其弱轴线上得到显著增强,从而提高其抗剪性能。ODC-SPSW 两侧均有边界元素,仅在其顶部和底部与框架梁连接,因此可方便地在框架内移动。本文对 ODC-SPSW 的抗剪性能和滞后性能进行了实验和数值分析。对两个承受循环荷载的实验试样进行了测试,并相应地进行了有限元(FE)模拟,结果均非常吻合。首先,报告并分析了两个 ODC-SPSW 试样在循环加载下的测试结果。其次,建立了 FE 模型来模拟试样的滞后能量耗散性能。FE 模型的数值结果与试验结果吻合良好,从而验证了 FE 模型。此外,通过改变 ODC-SPSW 的各种几何参数,如长宽比、螺栓数量和排列、波纹深度、波纹钢板厚度、边界元素尺寸等,利用验证后的 FE 模型进行了参数研究。结果发现,这些参数对 ODC-SPSW 的极限抗剪能力和滞后耗能能力有很大影响。数值结果表明,边界元素的尺寸对 ODC-SPSW 的抗剪性能和滞后性能影响不大。最后,总结出了一些设计建议,可为 ODC-SPSW 的实际设计提供有价值的参考。Experimental study on Q355 steel T-stubs connected through high-strength ring groove rivetsGao Fei, Wang Zongyi, Zhu Rui, Chen Zhenming, Ye Quanxi, Duan Yaqi, Jia Yunlong, Zhang Qindoi:10.1016/j.tws.2023.111399通过高强度环槽铆钉连接 Q355 钢 T 型管的实验研究High-strength ring groove rivet connections have several advantages over bolt connections, including anti-loosening performance and high fatigue resistance. This research aims to investigate the mechanical properties of high-strength ring groove rivet assemblies and load resistances of riveted T-stubs. Experimental tests on high-strength ring groove rivet assemblies were firstly carried out, including coupon tests, preload measurements, and load-bearing tests. Q355 steel T-stubs connected through ring groove rivets were subsequently tested. The effects of certain geometrical parameters and material grades of the rivets on the performance of the T-stubs were analyzed. The applicability of the Eurocode 3 and Demonceau methods to the T-stubs was discussed. The results show that the Grade 10.9 rivet possesses higher yield strength and strain, and lower ultimate strain, in comparison to the Grade 8.8 rivet. Increasing the diameter of the rivet is beneficial for the T-stubs, whereas increasing the flange thickness is not always advantageous. The Eurocode 3 method is unsuitable for the T-stubs connected through ring groove rivets, whereas the Demonceau method is conservative. The findings of this research provide guidance for engineering designs of high-strength ring groove rivet assemblies and steel T-stubs connected through ring groove rivets.与螺栓连接相比,高强度环槽铆钉连接具有防松性能和高抗疲劳性等优点。本研究旨在探讨高强度环槽铆钉组件的力学性能和铆接 T 形管的抗负载能力。首先对高强度环槽铆钉组件进行了实验测试,包括试样测试、预紧力测量和承载测试。随后对通过环槽铆钉连接的 Q355 钢 T 形管进行了测试。分析了铆钉的某些几何参数和材料等级对 T 型管性能的影响。讨论了欧洲规范 3 和 Demonceau 方法对 T 型管的适用性。结果表明,与 8.8 级铆钉相比,10.9 级铆钉具有更高的屈服强度和应变,而极限应变较低。增加铆钉直径对 T 型管有利,而增加凸缘厚度则不一定有利。欧洲规范 3 方法不适合通过环槽铆钉连接的 T 型管,而 Demonceau 方法则比较保守。研究结果为高强度环槽铆钉组件和通过环槽铆钉连接的钢 T 型管的工程设计提供了指导。Web crippling behaviour of cold-formed steel channels with elongated un-stiffened and edge-stiffened web holes under end-two-flange loading conditionWang Wei, Roy Krishanu, Fang Zhiyuan, Beulah Gnana Ananthi G, Lim James B.P.doi:10.1016/j.tws.2023.111398在两端法兰加载条件下,带有拉长的未加固和边缘加固腹板孔的冷弯型钢槽钢的腹板瘸腿行为Over the last decade, cold-formed steel (CFS) channels with circular edge-stiffened web holes have been widely used in New Zealand. In the case of web crippling, previous studies have revealed that the use of an edge-stiffened hole almost results in the same strength as an equivalent channel-section having a plain web. Such circular edge-stiffened web holes could be extended to elongated holes. In terms of web crippling, however, no experimental or numerical works on such elongated holes were reported in the literature. In this paper, a numerical investigation was carried out to investigate the web crippling behaviour of CFS channels with elongated un-stiffened and edge-stiffened web holes under the end-two-flange (ETF) loading condition. The finite element (FE) models were validated against the test results of CFS channels with circular edge-stiffened web holes; good agreement in terms of the load-displacement relationships and failure modes was shown. A parametric study was then conducted, comprising 1,536 FE models. Compared to CFS channels with a plain web, for the case of channels with an elongated un-stiffened web hole, the average web crippling strength reduction for sections with an aspect ratio of two and three was 21% and 36%, respectively. However, for an elongated edge-stiffened hole, the reduction in the web crippling strength was only 5% and 8%, respectively. Finally, design equations in the form of the web crippling reduction factor (Rp) and the equations based on the direct strength method (DSM) for CFS channels with elongated web holes under ETF loading conditions were recommended.在过去十年中,新西兰广泛使用了带有圆形边缘加固腹板孔的冷弯型钢(CFS)槽钢。以前的研究表明,在腹板脆化的情况下,使用边缘加固孔几乎可以获得与具有普通腹板的等效槽钢截面相同的强度。这种圆形边缘加固腹板孔可以扩展到细长孔。然而,在腹板跛行方面,文献中没有关于此类细长孔的实验或数值研究报告。本文进行了数值研究,以探讨在端部-两法兰(ETF)加载条件下,带有未加固和边缘加固细长腹板孔的 CFS 槽钢的腹板脆化行为。有限元(FE)模型与带有圆形边缘加固腹板孔的 CFS 槽钢的测试结果进行了验证,结果表明两者在载荷-位移关系和破坏模式方面具有良好的一致性。随后进行了参数研究,包括 1,536 个 FE 模型。与带有普通腹板的 CFS 槽道相比,对于带有拉长的未加固腹板孔的槽道,纵横比为 2 和 3 的截面的平均腹板破坏强度分别降低了 21% 和 36%。然而,对于边缘加固的细长孔,腹板挠曲强度的降低幅度分别仅为 5%和 8%。最后,腹板跛行降低系数(Rp)形式的设计方程和基于直接强度法(DSM)的方程,适用于 ETF 荷载条件下带有细长腹板孔的 CFS 渠道。来源:复合材料力学仿真Composites FEM