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【新文速递】2024年9月13日固体力学SCI期刊最新文章

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

Journal of the Mechanics and Physics of Solids

Nonlinear dynamics of a flexible rod partially sliding in a rigid sleeve under the action of gravity and configurational force

Yury Vetyukov, Alexander Humer, Alois Steindl

doi:10.1016/j.jmps.2024.105854

在重力和构形力作用下,柔性杆在刚性套筒中部分滑动的非线性动力学

We investigate various methods of analyzing systems with moving boundaries, using as an example a flexible rod sliding in an ideal frictionless sleeve in the field of gravity. Special attention is paid to the configurational force acting on the rod at the sleeve opening and thus determining the rod’s dynamics. The non-material kinematic description used in simulations is based on the re-parametrization of the Lagrangian arc length coordinate. The variational formulation uses the energy expressions written for the entire rod, comprising the free segment and the one inside the sleeve. A novel finite element scheme is efficient for highly flexible rods, which may undergo complete ejection. A simplified two degrees of freedom model, which accelerates simulations, shows a good agreement as the bending stiffness increases. An analytical study using Hamiltonian mechanics exploits the separation of variables into fast oscillations and slow axial motion. The adiabatic invariant approach leads to approximate closed-form solutions for the slow dynamics and yields the maximum injection depth of the rod into the sleeve.

我们研究了分析具有移动边界的系统的各种方法,以在重力场中理想无摩擦套筒中滑动的柔性杆为例。特别注意的是在套筒开口处作用在杆上的构形力,从而决定杆的动力学。仿真中使用的非物质运动学描述是基于拉格朗日弧长坐标的重新参数化。变分公式使用为整个杆写的能量表达式,包括自由段和套内段。一种新的有限元方案对高柔性杆的完全顶出是有效的。简化后的二自由度模型随着弯曲刚度的增大,与仿真结果吻合较好。一项利用哈密顿力学的分析研究利用了将变量分离为快速振荡和慢轴向运动。绝热不变量方法可以得到慢动力学的近似封闭解,并得到抽油杆注入滑套的最大注入深度。


How do multiple active cellular forces co-regulate wound shape evolution?

Qianchun Wang, Shijie He, Baohua Ji

doi:10.1016/j.jmps.2024.105864

多种活跃的细胞力量如何共同调节伤口形状的演变?

Wound closure is a fundamental procedure in many physiological and pathological processes, driven by multiple active cellular forces. In the closure process the wound shape can evolve into round, oval, or slit. However, the underlying mechanisms that determine the mechanical strategies of wound shape evolution are unclear. To understand how these active forces co-regulate wound shapes, we constructed a novel complex variable method-based mechanical model and obtained the stress field and free energy of cell layer with arbitrary wound shape. Our results revealed that there was a stress-driven cell polarization and arrangement around the wound under the cooperative regulation of the tissue pretension, cell protrusion stress and actomyosin ring tension that drove the direction of cell polarization and arrangement for the wound closure. In addition, a 3D phase diagram was obtained from minimizing the free energy of the cell layer that illustrates how the different active cellular forces co-regulate the wound shape evolution. In general, large cellular protrusion induces the evolution of the wound toward slit shape, and strong and medium contractions of the actomyosin ring correspond to the evolution toward oval shape and round shape, respectively. This study reveals a critical mechanism by which living organisms actively control complex processes via the coordination of multiple active cellular forces in tissue repair and development.

伤口愈合是许多生理和病理过程的基本过程,由多种活跃的细胞力量驱动。在缝合过程中,伤口的形状可以演变成圆形、椭圆形或狭缝。然而,决定伤口形状演变的机械策略的潜在机制尚不清楚。为了了解这些作用力如何共同调节伤口形状,我们构建了一种基于复变方法的新型力学模型,并获得了任意伤口形状的细胞层应力场和自由能。结果表明,在组织预张力、细胞突出应力和肌动球蛋白环张力的共同调节下,创面周围存在应力驱动的细胞极化和排列,驱动细胞极化和排列的方向。此外,通过最小化细胞层的自由能得到三维相图,说明了不同的活性细胞力如何共同调节伤口形状的演变。一般情况下,大的细胞突起诱导创面向狭缝形状演化,肌动球蛋白环的强收缩和中等收缩分别对应创面向椭圆形和圆形演化。这项研究揭示了生物体在组织修复和发育过程中通过多种活跃细胞力量的协调来主动控制复杂过程的关键机制。


Mechanics of Materials

A finite strain viscoelastic model with damage and tension-compression asymmetry considerations for solid propellants

F. Gouhier, J. Diani, A. Vandenbroucke

doi:10.1016/j.mechmat.2024.105152

考虑损伤和拉压不对称的固体推进剂有限应变粘弹性模型

A short survey on the experimental testing of solid propellants has highlighted finite strain responses that are temperature-dependent, viscoelastic with damage, and exhibit tension/compression asymmetry. Consequently, a finite strain viscoelastic model that satisfies the principles of thermodynamics has been developed. This model is based on the common multiplicative decomposition of the deformation gradient into elastic and viscous components, with considerations for damage and asymmetry. The model has been tested against three sets of data from the literature, carefully selected to represent the various characteristics of solid propellants. The model accurately reproduces uniaxial tension responses at different strain rates and temperatures, with the capability to account for superimposed hydrostatic pressure. Notably, these satisfactory representations require only five fitting parameters, in addition to the typical identification of polymer linear viscoelasticity and time–temperature superposition. Finally, an attempt to reproduce both tension and compression tests conducted independently on the same material underscores the need to account for tension-compression asymmetry, as defined in the proposed constitutive equations. This finding advocates for new tests, such as compression following tension and vice versa.

一项关于固体推进剂实验测试的简短调查表明,有限应变响应与温度有关,具有损伤的粘弹性,并表现出拉伸/压缩不对称。因此,建立了一个满足热力学原理的有限应变粘弹性模型。该模型基于将变形梯度分解为弹性和粘性分量的常见乘法分解,并考虑了损伤和不对称性。该模型已经用文献中的三组数据进行了测试,这些数据都是经过精心挑选的,以代表固体推进剂的各种特性。该模型精确地再现了在不同应变率和温度下的单轴拉伸响应,并具有考虑叠加静水压力的能力。值得注意的是,这些令人满意的表示只需要五个拟合参数,以及聚合物线性粘弹性和时间-温度叠加的典型识别。最后,试图重现在同一材料上独立进行的拉伸和压缩试验,强调了考虑拉伸-压缩不对称的必要性,正如所提议的本构方程所定义的那样。这一发现提倡新的测试,如压缩后张力,反之亦然。


Thin-Walled Structures

Investigation on load-bearing capacity improvement coefficient of CFRP-reinforced CHS KT-joints

Tiantian Wang, Lewei Tong, Feng Gao, Xiaoming Xu, Weizhou Shi, Madhup Pandey, Fangying Wang

doi:10.1016/j.tws.2024.112455

cfrp加固CHS - kt节点承载力提升系数研究

This study numerically analyzes the load-bearing capacity of Carbon Fibre Reinforced Polymer (CFRP) strengthened circular hollow section (CHS) multiplanar KT-joints based on experiments. Compared to unreinforced joints, the load-bearing capacity improvement coefficient k was proposed and investigated. First, the experiments on bare and CFRP-reinforced CHS KT-joints were briefly described. Three-dimensional numerical models were then established for bare and CFRP-strengthened CHS KT-joints. Refined and simplified CFRP models were established. The effectiveness of the simplified CFRP model was validated by comparing it with experimental results. To improve computational efficiency, the contact between CFRP and steel tubes was optimized by the combination of surface-based cohesive behavior and tie. A parametric study was carried out to analyze the effect of 20 independent parameters on k. We found that k is primarily influenced by non-dimensional geometric parameters, load of brace-T, number of CFRP layers, and CFRP properties. Parametric formulae for k were established through nonlinear regression analysis. The proposed parametric formulae agree well with numerical analysis and experimental results.

本文在试验的基础上,对碳纤维增强聚合物(CFRP)增强圆空心截面(CHS)多平面kt -节点的承载能力进行了数值分析。与未加筋节点相比,提出并研究了承载力提高系数k。首先,简要介绍了裸节点和cfrp增强CHS - kt节点的试验情况。建立了裸节点和cfrp加固节点的三维数值模型。建立了改进和简化的CFRP模型。通过与试验结果的对比,验证了简化CFRP模型的有效性。为了提高计算效率,采用基于表面的粘结行为和结合的方法对CFRP与钢管的接触进行了优化。我们进行了一项参数研究,分析了20个独立参数对k的影响。我们发现k主要受无因次几何参数、支撑- t的载荷、CFRP层数和CFRP性能的影响。通过非线性回归分析,建立了k的参数公式。所提出的参数公式与数值分析和实验结果吻合较好。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemDeform非线性ADS材料控制试验
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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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