【新文速递】2024年5月5日固体力学SCI期刊最新文章

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

International Journal of Solids and Structures

Solitary waves in slightly dispersive quasi-incompressible hyperelastic materials

Giuseppe Saccomandi, Luigi Vergori

doi:10.1016/j.ijsolstr.2024.112861

微色散准不可压缩超弹性材料中的孤波

Based on the classical theory of simple materials of differential type and the results on the analytical form of constitutive models consistent with the laws of thermodynamics, we introduce a very general response function for the Cauchy stress tensor of a dispersive hyperelastic solid. Next, by focusing on the propagation of localised waves in slightly dispersive quasi incompressible solids, we prove the existence of a rich variety of solitary wave solutions as well as kink wave solutions. Our analysis and results can be easily specialised to shape memory alloys.

基于微分型简单材料的经典理论和符合热力学规律的本构模型解析形式的结果，我们引入了色散超弹性固体的柯西应力张量的一个非常一般的响应函数。接下来，通过关注局域波在微色散准不可压缩固体中的传播，我们证明了各种各样的孤立波解和扭波解的存在性。我们的分析和结果可以很容易地专门用于形状记忆合金。

An exploration into surface wrinkling in 3D printing inspired orthotropic bilayer systems

Matteo Montanari, Ranim Hamaied, Chao Gao, Chiara Bertolin, Andrea Spagnoli

doi:10.1016/j.ijsolstr.2024.112862

基于正交各向异性双层系统的3D打印表面起皱研究

Surface instability, termed wrinkling, might occur in compressed bilayer systems constituted by an external rigid skin resting on an internal soft substrate, where wrinkling is favoured by the rigidity contrast between the two layers. In this paper, the same instability mechanism is explored by considering a substrate characterized by an orthotropic elastic response. By varying the orientation of the principal axes of the substrate’s material, the critical strain of wrinkling and the wrinkles’ wavelength can be tuned during compression. Theoretical formulations for wrinkling are discussed along with the results obtained by linear bifurcation and geometrically nonlinear analyses carried out with two-dimensional finite element models. To experimentally validate the results, the intrinsic properties of Fused Deposition Modeling (FDM) 3D printing technology are leveraged: bilayer objects are manufactured by printing continuous outer shells (corresponding to the rigid skin) along the borders, while the inner raster is shaped with a porous infill pattern, forming a substrate with an orthotropic elastic response.

表面不稳定，称为起皱，可能发生在由外部刚性皮肤放在内部软基板上构成的压缩双层系统中，其中两层之间的刚性对比有利于起皱。本文通过考虑具有正交各向异性弹性响应的衬底，探讨了相同的失稳机制。通过改变衬底材料主轴的方向，可以在压缩过程中调节起皱的临界应变和起皱的波长。讨论了起皱的理论公式，以及用二维有限元模型进行线性分岔和几何非线性分析的结果。为了实验验证结果，利用了熔融沉积建模(FDM) 3D打印技术的固有特性:通过沿边界打印连续的外壳(对应于刚性皮肤)来制造双层物体，而内部光栅则形成多孔填充图案，形成具有正交异性弹性响应的基板。

Mechanics of Materials

Fracture of four semi-regular lattices regulated by T-stress in modified boundary layer models

Xing Yang, Bin Zhang

doi:10.1016/j.mechmat.2024.105026

修正边界层模型中受t应力调节的四个半规则晶格的断裂

The development of additive manufacturing technology has promoted the rise of various lattice metamaterials, and evaluating their fracture properties is critical for both application and safety. Here, by conducting finite element simulations on four types of elastic-brittle semi-regular lattices (kagome, snub-trihexagonal, elongated-triangular, and snub-square), we indicate that the fracture toughness of lattice metamaterials is not solely determined by the crack-tip singular term, i.e., the critical stress intensity factor, but is also influenced by the non-singular T-stress term. T-stress regulates fracture toughness by modulating geometrical distortions and force-carrying modes of lattice bars around the crack front. This regulation effect depends on the lattice topology and becomes weaker under mixed-mode loading. As the relative density of lattices decreases, T-stress can force elastic buckling of bars around the crack front, which may deteriorate the fracture toughness. Additionally, positive T-stress tends to promote the crack deflection and negative T-stress tends to inhibit. Our results offer new insights into the structure-property relationships in the presence of T-stress, which may contribute to design the geometry of micro/nano-lattice metamaterials.

增材制造技术的发展促进了各种晶格超材料的兴起，对其断裂性能的评估对其应用和安全性至关重要。通过对四种类型的弹脆半规则晶格(kagome、snub- tri六边形、细长三角形和snub-正方形)进行有限元模拟，我们发现晶格超材料的断裂韧性不仅由裂纹尖端奇异项即临界应力强度因子决定，而且还受到非奇异t应力项的影响。t应力通过调节裂纹前缘晶格条的几何变形和受力模式来调节断裂韧性。这种调节效应依赖于晶格拓扑结构，在混合模式加载下减弱。随着晶格相对密度的减小，t应力会使裂纹前缘周围的杆件发生弹性屈曲，从而降低断裂韧性。正t应力有促进裂纹变形的趋势，负t应力有抑制裂纹变形的趋势。我们的研究结果为t应力存在下的结构-性能关系提供了新的见解，这可能有助于设计微/纳米晶格超材料的几何形状。

International Journal of Plasticity

Atomistic to continuum mechanics description of crystal defects with dislocation density fields: Application to dislocations and grain boundaries

Houssam Kharouji, Lucile Dezerald, Pierre Hirel, Philippe Carrez, Patrick Cordier, Vincent Taupin, Julien Guénolé

doi:10.1016/j.ijplas.2024.103990

具有位错密度场的晶体缺陷的原子-连续介质力学描述:位错和晶界的应用

The atomic structure of crystal defects such as dislocations, grain or phase boundaries, control these defects’ properties: their mobility, ability to cross-slip, or solute segregation. These crystal defects can be conveniently studied by atomistic simulations and one then needs to transfer relevant information at the upper scale to model microstructures containing a large number of defects, e.g., a polycrystal. Here, we propose an atomistic to continuum mechanics crossover method that (i) represents the atomic structure of dislocations cores by an appropriate Nye dislocation density tensor field and (ii), captures quantitatively the short and long range mechanical fields of defects. For (i), we propose a modified and improved interpolation method based on the original work by Hartley and Mishin. For (ii), we use a field dislocation mechanics framework that rigorously calculates/evaluates the mechanical fields associated with any Nye dislocation density distribution. The transfer method relies on molecular static calculations using two energetic models - ab-initio for screw dislocation core simulations in tungsten, and EAM potential for low and large angle grain boundaries in copper. Our findings demonstrate the effectiveness of the proposed approach in reconstructing the Burgers vector, and continuous strain and rotation fields. The framework is further applied to analyze the elastic interactions between extrinsic edge dislocations and a low angle grain boundary in copper.

晶体缺陷的原子结构，如位错、晶粒或相边界，控制着这些缺陷的性质:它们的迁移率、交叉滑移能力或溶质偏析。这些晶体缺陷可以通过原子模拟来方便地研究，然后需要在较高的尺度上传递相关信息来模拟包含大量缺陷的微观结构，例如多晶。在这里，我们提出了一种原子与连续介质力学交叉方法，该方法(i)通过适当的奈位错密度张量场表示位错核心的原子结构，(ii)定量捕获缺陷的短期和长期力学场。对于(i)，我们在Hartley和Mishin的原始工作的基础上提出了一种改进的插值方法。对于(ii)，我们使用场位错力学框架，严格计算/评估与任何Nye位错密度分布相关的力学场。传递方法依赖于两种能量模型的分子静力计算，一种是用于钨中螺位错核模拟的abi -initio模型，另一种是用于铜中低角和大角晶界的EAM势模型。我们的发现证明了所提出的方法在重建汉堡矢量，连续应变和旋转场方面的有效性。该框架进一步应用于分析铜中外源边缘位错与低角晶界之间的弹性相互作用。

Synergistic grain boundary engineering for achieving strength-ductility balance in ultrafine-grained high-Cr-bearing multicomponent alloys

Xiaoming Liu, Kaikai Song, Zongde Kou, Jianhong Gong, Xiangyan Chen, Qingwei Gao, Hui Sun, Pingping Liu, Ruitao Qu, Lina Hu, Zequn Zhang, Parthiban Ramasamy, Zengqian Liu, Zhenjun Zhang, Feng Liu, Zhefeng Zhang, Jürgen Eckert

doi:10.1016/j.ijplas.2024.103992

实现超细晶高含铬多组分合金强度-塑性平衡的协同晶界工程

Precipitation strengthening is a crucial strategy for ensuring the overall performance of conventional and multicomponent alloys to meet industrial demands. However, the mechanical properties of high-Cr-bearing alloys are often compromised by brittle Cr-rich precipitates at grain boundaries (GBs), leading to severe embrittlement. In this work, a multi-step thermomechanical process is employed to regulate discontinuous dynamic recrystallization (DDRX) and static recrystallization, achieving an ultrafine-grained microstructure. This optimized approach simultaneously impedes the continuous precipitation of the ordered L12 nanocrystals within the matrix and actively encourages the synergistic discontinuous precipitations of submicron L12 and Cr-rich σ particles at GBs, thereby enhancing (yield) strength and high-temperature thermal stability. The ultrafine grains facilitate uniform plastic deformation, characterized by pronounced parallel dislocation slip and stacking faults (SFs) within face-centered cubic (fcc) grains, while second-direction slips, SFs, and Lomer-Cottrell (L-C) lock networks near GB precipitates greatly alleviate stress concentration. Critically, the submicron L12 particles enveloping σ precipitates at GBs also display plastic deformation via mechanical twinning and dislocations, effectively impeding rapid crack propagation along GBs. This research not only provides new insights into the ductility-strength balance in advanced alloys but also proposes a compelling route for optimizing biphasic precipitation, expanding the applicability of high-Cr multicomponent alloys.

沉淀强化是确保常规和多组分合金整体性能满足工业需求的关键策略。然而，高含铬合金的力学性能往往受到晶界处脆性富cr析出物的影响，导致严重的脆化。在这项工作中，采用多步骤的热机械过程来调节不连续动态再结晶(DDRX)和静态再结晶，获得超细晶组织。这种优化方法同时阻止了有序L12纳米晶体在基体内的连续析出，并积极促进亚微米L12和富cr σ颗粒在GBs处的协同不连续析出，从而提高了(屈服)强度和高温热稳定性。超细晶粒有利于均匀的塑性变形，其特征是面心立方(fcc)晶粒内存在明显的平行位错滑移和层错(SFs)，而GB析出相附近的第二方向滑移、SFs和lmer - cottrell (L-C)锁网络极大地缓解了应力集中。重要的是，包裹σ相的亚微米L12颗粒也通过机械孪晶和位错表现出塑性变形，有效地阻碍了裂纹沿晶界的快速扩展。该研究不仅为先进合金的延性-强度平衡提供了新的见解，而且为优化双相析出，扩大高铬多组分合金的适用性提供了一条有吸引力的途径。

Thin-Walled Structures

A data-driven enhanced generalized differential quadrature algorithm in free vibration analysis of shells of revolution with free-form meridian and their combined structures

Qingyang Huang, Fenfei Hua, Qingquan You, Jie Gao, Xiaoqiang Zhou

doi:10.1016/j.tws.2024.111975

具有自由形式子午线的旋转壳及其组合结构自由振动分析中的数据驱动增强广义微分正交算法

In this paper, a data-driven enhanced generalized differential quadrature (DE-GDQ) algorithm in free vibration analysis is proposed, which can be applied to shells of revolution with free-form meridian and their combined structures. According to first order shear deformation theory (FSDT) and Hamilton's principle, the governing equation for doubly-curved shells is obtained. The general boundary conditions are considered through artificial springs. Then the GDQ is introduced to solve the governing equations and the DE-GDQ is proposed on the basis of GDQ. After a detailed solution procedure of DE-GDQ is introduced and the convergence analysis is finished, multiple models and boundary conditions are validated including shells of revolution with conic section meridian, Haack series meridian, rational Bézier curve meridian. Isotropic materials and anisotropic materials including functionally graded (FG) materials are both verified. The free vibration analysis of combined structures is also finished and compared with finite element method (FEM). The comparison among DE-GDQ, GDQ and FEM shows that the DE-GDQ has greater advantages in terms of calculation efficiency, accuracy, and scope of application.

提出了一种数据驱动的增强广义微分正交(DE-GDQ)自由振动分析算法，该算法可应用于具有自由形式子午线的旋转壳及其组合结构。根据一阶剪切变形理论(FSDT)和Hamilton原理，得到了双弯曲壳的控制方程。通过人工弹簧考虑一般边界条件。然后引入GDQ来求解控制方程，并在此基础上提出了DE-GDQ。介绍了DE-GDQ的详细求解过程，并进行了收敛性分析，验证了含圆锥截面子午线、Haack系列子午线、有理bsamizier曲线子午线的旋转壳的多种模型和边界条件。各向同性材料和各向异性材料包括功能梯度(FG)材料都进行了验证。对组合结构进行了自由振动分析，并与有限元法进行了比较。DE-GDQ与GDQ和FEM的比较表明，DE-GDQ在计算效率、精度和适用范围等方面具有更大的优势。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年5月7日复合材料SCI期刊最新文章

今日更新：Composite Structures 2 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 1 篇Composite StructuresEffects of long-term exposure of NSM CFRP-to-concrete bond to natural and accelerated aging environmentsAloys Dushimimana, José Sena-Cruz, Luís Correia, João Miguel Pereira, Susana Cabral-Fonseca, Ricardo Cruzdoi:10.1016/j.compstruct.2024.118174NSM cfrp -混凝土粘结剂长期暴露于自然和加速老化环境中的影响Carbon fiber reinforced polymer (CFRP) composites can be used to strengthen existing reinforced concrete (RC) structures. The CFRP laminate can be bonded to RC structure using epoxy adhesive via near-surface mounted (NSM) strengthening technique. However, existing literature generally lacks data about durability of NSM CFRP-to-concrete bond. In this study, strengthened concrete elements were exposed to laboratory-controlled environments (at approximately 20 °C/55 % RH, and water immersion at 20 °C) and natural field environments (to promote natural aging induced mainly by carbonation, high temperatures, freeze–thaw attack, and airborne chlorides) for up to four years. Durability tests were conducted yearly for the bond and its constituent materials. The highest bond strength degradations were nearly 12 % and 9 % for the specimens immersed in water and those exposed to freeze–thaw attack, respectively. Besides, environmental conversion factors of 0.88 and 0.93 were derived from a database of existing accelerated, and natural aging data from the present work, respectively.碳纤维增强聚合物(CFRP)复合材料可用于加固现有的钢筋混凝土(RC)结构。采用近表面安装(NSM)加固技术，采用环氧胶粘剂将CFRP复合材料粘接在RC结构上。然而，现有文献普遍缺乏关于NSM cfrp -混凝土粘结耐久性的数据。在这项研究中，加固混凝土元件暴露在实验室控制的环境(大约20 °C/55 % RH, 20 °C的水浸泡)和自然现场环境(促进主要由碳化、高温、冻融侵蚀和空气中的氯化物引起的自然老化)中长达四年。每年对粘结剂及其组成材料进行耐久性试验。浸水和冻融作用下的粘结强度下降幅度最大，分别接近12 %和9 %。环境转换因子分别为0.88和0.93，分别来自现有加速老化和自然老化数据库。High fidelity FEM based on deep learning for arbitrary composite material structureJiaxi Li, Weian Yao, Yu Lu, Jianqiang Chen, Yan Sun, Xiaofei Hudoi:10.1016/j.compstruct.2024.118176基于深度学习的任意复合材料结构高保真有限元分析Due to the outstanding performance, composite materials are widely used and analyzing their properties and designing them based on performance has become a crucial task in the field of many manufacturing industries. Composite materials possess complex multiscale structures, and traditional fine-scale finite element modeling and analysis may lead to severe computational resource challenges. To overcome this difficulty, breakthroughs in key technologies of multiscale accelerated analysis algorithms are required. In this study, an innovative approach based on artificial intelligence and multiscale finite element method is presented. This approach involves partitioning the entire composite material structure into coarse grids that resemble homogenous structures of similar size, providing results consistent to fine-grid finite element analysis. By utilizing CNN for image feature recognition and employing the CGAN adversarial method, coarse-grid equivalent stiffness matrices and multiscale shape functions from completely random microstructures of composite materials can be obtained. Consequently, this enables a rapid response process from microstructure to low-resolution grid to high-resolution physical field, with remarkably accurate physical field results. Moreover, compared to traditional fine-grid finite element methods, this approach significantly reduces memory usage and computation time. This method is applicable to composite materials with varying shaped inclusions, different component properties, and diverse geometric distributions, allowing these materials to perform high-fidelity finite element calculations on coarse grids and predict their mechanical behavior. Furthermore, this breakthrough opens avenues for accelerating the optimization design of composite materials with diverse mechanical functionalities, by employing a bottom-up approach.复合材料由于其优异的性能得到了广泛的应用，分析其性能并根据其性能进行设计已成为许多制造业领域的一项重要任务。复合材料具有复杂的多尺度结构，传统的精细尺度有限元建模和分析对计算资源构成了严峻的挑战。为了克服这一困难，需要突破多尺度加速分析算法的关键技术。本研究提出了一种基于人工智能和多尺度有限元方法的创新方法。这种方法包括将整个复合材料结构划分为粗网格，这些粗网格类似于大小相似的同质结构，从而提供与细网格有限元分析一致的结果。利用CNN进行图像特征识别，采用CGAN对抗方法，可以得到复合材料完全随机微观结构的粗网格等效刚度矩阵和多尺度形状函数。因此，这使得从微观结构到低分辨率网格再到高分辨率物理场的快速响应过程成为可能，并且具有非常精确的物理场结果。此外，与传统的细网格有限元方法相比，该方法显著减少了内存使用和计算时间。该方法适用于具有不同形状夹杂物、不同组分性能和不同几何分布的复合材料，允许这些材料在粗网格上进行高保真的有限元计算，并预测其力学行为。此外，通过采用自下而上的方法，这一突破为加速具有多种机械功能的复合材料的优化设计开辟了道路。Composites Part A: Applied Science and ManufacturingAn efficient finite element mesh generation methodology based on μCT images of multi-layer woven compositesXuanxin Tian, Heng Zhang, Zhaoliang Qu, Shigang Aidoi:10.1016/j.compositesa.2024.108255 基于多层编织复合材料μCT图像的高效有限元网格生成方法High-fidelity models are essential for accurate finite element (FE) simulations of composite material behavior. This paper proposes an efficient meshing methodology based on micro-Computed Tomography (μCT) images. U-Net convolutional neural network was used for image segmentation. Connected yarns were then separated using an improved procedure based on watershed algorithm and geometric transformations. The proposed Constrained Delaunay-Advancing Front Technique (CD-AFT) surface reconstruction algorithm extracts point cloud of yarns from segmented images and outputs high-quality and smooth orientable manifold watertight triangulated surface. Intersecting meshes of yarns are separated through node position detection and Laplacian moving. Experimental results show that proposed methodology is capable of accomplishing mesh generation for different mesh sizes. Compared with commercial software, it has obvious advantages in mesh quality and size control. Since the proposed method operates independently of commercial software and manual operation, it facilitates the automated generation of numerous high-fidelity models from μCT images for FE simulations.高保真模型对于复合材料性能的精确有限元模拟至关重要。提出了一种基于微计算机断层扫描(μCT)图像的高效网格划分方法。采用U-Net卷积神经网络进行图像分割。然后使用基于分水岭算法和几何变换的改进方法分离连接的纱线。提出的约束delaunay推进前沿技术(CD-AFT)曲面重建算法从分割图像中提取纱线点云，输出高质量、光滑的可定向流形水密三角曲面。通过节点位置检测和拉普拉斯移动分离纱线的相交网格。实验结果表明，该方法能够实现不同网格尺寸的网格生成。与商业软件相比，它在网格质量和尺寸控制方面具有明显的优势。由于该方法独立于商业软件和人工操作，它有助于从μCT图像中自动生成大量高保真模型用于FE模拟。Composites Part B: EngineeringIntegrated Accelerated Testing Methodology for CFRP DurabilityYasushi Miyano, Masayuki Nakadadoi:10.1016/j.compositesb.2024.111527CFRP耐久性综合加速试验方法Integrated ATM, an integrated accelerated testing methodology for CFRP durability, is described herein. It is expressed as a single formula including several parameters representing the life of CFRP under an arbitrary environmental temperature and an arbitrary strain ratio R from R =0 to 1. Integrated ATM is based on Christensen's viscoelastic crack kinetics and conventional ATM. First, Integrated ATM is introduced based on the matrix resin viscoelasticity. Second, important parameters which affect CFRP life are found for the longitudinal tensile strength of a unidirectional CFRP as an Integrated ATM application. Finally, the parameter influences on CFRP life are assessed.本文描述了集成ATM，一种CFRP耐久性的集成加速测试方法。在任意环境温度下，在R =0 ~ 1的任意应变比R下，CFRP的寿命可表示为包含多个参数的单一公式。综合自动取款机是基于克里斯坦森粘弹性裂纹动力学和传统自动取款机。首先，介绍了基于基体树脂粘弹性的集成ATM。其次，找到了影响碳纤维增强材料寿命的重要参数，用于单向碳纤维增强材料的纵向拉伸强度作为集成ATM应用。最后，评估了各参数对碳纤维布寿命的影响。Composites Science and TechnologyThe strength prediction model of unidirectional fiber reinforced composites based on the renormalization group methodYixing Qian, Zhinan Li, Xin Zhou, Tong Xia, Yao Zhang, Zhenyu Yang, Dayong Hu, Zixing Ludoi:10.1016/j.compscitech.2024.110639 基于重整化群法的单向纤维增强复合材料强度预测模型When unidirectional fiber reinforced composites are subjected to longitudinal tensile loading and reach a critical failure state, they experience a sudden transition from local damage to catastrophic failure, commonly termed as an avalanche event. This paper integrates the self-organized criticality theory (SOC) concepts into the prediction of longitudinal tensile strength of composites and establishes a strength prediction model of composites based on the renormalization group method (RGM). The predictions of the RGM model are successfully validated against experimental results in the literatures, and it demonstrates relatively acceptable predictive accuracy compared to classical strength criteria. Compared to other state-of-the-art prediction models considering stochastic fiber strength distribution, the RGM model effectively provides strength statistics for fiber bundles of any size and describes the occurrence of composites avalanche failure induced by local stress concentration. This present model can be very conveniently implemented as a User Material Subroutine (UMAT) for finite simulations, facilitating practical prediction of the strength of composite structures.当单向纤维增强复合材料受到纵向拉伸载荷并达到临界破坏状态时，它们会经历从局部损伤到灾难性破坏的突然转变，通常被称为雪崩事件。将自组织临界理论(SOC)概念融入到复合材料纵向拉伸强度预测中，建立了基于重整化群法(RGM)的复合材料强度预测模型。RGM模型的预测结果与文献中的实验结果进行了对比验证，与经典强度准则相比，RGM模型的预测精度相对较好。与考虑随机纤维强度分布的其他最新预测模型相比，RGM模型有效地提供了任何尺寸纤维束的强度统计数据，并描述了局部应力集中引起的复合材料雪崩破坏的发生。该模型可以很方便地作为有限模拟的用户材料子程序(UMAT)实现，便于对复合材料结构的强度进行实际预测。来源：复合材料力学仿真Composites FEM