【新文速递】2024年3月9日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 2 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 2 篇

International Journal of Solids and Structures

A thin-walled cavity structure with double-layer tapered scatterer locally resonant metamaterial plates for extreme low-frequency attenuation

Mohammad Ravanbod, Salman Ebrahimi-Nejad, Morteza Mollajafari

doi:10.1016/j.ijsolstr.2024.112742

带双层锥形散射体局部谐振超材料板的薄壁空腔结构，用于极低频衰减

Locally resonant acoustic metamaterials (LRAMs) are effective spatial frequency filters due to their local resonance system. However, they own narrow stopbands, charge additional weight on the primary system, and operate only at the adjusted frequency range. In this paper, a novel dual-target LRAM is proposed based on coupling the cavity and convex mechanisms, utilizing the benefits of both sound-barrier and sound-absorbing types of acoustic metamaterials. A combination of the cavity and convex structures is presented and investigated for the first time, which exploits both the reflection and absorption theories simultaneously to improve the sound attenuation performance of acoustic metamaterials. By arranging two-layer finite periodic of 5×5 proposed convex unit cells along x and y directions and separating them by an air cavity, a supercell named hybrid locally resonant acoustic metamaterials (HLRAM) baffle is designed. The band structures, transmission spectrum, and displacement vector fields are calculated employing the finite element method (FEM). In addition, vibration modes at the edges of stopbands are computed and carefully analyzed to determine the formation mechanism, mechanics/dynamic response, and dispersion features of stopbands. Meanwhile, sensitivity analyses have been conducted on the model to investigate the influence of material and geometry parameters on dispersion characteristics. Equivalent spring-mass analytic models are used to direct the modifications of structure and the adjustment of structural and material parameters in order to achieve a wide stopband with a low opening frequency. Thereby, the effective stiffness and mass values influencing the starting and cutoff frequencies are adjusted in a desirable manner. The results show that the structure can generate a wide stopband that covers the frequency range of 64.9-805.6Hz, allowing the structure to block incoming acoustic waves with 35.42 dB root mean square of noise attenuation (RMSNA) the given frequency range (0-1kHz). This study indicates that the HLRAM has a preponderance among conventional techniques as we can manipulate dispersion characteristics and the sound transmission loss (STL) based on the desired sound reduction level and shift stopbands to the intended frequency range. This can be achieved by altering cavity size, material, or geometry parameters.

局部谐振声超材料（LRAM）因其局部谐振系统而成为有效的空间频率滤波器。然而，它们的阻带较窄，会增加主系统的重量，而且只能在调整频率范围内工作。本文提出了一种基于空腔和凸机制耦合的新型双目标 LRAM，利用了声学超材料的声屏障和声吸收类型的优点。本文首次提出并研究了空腔和凸结构的组合，它同时利用了反射和吸收理论来改善声学超材料的声音衰减性能。通过沿 x 和 y 方向排列两层 5×5 拟凸单元的有限周期，并用一个空腔将它们隔开，设计出了一种名为混合局部共振声超材料（HLRAM）障板的超级单元。利用有限元法（FEM）计算了频带结构、传输谱和位移矢量场。此外，还计算并仔细分析了止带边缘的振动模式，以确定止带的形成机理、力学/动态响应和频散特征。同时，还对模型进行了敏感性分析，以研究材料和几何参数对分散特性的影响。利用等效弹簧-质量分析模型来指导结构的修改以及结构和材料参数的调整，以实现低开启频率的宽阻带。因此，影响起始频率和截止频率的有效刚度和质量值得到了理想的调整。结果表明，该结构可以产生一个覆盖 64.9-805.6Hz 频率范围的宽阻带，从而在给定频率范围（0-1kHz）内以 35.42 dB 的噪声衰减均方根值（RMSNA）阻挡传入声波。这项研究表明，HLRAM 在传统技术中占有优势，因为我们可以根据所需的降噪水平来操纵频散特性和声音传输损耗（STL），并将阻带转移到预定的频率范围。这可以通过改变腔体尺寸、材料或几何参数来实现。

An effective anisotropic visco-plastic model dedicated to high contrast ductile laminated microstructures: Application to lath martensite substructure

V. Rezazadeh, F. Maresca, J.P.M. Hoefnagels, M.G.D. Geers, R.H.J. Peerlings

doi:10.1016/j.ijsolstr.2024.112757

专用于高对比度韧性层状微结构的有效各向异性粘弹性模型：板条马氏体亚结构的应用

In particular types of layer- or lamellar-like microstructures such as pearlite and lath martensite, plastic slip occurs favorably in directions parallel to inter-lamellar boundaries. This may be due to the interplay between morphology and crystallographic orientation or, more generally, due to constraints imposed on the plastic slip due to the lamellar microstructural geometry. This paper proposes a micromechanics based, computationally efficient, scale independent model for a particular type of lamellar microstructures containing softer lamellae which are sufficiently thin to be considered as discrete slip planes embedded in a matrix representing the harder lamellae. Accordingly, the model is constructed as an isotropic visco-plastic model which is enriched with an additional orientation-dependent planar plastic deformation mechanism. This additional mode is activated when the applied load, projected on the direction of the soft films, induces a significant amount of shear stress. Otherwise, the plastic deformation is governed solely by the isotropic part of the model. The response of the proposed model is assessed via a comparison to an infinite periodic two-phase laminate. It is shown that the yielding of the model follows the same behavior as the reference model. The proposed model is highly anisotropic, and the degree of anisotropy depends on the contrast between the slip resistance of the planar mode versus that of the isotropic part. The framework is then applied to the substructure of lath martensite with thin films of inter-lath retained austenite, and exploited in a mesoscale simulation of a dual-phase steel microstructure. The results are compared with those of a standard isotropic model and a full crystal plasticity model which does not have the additional planar plastic mechanism. Predictions made with the proposed model show distinct differences compared with the crystal plasticity results, while keeping the computational cost comparable to that of the isotropic model – and significantly lower than that of the crystal plasticity simulation.

在波来石和板条马氏体等特定类型的层状或片状微结构中，塑性滑移发生在平行于层间边界的方向上。这可能是由于形态和晶体取向之间的相互作用，或者更广泛地说，是由于层状微结构几何形状对塑性滑移的限制。本文提出了一种基于微观力学、计算效率高、规模独立的模型，适用于包含较软薄层的特殊类型片状微结构，这些薄层可被视为嵌入代表较硬薄层的矩阵中的离散滑移面。因此，该模型被构建为一个各向同性的粘弹性模型，并增加了一个取向相关的平面塑性变形机制。当施加在软薄膜方向上的载荷引起大量剪应力时，这种附加模式就会被激活。否则，塑性变形仅由模型的各向同性部分控制。通过与无限周期两相层压板的比较，对所提出模型的响应进行了评估。结果表明，模型的屈服行为与参考模型相同。所提出的模型具有高度各向异性，各向异性的程度取决于平面模式的滑移阻力与各向同性部分的滑移阻力之间的对比。然后将该框架应用于带有板条间残留奥氏体薄膜的板条马氏体子结构，并在双相钢微观结构的中尺度模拟中加以利用。模拟结果与标准各向同性模型和没有附加平面塑性机制的全晶塑性模型进行了比较。与晶体塑性结果相比，使用所提出的模型进行的预测结果显示出明显的差异，同时计算成本与各向同性模型相当，明显低于晶体塑性模拟。

International Journal of Plasticity

Crack nucleation and dislocation activities in titanium alloys with the strong transverse texture: insights for enhancing dwell fatigue resistance

Runchen Jia, Weidong Zeng, Zibo Zhao, Boning Wang, Hanwen Chen, Jianwei Xu, Qingjiang Wang

doi:10.1016/j.ijplas.2024.103938

具有强横向纹理的钛合金中的裂纹成核和位错活动：增强驻留抗疲劳性的启示

Cold dwell sensitivity of near α titanium alloys has posed a significant challenge to the engineering safety within the aerospace industry. However, there exists inconsistency regarding the critical facet formation mechanism between basal and prismatic nucleation. A key revelation in this paper is that the controversy surrounding the facet nucleation plane primarily arises from variations in texture: when the loading direction is parallel to the c-axis or at a 45 ° angle, it leads to basal plane cracking, whereas loading direction perpendicular to the c-axis results in prismatic plane cracking. What's more, a large anisotropy is observed in the dwell fatigue performance in descending order: rolling direction (RD) > transverse direction (TD) >45° direction. To be specific, the dwell fatigue life of RD specimens was 2 times and 4.07 times longer than that of TD and 45 ° specimens, which exhibits excellent dwell fatigue resistance. Furthermore, the high prismatic dislocation density near the facet of RD specimen was confirmed through the Transmission Electron Microscope (TEM) and Transmission Kikuchi Diffraction (TKD) map, which is evidenced that prismatic slips lead to higher strain hardening during cyclic loading. The basal plane of facet grain is generally parallel to the facet line, indicating that the elliptical facet developed by the transgranular fracture through basal plane. Twinning activation in hard grain to accommodate deformation in Ti60 alloy is firstly observed under dwell fatigue tests, which is a product of high stress level in the hard grain. This paper unveils the significant impact of texture on dwell fatigue resistance, offering novel insights into enhancing dwell fatigue performance through texture control.

近 α 钛合金的冷停留敏感性对航空航天工业的工程安全提出了重大挑战。然而，关于基面成核和棱面成核之间的临界面形成机制存在着不一致。本文的一个重要发现是，围绕刻面成核平面的争议主要源于质地的变化：当加载方向平行于 c 轴或呈 45 ° 角时，会导致基面开裂，而垂直于 c 轴的加载方向则会导致棱面开裂。此外，在驻留疲劳性能方面还观察到了很大的各向异性，从大到小的顺序为：滚动方向（RD）>横向方向（TD）>45°方向。具体而言，RD 试样的驻留疲劳寿命分别是 TD 和 45° 试样的 2 倍和 4.07 倍，表现出优异的耐驻留疲劳性能。此外，透射电子显微镜（TEM）和透射菊池衍射（TKD）图证实，RD 试样刻面附近的棱柱位错密度较高，这证明棱柱滑移在循环加载过程中会导致较高的应变硬化。刻面晶粒的基底面一般与刻面线平行，表明椭圆刻面是通过基底面的跨晶断裂形成的。在驻留疲劳试验中，首次观察到在 Ti60 合金中硬质晶粒中激活孪晶以适应变形，这是硬质晶粒中高应力水平的产物。本文揭示了纹理对驻留疲劳抗性的重要影响，为通过纹理控制提高驻留疲劳性能提供了新的见解。

Thin-Walled Structures

Vibration transmission analyses of double-layer cylindrical shell with fully immersed elastic connections through experimental and analytical approaches

Anbin Yu, Yinglong Zhao, Qihang Chen, Jian liu, Zhiwei Zhou, Xiaofei Cao

doi:10.1016/j.tws.2024.111781

通过实验和分析方法对具有全浸弹性连接的双层圆柱形壳体进行振动传播分析

This paper investigates vibration transmission characteristics of the double-layer cylindrical shell with fully immersed elastic connections through experimental and analytical approaches. A test sample of the double-layer cylindrical shell connected by six vibration isolators is firstly manufactured and a forced vibration test is done with fully immersed interlayer. Meanwhile, a novel analytical approach is developed to calculate vibration responses of an unequal double-layer cylindrical shell with fully immersed elastic connections. The substructure receptance method and wave propagation method are combined in the coupling theoretical model. Springs are utilized to simulate elastic connections, that are considered as substructures. By comparing the achieved analytical and experimental vibration responses, good agreements are gained and the two approaches are demonstrated. Then the transmission characteristics are gradually analyzed with respect to the double-layer shell with elastic connections, double-layer shell with interlayer fluid and double-layer shell with fully immersed elastic connections. It is found that the interlayer water between the inner and outer shells plays a “short-circuit” role in vibration transmission, which greatly reduces the isolation performance of vibration isolators. Nevertheless, the fully immersed isolators with small stiffness still have the non-ignorable vibration isolation effect compared with the case of rigid connection.

本文通过实验和分析方法研究了具有全浸弹性连接的双层圆柱形壳体的振动传输特性。首先制作了由六个隔振器连接的双层圆柱形壳体的试验样品，并对完全浸没的夹层进行了强迫振动试验。同时，还开发了一种新的分析方法来计算全浸弹性连接的不等双层圆柱形壳体的振动响应。在耦合理论模型中结合了下部结构接受法和波传播法。利用弹簧模拟弹性连接，将其视为子结构。通过比较所获得的分析和实验振动响应，两种方法获得了良好的一致性，并证明了这两种方法的有效性。然后逐步分析了带弹性连接的双层壳体、带层间流体的双层壳体和带全浸弹性连接的双层壳体的传动特性。结果发现，内外壳之间的夹层水在振动传递中起到了 "短路 "作用，大大降低了隔振器的隔振性能。尽管如此，与刚性连接相比，刚度较小的全浸没隔振器仍具有不可忽视的隔振效果。

Crashworthiness Study of Multi-Tube Assemblies of Corrugated Spacer Tubes Based on the Height Difference Staggered Compensation Method

Suchao Xie, Guandi He, Jing Zhang, Lei He, Jiacheng Wang, Hui Zhou

doi:10.1016/j.tws.2024.111783

基于高差交错补偿法的波纹间隔管多管组件耐撞性研究

To address the limitation of inflexible dimension parameters in thin-walled structures for ensuring energy absorption effectiveness, a design approach for a multi-tube combination of Corrugated Spacer Tubes (CST) based on a height difference staggered compensation method was proposed. The theoretical and finite element models of CST were established, and the accuracy of both models was validated through experiments. Based on the theoretical model, a design approach for the CST multi-tube combination was presented. By sequentially selecting the structural parameters of CST to induce stable and ordered circumferential deformation, consistent peak impact forces and equal intervals were ensured during axial compression. Subsequently, different CSTs with the same properties were distributed at different heights with offsets, causing the peak impact forces of different tubes to be uniformly distributed as designed within a folding wavelength, achieving a staggered compensation effect for overall smooth energy absorption. Building on this, six combination tubes were designed, and finite element models were established. The results indicate that compared to regular combination tubes, the load fluctuation of the height difference combination tubes was significantly reduced by approximately 80%, with no significant loss in energy absorption, specific energy absorption, or mean crushing force. Moreover, the initial peak impact force was also moderately reduced. Furthermore, as the wall thickness of the CST corrugated part increased, the specific energy absorption improved by 61.5% and 34.7%, while the load fluctuation remained consistently low, demonstrating the effectiveness of this method in separating and compensating for CST peak impact forces.

为解决薄壁结构尺寸参数不灵活的问题，确保能量吸收效果，提出了一种基于高差交错补偿法的波纹间隔管（CST）多管组合设计方法。建立了 CST 的理论模型和有限元模型，并通过实验验证了两个模型的准确性。在理论模型的基础上，提出了 CST 多管组合的设计方法。通过依次选择 CST 的结构参数来诱导稳定有序的圆周变形，确保了轴向压缩过程中一致的峰值冲击力和相等的间隔。随后，将具有相同特性的不同 CST 分布在不同的高度，并相互偏移，使不同管材的峰值冲击力在折叠波长内按设计均匀分布，达到交错补偿的效果，从而实现整体能量的平稳吸收。在此基础上，设计了六种组合管，并建立了有限元模型。结果表明，与普通组合管相比，高差组合管的载荷波动明显降低了约 80%，能量吸收、比能量吸收和平均压溃力均无明显损失。此外，初始峰值冲击力也适度降低。此外，随着 CST 波纹部分壁厚的增加，比能量吸收分别提高了 61.5%和 34.7%，而载荷波动却始终保持在较低水平，这表明该方法在分离和补偿 CST 峰值冲击力方面非常有效。