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【新文速递】2024年9月11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 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Mechanics of Materials 2 篇,Thin-Walled Structures 1 篇

International Journal of Solids and Structures

Towards a rational approach for multi-axial experimental campaigns for rubberlike material

Benjamin Martin, Erwan Verron, Michel Coret, Nathan Selles

doi:10.1016/j.ijsolstr.2024.113060

探讨类橡胶材料多轴实验运动的合理方法

This work takes up the developments around the logarithmic strain tensor and uses the invariants of this tensor to propose a new approach to multi-axiality of fatigue experiments for elastomers. This study leads to the introduction of a new notion, modality, which is intended as the microscopic counterpart of uni- and multi-axiality. This notion is quantified by the K3 invariant (mode of deformation) of the logarithmic strain tensor, and is used to rationalize tension-torsion experimental campaigns. It is illustrated using two examples: the perfect cylinder and the AE2 “diabolo” sample. We then propose a methodology for building a test campaign based on this new definition.

这项工作围绕对数应变张量展开,并利用该张量的不变量提出了弹性体疲劳实验多轴性的新方法。这项研究引入了一个新概念--模态,作为单轴性和多轴性的微观对应概念。该概念通过对数应变张量的 K3 不变式(变形模式)进行量化,并用于合理解释拉伸-扭转实验活动。我们用两个例子对其进行了说明:完美圆柱体和 AE2 “空竹”样品。然后,我们提出了基于这一新定义的试验方法。


Journal of the Mechanics and Physics of Solids

A covariant formulation for finite strain modelling of orthotropic elasticity and orthotropic plasticity with plasticity-induced evolution of orthotropy: Application to natural fibres

Christian C. Celigoj, Manfred H. Ulz

doi:10.1016/j.jmps.2024.105846

具有塑性诱导正交异性演化的正交异性弹性和正交异性塑性有限应变模型的协变公式:在天然纤维中的应用

We introduce a rate-independent model for orthotropic elastic and orthotropic plastic material behaviour in a hyper-elasto-plastic framework at finite strains. The model is based on the postulate of covariance and does not rely on a multiplicative decomposition of the deformation gradient. Furthermore, a plastic-deformation-induced evolution of orthotropy is considered, similar to the notion of plastic spin. We propose that the orthotropic strain energy function and the orthotropic yield criterion are guided by identical structural tensors that evolve with plasticity. The modelled material behaviour is significant for natural fibres such as flax, hemp, or pulp fibres. Our formulation has three findings. Firstly, the covariant formulation of plasticity provides rate equations for the plastic variables and the structural tensors suitable for reproducing stress–strain diagrams of natural fibres. Secondly, the introduction of plastic-deformation-induced evolution of orthotropy in the proposed covariant setting results in a non-associative plasticity algorithm. Thirdly, the covariant setting allows the incorporation of suitable constitutive equations for the structural tensors to evolve orthotropy. The latter successfully models the stiffness increase in stress–strain diagrams of cyclic tensile tests of natural fibres.

我们介绍了在有限应变下超弹塑性框架中正交各向异性弹性和正交各向异性塑性材料行为的速率无关模型。该模型基于协方差假设,不依赖于变形梯度的乘法分解。此外,考虑了塑性变形诱导的正交异性演化,类似于塑性自旋的概念。我们提出正交各向异性应变能函数和正交各向异性屈服准则由相同的随塑性演化的结构张量指导。模拟材料的行为是显著的天然纤维,如亚麻,大 麻,或纸浆纤维。我们的公式有三个发现。首先,塑性协变公式提供了适于再现天然纤维应力-应变图的塑性变量和结构张量的速率方程。其次,在所提出的协变设置中引入塑性变形诱导的正交异性进化导致非关联塑性算法。第三,协变设置允许结合合适的本构方程的结构张量发展正交异性。后者成功地模拟了天然纤维循环拉伸试验的应力-应变图中的刚度增加。


Mechanics of Materials

A Statistical High-order Reduced Model for Nonlinear Random Heterogeneous Materials with Three-scale Micro-Configurations

Zhiqiang Yang, Shanqiao Huang, Yi Sun

doi:10.1016/j.mechmat.2024.105149

具有三尺度微观结构的非线性随机非均质材料的统计高阶简化模型

An effective statistical higher-order three-scale reduced homogenization (SHTRH) method is established to analyze the nonlinear random heterogeneous materials with multiple micro-configurations. Firstly, the various unit cell functions based on the microscale and mescoscale regions are given, and two expected homogenization coefficients are computed through Kolmogorov’s strong laws of large number. Further, the nonlinear homogenized equations are formulated, and the corresponding reduced-order multiscale systems for displacement and stress solutions are derived by using the high-order unit cell solutions and homogenized solutions. The key features of the new statistical multiscale methods are (i) the novel reduced models established to solve the inelastic problems of random composites at a fraction of cost, (ii) the high-order homogenized solutions which do not need high-order continuity for the macro solutions of the random problems and (iii) the statistical high-order multiscale algorithms developed for analyzing the nonlinear random composites with three-scale structures. Finally, the effectiveness and correctness of the algorithm are confirmed according to several hyperelastic, plasticity and damage periodic/random composites with multiple-scale configurations. The computation shows that the proposed SHTRH methods are useful for analyzing the macroscopic nonlinear performance, and can efficiently catch the microscopic and mesoscopic information for the random heterogeneous composites.

建立了一种有效的统计高阶三尺度简化均质化(SHTRH)方法来分析具有多种微观构型的非线性随机非均质材料。首先,给出了基于微尺度和中尺度区域的各种单体胞函数,并利用Kolmogorov强大数定律计算了两个期望的均匀化系数。在此基础上,建立了非线性均质化方程,并利用高阶单元胞解和均质化解导出了相应的降阶多尺度位移和应力解。新统计多尺度方法的主要特点是:(1)建立了新的简化模型,以较低的成本求解随机复合材料的非弹性问题;(2)随机问题宏观解的高阶均匀化解不需要高阶连续性;(3)开发了用于分析具有三尺度结构的非线性随机复合材料的统计高阶多尺度算法。最后,以多尺度结构的超弹性、塑性和损伤周期/随机复合材料为例,验证了算法的有效性和正确性。计算结果表明,所提出的SHTRH方法可用于分析随机非均质复合材料的宏观非线性性能,并能有效地捕获其微观和细观信息。


Modeling plasticity-mediated void growth at the single crystal scale: A physics-informed machine learning approach

Karl Garbrecht, Andrea Rovinelli, Jacob Hochhalter, Paul Christodoulou, Ricardo A. Lebensohn, Laurent Capolungo

doi:10.1016/j.mechmat.2024.105151

在单晶尺度上模拟塑性介导的空洞生长:一种物理信息的机器学习方法

Modeling the evolution of voids during plastic flow as well as their effects on plastic dissipation is critical for both component manufacturing and lifetime estimation purposes. To this end, we propose a rate-dependent constitutive model to homogenize the effects of semi-randomly distributed voids on single crystal plasticity whilst capturing void interaction and plastic anisotropy. The present work focuses on the case of face centered cubic crystals to introduce an anisotropic gauge function applicable within the crystal plasticity formalism. The approach combines analytical methods to describe the micromechanics of the system in combination with symbolic regression to capture analytically intractable mechanisms from data. The hybrid framework uses a physics-informed genetic programming-based symbolic regression algorithm to solve a multiform optimization problem simultaneously producing a new gauge function and a new strain rate equation. This is also a multi-objective optimization problem with many competing objectives. A new search and selection step is introduced to the genetic algorithm that promotes convergence toward a global solution that better satisfies all the objectives. Overall, the symbolic equations produced leverage data-driven methods to achieve greater accuracy than comparable alternatives on an analytically intractable problem while maintaining model transparency.

模拟塑性流动过程中空洞的演化及其对塑性耗散的影响对于部件制造和寿命估计都是至关重要的。为此,我们提出了一个速率相关的本构模型,以均匀化半随机分布的空洞对单晶塑性的影响,同时捕捉空洞相互作用和塑性各向异性。本文以面心立方晶体为例,介绍了一种适用于晶体塑性形式的各向异性规范函数。该方法结合了分析方法来描述系统的微观力学,并结合符号回归从数据中捕获分析难以处理的机制。该混合框架采用基于物理信息遗传规划的符号回归算法来解决多形式优化问题,同时产生新的规范函数和新的应变率方程。这也是一个有许多竞争目标的多目标优化问题。在遗传算法中引入了一个新的搜索和选择步骤,以促进收敛到一个更好地满足所有目标的全局解。总的来说,产生的符号方程利用数据驱动的方法,在保持模型透明度的同时,在分析棘手问题上获得比可比替代方案更高的准确性。


Thin-Walled Structures

Experimental and theoretical studies on 3D printed short and continuous carbon fiber hybrid reinforced composites

Xiangren Kong, Guangyong Sun, Quantian Luo, Veniamin Brykin, Jin Qian

doi:10.1016/j.tws.2024.112406

3D打印短连续碳纤维混杂增强复合材料的实验与理论研究

3D-printed carbon fiber composites hold significant potential in aerospace applications because of their lightweight, high strength and complex structure fabrication capabilities. However, additive manufacturing characteristics such as high porosity, anisotropy and continuous fiber content significantly affect the mechanical properties of printed parts. The aim of this study is to investigate the influence of hybrid printing of short and continuous carbon fibers on the mechanical properties and failure mechanisms of composites and to develop a model to predict elastic properties considering porosity. First, mechanical testing and characterization of short and continuous fiber reinforced polyamide (nylon) print filaments are performed. The results indicate that the elastic modulus and ultimate strength of continuous carbon fiber filaments reach 60 GPa and 1500 MPa, respectively, while the strength and elastic modulus of short carbon fiber filaments reach 60 MPa and 1 GPa, respectively. Then tensile specimens with different continuous fiber orientations and different continuous fiber placement sequences are printed and tested using a multi-material 3D printing technique. The specimens are characterized before and after testing using scanning electron microscopy and microscopy to assess the porosity and failure mechanisms of specimens with different configurations. The results show that the mechanical properties of the printed parts are much lower than those of the print filaments, which proves the serious negative impact of the material extrusion process on the mechanical properties of the printed structural parts. Finally, an analytical method for predicting the elastic behavior of printed composites is developed by introducing the porosity factor in the volume-averaged stiffness model. For continuous and short fiber filled composites with different fiber contents and printing orientations, the predicted results are in agreement with the experiments, and the prediction error is greatly reduced from 30% to less than 5%.

3d打印碳纤维复合材料由于其轻量化、高强度和复杂结构的制造能力,在航空航天应用中具有巨大的潜力。然而,增材制造的高孔隙率、各向异性和连续纤维含量等特性会显著影响打印件的力学性能。本研究的目的是研究短碳纤维和连续碳纤维混合打印对复合材料力学性能和破坏机制的影响,并建立考虑孔隙率的弹性性能预测模型。首先,对短纤维和连续纤维增强聚酰胺(尼龙)打印长丝进行了力学测试和表征。结果表明:连续碳纤维长丝的弹性模量和极限强度分别达到60 GPa和1500 MPa,短碳纤维长丝的强度和弹性模量分别达到60 MPa和1 GPa。然后采用多材料3D打印技术对不同连续纤维取向和不同连续纤维放置顺序的拉伸试样进行打印和测试。利用扫描电镜和显微镜对试验前后的试样进行表征,评估不同构型试样的孔隙率和破坏机制。结果表明,打印件的力学性能远低于打印长丝的力学性能,证明了材料挤压工艺对打印结构件力学性能的严重负面影响。最后,在体积平均刚度模型中引入孔隙率因子,提出了一种预测打印复合材料弹性性能的解析方法。对于不同纤维含量和打印方向的连续和短纤维填充复合材料,预测结果与实验结果吻合较好,预测误差从30%大大降低到5%以下。




来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveSystemDeform疲劳复合材料非线性航空航天增材理论材料多尺度试验
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首次发布时间:2024-11-21
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【新文速递】2024年8月2日复合材料SCI期刊最新文章

今日更新:Composite Structures 10 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Science and Technology 3 篇Composite StructuresAn experimental-analytical investigation of particle size effect on the mode I fracture behavior of polymer/graphene nanocompositesSara Amirahmadi, Sankha Aditya, Samit Roydoi:10.1016/j.compstruct.2024.118420颗粒尺寸对聚合物/石墨烯纳米复合材料I型断裂行为影响的实验分析研究Due to their outstanding specific mechanical and functional properties, the engineering use of polymer nanocomposites and their carbon composites is becoming increasingly pervasive. Current and potential applications include micro- and flexible electronics, energy storage devices, and the use as reinforcement for advanced carbon fiber composites for light-weighting of aerospace and mechanical structures, thereby reducing their fuel consumption and carbon footprint. While a large amount of data and models regarding the effect of the weight fraction of nanoplatelets on the mechanical properties of nanocomposites is currently available in the literature, an aspect often overlooked is the scaling of the fracture behavior and the related particle size effects. Not only is the lack of understanding of size effects in nanomaterials hindering the full exploitation of their properties, it is also a serious issue since the design of large nanocomposite structures or small-scale electronic components requires capturing the scaling of their mechanical properties and developing predictive capabilities. This paper aims at filling this knowledge gap by proposing a novel analytical and experimental approach to investigate particle size effects in nanocomposites at and leveraging the acquired knowledge to improve their fracture properties, from the nanoscale all the way to the macroscale. To this end, crack initiation fracture toughness data for graphene/epoxy nanocomposite are presented as a function of nanoparticle size and weight fraction and compared with model predictions using a novel analytical model based on enhanced crack-tip shielding effect due to the reduced nanoparticle size. Extensive fracture test data are presented for model calibration and model verification.由于聚合物纳米复合材料及其碳复合材料具有优异的机械性能和功能特性,其工程应用日益广泛。目前和潜在的应用包括微型和柔性电子产品、能量存储设备,以及用作航空航天和机械结构轻量化的先进碳纤维复合材料的增强材料,从而降低其燃料消耗和碳足迹。虽然目前文献中有大量关于纳米薄片重量分数对纳米复合材料力学性能影响的数据和模型,但一个经常被忽视的方面是断裂行为的尺度和相关的粒径效应。缺乏对纳米材料尺寸效应的理解不仅阻碍了其性能的充分利用,而且由于大型纳米复合材料结构或小型电子元件的设计需要捕获其机械性能的缩放并开发预测能力,这也是一个严重的问题。本文旨在通过提出一种新的分析和实验方法来研究纳米复合材料中的颗粒尺寸效应,并利用所获得的知识来改善纳米复合材料的断裂性能,从纳米尺度一直到宏观尺度。为此,将石墨烯/环氧纳米复合材料的裂纹起裂韧性数据作为纳米颗粒尺寸和重量分数的函数,并使用基于纳米颗粒尺寸减小导致裂纹尖端屏蔽效应增强的新型分析模型与模型预测进行了比较。提供了大量的断裂试验数据,用于模型校准和模型验证。The deployment of 3-D morphing surfaces: A 2-D auxetic metamaterial approach through buckling-induced mechanismChengyang Lu, Ruizhi Li, Yifan Zheng, Fei Pan, Yuli Chen, Xiaotian Zhangdoi:10.1016/j.compstruct.2024.118432三维变形表面的展开:一种基于屈曲诱导机制的二维形变超材料方法The 3-dimensional shape morphing is desired in applications such as aerospace, soft robotics and medical devices. Via the arrangement of auxetic cells, this paper proposes a box-shaped morphing block concept consisting of 2-dimensional metamaterial to realize 3D shape morphing driven through the structural buckling approach. Firstly, the expansion, bending and twisting deformation modes of the morphing block distinguished by varied Poisson’s ratio arrangement of the auxetic face cells on boundary lattices are introduced. Then, we verify the deployment of 3D deformation through a series of quasi-static tensile experiments, which present a good agreement with our simulation results and demonstrate the effectiveness of induced buckling mechanism. Finally, more complex morphing features are realized by a hybrid combination of the different deformation modes, while their deployment mechanisms are discussed. This morphing block concept with tailorable shape-shifting capability can be an excellent candidate in the 3D morphing structure application.在航空航天、软机器人和医疗设备等应用中需要三维形状变形。本文提出了一种由二维超材料组成的箱形变形块概念,通过结构屈曲驱动实现三维形状变形。首先,介绍了变形块的膨胀、弯曲和扭转变形模式,这些变形块是由边界格上的异形面单元的不同泊松比排列来区分的。然后,我们通过一系列的准静态拉伸实验验证了三维变形的部署,结果与我们的模拟结果吻合良好,证明了诱导屈曲机制的有效性。最后,通过不同变形模式的混合组合实现了更复杂的变形特征,并讨论了它们的展开机制。这种具有可定制变形能力的变形块概念在三维变形结构应用中具有良好的应用前景。SiCp/Al composites from conventional to empowered machining: Mechanisms and processabilityDewei Liu, Changhe Li, Peiming Xu, Wei Wang, Yanbin Zhang, Min Yang, Xin Cui, Benkai Li, Mingzheng Liu, Teng Gao, Yusuf Suleiman Dambatta, Aiguo Qindoi:10.1016/j.compstruct.2024.118433SiCp/Al复合材料从传统加工到强化加工:机理和可加工性SiCp/Al composites, known for their outstanding properties, are widely used in aerospace, automotive, and other fields. Despite extensive research, a complete theoretical framework and evaluation system for processing these composites have not yet been established. To enhance their processability, it is crucial to understand how processing-induced characteristics affect their machinability and to establish a robust evaluation system. This study addresses this gap by first reviewing the influence of particle properties on the mechanical properties of SiCp/Al composites. Next, both conventional and advanced machining mechanisms are analyzed, and the processability based on the cutting/grinding forces and surface roughness is evaluated. The results show that advanced machining techniques significantly improve processability compared to conventional methods. The ultrasonic elliptical vibration-assisted turning of the 25 vol% SiCp/Al6061 composites resulted in an 82.4% reduction in the cutting force. Laser-assisted turning of 45 vol% SiCp/Al composites achieved an 89.8% improvement in surface roughness (Sa). Finally, we identify research gaps and future challenges in processing SiCp/Al composites, providing technical support and theoretical guidance for both industry and academia.SiCp/Al复合材料以其优异的性能而闻名,广泛应用于航空航天、汽车等领域。尽管进行了广泛的研究,但尚未建立完整的加工这些复合材料的理论框架和评价体系。为了提高其可加工性,了解加工诱发特性如何影响其可加工性并建立健全的评价体系至关重要。本研究首先回顾了颗粒性能对SiCp/Al复合材料力学性能的影响,从而解决了这一空白。其次,分析了传统和先进的加工机构,并基于切削/磨削力和表面粗糙度评估了可加工性。结果表明,与传统加工方法相比,先进的加工技术显著提高了加工性能。超声椭圆振动辅助车削25 vol% SiCp/Al6061复合材料的切削力降低了82.4%。激光辅助车削45 vol% SiCp/Al复合材料的表面粗糙度(Sa)提高了89.8%。最后,我们确定了SiCp/Al复合材料加工的研究差距和未来挑战,为工业界和学术界提供了技术支持和理论指导。Bio-inspired topology optimization driven design for 3D printed radially graded meta-structures; Design, modeling and mechanical characteristicsKhalegh Kouhi-Lakeh, Mohsen Teimouri, Masoud Asgaridoi:10.1016/j.compstruct.2024.118435三维打印径向梯度元结构仿生拓扑优化驱动设计设计,建模和机械特性This study is focused on applying a topology optimization-driven design procedure on a predefined radial design domain to generate bio-inspired radially graded porous structures which are suitable to be used as energy absorbers and lightweight structures, bone scaffolds and implants in biomechanical applications. A topology optimization method is applied on two predefined design domains as well as a theoretical design approach based on geometrical parameters. In this regard, the optimized structures are geometrically studied and the design areas are formulated parametrically. The topology-optimized graded structures have been manufactured using the SLA 3D printing technology for sample compression tests. Numerical and experimental approaches are applied to them simultaneously and the finite element analyses (FEA) are verified. Finally, a parametric study is done to study the effects of the design variables on the architecture of generated designs and their mechanical properties, revealing a non-linear relation between design variables and properties. This study proposes a theoretical design method based on a topology-optimized design domain. A parametric study has been done, which allows designers to produce various geometries and choose the best one according to their needs. The design step is followed by mechanical characterization of the novel radial structures using experimentally-validated FE analyses.本研究的重点是在预定义的径向设计域上应用拓扑优化驱动设计程序,生成仿生径向梯度多孔结构,该多孔结构适用于生物力学应用中的能量吸收器和轻质结构,骨支架和植入物。在两个预先确定的设计域上采用拓扑优化方法和基于几何参数的理论设计方法。在这方面,优化结构进行了几何研究,并制定了参数化设计区域。利用SLA 3D打印技术制造了拓扑优化的梯度结构,并进行了样品压缩测试。采用数值和实验相结合的方法对其进行了分析,并对有限元分析结果进行了验证。最后,进行了参数化研究,研究了设计变量对生成设计的结构及其力学性能的影响,揭示了设计变量与力学性能之间的非线性关系。本研究提出一种基于拓扑优化设计域的理论设计方法。进行了参数化研究,使设计人员能够产生各种几何形状,并根据他们的需要选择最佳的几何形状。设计步骤之后是利用实验验证的有限元分析对新型径向结构进行力学表征。Parametric optimization framework for designing sandwich panels with auxetic core subjected to impact loadEdinilson A. Costa, Larissa Driemeierdoi:10.1016/j.compstruct.2024.118436抗冲击夹层板减芯设计的参数化优化框架An auxetic material can use the negative Poisson ratio to make the impact area denser and better absorb energy. This unique behavior can be exploited for building sandwich panels that absorb more energy per unit of weight. This work proposes a methodology to design lightweight auxetic-core sandwich panels with enhanced impact energy absorption capability. The method is based on an optimization framework whose function is a parameterized Finite Element model of a 3D auxetic structure. Metamodeling is used instead of direct optimization. The performance of different surrogate models, including Artificial Neural Networks, are computed and the best-ranked model is used for the subsequent optimization task carried-out with the aid of a genetic algorithm. The applicability of the framework is demonstrated by creating a sandwich panel with a 3D reentrant auxetic core subjected to a ballistic load, which is 36% lighter than the baseline design and 28% thinner than the literature reference honeycomb sandwich.减振材料可以利用负泊松比使冲击区域更致密,吸收能量更好。这种独特的性能可以用于建造每单位重量吸收更多能量的夹层板。这项工作提出了一种设计具有增强冲击能量吸收能力的轻质异形芯夹芯板的方法。该方法基于优化框架,其函数是三维结构的参数化有限元模型。使用元建模代替直接优化。计算了包括人工神经网络在内的不同代理模型的性能,并将排名最高的模型用于借助遗传算法执行的后续优化任务。该框架的适用性通过创建一个具有三维可入式辅助核心的夹层板来证明,该夹层板承受弹道载荷,比基准设计轻36%,比文献参考蜂窝夹层薄28%。Prediction of bond strength and failure mode of FRP bars embedded in UHPC or UHPSSC utilising extreme gradient boosting techniquePei-Fu Zhang, Xiao-Ling Zhao, Daxu Zhang, Mudassir Iqbal, Xuan Zhao, Qi Zhao, Yiliyaer Tuerxunmaimaiti, Congshui Yudoi:10.1016/j.compstruct.2024.118437利用极端梯度增强技术预测嵌入UHPC或UHPSSC的FRP筋的粘结强度和破坏模式The bond strength and failure mode of fibre-reinforced polymer (FRP) bars embedded in ultra-high-performance concrete (UHPC) and ultra-high-performance seawater sea sand concrete (UHPSSC) are significant to ensure the structural integrity of FRP-UHPC/UHPSSC structures. Given the multiplicity influencing bond interaction, conventional methods face challenges in developing predictive models and equations. For precise prediction and comprehensive investigation of bond performance in FRP-UHPC/UHPSSC, this paper employed an effective approach utilising extreme gradient boosting (XGBoost) technique to predict bond strength and failure mode. Two XGBoost predictive models were established based on a dataset comprising 542 data points with 14 input parameters. The developed models demonstrated reliable performances through an exhaustive assessment. SHAP (SHapley Additive exPlanations) analysis was employed to study the influences of input variables considering the bond mechanism. Specifically, the bonded-length-to-diameter ratio is pivotal in bond strength prediction, followed by FRP surface properties, concrete compressive strength and cover-to-diameter ratio; while cover-to-diameter ratio, bar diameter and concrete compressive strength stand out in failure mode prediction. Furthermore, explicit SHAP-based bond strength predictive equations were derived for concrete splitting and pullout failures. The developed model and equation demonstrate a closer approximation to experimental results compared to that in ACI 440.1R-15纤维增强聚合物(FRP)筋在高性能混凝土(UHPC)和高性能海水海砂混凝土(UHPSSC)中的粘结强度和破坏模式对保证FRP-UHPC/UHPSSC结构的完整性具有重要意义。考虑到影响键相互作用的多样性,传统方法在建立预测模型和方程方面面临挑战。为了准确预测和全面研究FRP-UHPC/UHPSSC的粘结性能,本文采用了一种有效的方法,利用极端梯度增强(XGBoost)技术来预测粘结强度和破坏模式。基于包含542个数据点和14个输入参数的数据集,建立了两个XGBoost预测模型。通过详尽的评估,所开发的模型显示了可靠的性能。采用SHapley加性解释(SHapley Additive explanatory, SHapley可加性解释)分析,考虑键合机制,研究输入变量的影响。具体而言,粘结长径比是预测粘结强度的关键,其次是FRP表面性能、混凝土抗压强度和覆盖直径比;而覆盖直径比、钢筋直径和混凝土抗压强度在破坏模式预测中较为突出。此外,导出了基于shap的混凝土劈裂和拉拔破坏的显式粘结强度预测方程。与aci440.1 r -15相比,所建立的模型和方程更接近实验结果Damage characterization of CFRP /steel double-lap bonded joints based on AE and DICZhiyuan Zhang, Changhang Xu, Jing Xie, Xueying Sun, Wenao Wang, Na Lidoi:10.1016/j.compstruct.2024.118441基于声发射和DIC的CFRP /钢双搭接接头损伤表征CFRP/steeljoints are commonly used in construction and can cause unpredictable damage when subjected to external loading. However, it is still challenging tocharacterize the damage evolution behavior of joints under different loads. In this study, acoustic emission (AE) and digital image correlation (DIC) techniques are used to monitor the damaged state of joints, and a decision tree (DT) algorithm was proposed. From the monitoring results of AE and DIC, it can be found that the damage process of the joint is divided into three stages and is mainly accompanied by four damage modes, namely adhesive failure, cohesive failure, skin failure, and steel deformation. In addition, it also reveals that the AE signal is more sensitive to the early damage of the joint, while the DIC is more sensitive to the late damage of the joint. The identification results of the DT algorithm show that the main damage mechanisms of the joints under the tensile loading conditions are adhesive failure and cohesive failure, while the primary damage mechanism under the bending loading conditions is adhesive failure. The combination of these two techniques successfully enables the damage characterization of joints and provides a framework for analyzing the damage mechanisms of joints.CFRP/钢节点通常用于建筑中,当受到外部载荷时可能造成不可预测的损伤。然而,表征不同荷载作用下节点的损伤演化行为仍然是一个挑战。本文采用声发射(AE)和数字图像相关(DIC)技术对关节损伤状态进行监测,并提出了一种决策树(DT)算法。从声发射和DIC的监测结果可以发现,接头的损伤过程分为三个阶段,主要伴随着粘结破坏、内聚破坏、蒙皮破坏和钢材变形四种损伤模式。此外,还揭示了声发射信号对关节早期损伤更敏感,而DIC对关节晚期损伤更敏感。DT算法的识别结果表明,在拉伸加载条件下,接头的主要损伤机制为粘结破坏和内聚破坏,而在弯曲加载条件下,接头的主要损伤机制为粘结破坏。这两种技术的结合成功地实现了关节损伤表征,为分析关节损伤机理提供了框架。Compression-compression fatigue damage of wrinkled carbon/glass hybrid composite laminatesXing-Yuan Miao, Xiao Chen, Steffen Rasmussen, Malcolm McGugandoi:10.1016/j.compstruct.2024.118443起皱碳/玻璃杂化复合材料层合板的压缩疲劳损伤Compression-compression fatigue tests were carried out to study the compressive fatigue damage mechanisms of a carbon/glass hybrid composite laminate with a manufacturing-induced wrinkle defect. As reported in literature, thin wrinkled composite laminates could show sensibly different fatigue behaviours and damage mechanisms in the presence of tension and compression cyclic loadings. The sensitivities of composites to tension and compression cyclic loadings were not the same. In this study, the damage modes and cracking sequence of a thick wrinkled laminate were identified by the strain fields from digital image correlation (DIC). Acoustic emission (AE) and infrared (IR) thermography were used to detect the damages and explore the potential capabilities of non-destructive evaluation methods when applied to detection of fatigue induced damages in composite structures under operational cyclic loadings. Two primary damage modes were identified and detected before the final failure of the laminate i.e. debonding between the resin-rich layer and the laminate and interlaminar cracks. Debonding occurred earlier than interlaminar cracking. Out-of-plane stresses due to fibre waviness drove the initiation of these damages. Under the settings of AE in this study AE captured early debonding activities but did not detect the micro damage accumulating before the formation of interlaminar crack. Interlaminar crack initiation was tracked by IR thermography at cross-section of the specimen based on the distinct temperature localisations that occur with this micro damage. No distinct temperature localisations occurred during the formation of debonding as it is mode-I driving under compression-compression cyclic loading, so IR thermography did not detect the debonding crack. The results of this study show the potential of using complementary non-destructive damage evaluation methods to inspect early damages in composite structures. The early detection of damages would give early warning signs before the damages become critical. It is found that AE and IR thermography should be used as complementary tools to detect different damage modes.采用压缩-压缩疲劳试验研究了一种带有制造诱导褶皱缺陷的碳/玻璃杂化复合材料层合板的压缩疲劳损伤机理。据文献报道,薄皱复合材料层合板在拉伸和压缩循环载荷下表现出明显不同的疲劳行为和损伤机制。复合材料对拉伸和压缩循环载荷的敏感性不相同。利用数字图像相关(DIC)的应变场识别厚起皱层压板的损伤模式和开裂顺序。利用声发射(AE)和红外(IR)热成像技术对复合材料结构进行损伤检测,探索无损评价方法在循环荷载作用下检测复合材料结构疲劳损伤的潜力。在层板最终破坏前,识别并检测到两种主要的破坏模式,即富树脂层与层板之间的脱粘和层间裂纹。剥离发生早于层间开裂。纤维波纹性引起的面外应力导致了这些损伤的发生。在本研究的声发射设置下,声发射捕获了早期的脱粘活动,但没有检测到层间裂纹形成之前积累的微损伤。基于这种微损伤产生的不同温度定位,通过红外热像仪在试样的横截面上跟踪层间裂纹的起裂。由于在压缩-压缩循环加载下为i型驱动,在脱粘形成过程中没有明显的温度局部化,因此红外热像仪未检测到脱粘裂纹。本研究结果显示了利用互补无损损伤评估方法检测复合材料结构早期损伤的潜力。损害的早期发现可以在损害变得严重之前提供早期预警信号。发现声发射和红外热成像可以作为互补工具来检测不同的损伤模式。Energy absorption assessment of recovered shapes in 3D-printed star hourglass honeycombs: Experimental and numerical approachesAmin Farrokhabadi, Houyu Lu, Xin Yang, Ali Rauf, Reza Talemi, Amir Hossein Behravesh, Seyyed Kaveh Hedayati, Dimitrios Chronopoulosdoi:10.1016/j.compstruct.2024.1184443d打印星形沙漏蜂窝恢复形状的能量吸收评估:实验和数值方法This study provides an experimental and numerical evaluation of the energy absorption performance of a 3D-printed star hourglass honeycomb structure with a novel design made from pure and reinforced PLA by chopped carbon fibers and continuous glass fiber. The study further investigates the energy absorption response of this structure after the shape recovery due to thermal stimuli under the quasi-static compressive loading. As an additive manufacturing process, Fused Deposition Modeling is used to produce the specimens with pure and reinforced PLA filament. The difference in the nonlinear response of PLA due to plasticity and damage in tension and compression loading directions, as a feature that helps the shape recovery, is considered in mechanical response analysis using the Finite Element approach. Then, in the obtained results distinguish constitutive laws in tension and compression mechanical properties are employed leading to a failure model using the appropriate algorithm consistent with the experiments. According to the obtained results which reveal good agreement regarding the experimental results, by designing appropriate auxetic configuration selecting suitable geometry parameters, and employing the proper material with diverse properties in tension and compression directions, it is possible to fabricate a lattice structure inherits the shape recovery after the compression deformation which exhibits acceptable energy absorption performance even the second shape recovery.本研究通过实验和数值方法对一种新型的3d打印星形沙漏蜂窝结构的吸能性能进行了评估。该结构由纯聚乳酸增强,由短切碳纤维和连续玻璃纤维制成。进一步研究了在准静态压缩载荷作用下,该结构在热刺 激下恢复形状后的能量吸收响应。作为一种增材制造工艺,熔融沉积建模被用于生产纯PLA和增强PLA长丝的样品。利用有限元方法进行力学响应分析时,考虑了PLA在拉伸和压缩加载方向上由于塑性和损伤引起的非线性响应差异,这是一种有助于形状恢复的特征。然后,在得到的结果中,区分拉伸和压缩力学性能的本构规律,采用与实验相一致的适当算法建立失效模型。所得结果与实验结果吻合较好,通过设计适当的形变构型,选择合适的几何参数,采用适当的拉伸和压缩方向性能不同的材料,可以制造出继承压缩变形后形状恢复的晶格结构,即使是第二次形状恢复也具有良好的吸能性能。A novel strategy for constructing electro-conductive segregated network of polyphenylene sulfide-based foam enables electromagnetic shielding effectivenessXinyi Liu, Zun Yuan, Yuanchun Zhang, Ping Xu, Xiaowen Zhao, Yun Yu, Lin Yedoi:10.1016/j.compstruct.2024.118446 一种新型的聚苯硫醚基泡沫导电隔离网络构建策略,使其具有良好的电磁屏蔽效果Developing polyphenylene sulfide (PPS)-based electromagnetic shielding foam is significant to broaden its applications in aerospace, electronic communications, etc., while introducing too many conductive fillers induced poor foaming ability of PPS. In this work, the skinless PPS foamed beads (S-PPS) were prepared, and coated with epoxy (EP)/carbon nanotubes (CNT) conductive interface layer, while the porous structure of bead surface greatly enhanced interface interaction between the two phases by forming interfacial mechanical interlocking structure with high adhesive strength. Thereby S-PPS@EP/CNT foam with conductive segregated network was obtained by surface adhesion-assisted molding method of supercritical CO2 (scCO2) bead foaming. CNTs were dispersed uniformly and entangled with each other in interface layer, and the conductivity of interface layer and S-PPS@EP/CNT foam increased remarkably with extremely low percolation threshold, attributed to confined distribution of CNTs in interface layer, and perfect conductive segregated network formed at lower CNT content. With increasing CNT content, the complex permittivity, dielectric loss factor and conductivity of foams increased, so that the ability to attenuate electromagnetic waves through polarization loss and conductivity loss was enhanced, showing significantly improved electromagnetic shielding performance and absorption-based shielding mechanism. This work provided a facile and innovative way for fabrication of PPS-based electromagnetic shielding foam.开发基于聚苯硫醚(PPS)的电磁屏蔽泡沫对拓宽其在航空航天、电子通信等领域的应用具有重要意义,但过多导电填料的引入会导致 PPS 的发泡能力变差。本研究制备了无皮 PPS 发泡珠子(S-PPS),并在其表面涂覆了环氧树脂(EP)/碳纳米管(CNT)导电界面层,而珠子表面的多孔结构大大增强了两相之间的界面相互作用,形成了具有高粘合强度的界面机械互锁结构。因此,通过超临界二氧化碳(scCO2)微珠发泡的表面粘附辅助成型方法,获得了具有导电离析网络的 S-PPS@EP/CNT 泡沫。CNT在界面层中均匀分散并相互缠结,界面层和S-PPS@EP/CNT泡沫的导电率显著提高,渗流阈值极低,这归功于CNT在界面层中的密闭分布,并且在CNT含量较低时形成了完美的导电隔离网络。随着 CNT 含量的增加,泡沫的复介电常数、介质损耗因数和电导率也随之增加,从而提高了通过极化损耗和电导率损耗衰减电磁波的能力,显著改善了电磁屏蔽性能和基于吸收的屏蔽机理。这项工作为制备基于 PPS 的电磁屏蔽泡沫提供了一种简便、创新的方法。Composites Part A: Applied Science and ManufacturingIntegrating experimental and numerical analyses for microscale tensile behavior of ceramic particle reinforced TRIP steel composites: A study on local deformation and damage evolutionChenChun Chiu, Vimal Prabhakar, ShaoChen Tseng, Faisal Qayyum, Sergey Guk, ChingKong Chao, Ulrich Prahldoi:10.1016/j.compositesa.2024.108384 陶瓷颗粒增强TRIP钢复合材料微尺度拉伸行为的实验与数值分析:局部变形与损伤演化研究This study investigates deformation, interfacial, and particle damage in a magnesium-partially stabilized zirconia (Mg-PSZ) particle-reinforced transformation-induced plasticity (TRIP) steel composite using SEM in situ tensile tests and finite element simulations. The simulation models employ an elastic model for ceramic particles and a Johnson-Cook plastic model for the matrix, considering individual perfect cohesive zone model (CZM) and combined CZM/extended finite element method (XFEM) models along the interface. The simulation and experimental results are qualitatively and quantitatively consistent for the initiation and evolution of interfacial and particle failure with a relative error in crack length of only 4.6 %. Furthermore, crack propagation analysis by the debonding angle reveals that damage starts earlier with a sharper particle geometry. Prioritizing non-linear interfacial morphologies in particles and controlling reinforcement edges perpendicular to the loading can achieve lower and constrained debonding angles, thereby continuing to provide a strengthening effect and finally enhancing material behavior.本研究利用SEM原位拉伸试验和有限元模拟研究了镁-部分稳定氧化锆(Mg-PSZ)颗粒增强相变诱发塑性(TRIP)钢复合材料的变形、界面和颗粒损伤。仿真模型采用陶瓷颗粒的弹性模型和基体的Johnson-Cook塑性模型,考虑了沿界面的单个完美黏聚区模型(CZM)和CZM/扩展有限元法联合模型(XFEM)。模拟结果与实验结果在定性和定量上基本一致,裂纹长度的相对误差仅为4.6%。此外,裂纹扩展分析通过剥离角揭示损伤开始早,更尖锐的颗粒几何形状。优先考虑颗粒中的非线性界面形态,并控制垂直于加载的增强边缘,可以实现较低的约束脱粘角,从而继续提供强化效果,最终提高材料性能。Composites Science and TechnologyCoaxial direct ink writing of ZnO functionalized continuous carbon fiber-reinforced thermosetting compositesZhuoyuan Yang, Evan Medora, Zefu Ren, Meng Cheng, Sirish Namilae, Yizhou Jiangdoi:10.1016/j.compscitech.2024.110782 ZnO功能化连续碳纤维增强热固性复合材料的同轴直墨书写Additive manufacturing of fiber-reinforced thermosetting composites is of great importance for various applications. However, improving the quality of the fiber/matrix interface under various additive manufacturing processes is still in the early stages. Herein, for the first time, we report the coaxial direct ink writing of zinc oxide (ZnO) functionalized continuous carbon fiber-reinforced thermosetting polymer composites. Both elastomeric and rigid thermosetting polymers reinforced with ZnO functionalized continuous carbon fiber composites can be printed into single filaments with turning angles and multi-layer tall arbitrary structures. The printed ZnO functionalized epoxy composites achieve Young's modulus of 3.69 GPa, which is 15.3% higher than pristine fiber-reinforced composites. The printed composite exhibits resistance under various environmental conditions. Additionally, ZnO functionalization significantly enhanced the fiber-matrix interface strength, with improvements of 57%. The reduced modulus of ZnO functionalized fibers is 174% higher than that of pristine fibers. ZnO nanowires enhance the heating transfer rate of carbon fibers by 17% within the same heating time. Our innovative coaxial direct ink writing offers a general strategy for multi-material printing, laying the groundwork for future additive manufacturing of functional composite devices and structures with enhanced performance.增材制造纤维增强热固性复合材料在各种应用中具有重要意义。然而,在各种增材制造工艺下,提高纤维/基体界面质量仍处于早期阶段。在此,我们首次报道了氧化锌功能化连续碳纤维增强热固性聚合物复合材料的同轴直接墨水书写。用ZnO功能化连续碳纤维复合材料增强弹性体和刚性热固性聚合物都可以打印成具有转角的单长丝和多层高任意结构。打印的ZnO功能化环氧复合材料的杨氏模量为3.69 GPa,比原始纤维增强复合材料高15.3%。打印的复合材料在各种环境条件下都具有良好的耐受性。此外,ZnO功能化显著提高了纤维-基体界面强度,提高了57%。氧化锌功能化纤维的还原模量比原始纤维高174%。在相同的加热时间内,ZnO纳米线使碳纤维的传热速率提高了17%。我们创新的同轴直接墨水书写为多材料打印提供了一种通用策略,为未来功能复合材料器件和结构的增材制造奠定了基础。Customizable 3D-printed decoupled structural lithium-ion batteries with stable cyclability and mechanical robustnessXu Ma, Yinhua Bao, Na Li, Bo Lu, Yicheng Song, Junqian Zhang, Daining Fangdoi:10.1016/j.compscitech.2024.110783可定制的3d打印解耦结构锂离子电池,具有稳定的可循环性和机械稳健性Structural batteries are considered one of the promising strategies for improving the endurance of electric vehicles. However, the trade-off between load-bearing capability and electrochemical performance remains a significant challenge. This paper proposes an efficient 3D printing-assisted fabrication strategy for high-performance structural batteries with customizable geometric configurations. The composite structural battery sample shows a bending modulus of 24.5 GPa, which could withstand maximum tensile stress and three-point bending stress of 155 MPa (specific tensile strength of 88340 N m kg-1) and 123 MPa (specific bending strength of 61553 N m kg-1). Meanwhile, it can achieve a high energy density of 120 Wh kg-1 and 210 Wh L-1 (3.5 mA cm-2) and superior capacity retention of up to 92% after 500 cycles (10.5 mA cm-2). More importantly, the in-situ mechanical-electrochemical test demonstrates exceptional performance, retaining an ultra-high capacity of 98.7% under a tensile stress of 80 MPa, and maintaining a capacity retention rate of 97 % with an average capacity decay per cycle of only 0.18 % under a bending stress of 96.3 MPa. In addition, finite element analysis is also used to verify the failure mechanism of the battery under bending load. Meanwhile, the fabricated structural battery can be applied to autonomous mobile robots, showing the multifunction energy storage and load-bearing. As a result, this work showcases the great potential of incorporating high-performance structural batteries into engineering applications such as small-scale warehousing, logistics equipment, and intelligent robotics.结构电池被认为是提高电动汽车续航能力的有前途的策略之一。然而,在承载能力和电化学性能之间的权衡仍然是一个重大挑战。本文提出了一种高效的3D打印辅助制造策略,用于具有可定制几何结构的高性能结构电池。复合材料结构电池样品的弯曲模量为24.5 GPa,可承受最大拉伸应力155 MPa(比拉伸强度88340 N m kg-1)和三点弯曲应力123 MPa(比弯曲强度61553 N m kg-1)。同时,它可以实现120 Wh kg-1和210 Wh L-1 (3.5 mA cm-2)的高能量密度,并在500次循环(10.5 mA cm-2)后保持高达92%的卓越容量。更重要的是,原位力学电化学测试显示了优异的性能,在80 MPa的拉伸应力下保持了98.7%的超高容量,在96.3 MPa的弯曲应力下保持了97%的容量保持率,平均每循环容量衰减仅为0.18%。此外,还采用有限元分析验证了电池在弯曲载荷作用下的失效机理。同时,制造的结构电池可应用于自主移动机器人,显示出多功能储能和承载能力。因此,这项工作展示了将高性能结构电池纳入小型仓储、物流设备和智能机器人等工程应用的巨大潜力。Loading rate effect on the shear behavior of the carbon fiber/epoxy interfaceKai Yan, Xunqiandi Cao, Ximing Xie, Haijuan Mei, Jianbo Tang, Xiangyu Sun, Fuzeng Rendoi:10.1016/j.compscitech.2024.110785 加载速率对碳纤维/环氧树脂界面剪切性能的影响Carbon fiber (CF)/epoxy (EP) composites are widely used in structural components. Quasistatic and dynamic shear experiments were designed and conducted to investigate the effect of the loading rate on the shear behavior of the CF/EP interface. Using numerical simulation, the accuracy of the new shear testing methods to test the shear behavior of interface under both quasistatic and dynamic loading conditions was verified. The shear failure stress increases with increasing loading rate, and the failure mode of the CF/EP interface changes from fiber-matrix debonding to almost entirely brittle fracture of the matrix and fiber-matrix debonding. The proposed dynamic shear test method is promising for testing the shear behavior of interface between two kinds of materials or phases, and the shift in the failure mode is a consequence of the effect of the loading rate on the shear behavior of the CF/EP interface.碳纤维(CF)/环氧树脂(EP)复合材料在结构部件中有着广泛的应用。设计了准静态和动态剪切实验,研究了加载速率对CF/EP界面剪切性能的影响。通过数值模拟,验证了新剪切试验方法在准静态和动加载条件下测试界面剪切性能的准确性。剪切破坏应力随加载速率的增加而增大,CF/EP界面的破坏模式由纤维-基体脱粘转变为基体和纤维-基体几乎完全脆性断裂。所提出的动态剪切试验方法有望测试两种材料或相之间界面的剪切行为,而破坏模式的转变是加载速率对CF/EP界面剪切行为影响的结果。来源:复合材料力学仿真Composites FEM

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