【新文速递】2024年3月18日固体力学SCI期刊最新文章_ACT_Mechanical_Maxwell_System_Marc_断裂_复合材料_非线性_通用_建筑_ECAD_理论_爆炸_材料

【新文速递】2024年3月20日固体力学SCI期刊最新文章

今日更新：Journal of the Mechanics and Physics of Solids 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 3 篇Journal of the Mechanics and Physics of SolidsOptimizing nanoporous metallic actuators through multiscale calculations and machine learningSheng Sun, Menghuan Wang, Hanqing Jiang, Ying Zhang, Hang Qiao, Tong-Yi Zhangdoi:10.1016/j.jmps.2024.105611 通过多尺度计算和机器学习优化纳米多孔金属致动器Nanoporous materials (NMs) immersed in electrolytes can achieve approximately 1% deformation at a low operating voltage of about 1 V. The actuation renders them promising artificial muscles. The actuation performance significantly hinges on the structure and size of nanopores and ligaments in NMs. Consequently, designing an optimal configuration is imperative for excellent performance. The actuation mechanism of NMs involves the coupling of multiple fields at various length scales, posing a formidable challenge to conventional simulation and design approaches. To surmount this challenge, we have developed a computational framework capable of conducting concurrent and sequential multiscale calculations. By utilizing artificial neural network (ANN) surrogate models trained on data obtained through the finite element method (FEM), the framework achieves optimized values for both actuation strain and effective Young's modulus within a designated design space. The constitutive model, which establishes the relationship between surface stress and charges in FEM, is derived from the surface eigenstress model and symbolic regression. This involves utilizing data calculated through joint density functional theory. This framework not only ensures the desired properties but also demonstrates its potential for effectively addressing other multiscale optimization problems.浸入电解质中的纳米多孔材料（NMs）可在约 1 V 的低工作电压下实现约 1% 的变形。驱动性能在很大程度上取决于纳米多孔材料中纳米孔和韧带的结构和尺寸。因此，要想获得出色的性能，必须设计出最佳配置。核磁共振的致动机制涉及不同长度尺度上多个场的耦合，这对传统的模拟和设计方法提出了严峻的挑战。为了克服这一挑战，我们开发了一种能够进行并发和顺序多尺度计算的计算框架。该框架利用人工神经网络 (ANN) 代理模型对通过有限元法 (FEM) 获得的数据进行训练，从而在指定的设计空间内实现致动应变和有效杨氏模量的优化值。在有限元法中，建立表面应力和电荷之间关系的构成模型来自表面特征应力模型和符号回归。这涉及到利用联合密度泛函理论计算的数据。这一框架不仅确保了所需的性能，还展示了其有效解决其他多尺度优化问题的潜力。Mechanics of MaterialsDuctile rupture under cyclic loadings at high triaxiality: The influence of strain hardening and elasticityAlmahdi Remmal, Jean-Baptiste Leblonddoi:10.1016/j.mechmat.2024.104982高三轴度循环载荷下的韧性断裂：应变硬化和弹性的影响Previous works (Devaux et al., 1997; Cheng et al., 2017) have emphasized the effects of strain hardening and elasticity upon ductile rupture of metals under cyclic loading conditions. This work pursues the study and modelling of these two effects by distinct theoretical methods, each coupled with micromechanical finite element simulations of the behaviour of some “representative cell”. For the effect of strain hardening, we employ Morin et al. (2017)’s approach, based on the theory of sequential limit-analysis (Yang, 1993; Leu, 2007; Leblond et al., 2018). This approach is applied to various types of hardening of the metallic matrix: isotropic, linear kinematic, nonlinear kinematic with one or two kinematic variables (Armstrong and Frederick, 2007) , and even a simplified version of Chaboche (1991)’s model accounting for complex cyclic effects. Numerical micromechanical simulations of a hollow sphere made of elastic–plastic materials obeying the various hardening laws considered, and subjected to cyclic loadings at high triaxiality, fully confirm the predictions of the model developed, provided elasticity is made negligible by using an artificially high value of Young’s modulus. When a realistic value is employed, however, the agreement between theoretical predictions and numerical results is degraded, thus emphasizing again the importance of the effect of elasticity in cyclic ductile rupture. To deal with this effect we derive, apparently for the first time, an evolution equation of the porosity accounting for (compressible) elasticity. However, numerical micromechanical simulations reveal that simply using this new evolution law, while keeping all other aspects of the model unchanged, remains insufficient to get a good match of theoretical and numerical results. Such a match is achieved by introducing the ad hoc hypothesis that the yield criterion and flow rule derived from sequential analysis still apply in the presence of elasticity, but with some “effective porosity” slightly differing from the true one through some heuristic, adjustable factor.之前的研究（Devaux 等人，1997 年；Cheng 等人，2017 年）强调了应变硬化和弹性对循环加载条件下金属韧性断裂的影响。本研究采用不同的理论方法对这两种效应进行研究和建模，每种方法都与某些 "代表性单元 "行为的微机械有限元模拟相结合。对于应变硬化效应，我们采用了 Morin 等人（2017 年）基于顺序极限分析理论（Yang，1993 年；Leu，2007 年；Leblond 等人，2018 年）的方法。这种方法适用于各种类型的金属基体硬化：各向同性硬化、线性运动硬化、带有一个或两个运动变量的非线性运动硬化（Armstrong 和 Frederick，2007 年），甚至是 Chaboche（1991 年）模型的简化版，以考虑复杂的循环效应。对空心球体进行的微观力学数值模拟符合所考虑的各种硬化规律，并在高三轴度下承受循环载荷，完全证实了所建立模型的预测，前提是通过使用人为的高杨氏模量值来忽略弹性。然而，当采用实际值时，理论预测与数值结果之间的一致性就会下降，从而再次强调了弹性效应在周期性韧性断裂中的重要性。为了解决这一问题，我们首次推导出了一个考虑到（可压缩）弹性的孔隙率演化方程。然而，微观力学数值模拟显示，仅仅使用这一新的演化规律，而保持模型的所有其他方面不变，仍然不足以使理论和数值结果很好地匹配。为了实现这种匹配，我们引入了一个特别假设，即从顺序分析中得出的屈服标准和流动规则仍然适用于存在弹性的情况，但通过一些启发式的可调系数，使 "有效孔隙率 "与真实孔隙率略有不同。International Journal of PlasticityA general micromechanics-based model for precipitate strengthening and fracture toughness in polycrystal high entropy alloysYankai Wang, Fusheng Tan, Yang Chen, Hui Feng, Jia Li, Peter K Liaw, Qihong Fangdoi:10.1016/j.ijplas.2024.103949基于微观力学的多晶高熵合金析出强化和断裂韧性通用模型High-entropy alloys (HEAs) usually exhibit exceptional mechanical properties attributed to one of important core effects for serious lattice strain to impede dislocation motion compared to the traditional alloys. However, their roles on the quantitative measurement for precipitate strengthening and fracture toughness are lack using the existing physical model. Here, we propose a mechanistic modelling to study effect of heterogeneous strain caused by lattice distortion on the precipitate strengthening and fracture toughness in the HEAs, and then verify this role using atomic simulation. The results indicate that the lattice distortion and precipitate synergistically impede the grain boundary migration, increasing the strength. In the dilute alloy with a low lattice distortion, the grain boundary migration process is less sensitive to the precipitate size. The stress field generated by the lattice distortion relieves the stress concentration at the crack tip under external force. This in turn alleviates the accumulation of dislocations and reduces the probability of crack extension. Furthermore, the heterogeneous strain caused by lattice distortion counteracts some of the applied stress and raises the critical stress for crack extension, which enhances the plasticity and the critical stress intensity factor. The developed unified model would be applicable to high entropy ceramics in similar scenario.与传统合金相比，高熵合金（HEAs）通常表现出优异的机械性能，其重要的核心效应之一是严重的晶格应变阻碍了位错运动。然而，现有的物理模型缺乏对析出强化和断裂韧性的定量测量。在此，我们提出了一种机理模型来研究晶格畸变引起的异质应变对 HEAs 中沉淀强化和断裂韧性的影响，并利用原子模拟验证了这种作用。结果表明，晶格畸变和析出物协同阻碍了晶界迁移，从而提高了强度。在晶格畸变较小的稀合金中，晶界迁移过程对沉淀尺寸的敏感性较低。晶格畸变产生的应力场可缓解裂纹尖端在外力作用下的应力集中。这反过来又缓解了位错的积累，降低了裂纹扩展的概率。此外，晶格畸变引起的异质应变抵消了部分外加应力，提高了裂纹扩展的临界应力，从而增强了塑性和临界应力强度因子。所开发的统一模型适用于类似情况下的高熵陶瓷。Thin-Walled StructuresNovel conformal sandwich lattice structures: Design concept, fabrication and mechanical propertiesMing Lei, Pan Wang, Shengyu Duan, Weibin Wen, Jun Liangdoi:10.1016/j.tws.2024.111806 新型保形夹层晶格结构：设计理念、制造和机械性能A novel conformal sandwich lattice is proposed by introducing the design concept of bioinspired sandwich structures into the microstructure design of triply periodic minimal surface (TPMS) lattices, and the mechanical properties of the conformal sandwich lattice (P-SC) with P-TPMS lattice skins and simple cubic (SC) plate lattice cores are investigated numerically and experimentally. The P-SC specimen manufactured by the laser powder bed fusion (L-PBF) with glass bead-filled polyamide composite exhibits negligible anisotropy in its mechanical properties, as confirmed by tensile tests conducted on specimens fabricated at various build orientations. The elastic properties of the P-SC can be widely tailored by modifying the structural parameters. Especially, the anisotropic index can be tailored to obtain an elastically-isotropic P-SC sandwich lattice. Additionally, the P-SC exhibits superior elastic properties and energy absorption compared with the conventional lattices. The findings provide insights into the design flexibility of advanced high-performance structural materials for complex engineering applications.通过将生物灵感夹层结构的设计理念引入三周期最小面（TPMS）晶格的微结构设计，提出了一种新型共形夹层晶格，并通过数值和实验研究了具有 P-TPMS 晶格表皮和简单立方（SC）板晶格核心的共形夹层晶格（P-SC）的力学性能。通过激光粉末床熔融（L-PBF）与玻璃珠填充聚酰胺复合材料制造的 P-SC 试样，其机械性能的各向异性几乎可以忽略不计，这一点已在以不同构建方向制造的试样上进行的拉伸试验中得到证实。通过修改结构参数，可对 P-SC 的弹性性能进行广泛定制。特别是各向异性指数可以通过调整来获得弹性各向异性的 P-SC 夹层晶格。此外，与传统晶格相比，P-SC 具有更优越的弹性性能和能量吸收能力。这些发现为复杂工程应用中先进高性能结构材料的设计灵活性提供了启示。A numerical study on a novel demountable cold-formed steel composite beam with profiled steel sheetingAhmad Karimipanah, Mehran Zeynalian, Abdolreza Ataeidoi:10.1016/j.tws.2024.111812带异型钢板的新型可拆卸冷弯钢复合梁数值研究Cold-formed steel composite beams are known for their unique advantages, like being lightweight and ease of installation. The use of profiled steel sheeting in cold-formed composite beams reduces construction time and costs by acting as a permanent formwork in the composite beams. The current study presents a 3D finite element model of cold-formed steel composite beam specimens comprising a cold-formed double-lipped channel section, profiled steel sheeting, concrete slab, and bolted shear connector. Employing bolted shear connectors, structural components can be deconstructed and replaced after their service life expires or if they are damaged. The characteristics of the materials obtained from an experimental program were assigned to the finite element model. Geometric characteristics, material nonlinearities, and loading procedures were attentively simulated, and a dynamic explicit procedure was employed for the numerical analyses. A comparison of the results obtained from the finite element models and the available experimental results validated the precision of the models. Then, numerical studies were conducted to investigate the effects of various parameters, including compressive strength of concrete, thickness of concrete slab, height and grade of cold-formed steel section, thickness of profiled steel sheeting, number and diameter of shear connectors, on the behavior of the composite beam. The results showed that the height and grade of the cold-formed steel section and compressive strength and thickness of the concrete slab have a significant effect on increasing the capacity of the composite beam.冷弯型钢组合梁以其独特的优势而闻名，例如重量轻和易于安装。在冷弯型钢组合梁中使用异型钢板作为组合梁的永久模板，可以减少施工时间和成本。本研究介绍了冷弯型钢复合梁试件的三维有限元模型，该试件由冷弯型钢双立面槽钢截面、异型钢板、混凝土板和螺栓剪力连接件组成。采用螺栓剪力连接件，结构组件可以在使用寿命到期或损坏后进行拆卸和更换。从实验程序中获得的材料特性被分配到有限元模型中。对几何特征、材料非线性和加载程序进行了细致的模拟，并在数值分析中采用了动态显式程序。通过比较有限元模型和现有实验结果，验证了模型的精确性。然后，对混凝土抗压强度、混凝土板厚度、冷弯型钢截面高度和等级、异型钢板厚度、剪力连接件数量和直径等参数对复合梁行为的影响进行了数值研究。结果表明，冷弯型钢截面的高度和等级、混凝土板的抗压强度和厚度对提高组合梁的承载能力有显著影响。Computation of Shear Buckling Stress of Thin-Walled Sections Using Constrained Spline Finite Strip MethodAjeesh S S, S Arul Jayachandrandoi:10.1016/j.tws.2024.111813使用约束样条有限条法计算薄壁截面的剪切屈曲应力The direct strength method (DSM) design for shear incorporates the elastic shear buckling stress of the cross-section to evaluate the ultimate shear capacity of thin-walled members. To calculate the shear buckling stress using the finite strip method (FSM), the shape functions for longitudinal interpolation are an issue, while capturing the phase change of displacements along the plate strip. This paper presents a novel constrained spline finite strip method (cSFSM) that eliminates the phase change of displacements. Although constrained buckling analysis for shear stresses is reported in the literature based on FSM, the present study is unique in determining pure buckling stresses for simply supported members subjected to shear edge stress. The formulation also provides an accurate representation of the variation of shear stress along the longitudinal and transverse directions of the plate. Hence, coarse discretization of cross-section is sufficient to obtain the accurate shear buckling stress. The formulation is demonstrated on channel sections with lips subjected to shear edge stresses, and elastic buckling stresses are compared with results available in the literature and also with the finite element method (FEM). Illustrative examples are presented on lipped channel members with different end conditions and longitudinal stiffeners on flanges and webs, to calculate the pure elastic buckling stresses under shear edge stresses. The calculation of buckling stresses for members subjected to longitudinal variation of shear and flexural stresses is also presented to calculate coupled and uncoupled buckling stresses.剪切直接强度法（DSM）设计采用截面弹性剪切屈曲应力来评估薄壁构件的极限剪切能力。要使用有限带材法（FSM）计算剪切屈曲应力，纵向插值的形状函数是一个问题，同时还要捕捉板带位移的相位变化。本文提出了一种消除位移相变的新型约束样条有限元法（cSFSM）。虽然基于 FSM 的剪应力约束屈曲分析在文献中已有报道，但本研究在确定受剪切边缘应力作用的简支撑构件的纯屈曲应力方面是独一无二的。该公式还能准确表示剪应力沿板的纵向和横向的变化。因此，横截面的粗离散化足以获得精确的剪切屈曲应力。该公式在受到剪切边缘应力作用的带唇槽截面上进行了演示，并将弹性屈曲应力与文献中的结果以及有限元法（FEM）进行了比较。示例介绍了具有不同端部条件和翼缘板及腹板上的纵向加强筋的唇缘槽钢构件，以计算剪切边缘应力下的纯弹性屈曲应力。还介绍了受剪应力和挠曲应力纵向变化影响的构件的屈曲应力计算，以计算耦合和非耦合屈曲应力。来源：复合材料力学仿真Composites FEM