【新文速递】2024年3月26日复合材料SCI期刊最新文章_ACT_Mechanical_Maxwell_System_HPC_Inspire_振动_复合材料_碰撞_建筑_声学_理论_化机_爆炸_材料

【新文速递】2024年3月10日固体力学SCI期刊最新文章

今日更新：International Journal of Solids and Structures 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 2 篇International Journal of Solids and StructuresMechanics of inner core debonding of composite sandwich beam with CFRP hexagonal honeycombPengcheng Xue, Xingyu Wei, Zhibin Li, Yan Wang, Mikhailo F. Selivanov, Jian Xiongdoi:10.1016/j.ijsolstr.2024.112760 带有 CFRP 六边形蜂窝的复合材料夹层梁内芯脱落的力学原理The inner core debonding of composite sandwich beams with carbon fiber reinforced polymer (CFRP) hexagonal honeycomb core is investigated theoretically and experimentally. Based on the principle of minimum potential energy, a theoretical model is established to reveal the core debonding mechanism with Timoshenko’s beam theory and Extended High-Order Sandwich Panel Theory (EHSAPT) for composite face sheets and CFRP hexagonal honeycomb core, respectively. The theoretical approach of core debonding simulation is based on the framework of the cohesive zone model (CZM). By constructing the constitutive relation of the core interface as the discontinuous stress and displacement boundary conditions, the vertical core debonding can be simulated overcoming the singularity of equilibrium equations. The crack propagation process is decomposed into three stages with the consideration of the double crack propagation mechanism. In experiments, the regular and reinforced hexagonal honeycomb sandwich beams are designed and fabricated, and the quantification of the defect degree of the core bonding interface is achieved by equivalent energy release rate obtained from the homogenized hexagonal honeycomb. The double cantilever beam (DCB) experiments are performed to determine the equivalent energy release rate and reveal the core debonding mechanism of CFRP hexagonal honeycomb sandwich beams. Comparing the load–displacement curves and debonding deformation patterns indicates that the established theoretical model can effectively predict the core debonding mechanical response. Finally, parametric analysis is carried out to discuss the impact of structural dimension parameters, defect location and defect degree on the debonding modes of CFRP hexagonal honeycomb sandwich beams.本文从理论和实验两方面研究了碳纤维增强聚合物（CFRP）六边形蜂窝芯复合材料夹层梁的内芯脱落问题。根据最小势能原理，分别针对复合材料面片和碳纤维增强聚合物六边形蜂窝夹芯，利用季莫申科梁理论和扩展高阶夹芯板理论（EHSAPT）建立了理论模型，揭示了夹芯脱粘机理。芯材脱粘模拟的理论方法基于内聚区模型（CZM）框架。通过构建作为不连续应力和位移边界条件的芯材界面构成关系，克服了平衡方程的奇异性，从而模拟了垂直芯材脱粘。考虑到双重裂纹扩展机制，将裂纹扩展过程分解为三个阶段。在实验中，设计并制造了规则六边形和增强六边形蜂窝夹层梁，并通过从均质化六边形蜂窝中获得的等效能量释放率量化了芯材结合界面的缺陷程度。通过双悬臂梁（DCB）实验确定了等效能量释放率，并揭示了 CFRP 六边形蜂窝夹层梁的夹芯脱粘机理。比较荷载-位移曲线和脱粘变形模式表明，所建立的理论模型能有效预测夹芯脱粘的力学响应。最后，通过参数分析讨论了结构尺寸参数、缺陷位置和缺陷程度对 CFRP 六角蜂窝夹层梁脱胶模式的影响。International Journal of PlasticityCross-slip of extended dislocations and secondary deformation twinning in a high-Mn TWIP steelShucheng Shen, Pan Xie, Cuilan Wu, Jing Luo, haifeng Ye, Jianghua Chendoi:10.1016/j.ijplas.2024.103922高锰 TWIP 钢中扩展位错的交叉滑移和二次变形孪晶Twinning-induced plasticity (TWIP) steels have become important materials in industry owing to the good combination of strength and ductility and high strain hardening rate. The excellent mechanical properties are highly related to the glide of dislocation and deformation twinning. However, the cross-slip behavior of the extended dislocation and the mechanism of deformation twinning are still controversial. Here, the partial dislocation motion and austenite twinning of a high-Mn steel at the early stage of deformation were investigated using in-situ tensile transmission electron microscope (TEM) technique. Results show that a large number of plane glide and cross-slip of extended dislocations can occur at the early stage of deformation. Extended dislocation nodes can be formed as a result of the reaction between adjacent extended dislocations on the same glide plane. In-situ tensile TEM experiments confirm two cross-slip models of partial dislocation: (1) the Friedel-Escaig model, cross-slip based on constriction of extend dislocation and re-dissociation; (2) the Fleischer model, cross-slip involving Lomer-Cottrell dislocation. Based on experimental results and energy calculations, it can be confirmed that the formation mechanism of austenite primary deformation twin induced by partial dislocations is different from that of secondary deformation twin. Grain boundary emits partial dislocation into the grain to form stable stacking fault which induces austenite primary deformation twin. The formation of secondary deformation twin is related to cross-slip of extended dislocation. Only the cross-slip of an extended dislocation containing a 90° partial dislocation can induce the formation of secondary deformation twin by introducing the Frank partial dislocation.孪晶诱导塑性钢（TWIP）具有良好的强度和延展性组合以及高应变硬化率，已成为工业领域的重要材料。优异的机械性能与位错滑移和变形孪晶密切相关。然而，扩展位错的交叉滑移行为和变形孪晶的机理仍存在争议。本文利用原位拉伸透射电子显微镜（TEM）技术，研究了高锰钢在变形早期的部分位错运动和奥氏体孪晶。结果表明，在变形早期，扩展位错会发生大量的平面滑移和交叉滑移。在同一滑行面上的相邻扩展位错之间的反应会形成扩展位错节点。原位拉伸 TEM 实验证实了部分位错的两种交叉滑移模型：(1) Friedel-Escaig 模型，即基于扩展位错收缩和再解离的交叉滑移；(2) Fleischer 模型，即涉及 Lomer-Cottrell 位错的交叉滑移。根据实验结果和能量计算，可以确定部分位错诱发的奥氏体一次变形孪晶的形成机制与二次变形孪晶的形成机制不同。晶界将部分位错释放到晶粒中，形成稳定的堆积断层，从而诱发奥氏体一次变形孪晶。二次变形孪晶的形成与扩展位错的交叉滑移有关。只有含有 90° 局部位错的扩展位错的交叉滑动才能通过引入弗兰克局部位错而诱发二次变形孪晶的形成。Thin-Walled StructuresA novel combined rivet and its effect on mechanical properties and failure behavior in double-sided self-pierce rivetingPengyi WANG, Peng ZUO, Jiageng JIN, Rafael M. Afonso, Nan XIANG, Xiaokai ZHAO, Xueni ZHAOdoi:10.1016/j.tws.2024.111788 新型组合铆钉及其对双面自冲铆接机械性能和失效行为的影响Double-sided self-pierce riveting (DSSPR) has great application potential in joining the same or dissimilar sheets due to its simplified die structure, high joining efficiency, and smooth joint surface. Previous studies have shown that changing rivet parameters, such as chamfered angle position, can improve joining strength, but the improvement effect is still relatively limited. In this paper, to significantly enhance the joining strength, a novel combined rivet structure was proposed and used in the DSSPR process of Al5052 sheets, and its effect on strength improvement and the underlying mechanism were investigated. Morphological change, strain, and stress distribution of the combined rivets during the joining process were investigated through experiments and numerical simulations. Tensile shear tests were conducted to compare the shear strength of the combined rivets and conventional rivets. Moreover, the failure behaviors of joints including macroscopic failure mode and microscopic surface morphology were analyzed, and the mechanism for combined rivets to enhance the joining strength was illustrated. Results showed that adopting the new combined rivets can significantly improve joint strength. Compared with a single conventional tubular rivet, the tensile shear strength and energy absorption of combined rivets can increase by up to 91% and 261%, respectively. Two types of failure modes were discovered according to the failure behaviors of sheets, which were characterized by the detachment of rivets and the tearing characteristics of the sheet. This paper provides a new approach for the rivet design and joining strength improvement strategy for the DSSPR process.双面自冲铆接（DSSPR）因其简化的模具结构、较高的接合效率和光滑的接合面，在接合同种或异种板材方面具有很大的应用潜力。以往的研究表明，改变铆钉参数（如倒角位置）可以提高接合强度，但改善效果仍相对有限。本文提出了一种新型组合铆钉结构，并将其应用于 Al5052 板材的 DSSPR 工艺中，以显著提高接合强度，并研究了其对强度改善的影响及其内在机理。通过实验和数值模拟研究了组合铆钉在连接过程中的形态变化、应变和应力分布。通过拉伸剪切试验，比较了组合铆钉和传统铆钉的剪切强度。此外，还分析了接合处的失效行为，包括宏观失效模式和微观表面形态，并说明了组合铆钉提高接合强度的机理。结果表明，采用新型组合铆钉可显著提高连接强度。与单一的传统管状铆钉相比，组合铆钉的拉伸剪切强度和能量吸收率可分别提高 91% 和 261%。根据板材的失效行为，发现了两种失效模式，分别以铆钉脱落和板材撕裂为特征。本文为 DSSPR 工艺的铆钉设计和连接强度改进策略提供了一种新方法。Vortex-induced vibration of a functionally graded metamaterial plate attached to a cylinder in laminar flowBill Murari, Shaoyu Zhao, Yihe Zhang, Jie Yangdoi:10.1016/j.tws.2024.111790层流中连接到圆柱体上的功能分级超材料板的涡激振动Understanding the interaction between fluid and structures under various fluid conditions is critical for engineering applications, with vortex-induced vibration (VIV) being a significant area of research. This study presents a comprehensive numerical investigation on the VIV behaviors of functionally graded (FG) graphene origami (GOri)-enabled auxetic metamaterial (GOEAM) splitter plates attached to a circular cylinder by employing the finite element analysis. The splitter plate is composed of multiple GOEAM layers with the material properties possessing a gradient variation along the thickness direction. The local mesh quality is monitored and improved by Yeoh smoothing. The present work is focused on the effect of the auxetic properties of GOEAM on plate vibrations, the influence of plate length on wake patterns, and the effect of fluid loads on the cylinder–plate body and vortex pattern. The study reveals that: (1) the plate structure with HGRX-WGRX metamaterial distribution pattern with high elastic moduli in surface layers exhibits low deflection amplitudes, (2) shorter plates intensify vortices while longer plates reduce vortex prevalence, (3) the natural frequencies of both FG-GOEAM and pure metallic plates are found to be well above the vortex shedding frequency and as such, the fluid loads have a negligible effect on the cylinder–plate body and vortex patterns. These insights offer an in-depth understanding of fluid-structure interactions and valuable knowledge for the design and optimisation of graphene based metamaterial structures in engineering applications.了解各种流体条件下流体与结构之间的相互作用对于工程应用至关重要，而涡流诱导振动（VIV）则是一个重要的研究领域。本研究采用有限元分析方法，对连接到圆柱体上的功能分级（FG）石墨烯折纸（GOri）辅助超材料（GOEAM）分流板的 VIV 行为进行了全面的数值研究。分流板由多个 GOEAM 层组成，其材料特性沿厚度方向呈梯度变化。通过杨氏平滑法对局部网格质量进行了监测和改进。本研究的重点是 GOEAM 的辅助特性对板振动的影响、板长度对尾流模式的影响，以及流体载荷对圆筒-板体和涡流模式的影响。研究结果表明(1) 表层具有高弹性模量的 HGRX-WGRX 超材料分布模式的板结构表现出较低的挠度振幅；(2) 较短的板会加剧涡流，而较长的板则会降低涡流的普遍性；(3) FG-GOEAM 和纯金属板的固有频率都远高于涡流脱落频率，因此流体载荷对圆柱板本体和涡流模式的影响可以忽略不计。这些见解提供了对流体与结构相互作用的深入理解，以及在工程应用中设计和优化基于石墨烯的超材料结构的宝贵知识。来源：复合材料力学仿真Composites FEM

【新文速递】2024年3月26日复合材料SCI期刊最新文章

Composite Structures

【新文速递】2024年3月10日固体力学SCI期刊最新文章