【新文速递】2024年4月27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 3 篇，International Journal of Plasticity 2 篇，Thin-Walled Structures 5 篇

International Journal of Solids and Structures

Buckling optimization of variable-stiffness composite plates with two circular holes using discrete Ritz method and potential flow

Zhao Jing, Lei Duan, Siqi Wang

doi:10.1016/j.ijsolstr.2024.112845

基于离散Ritz法和势流的双孔变刚度复合材料板屈曲优化

Potential flow around two equal-radius cylinders is derived analytically and applied to generate the curvilinear fiber path of variable-stiffness composite (VSC) plates with two circular holes. As complex variable theory and conformal mapping are used to generate the potential flow around two equal-radius cylinders, the location and size of the two equal-radius circular holes are arbitrary. By changing the angle of incoming flow, the global fiber angle of a variable-stiffness lamina can be simulated and the local fiber orientation angle at any point is determined by the global potential flow field. Buckling performance of variously-shaped VSC plates with two circular holes are investigated via a novel numerical method − discrete Ritz method (DRM). DRM combines the extended interval integral, Gauss quadrature, and variable stiffness within a rectangular domain and builds a discrete energy system to simulate the plate, which allows the geometric boundaries of the plate to vary. The strain energy of a plate is modeled in the rectangular domain, discretized using Gauss points, and is characterized by variable stiffness, which characterizes both the material distribution and plate geometry simultaneously. After that, a three-dimensional sampling optimization (3DSO) method is adopted to optimize the curvilinear fiber configurations of VSC plates, and its buckling performances are compared with those of constant stiffness composites (CSC) with straight fibers. Significant improvements on load-carrying capacity can be achieved compared to straight ones, demonstrating that using potential flow is one of the most efficient way to generate curvilinear optimal fiber path with maximum load-carrying capacity for VSC plates with material discontinuity. Moreover, DRM exhibits good precision and stability for buckling analysis of VSC plates with complex geometries

分析了两等半径圆柱体周围的势流，并将其应用于两圆孔变刚度复合材料板的曲线纤维路径的生成。由于采用复变理论和保角映射生成两个等半径圆柱体周围的势流，两个等半径圆孔的位置和大小是任意的。通过改变入射气流的角度，可以模拟变刚度板的整体纤维角，并由整体势流场确定任意点的局部纤维取向角。采用一种新的数值方法——离散里兹法(DRM)研究了带两个圆孔的不同形状VSC板的屈曲性能。DRM结合了扩展区间积分、高斯正交和矩形域内变刚度，建立了一个离散能量系统来模拟板，允许板的几何边界变化。板的应变能在矩形域中建模，采用高斯点离散，并具有变刚度的特征，同时表征了材料分布和板的几何形状。然后，采用三维采样优化(3DSO)方法对VSC板的曲线纤维结构进行优化，并将其屈曲性能与直纤维恒刚度复合材料(CSC)的屈曲性能进行比较。与直线路径相比，该路径的承载能力得到了显著提高，这表明对于材料不连续的VSC板，利用势流是生成承载能力最大的曲线最优光纤路径的最有效方法之一。此外，对于具有复杂几何形状的VSC板的屈曲分析，DRM具有良好的精度和稳定性

Journal of the Mechanics and Physics of Solids

Contact stiffness of the multi-indenter contact interface

Yongbin Wang, Jinsheng Zhao, Yuxiang He, Mingshan Yang, Jielei Chu, Jianghong Yuan, Xiangyu Li, Weiqiu Chen

doi:10.1016/j.jmps.2024.105659

多压头接触界面的接触刚度

Mechanical contact plays a pivotal role in both industrial and daily life applications. Contact stiffness of a multi-indenter contact interface fundamentally determines force–deformation relations. However, the understanding of the overall contact stiffness from the historical perspective is limited owing to inherent difficulties in precisely characterizing the interaction in multi-indenter contacts. In this study, the mechanical strong interaction among indenters is pinpointed. A theoretical model for accurately determining the contact stiffness of multi-indenter contact interface is developed. The physical mechanism of the contact stiffness of multi-indenter contact interface is revealed. The theoretical model is solidly validated by experiment and simulation. More importantly, the present theoretical model can predict the contact stiffness of contact interfaces with complex and irregular configurations, which may be filled up with indenters of hierarchical structures. The critical load is determined to guarantee the finished product rate during transfer printing. This is experimentally evidenced by the transfer printing of silicon wafer with complexly customized patterns. The present study provides a profound guidance for various engineering applications such as fabrication and integration of micro- and nano-electronic chips as well as electronic devices.

机械接触在工业和日常生活中都起着举足轻重的作用。多压头接触界面的接触刚度从根本上决定了力-变形关系。然而，从历史角度理解整体接触刚度是有限的，因为在精确表征多压头接触中的相互作用方面存在固有的困难。在这项研究中，确定了压头之间的机械强相互作用。建立了精确确定多压头接触界面接触刚度的理论模型。揭示了多压头接触界面接触刚度的物理机理。通过实验和仿真验证了理论模型的正确性。更重要的是，该理论模型可以预测具有复杂和不规则结构的接触界面的接触刚度，这些界面可能充满分层结构的压痕。为保证转移印花的成品率，确定了临界负荷。通过实验证明了这一点，并对具有复杂定制图案的硅片进行了转移印刷。本研究对微纳电子芯片及电子器件的制造与集成等多种工程应用具有深远的指导意义。

Incompatibility-driven growth and size control during development

A. Erlich, G. Zurlo

doi:10.1016/j.jmps.2024.105660

开发过程中不兼容性驱动的增长和规模控制

Size regulation in living organisms is a major unsolved problem in developmental biology. This is due to the intrinsic complexity of biological growth, which simultaneously involves genetic, biochemical, and mechanical factors. In this article, we propose a novel theoretical framework that explores the role of incompatibility, the geometric source of residual stress in a growing body, as a possible regulator of size termination during development. We explore this paradigm both at the level of a model 2D cell, and at the level of continuous tissues. After establishing a parallel between incompatibility and the shape parameter of vertex models, we show that incompatibility-driven growth leads to size control in a model 2D cell. We then extend the same paradigm to the level of continuous bodies, where incompatibility is measured by the Ricci curvature of the growth tensor. By using the model 2D cell as a template, we now derive an evolutionary law for the growth tensor with curvature fixed at a physiological value. When the analysis is specialised to radial symmetry (discs and spheres), this model captures the salient features observed in Drosophila wing discs and multicellular spheroids: these systems have a target size and build up residual stresses that cause the tissue to open in response to a radial cut, with the cut edges curling outward. The theory proposed in this work suggests that incompatibility in a growing biological tissue is potentially controllable at the cell level, and that incompatibility-driven growth provides an effective method of controlling global information (stress, size) through local geometric controls.

生物的大小调节是发育生物学中尚未解决的主要问题。这是由于生物生长的内在复杂性，它同时涉及遗传、生化和机械因素。在本文中，我们提出了一个新的理论框架，探讨了不相容的作用，在一个生长体的几何来源的残余应力，作为一个可能的调节尺寸终止在发展过程中。我们在模型二维细胞水平和连续组织水平上探索这种范式。在建立顶点模型的不兼容性和形状参数之间的平行关系后，我们表明不兼容性驱动的增长导致模型二维单元的大小控制。然后，我们将相同的范例扩展到连续体的水平，其中不相容是通过生长张量的里奇曲率来测量的。通过使用模型二维细胞作为模板，我们推导出曲率固定在生理值的生长张量的进化规律。当分析专门针对径向对称(圆盘和球体)时，该模型捕捉到了在果蝇翅盘和多细胞球体中观察到的显著特征:这些系统有一个目标尺寸，并建立残余应力，导致组织在径向切割时打开，切割边缘向外卷曲。这项工作提出的理论表明，生长中的生物组织中的不相容性在细胞水平上是潜在的可控的，并且不相容性驱动的生长提供了一种通过局部几何控制来控制全局信息(应力，大小)的有效方法。

Mechanics of Abrasion-Induced Particulate Matter Emission

Ketian Li, Yanchu Zhang, Kunhao Yu, Haixu Du, Constantinos Sioutas, Qiming Wang

doi:10.1016/j.jmps.2024.105661

磨损诱发颗粒物排放的力学研究

Microplastic pollution constitutes a substantially detrimental type of environmental contamination and poses threats to human health. Among the sources of airborne and marine microplastics, evidence indicates that non-exhaust emissions resulting from tire abrasion and other organic materials have emerged as a notable contributor. However, the mechanistic understanding of abrasion emission of organic materials has remained elusive. To fill the gap, we here develop a multi-scale abrasion mechanics model using the principles of linear elastic fracture mechanics. Macroscopically, material wear and tear can be viewed as a process of macro-crack propagation associated with the fatigue fracture. Microscopically, we consider the effect of microcracks propagating under cyclic loading on the material modulus and energy release rate during fatigue fracture. This framework leads to an evaluation of the effective energy release rate for the abrasion-induced emission of particulate matter, thus leading to a calculation of the concentration of the emitted particulate matter with varied sizes. The theory is validated by corresponding experiments and high consistency is exhibited between the theoretical and experimental results. This research constructs a quantitative relationship between fracture mechanics and abrasion emissions. This research not only paves the way for a mechanistic understanding of particulate matter pollution from a solid mechanics perspective but also offers rational guidance for modern society to alleviate airborne particulate matter and marine microplastic abrasion emissions.

微塑料污染是一种极为有害的环境污染，对人类健康构成威胁。在空气和海洋微塑料的来源中，有证据表明，轮胎磨损和其他有机材料产生的非废气排放已成为一个显着的贡献者。然而，有机材料的磨损发射机理的理解仍然是难以捉摸的。为了填补这一空白，我们利用线弹性断裂力学原理建立了一个多尺度磨损力学模型。从宏观上看，材料的磨损可以看作是伴随疲劳断裂的宏观裂纹扩展过程。微观上考虑了循环载荷下微裂纹的扩展对疲劳断裂过程中材料模量和能量释放率的影响。该框架可用于评估磨损引起的颗粒物排放的有效能量释放率，从而计算不同大小的排放颗粒物的浓度。通过相应的实验对理论进行了验证，理论结果与实验结果具有较高的一致性。本研究建立了断裂力学与磨损排放之间的定量关系。本研究不仅为从固体力学角度对颗粒物污染的机理认识铺平了道路，而且为现代社会减轻大气颗粒物和海洋微塑料磨损排放提供了合理的指导。

International Journal of Plasticity

Understanding the strain localization in additively manufactured materials: Micro-scale tensile tests and crystal plasticity modeling

Daijun Hu, Zixu Guo, Nicolò Grilli, Aloysius Tay, Zhen Lu, Wentao Yan

doi:10.1016/j.ijplas.2024.103981

了解增材制造材料中的应变局部化:微尺度拉伸试验和晶体塑性建模

Metallic parts fabricated by additive manufacturing (AM) usually exhibit unique microstructures and non-negligible residual stresses compared with the counterparts produced by conventional manufacturing. These inherent microstructural factors strongly affect the mechanical response of the as-built AM parts. In this study, we focus on the strain localization behavior of 316L stainless steel produced by laser powder-bed-fusion. In-situ tensile tests under a scanning electron microscope are performed, and the digital image correlation method is used to measure the strain distribution combined with electron backscatter diffraction. Meanwhile, a dislocation-based crystal plasticity finite element model incorporating residual stresses is developed to study the origins of the strain localization in the AM material. The results indicate that strain localization in AM materials is closely associated with microstructural features, encompassing behaviors related to slip activities, interactions with neighboring grains and dislocation evolutions. Additionally, the columnar grain features also render the strain distribution sensitive to the loading direction. The strain localization is serious in some small grains with high residual stresses, while in large grains the effect is less significant. These factors collectively contribute to the increasing likelihood of strain localization occurring in the AM microstructures with heterogeneous grain size and texture distribution. This work provides detailed insights into the strain localization in AM materials and would facilitate the manufacturing parameter optimization of AM materials by tuning the microstructure to reduce deformation inhomogeneity.

与传统制造的金属零件相比，增材制造制造的金属零件通常具有独特的微观结构和不可忽略的残余应力。这些固有的微观结构因素强烈地影响着成品增材制造零件的力学响应。在本研究中，我们重点研究了激光粉末床熔合生产的316L不锈钢的应变局部化行为。在扫描电镜下进行了原位拉伸试验，并采用数字图像相关法结合电子背散射衍射测量了应变分布。同时，建立了包含残余应力的位错晶体塑性有限元模型，研究了增材制造材料应变局部化的根源。结果表明，AM材料中的应变局部化与微观结构特征密切相关，包括与滑移活动、与邻近晶粒的相互作用和位错演化相关的行为。此外，柱状晶粒特征也使得应变分布对加载方向敏感。在残余应力较大的小晶粒中，应变局部化现象较为严重，而在大晶粒中则不太明显。这些因素共同导致了具有非均匀晶粒尺寸和织构分布的AM微结构中应变局部化的可能性增加。这项工作为增材制造材料的应变局部化提供了详细的见解，并将通过调整微观结构来减少变形不均匀性，从而促进增材制造材料的制造参数优化。

Study of the mechanism of the strength-ductility synergy of α-Ti at cryogenic temperature via experiment and atomistic simulation

Heng Yang, Heng Li, Hong Sun, Haipeng Wang, M.W. Fu

doi:10.1016/j.ijplas.2024.103971

通过实验和原子模拟研究α-Ti在低温下强度-延性协同作用的机理

Alpha titanium (α-Ti) is a promising material for making high-performance components for applications in aerospace, marine, energy and healthcare fields. The excellent strength-ductility synergy has been observed for α-Ti at cryogenic temperature. Twinning is generally considered a key mechanism of outstanding cryogenic ductility. The dislocation-grain boundaries (GBs) interaction and void nucleation usually play crucial roles in the plastic deformation of polycrystalline materials, but their effects on the cryogenic ductility of α-Ti are rarely considered. To eliminate this confusion and gain an in-depth insight into the mechanism of the cryogenic strength-ductility synergy of α-Ti, in this work, a series of characterization experiments and molecular dynamics (MD) simulations were designed and carried out. 1) From uniaxial tension tests of the coarse-grained α-Ti sheets at the temperature from 25 to -180°C, the uniform elongation and post-necking elongation were increased by 92% and 20%, respectively. The material maintained a larger strain hardening rate within a greater range of strain at cryogenic temperature compared with room temperature. 2) Via microstructure and fractography observations and the analysis of slip and geometrically necessary dislocation (GND) activities, the uniform plastic deformation was mainly accomplished by prismatic slip, whether at room temperature or at cryogenic temperature. The significantly increased uniform elongation is mainly attributed to the more uniform distribution of GND pile-ups at cryogenic temperature. 3) The MD simulations revealed that cryogenic temperatures made the GBs present a stronger barrier effect on dislocation transmission compared with that at room temperature, contributing to the more uniform distribution of GNDs and lower densities of GND pile-ups. The GBs at cryogenic temperature show a greater ability to resist void nucleation due to the decreased accumulation rate of excess potential energy and increased energy required to void nucleation. The larger strains were thus required to increase the densities of GND pile-ups to induce large stress concentrations for driving void nucleation. This made the uniform elongation of α-Ti increase significantly at cryogenic temperature. This study revealed that the enhanced barrier effect of GBs on dislocation transmission and the improved ability of GBs to resist void nucleation are key mechanisms besides twinning governing the cryogenic strength-ductility synergy of α-Ti. The understanding developed in this work can be useful for the development of new high-performance materials and the precise forming of complex components with high quality.

α钛(α-Ti)是一种很有前途的材料，可用于制造应用于航空航天、海洋、能源和医疗保健领域的高性能部件。α-Ti在低温下表现出优异的强度-塑性协同效应。孪生通常被认为是突出的低温延展性的关键机制。位错-晶界相互作用和空穴成核在多晶材料的塑性变形中起着至关重要的作用，但它们对α-Ti低温塑性的影响却很少被考虑。为了消除这种混淆，深入了解α-Ti低温强度-延性协同作用的机制，本研究设计并开展了一系列表征实验和分子动力学(MD)模拟。1)粗晶α-Ti片材在25 ~ -180℃的单轴拉伸试验中，均匀伸长率和后颈伸长率分别提高了92%和20%。与室温相比，材料在低温下在更大的应变范围内保持了更大的应变硬化速率。2)通过显微组织和断口形貌观察以及滑移和几何必要位错(GND)活动分析，无论在室温还是低温下，均匀塑性变形主要由棱柱滑移完成。均匀伸长率的显著提高主要是由于低温下GND堆积分布更加均匀。3) MD模拟结果表明，与室温相比，低温使gds对位错传递具有更强的阻挡作用，使得gds分布更均匀，堆积密度更低。低温下的GBs由于多余势能积累速率的降低和空穴成核所需能量的增加而表现出更强的抗空穴成核能力。因此，需要较大的应变来增加GND堆积的密度，以诱导大的应力集中以驱动空洞成核。这使得α-Ti在低温下的均匀伸长率显著提高。研究表明，除了孪晶外，GBs对位错传递的阻挡作用增强和抗空洞成核能力的提高是控制α-Ti低温强度-塑性协同作用的关键机制。在这项工作中发展起来的理解对于开发新的高性能材料和高质量复杂部件的精确成形是有用的。

Thin-Walled Structures

Global interactive-mode imperfection generation for K6 single-layer latticed shell using generative adversarial networks

Kaidong Wu, Yecheng Zhang, Bingbing San, Zhe Xing

doi:10.1016/j.tws.2024.111932

基于生成对抗网络的K6单层格壳全局交互模式缺陷生成

The worst imperfection shape of K6 single-layer latticed shells corresponding to the lowest nonlinear load-carrying capacity is difficult to be obtained in design owing to significant multi-modal interaction. The global interactive buckling of the K6 single-layer latticed shell is investigated numerically, and the intelligent model for generating its worst global interactive-mode imperfection is developed via generative adversarial networks (GAN). For the cases vulnerable to interactive buckling, the load-carrying capacity is found to be reduced significantly up to 35% with two-mode interaction considered, and unstable behaviour, such as the dominant mode changing due to the deformation evolution of different modal components, is observed at the post-buckling stage. Moreover, the GAN model for generating the worst imperfection shape and the artificial neural network for evaluating the corresponding ultimate load are developed based on the data obtained from numerical analysis. The time of training model to converge is less than 30 min, and the generating process using the trained model only takes a few seconds. It is demonstrated that for the K6 single-layer latticed shells, the developed models can give the worst imperfection and the corresponding ultimate load accurately and efficiently with interactive buckling considered well. This work can be used to develop the programming module for the intelligent design of latticed shells in future.

由于存在明显的多模态相互作用，在设计中很难得到K6单层网壳非线性承载能力最低的最大缺陷形状。对K6单层网壳的全局交互屈曲进行了数值研究，并利用生成对抗网络(GAN)建立了生成其最坏全局交互模态缺陷的智能模型。对于易受交互屈曲影响的情况，考虑双模态相互作用的情况下，承载能力显著降低35%，并且在屈曲后阶段观察到不稳定行为，例如由于不同模态分量的变形演变而导致的主导模态变化。基于数值分析数据，建立了最坏缺陷形状生成的GAN模型和相应极限荷载的人工神经网络。训练模型收敛时间小于30 min，使用训练模型生成过程仅需几秒。结果表明，对于K6单层网壳，所建立的模型在充分考虑相互屈曲的情况下，能准确有效地给出最大缺陷和相应的极限载荷。本文的工作可为今后格壳智能化设计的编程模块的开发提供参考。

Nonlinear Thermoelastic Wave Propagation in General FGM Sandwich Rectangular Plates

Chen Liang, Guifeng Wang, Zhenyu Chen, C.W. Lim

doi:10.1016/j.tws.2024.111933

非线性热弹性波在一般FGM夹层矩形板中的传播

The present work is dedicated to investigating the thermoelastic wave propagation behavior of sandwich rectangular plates (SRP) made of functionally graded material (FGM). The main contribution lies in the partial modification of basic theoretical expressions and solution methods to improve the accuracy of practical system models. An analytical model with three types of general configurations is established. The porosity distribution in FGM layers depends on the degree of mixture of the constituent materials, with the FGM layers without porosity taken as a reference model. The effect of porosity within FGMs is addressed through a refined analytical formulation of material properties, and the temperature-dependent material properties of FGM sandwich structures (FGMSS) maintain continuity through the thickness. This improved framework introduces a porosity function encompassing three distinct structural and geometrical functions: the core-to-thickness ratio (CTR), porosity volume fraction (PVF), and porosity distribution function (PDF). It is worth mentioning that the theoretical expressions maintain good continuity and reliability under the influence of thermal conditions and system parameters of the proposed structures. Furthermore, considering the generation of thermal strain energy caused by thermal expansion of the structure in the normal direction, an improved analytical approach for determining thermal strain energy (TSE) in rectangular plate structures is then investigated by introducing the Green's nonlinear strain (GNS). Hamilton's principle is applied to derive the wave motion equations and analytical solutions for the wave dispersion relations are derived. Furthermore, accurate numerical simulation is performed and the solution is verified with data available in published resources. In addition, we present a systematic parametric analysis to examine the effects of porosity, configuration, power-law exponent (PLE), PVF, CTR, temperature, and wave number on the thermoelastic wave propagation behavior of FGMSRP.

本文研究了功能梯度材料夹心矩形板的热弹性波传播特性。主要贡献在于部分修改了基本理论表达式和求解方法，提高了实际系统模型的准确性。建立了具有三种一般构型的解析模型。FGM层的孔隙度分布取决于组成材料的混合程度，以无孔隙度的FGM层为参考模型。通过精细的材料性能分析公式，可以解决FGM内部孔隙率的影响，FGM夹层结构(FGMSS)的温度依赖材料性能在厚度上保持连续性。这种改进的框架引入了孔隙度函数，包括三种不同的结构和几何函数:岩心厚度比(CTR)、孔隙体积分数(PVF)和孔隙度分布函数(PDF)。值得一提的是，在热条件和系统参数的影响下，理论表达式保持了良好的连续性和可靠性。此外，考虑到结构在法向热膨胀引起的热应变能的产生，引入格林非线性应变(GNS)，研究了矩形板结构热应变能的改进解析方法。应用哈密顿原理推导了波浪运动方程，导出了波频散关系的解析解。最后进行了精确的数值模拟，并与文献资料进行了验证。此外，我们提出了一个系统的参数分析，以检验孔隙率、结构、幂律指数(PLE)、PVF、CTR、温度和波数对FGMSRP热弹性波传播行为的影响。

Advances in suppression of structural vibration and sound radiation by flexural wave manipulation

Feng Liu, Pengtao Shi, Yizhou Shen, Yanlong Xu, Zhichun Yang

doi:10.1016/j.tws.2024.111936

弯曲波抑制结构振动和声辐射的研究进展

The newly generated artificial structures, including phononic crystals, elastic metamaterials, acoustic black holes (ABHs) and elastic metasurfaces, can abnormally control wave propagations. In this paper, focusing on plate structures and from the perspective of the suppression of vibration and especially sound radiation by manipulating flexural waves, we give a thorough review of the advances of above-mentioned artificial structures, involving their extraordinary characteristics corresponding mechanisms of vibration and sound radiation suppression, design methods of phase-gradient elastic metasurfaces, and some representative works on suppressing vibration and sound radiation of plates by flexural wave manipulations. Additionally, we compare the advantages and disadvantages of these artificial structures in vibration and sound radiation suppression. Finally, we look forward to the prospects on vibration and sound radiation suppression of plates based on wave manipulations. This paper will provide a timely and practical assistance to academic and technical researchers in the field of vibration and noise reduction.

声子晶体、弹性超材料、声黑洞和弹性超表面等新产生的人工结构可以异常地控制波的传播。本文以平板结构为研究对象，从操纵弯曲波抑制振动特别是声辐射的角度，综述了上述人工结构的研究进展，包括它们的特殊特性、相应的抑制振动声辐射的机理、相梯度弹性超表面的设计方法、并介绍了用弯曲波法抑制板材振动和声辐射的代表性工作。此外，我们还比较了这些人工结构在抑制振动和声辐射方面的优缺点。最后，展望了基于波处理的平板振动声辐射抑制研究的前景。本文将为减振降噪领域的学术和技术研究人员提供及时和实用的帮助。

Evaluation of crush performance of extruded aluminum alloy tubes based on finite element analysis with ductile fracture modeling

Jung Yun Won, Chanyang Kim, Seojun Hong, Hyeong-Seop Yoon, Jong Kyu Park, Myoung-Gyu Lee

doi:10.1016/j.tws.2024.111937

基于延性断裂建模的挤压铝合金管挤压性能有限元评价

In this study, the crush performance of four aluminum extrusions are investigated through analysis based on finite element (FE) simulation incorporating experiment-numerical hybrid ductile fracture modeling. Tensile tests on standard and non-standard specimens, coupled with digital image correlation and FE analyses, are employed to establish constitutive models for the materials. The evaluation of crush performance is performed based on both axial crush test and corresponding 3-dimensional FE simulation, which could validate the employed plasticity and fracture laws and predict crush performance indicators with reliable accuracy. Additionally, FE modeling enables thorough analysis of highly non-proportional loading paths and potential crack initiation sites, with the crack formation mechanism elucidated through the evolution of a proposed damage variable. Furthermore, the modified crush performance indicators are newly suggested, which could explain the dependence on both the absorbed energy of tubular extrusion and properties of ductile fracture.

采用基于有限元模拟的实验-数值混合韧性断裂模型分析方法，对4种铝型材的挤压性能进行了研究。通过标准和非标准试样的拉伸试验，结合数字图像相关和有限元分析，建立了材料的本构模型。基于轴向挤压试验和相应的三维有限元模拟进行了挤压性能评价，验证了塑性和断裂规律，预测了挤压性能指标，具有可靠的准确性。此外，有限元建模可以对高度非比例加载路径和潜在裂纹起裂部位进行深入分析，并通过提出的损伤变量的演化来阐明裂纹形成机制。此外，还提出了改进后的挤压性能指标，这可以解释管状挤压吸收能与韧性断裂性能的依赖关系。

Polyurea elastomer for enhancing blast resistance of structures: Recent advances and challenges ahead

Haojie Zhu, Chong Ji, Ke Feng, Jiangang Tu, Xin Wang, Changxiao Zhao

doi:10.1016/j.tws.2024.111938

聚脲弹性体增强结构的抗爆炸能力:最近的进展和未来的挑战

As an excellent anti-blast material, polyurea (PU) has been widely used in the reinforcement of masonry walls, RC structures, steel structures, and composite materials. The advances in the static and dynamic mechanical properties, dynamic constitutive models, and applications of PU in the field of blast resistance are reviewed. Although results have indicated the potential of PU in anti-blast reinforcement, the underlying mechanisms are not fully understood. Widely recognized mechanisms include shock wave induced ordering and hydrogen bonding changes in the hard domain, viscoelastic energy dissipation, and impedance matching between PU and matrix. Potential problems in the field of PU anti-blast transformation are summarized, and corresponding solutions are proposed.

聚脲(PU)作为一种优良的抗爆材料，已广泛应用于砌体墙体、钢筋混凝土结构、钢结构、复合材料的加固。综述了聚氨酯的静、动态力学性能、动态本构模型及其在抗爆领域的应用研究进展。虽然结果表明PU在抗爆炸加固中的潜力，但其潜在机制尚未完全了解。广泛认识的机制包括激波诱导的硬畴有序和氢键变化、粘弹性能量耗散以及PU与基体之间的阻抗匹配。总结了聚氨酯抗爆改造领域存在的问题，并提出了相应的解决方案。