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【新文速递】2024年2月19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,International Journal of Plasticity 1 篇,Thin-Walled Structures 1 篇

Journal of the Mechanics and Physics of Solids

A reactive electrochemomechanical theory for growth and remodeling of polyelectrolyte hydrogels and application to dynamic polymerization of DNA hydrogels

Brandon K. Zimmerman, Bibekananda Datta, Ruohong Shi, Rebecca Schulman, Thao D. Nguyen

doi:10.1016/j.jmps.2024.105568

聚电解质水凝胶生长和重塑的反应电化学机械理论及其在 DNA 水凝胶动态聚合中的应用

This study develops a framework for growth and remodeling of active polyelectrolyte hydrogels that accounts for effects of compositional changes on the mechanical response. By developing a reactive electrochemomechanical theory, thermodynamical constraints upon reactive and remodeling processes are elucidated within a general framework that allows any number of chemical reactions to evolve the response of the gel and transfer mass and charge between constituents. Fully coupled, nonlinear constitutive relations are adopted for molar fluxes, allowing exploration of effects including cross-diffusion, electrophoresis, and electro-osmosis. A robust finite element implementation is developed in the open source FEBio software (febio.org) by exploiting an equivalence between electrochemomechanics and mixture theory. The implementation is verified against analytical solutions for free swelling, and a proper reduction to a prior chemomechanical theory is demonstrated for neutral gels swollen only by a solvent with no solutes. The theory and implementation are then applied to model the tunable large swelling achieved through dynamic polymerization of DNA crosslinkers seen in our recently developed experimental hydrogel system (Cangialosi et al., 2017). A novel constitutive model for reaction-driven evolution of the locking stretch λL in a non-Gaussian mechanical free energy was developed, where the increasing concentration of DNA crosslinkers makes further swelling energetically favorable. With a single free parameter, excellent agreement was found between measured and predicted equilibrium swelling ratios. This study demonstrated the ability to extend the electrochemomechanical framework to include chemical reactions and composition-aware constitutive models, and showed that development of reactive models allows simulation of complex dynamic polymerization phenomena not treated before. The theoretical frame here can be further expanded in scope to incorporate additional non-ideal and nonlinear phenomena.

本研究为活性聚电解质水凝胶的生长和重塑建立了一个框架,该框架考虑了成分变化对机械响应的影响。通过发展反应电化学机械理论,在一个允许任何数量的化学反应来改变凝胶反应并在成分间传递质量和电荷的通用框架内,阐明了反应和重塑过程的热力学约束。摩尔通量采用完全耦合的非线性构成关系,允许探索包括交叉扩散、电泳和电渗在内的效应。利用电化学力学和混合物理论之间的等效性,在开源 FEBio 软件(febio.org)中开发了稳健的有限元实现方法。该实现方法与自由溶胀的分析解决方案进行了验证,并证明了对于仅由无溶剂的溶剂溶胀的中性凝胶,可以适当还原为先前的化学机械理论。然后将该理论和实现方法应用于模拟我们最近开发的实验水凝胶系统(Cangialosi 等人,2017 年)中通过 DNA 交联剂的动态聚合实现的可调大溶胀。针对非高斯机械自由能中锁定拉伸 λL 的反应驱动演化建立了一个新的构成模型,在该模型中,DNA 交联剂浓度的增加使进一步溶胀在能量上变得有利。只需一个自由参数,就能发现测量值与预测值之间的平衡溶胀率非常一致。这项研究证明了将电化学机械框架扩展到包括化学反应和成分感知构成模型的能力,并表明开发反应模型可以模拟以前未处理过的复杂动态聚合现象。这里的理论框架还可以进一步扩展,纳入更多的非理想和非线性现象。


Prediction of yield surface of single crystal copper from discrete dislocation dynamics and geometric learning

Wu-Rong Jian, Mian Xiao, WaiChing Sun, Wei Cai

doi:10.1016/j.jmps.2024.105577

从离散位错动力学和几何学习预测单晶铜的屈服面

The yield surface of a material is a criterion at which macroscopic plastic deformation begins. For crystalline solids, plastic deformation occurs through the motion of dislocations, which can be captured by discrete dislocation dynamics (DDD) simulations. In this paper, we predict the yield surfaces and strain-hardening behaviors using DDD simulations and a geometric manifold learning approach. The yield surfaces in the three-dimensional space of plane stress are constructed for single-crystal copper subjected to uniaxial loading along the [100] and [110] directions, respectively. With increasing plastic deformation under [100] loading, the yield surface expands nearly uniformly in all directions, corresponding to isotropic hardening. In contrast, under [110] loading, latent hardening is observed, where the yield surface remains nearly unchanged in the orientations in the vicinity of the loading direction itself but expands in other directions, resulting in an asymmetric shape. This difference in hardening behaviors is attributed to the different dislocation multiplication behaviors on various slip systems under the two loading conditions.

材料的屈服面是宏观塑性变形开始的标准。对于晶体固体,塑性变形是通过位错运动发生的,而位错运动可以通过离散位错动力学(DDD)模拟捕捉到。本文利用 DDD 模拟和几何流形学习方法预测屈服面和应变硬化行为。我们为分别沿 [100] 和 [110] 方向承受单轴载荷的单晶铜构建了平面应力三维空间中的屈服面。在[100]方向加载时,随着塑性变形的增加,屈服面几乎在所有方向上均匀扩展,相当于各向同性硬化。相反,在[110]加载条件下,则出现了潜伏硬化,屈服面在加载方向附近的方向上几乎保持不变,但在其他方向上却扩大了,从而形成了不对称的形状。硬化行为的这种差异归因于两种加载条件下不同滑移系统上不同的位错倍增行为。


Mechanics of Materials

Mechanical properties and deformation mechanisms of single crystal Mg micropillars subjected to high-strain-rate C-axis compression

Z. Lin, D.J. Magagnosc, J. Wen, X. Hu, H.D. Espinosa

doi:10.1016/j.mechmat.2024.104951

单晶镁微柱在高应变速率 C 轴压缩条件下的力学性能和变形机制

The mechanical properties and deformation mechanisms of single crystal magnesium under c-axis quasi-static and high-strain rate compressions are investigated through in situ scanning electron microscope (SEM) experiments and post-mortem transmission electron microscope (TEM) characterization. The findings revealed that ductility and high rates of hardening are preserved for pillars as large as 15 μm. Furthermore, rate effects result in a mild increase in flow stress with plastic deformations controlled primarily by the slip of <a+c> type dislocations. Importantly and in contrast to other literature reports, plastic deformation occurs in the absence of twining. As the strain increases and plastic deformation exceeds about 4%, crystal rotation activates basal slip, type dislocations, resulting in a more rate independent flow stress. TEM observation on micropillars compressed at a strain rate of 250/s, revealed the activation of {11 2¯2¯} <1¯1¯23> slip systems and high mobility of screw dislocations as major contributors to plastic strains in excess of 10% without fracture. These findings are relevant to the design of lightweight materials used in transportation systems, e.g., selection of material grain size. Moreover, the experimental data here reported provides the materials science community with a unique opportunity to validate discrete dislocation dynamics (DDD) formulations employed in multiscale design of materials.

通过原位扫描电子显微镜(SEM)实验和死后透射电子显微镜(TEM)表征,研究了单晶镁在 c 轴准静态和高应变率压缩条件下的机械性能和变形机制。研究结果表明,大至 15 μm 的柱体仍保持了延展性和高硬化率。此外,速率效应导致流动应力轻度增加,塑性变形主要由 <a+c> 型位错滑移控制。重要的是,与其他文献报道不同,塑性变形是在没有缠绕的情况下发生的。随着应变的增加和塑性变形超过约 4%,晶体旋转激活了基底滑移和 型位错,从而产生了与速率更不相关的流动应力。对以 250/s 应变速率压缩的微柱体进行的 TEM 观察显示,基底滑移和 型位错的激活与应变速率无关。{11 2¯2¯} <1¯1¯23> 滑移系统和螺钉位错的高流动性是导致塑性应变超过 10%而不断裂的主要原因。这些发现与运输系统中使用的轻质材料的设计有关,例如材料晶粒大小的选择。此外,本文报告的实验数据为材料科学界提供了一个独特的机会,以验证多尺度材料设计中采用的离散位错动力学(DDD)公式。


International Journal of Plasticity

Modelling and simulation of dynamic compression of Bulk Metallic Glasses at room and elevated temperatures using split Hopkinson pressure bar setup

Arun Kamble, Parag Tandaiya

doi:10.1016/j.ijplas.2024.103915

使用分体式霍普金森压力棒装置对散装金属玻璃在室温和高温下的动态压缩进行建模和模拟

This paper presents a modelling and simulation study of dynamic compression behaviour of Bulk Metallic Glasses (BMGs) at room and elevated temperatures using the split Hopkinson pressure bar (SHPB) setup. The primary objective of this study is to develop and validate a constitutive model and simulation methodology capable of predicting the high strain rate response of BMGs at different temperatures. We propose a constitutive model for BMGs that accounts for the effects of high strain rates and elevated temperatures. We numerically implemented this model in ABAQUS/Explicit Finite Element Analysis software by writing a Vectorized User Material (VUMAT) subroutine. The methodology for modelling and simulation of dynamic compression of BMG specimens using the SHPB setup is developed. The present simulations are able to correctly predict the rate-independent response of Zr41.2Ti13.8Cu12.5 Ni10Be22.5 (Vitreloy-1) BMG under dynamic compression at room and elevated temperatures. Furthermore, the present simulations are also able to correctly predict the negative strain rate sensitivity (SRS) of Zr52.5Cu17.9Ni14.6Al10Ti5 (Vitreloy-105) BMG at room temperature. Finally, the present simulations correctly predict that the failure stress of Zr64.13Cu15.75Ni10.12Al10 BMG decreases with increasing temperature and exhibits a minimal positive SRS. The present study is the first successful attempt to model the mechanical response of various BMGs under dynamic compression and at room and elevated temperatures. In particular, the experimentally observed negative SRS in some BMGs has been successfully simulated. The present work has important implications for the design of next generation spacecraft shields that are based on BMGs for mitigating the effects of hypervelocity impacts from debris in space.

本文介绍了利用分体式霍普金森压力棒(SHPB)装置对块状金属玻璃(BMG)在室温和高温下的动态压缩行为进行建模和模拟研究的情况。本研究的主要目的是开发和验证能够预测不同温度下 BMG 高应变率响应的构成模型和模拟方法。我们提出了一种考虑到高应变率和高温影响的 BMG 构成模型。通过编写矢量化用户材料 (VUMAT) 子程序,我们在 ABAQUS/显式有限元分析软件中对该模型进行了数值化实现。我们开发了使用 SHPB 设置对 BMG 试样进行动态压缩建模和模拟的方法。本模拟能够正确预测 Zr41.2Ti13.8Cu12.5 Ni10Be22.5 (Vitreloy-1) BMG 在室温和高温动态压缩下与速率无关的响应。此外,本模拟还能正确预测室温下 Zr52.5Cu17.9Ni14.6Al10Ti5(Vitreloy-105)BMG 的负应变速率敏感性(SRS)。最后,本模拟结果正确预测了 Zr64.13Cu15.75Ni10.12Al10 BMG 的破坏应力随温度升高而减小,并表现出最小的正 SRS。本研究首次成功模拟了各种 BMG 在动态压缩、室温和高温条件下的机械响应。特别是成功模拟了实验观察到的某些 BMG 的负 SRS。本研究成果对于设计基于 BMG 的下一代航天器防护罩以减轻空间碎片的超高速撞击影响具有重要意义。


Thin-Walled Structures

The phase-field fracture model enriched by interpolation cover functions for brittle fracture problems

Jiye Wang, Liming Zhou, Zhiqiang Gao, Peng Liu

doi:10.1016/j.tws.2024.111724

针对脆性断裂问题的插值覆盖函数丰富的相场断裂模型

In this study, interpolation cover functions were introduced into the phase-field fracture model (PFM) to improve its convergence and efficiency. The traditional PFM has proven to be successful in simulating brittle fracture problems. However, one disadvantage is that it requires a relatively dense mesh. The PFM model enriched by interpolation cover functions (EPFM) was used for numerical fracture analysis under a relatively coarse mesh. The rank deficiency problem caused by the introduction of interpolation cover functions was resolved using the rank deficiency repair technique. Higher gradients were captured by introducing interpolation cover functions without changing the mesh structure. The numerical examples showed the improvement in convergence. The high efficiency of the proposed EPFM was demonstrated through a series of numerical examples. The numerical results of the EPFM and PFM under different length-scale parameters and meshes were also compared. The results showed that the proposed EPFM is an excellent alternative for evaluating engineering fracture problems.

本研究在相场断裂模型(PFM)中引入了插值覆盖函数,以提高其收敛性和效率。事实证明,传统的相场断裂模型在模拟脆性断裂问题上是成功的。但其缺点是需要相对密集的网格。通过插值覆盖函数(EPFM)丰富的 PFM 模型被用于在相对较粗的网格下进行断裂数值分析。使用秩缺陷修复技术解决了因引入插值覆盖函数而导致的秩缺陷问题。通过引入插值覆盖函数,在不改变网格结构的情况下捕捉到了更高的梯度。数值实例表明收敛性得到了改善。通过一系列数值示例,证明了所提出的 EPFM 的高效性。此外,还比较了 EPFM 和 PFM 在不同长度尺度参数和网格下的数值结果。结果表明,所提出的 EPFM 是评估工程断裂问题的最佳选择。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemFluxAbaqus断裂非线性化学通用航天电子理论材料多尺度控制
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首次发布时间:2024-11-06
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【新文速递】2024年2月4日复合材料SCI期刊最新文章

今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 4 篇,Composites Part B: Engineering 6 篇,Composites Science and Technology 4 篇Composite StructuresTheoretical and numerical analysis on elastic-plastic bending responses of honeycomb beamsXiong Zhang, Xinrong Fudoi:10.1016/j.compstruct.2024.117948蜂窝梁弹塑性弯曲响应的理论和数值分析Cellular honeycomb beams are widely encountered in nature and engineering applications. The mechanical responses of them under various loads are critical to their applications. However, theoretical analyses and predictions of these mechanical responses are quite challenging. In this paper, theoretical studies are carried out to predict their large deformation bending responses. Theoretical expressions are derived for bending moment responses of honeycomb beams under both pure bending and three-point bending by considering the bending theory of solid beams and incorporating the relative density ρ* of the cellular honeycomb beams. Numerical simulations are performed to demonstrate the effectiveness and accuracy of the proposed theories by using the numerical model validated by experiment. Rectangular honeycomb beams with the relative density 0&lt;ρ*≤1 are selected by Latin hypercube sampling. The theoretical bending moment curves of these beams predicted by the proposed theories agree well with the numerical results for both pure bending and three-point bending. In addition, the proposed theories are also validated to be effective in predicting the bending responses of honeycomb beams with different sectional cell shapes.蜂窝梁在自然界和工程应用中广泛存在。它们在各种载荷作用下的机械响应对其应用至关重要。然而,对这些机械响应进行理论分析和预测是相当具有挑战性的。本文通过理论研究来预测其大变形弯曲响应。通过考虑实心梁的弯曲理论并结合蜂窝梁的相对密度 ρ,得出了蜂窝梁在纯弯曲和三点弯曲下的弯矩响应理论表达式。通过实验验证的数值模型进行了数值模拟,以证明所提理论的有效性和准确性。通过拉丁超立方取样法选取了相对密度为 0&lt;ρ≤1 的矩形蜂窝梁。所提出理论预测的这些梁的理论弯矩曲线与纯弯曲和三点弯曲的数值结果非常吻合。此外,还验证了所提出的理论能有效预测不同截面单元形状的蜂窝梁的弯曲响应。Behavior and theoretical model of FRP-RC columns under cyclic axial compressionJie-Kai Zhou, Jun-Jie Zeng, Yong-Chang Guo, Yan Zhuge, Wei-Te Liu, Z.H. Xie, Y. Zhengdoi:10.1016/j.compstruct.2024.117947FRP-RC 柱在循环轴向压缩下的行为和理论模型Fibre-reinforced polymer (FRP) bars have been used as reinforcement for reinforced concrete (RC) structures to solve the problems associated with steel reinforcement corrosion. Although axial compression tests have been conducted and mechanical behavior of RC columns reinforced with FRP bars (FRP-RC columns) has been known to some extent, the cyclic compressive behavior of FRP-RC columns remains unclear. To tackle this research gap, an experimental study was conducted to explore the cyclic compressive behavior of FRP-RC columns, with effects of parameters including confinement stiffness (i.e., spiral pitch), reinforcement ratio and loading scheme being carefully explored. The experimental study reveals that, interestingly, the FRP longitudinal bars can significantly reduce the concrete plastic strains in FRP-RC columns (referred to as plastic strain recovery). It is also found that the axial load-strain curves exhibit a three-portion behavior, and the FRP longitudinal bars plays an important role in resisting the axial stresses. The existing model for FRP-confined concrete under cyclic loading fails to predict the axial cyclic behavior of FRP-RC columns. A new model for FRP-RC columns is proposed and the accuracy of the proposed model is verified against the test results.纤维增强聚合物(FRP)钢筋已被用作钢筋混凝土(RC)结构的配筋,以解决与钢筋腐蚀相关的问题。虽然已经进行了轴向压缩试验,并在一定程度上了解了 FRP 杆件加固的 RC 柱(FRP-RC 柱)的力学行为,但 FRP-RC 柱的循环压缩行为仍不清楚。针对这一研究空白,我们开展了一项实验研究,以探索 FRP-RC 柱的循环抗压行为,并仔细探讨了约束刚度(即螺旋间距)、配筋率和加载方案等参数的影响。实验研究发现,有趣的是,玻璃钢纵筋可以显著降低玻璃钢-RC 柱中的混凝土塑性应变(称为塑性应变恢复)。研究还发现,轴向荷载-应变曲线呈现三比例行为,FRP 纵筋在抵抗轴向应力方面发挥了重要作用。现有的循环荷载下 FRP 密实混凝土模型无法预测 FRP-RC 柱的轴向循环行为。本文提出了 FRP-RC 柱的新模型,并根据试验结果验证了模型的准确性。Dynamic characterisation of novel three-dimensional axisymmetric chiral auxetic structureAnja Mauko, Yunus Emre Yilmaz, Nejc Novak, Tomáš Doktor, Matej Vesenjak, Zoran Rendoi:10.1016/j.compstruct.2024.117949新型三维轴对称手性助剂结构的动态表征The study presents an extensive mechanical and computational characterisation of novel cellular metamaterial with axisymmetric chiral structure (ACS) at different strain rates. The Direct Impact Hopkinson Bar (DIHB) testing device was used for impact testing up to 21 m/s striker speed, which was insufficient to reach the shock deformation regime. Thus, using computational simulations to estimate the structure behaviour at high strain rates was necessary. Experimental and computational results showed that all ACS structures exhibit a nominal stress-strain relationship typical for cellular materials. As the loading conditions shifted to a dynamic regime, the micro–inertia effect became increasingly pronounced, leading to a corresponding rise in structure stiffness. The Poisson&#39;s ratio in all ACS increases gradually, making them superior to traditional cellular materials, which experience a sudden increase in Poisson&#39;s ratio during loading. Additionally, the study found that the structures exhibited a rise in the auxetic effect with an increase in strain rate, highlighting the benefits of axisymmetric structures in high-loading regimes. Overall, the obtained results provide valuable insights into the mechanical properties of ACS under different loading regimes and will contribute to further design improvements and the fabrication of novel ACS metamaterials.该研究介绍了具有轴对称手性结构(ACS)的新型蜂窝超材料在不同应变速率下的广泛机械和计算特性。直接冲击霍普金森棒(DIHB)测试装置用于冲击测试,冲击速度最高达 21 m/s,但不足以达到冲击变形机制。因此,有必要使用计算模拟来估计高应变速率下的结构行为。实验和计算结果表明,所有 ACS 结构都表现出典型的蜂窝材料名义应力-应变关系。随着加载条件转向动态机制,微惯性效应变得越来越明显,导致结构刚度相应增加。所有 ACS 的泊松比都是逐渐增加的,这使它们优于传统的蜂窝材料,后者在加载过程中泊松比会突然增加。此外,研究还发现,随着应变率的增加,这些结构的辅助效应也会增加,这突出表明了轴对称结构在高负载条件下的优势。总之,研究结果为了解 ACS 在不同加载条件下的机械特性提供了宝贵的见解,将有助于进一步改进设计和制造新型 ACS 超材料。Composites Part A: Applied Science and ManufacturingMulti-objective optimization of HUMM3-assisted ICAT repass treatment using Taguchi method in DoEChenping Zhang, Yugang Duan, Sunil Chandrakant Joshi, Hong Xiao, Ben Wang, Weijun Cui, Wei Zhao, Mengru Jiangdoi:10.1016/j.compositesa.2024.108051 在 DoE 中使用田口方法对 HUMM3 辅助 ICAT 重通处理进行多目标优化The multi-objective optimization of the repass consolidation process was carried out by the Taguchi analysis algorithm, and the mechanism of its effect on warpage-deformation, porosity, crystallinity and mechanical properties was revealed in this work. An optimization method to quantify warpage-deformation was proposed, and the relationship between residual stress and warpage-deformation was analyzed by the hole-drilling method. The significance of repass consolidation speed (RCS), temperature (RCT) and force (RCF) on multi-objective response values such as warpage-deformation was analyzed, e.g., for warpage-deformation, the significance of repass consolidation parameters was RCS (83.23%) &gt; RCF (8.55%) &gt; RCT (8.22%). It is shown that the oriented state of the molecular chain is a thermodynamic disequilibrium and that thermal motion will cause the oriented state structure to be auto-unoriented. The repass treatment promoted the deorientation behavior of the molecular chains, thus reducing the residual stresses and suppressing the warpage-deformation. This work validates the feasibility of repass treatment and inspires the inception and development of a potential optimization process for thermoplastic composites.利用田口分析算法对再传固结工艺进行了多目标优化,揭示了其对翘曲变形、孔隙率、结晶度和力学性能的影响机理。提出了量化翘曲变形的优化方法,并通过钻孔法分析了残余应力与翘曲变形之间的关系。分析了再传固结速度(RCS)、温度(RCT)和力(RCF)对翘曲变形等多目标响应值的意义,例如,对于翘曲变形,再传固结参数的意义为 RCS (83.23%) &gt; RCF (8.55%) &gt; RCT (8.22%)。这表明分子链的取向态是一种热力学不平衡状态,热运动会导致取向态结构自动失向。再传递处理促进了分子链的去定向行为,从而降低了残余应力,抑制了翘曲变形。这项工作验证了再传递处理的可行性,并启发了热塑性复合材料潜在优化工艺的雏形和发展。Preparation, mechanical, acoustic and thermal properties of silica composite aerogel using wet-laid glass fiber felt as scaffoldJieyu Xue, Ruonan Han, Yinmei Ge, Liping Liu, Yong Yangdoi:10.1016/j.compositesa.2024.108058以湿铺玻璃纤维毡为支架的二氧化硅复合气凝胶的制备、机械、声学和热学特性Silica aerogels with high porosity, low density, and unusual three-dimensional network space structure are interesting for various applications. However, there are easily collapsed structures and poor mechanical qualities, which present a great obstacle to their practical applications. Herein, we reported a universal strategy to realize by combining wet-laid glass fiber felt (80 % glass fiber and 20 % hot melt fiber) with silica aerogel to assemble micro-nanopore structures. The results demonstrated that, compared to glass fiber felt (GF), the silica aerogel/glass fiber/hot melt fiber composites (SGMs) increased 0.33 MPa in tensile strength, and sound transmission loss (STL) could be improved by more than 10 dB when the frequency was above 2000 Hz. Besides, SGMs had good thermal stability (375 °C) and excellent thermal insulation with the optimal thermal conductivity coefficient 0.038 W (m k)-1. It can be widely used in the field of sound insulation and thermal insulation.具有高孔隙率、低密度和非同寻常的三维网络空间结构的二氧化硅气凝胶在各种应用领域都很有吸引力。然而,二氧化硅气凝胶存在结构易坍塌、机械性能差等问题,这给其实际应用带来了巨大障碍。在此,我们报告了一种通用策略,即通过将湿法铺设的玻璃纤维毡(80% 玻璃纤维和 20% 热熔纤维)与二氧化硅气凝胶相结合来实现微纳米孔结构的组装。结果表明,与玻璃纤维毡(GF)相比,二氧化硅气凝胶/玻璃纤维/热熔纤维复合材料(SGMs)的抗拉强度提高了 0.33 兆帕,当频率高于 2000 赫兹时,传声损耗(STL)可提高 10 分贝以上。此外,SGMs 还具有良好的热稳定性(375 °C)和优异的隔热性能,最佳导热系数为 0.038 W (m k)-1。它可广泛应用于隔音和隔热领域。Damage tolerancing in carbon fiber-reinforced polymer (CFRP) laminates under combined impact fatigue and environmental conditioningIsabella Mendoza, Leslie Lambersondoi:10.1016/j.compositesa.2024.108062碳纤维增强聚合物(CFRP)层压板在组合冲击疲劳和环境条件下的损伤公差分析This paper presents a non-destructive damage evaluation technique for carbon fiber-reinforced polymers (CFRP) subjected to combined impact fatigue and hygrothermal degradation. Low-cycle repetitive impacts at 2J were performed on pristine and soaked quasi-isotropic plates, resulting in barely visible impact damage (BVID). Stereo-digital image correlation (DIC) and the virtual fields method (VFM) were employed to create equilibrium gap (EG) maps on post-impact specimens under a static bending load, locating and measuring damage simultaneously. A normalization based on data gathered from EG maps was developed to measure damage severity and showed that damage increased two to five-fold after approximately 1% moisture absorption compared to ambient specimens, and by an order of magnitude after approximately 2% absorption. These findings highlight the detrimental effect of moisture on the structural integrity of CFRP under impact fatigue, and demonstrate that under these conditions BVID can be measured using non-destructive full-field kinematics and the virtual fields method.本文介绍了一种针对碳纤维增强聚合物(CFRP)在冲击疲劳和湿热降解双重作用下的非破坏性损伤评估技术。对原始板材和浸泡过的准各向同性板材进行了 2J 的低周期重复冲击,导致了几乎不可见的冲击损伤(BVID)。采用立体数字图像相关(DIC)和虚拟场法(VFM)在静态弯曲载荷下的冲击后试样上绘制平衡间隙(EG)图,同时定位和测量损伤。根据从 EG 图中收集的数据开发了一种归一化方法来测量损坏严重程度,结果表明,与环境试样相比,吸湿约 1% 后损坏程度增加了 2 到 5 倍,吸湿约 2% 后损坏程度增加了一个数量级。这些发现凸显了湿气对冲击疲劳下 CFRP 结构完整性的不利影响,并证明在这些条件下,可以使用非破坏性全场运动学和虚拟场方法测量 BVID。Effects of thermoforming parameters and layup on unidirectional reinforced amorphous thermoplastic composite surfacesMarc Oliver Voltz, Olaf Zöllner, Peter Mitschangdoi:10.1016/j.compositesa.2024.108063热成型参数和铺层对单向增强无定形热塑性复合材料表面的影响Surface quality is a critical issue for thermoplastic composites to be used in a variety of visible applications. A set of trials has been set up by means of Design of Experiment and executed to determine the effects of thermoforming parameters on the achievable surface quality of unidirectional reinforced amorphous thermoplastic composites. The surfaces were measured by white light profilometry, standard key figures were derived and statistically analyzed. The results show significant effects of the investigated parameters as well as potential for further research.表面质量是热塑性复合材料用于各种可见应用的一个关键问题。为了确定热成型参数对单向增强无定形热塑性复合材料表面质量的影响,我们通过实验设计法进行了一系列试验。通过白光轮廓仪对表面进行了测量,得出了标准关键数据并进行了统计分析。结果表明,所研究的参数具有明显的影响,并具有进一步研究的潜力。Composites Part B: Engineering3D-printed conical structure absorber based on NFG/Fe3Si/SiCnw ternary composites for multifunctional integrated electromagnetic microwave absorptionKaixin Deng, Haihua Wu, Bo Song, Yan Li, Jiahuan Hao, Yunxin Ji, Heng Wei, Shaokang Liu, Bin Chao, Wenxin Fudoi:10.1016/j.compositesb.2024.111243基于 NFG/Fe3Si/SiCnw 三元复合材料的 3D 打印锥形结构吸收器,用于多功能集成电磁微波吸收The wave absorbers with dual functions of structural load-bearing and radar absorption have become the solution strategy to cope with the increasingly complex electromagnetic environment. In this paper, a conical structure absorber based on natural flake graphite (NFG)/Fe3Si/SiCnw ternary composites was successfully prepared by selective laser sintering (SLS) 3D printing technique starting from multi-scale design. From the material level, the in-situ grown one-dimensional SiC nanowires effectively improve the dielectric properties of the material, which increases the magnetic/dielectric loss synergy together with the magnetic material Fe3Si. The minimum reflection loss is −54.21 dB and the effective absorption bandwidth (EAB) is 4.6 GHz when the thickness is 1.5 mm. The unit structure of the conical structure absorber was structurally designed and experimentally verified at the structural level, and broadband electromagnetic absorption at 14.45 GHz was achieved and the compressive yield stress was 5.21 MPa. In addition, the EAB of both transverse electric-polarization (TE) and transverse magnetic-polarization (TM) under the variation of incidence angle from 0 to 50° exceeded 12 GHz, indicating that the conical structure absorber has excellent wide-angle absorption properties. The broadband microwave absorption performance of conical structure absorbers is attributed to the synergistic enhancement effect of improved impedance matching on the macroscopic scale and multiple electromagnetic loss mechanisms on the microscopic scale. The conical structure absorber prepared by SLS achieves material-structure-function integration of electromagnetic microwave absorption, and the multifunctional integrated design contributes to the practical application of stealth technology in the field of industrialized electromagnetic microwave absorption.具有结构承载和雷达吸收双重功能的吸波材料已成为应对日益复杂的电磁环境的解决策略。本文从多尺度设计出发,采用选择性激光烧结(SLS)三维打印技术,成功制备了基于天然鳞片石墨(NFG)/Fe3Si/SiCnw三元复合材料的锥形结构吸波材料。从材料层面来看,原位生长的一维 SiC 纳米线有效地改善了材料的介电性能,与磁性材料 Fe3Si 一起增加了磁/介电损耗协同效应。当厚度为 1.5 毫米时,最小反射损耗为 -54.21 dB,有效吸收带宽(EAB)为 4.6 GHz。锥形结构吸收器的单元结构经过结构设计和实验验证,在 14.45 GHz 频率下实现了宽带电磁吸收,压缩屈服应力为 5.21 MPa。此外,在入射角从 0° 到 50° 变化的条件下,横向电极化(TE)和横向磁极化(TM)的 EAB 均超过了 12 GHz,表明锥形结构吸收器具有优异的广角吸收特性。锥形结构吸收体的宽带微波吸收性能得益于宏观上阻抗匹配的改善和微观上多重电磁损耗机制的协同增强效应。SLS 制备的锥形结构吸收体实现了电磁微波吸收的材料-结构-功能一体化,多功能集成设计有助于隐身技术在工业化电磁微波吸收领域的实际应用。Thermal-, magnetic-, and light-responsive 4D printed SMP composites with multiple shape memory effects and their promising applicationsCheng Lin, Xiaozhou Xin, Linfeng Tian, Dou Zhang, Liwu Liu, Yanju Liu, Jinsong Lengdoi:10.1016/j.compositesb.2024.111257具有多重形状记忆效应的热响应、磁响应和光响应 4D 印刷 SMP 复合材料及其应用前景Driven by increasingly complex functional requirements, the shape memory polymer (SMP) is more competitive due to its convertible configuration and tunable properties. In particular, the multi-shape SMP that is not limited to one temporary configuration gives more possibilities for intelligent applications of SMP. However, it is still challenging to manufacture highly controllable and selectively programmable multi-shape SMP in a facile and scalable manner. Here, thermal-, magnetic-, and light-responsive 4D printed SMP composites with up to eight shape memory effects were developed, with the advantages of selective programming, highly controllable deformation in time and space, and configuration customization. The introduction of 4D printing into the manufacturing of multi-responsive SMP composites allowed for easy implementation and rapid manufacturing of controllable and customizable dynamic structures. Through the design of multi-material and multi-structural modules, coupled with 4D printing technology, the multi-responsive SMP composites were endowed with unlimited design freedom. 4D printed multi-responsive SMP composites realized accurate and selective actuation, tripled programmability, and efficient encrypted transmission of multiple types of information (e.g., encrypted transmission of idioms in the form of combined graphs and text), showing attractive application prospects in flexible robots, highly programmed metamaterials, information encryption carriers, etc.在日益复杂的功能要求的推动下,形状记忆聚合物(SMP)因其可转换的构型和可调整的特性而更具竞争力。特别是不局限于一种临时配置的多形状 SMP 为 SMP 的智能应用提供了更多可能性。然而,如何以简便、可扩展的方式制造高度可控、可选择编程的多形状 SMP 仍是一项挑战。在此,我们开发了具有多达八种形状记忆效应的热响应、磁响应和光响应 4D 印刷 SMP 复合材料,其优点是可选择性编程、时间和空间变形高度可控以及配置可定制。将 4D 打印技术引入多响应 SMP 复合材料的制造中,可轻松实现并快速制造可控和可定制的动态结构。通过多材料和多结构模块的设计,再加上 4D 打印技术,多反应 SMP 复合材料被赋予了无限的设计自由度。4D 打印多响应 SMP 复合材料实现了精确的选择性驱动、三倍的可编程性以及多种类型信息的高效加密传输(例如以图文结合的形式加密传输成语),在柔性机器人、高编程超材料、信息加密载体等方面展现出诱人的应用前景。That’s how the preform crumples: Wrinkle creation during forming of thick binder-stabilised stacks of non-crimp fabricsPeter H. Broberg, Esben Lindgaard, Christian Krogh, Adam J. Thompson, Jonathan P.-H. Belnoue, Stephen R. Hallett, Brian L.V. Bakdoi:10.1016/j.compositesb.2024.111269这就是预成型件皱缩的原因:无皱织物的厚粘合剂稳定堆叠成形过程中产生的褶皱The simultaneous forming of multiple layers of fabric is being used in industry to increase the throughput of composite parts. A polymeric binder may be used to stabilise the fabric layers to make it easier to handle, however, the binder may also restrict relative fibre movement, which may lead to wrinkles during forming. Despite the increasing interest in using binder-stabilised preforms in the wind industry, defects arising during forming have scarcely been investigated. This study investigates fibre wrinkling in binder-stabilised preforms (layers of dry non-crimp fabric stabilised with an interply polymeric binder) during forming. The results from an experimental campaign are presented, in which full-thickness pre-consolidated preform specimens are being formed over two different ramp geometries. Wrinkles are observed at the transition edges during forming. To aid the discussion on wrinkle mechanisms, a numerical model is presented that uses continuum shell elements for modelling the NCFs and a cohesive law for modelling the interface. This model is capable of predicting the wrinkle onset and wrinkle location and may be used to study the formability of the preform.在工业中,多层织物的同时成型被用于提高复合材料部件的产量。聚合物粘合剂可用于稳定织物层,使其更易于处理,但粘合剂也可能限制纤维的相对运动,从而导致成型过程中出现皱褶。尽管风能行业对使用粘合剂稳定的预成型件越来越感兴趣,但对成型过程中出现的缺陷却很少进行研究。本研究调查了成型过程中粘合剂稳定预型件(使用交联聚合物粘合剂稳定的干法非卷曲织物层)中的纤维起皱情况。实验结果显示,全厚预凝固预成型试样在两种不同的斜坡几何形状上成型。在成型过程中,在过渡边缘观察到了皱纹。为了帮助讨论起皱机理,介绍了一个数值模型,该模型使用连续壳元素对 NCF 进行建模,并使用内聚法则对界面进行建模。该模型能够预测起皱和起皱位置,可用于研究预成型件的成型性。Screen-printed piezoelectric composites for vibrational energy harvesting in combination with structural composite laminates for powering a sensing nodeBoyue Chen, Yu Jia, Fumio Narita, Hiroki Kurita, Yu Shidoi:10.1016/j.compositesb.2024.111274用于振动能量采集的丝网印刷压电复合材料与结构复合层压板相结合,为传感节点供电This paper developed smart composite structures with screen-printed piezoelectric composite energy harvesters. P(VDF-TrFE) based composites with BaTiO3 particles of different concentrations were deposited via screen printing and studied regarding surface morphology, crystalline structure, piezoelectric, dielectric and mechanical properties. It was identified that P(VDF-TrFE) with 5 wt% BaTiO3 addition exhibited the best piezoelectric property. Even with a monotonic reduction in the β phase crystallisation as the BaTiO3 concentration was increased, a 5 wt% inclusion of BaTiO3 led to the rise of d33 from −28.63 pC/N to −33.90 pC/N. This was attributed to the enhanced interfacial polarisation and the stress concentration induced by the addition of the ceramic particles. Subsequently, the printed piezoelectric composites were co-cured with glass fibre reinforced composites (GFRPs) and carbon fibre reinforced composites (CFRPs). The assembled harvesters were tested under both sinusoidal excitation and real industrial vibration. It was found that the smart composites with 5 wt% BaTiO3 always manifested the best energy harvesting performance. For the optimised generator, maximum power of 2 μW and 1.5 μW could be obtained when using GFRPs and CFRPs as substrates under 1 g peak-peak sinusoidal excitation, respectively. The harvested energy could be used to power a commercial accelerometer with the help of a power management system. When exciting the GFRP-based energy harvester with an optimised printed piezoelectric generator at 7 g p-p acceleration, the power harvested was sufficient to maintain the operation of the accelerometer for 0.34 s.本文利用丝网印刷压电复合能量收集器开发了智能复合结构。通过丝网印刷沉积了含有不同浓度 BaTiO3 颗粒的 P(VDF-TrFE)基复合材料,并对其表面形貌、晶体结构、压电、介电和机械性能进行了研究。结果表明,添加 5 wt% BaTiO3 的 P(VDF-TrFE)具有最好的压电特性。即使随着 BaTiO3 浓度的增加,β 相结晶单调减少,5 wt% 的 BaTiO3 添加量也会使 d33 从 -28.63 pC/N 上升到 -33.90 pC/N。这归因于陶瓷颗粒的加入增强了界面极化和应力集中。随后,印刷压电复合材料与玻璃纤维增强复合材料 (GFRP) 和碳纤维增强复合材料 (CFRP) 共同固化。组装好的收割机在正弦激励和实际工业振动下进行了测试。结果发现,含 5 wt% BaTiO3 的智能复合材料始终表现出最佳的能量收集性能。对于优化后的发电机,在 1 g 峰-峰正弦激励下,以 GFRP 和 CFRP 为基材可分别获得 2 μW 和 1.5 μW 的最大功率。在电源管理系统的帮助下,采集的能量可用于为商用加速度计供电。在 7 g p-p 的加速度下,用优化的印刷压电发生器激励基于 GFRP 的能量收集器时,所收集的能量足以维持加速度计运行 0.34 秒。Tadpole-like bottlebrush polymer-modified multiwalled carbon nanotubes: A strategy for interface-strengthened polymer nanocomposites with exceptional performanceTianbo Deng, Zhiyuan Peng, Yuan Gao, He Zhao, Binbin Xu, Ling Zhang, Chunzhong Lidoi:10.1016/j.compositesb.2024.111275 蝌蚪状底层聚合物改性多壁碳纳米管:具有优异性能的界面强化聚合物纳米复合材料战略Nanocomposites incorporating hierarchically structured nanofillers create great opportunities to generate high-performance artificial materials. However, the rational design of the chemistry and structure of interfaces within polymer matrix is still challenging due to the intrinsic mismatch between nanofiller and matrix. Herein, we report an effective approach to fabricate chitosan (CS)-based nanocomposites with integrated high strength and toughness whose interfaces are chemically modulated by tadpole-like bottlebrush polymers (BBPs) modified multiwalled carbon nanotubes (MWCNTs). The tadpole-like PCL-b-(PCL-g-PGMA) BBPs, containing a bottlebrush poly(ε-caprolactone)-g-poly(glycidyl methacrylate) (PCL-g-PGMA) main body and a linear soft PCL tail, act as a bridge to connect the MWCNTs and CS matrix, resulting in the soft inner layer (PCL tail) and the stretchable cross-linked outer layer (PCL-g-PGMA main body) at the interface of the CS/MWCNTs-BBPs nanocomposite films. Significantly, unlike traditional block copolymers (BCPs) toughening with limited stretching spacing, the coupling of stretched PGMA brush and soft PCL backbone in PCL-g-PGMA main body impart the MWCNTs-BBPs with stretchable interfacial spatial distance when the MWCNTs bear stretching force. The resultant CS/MWCNTs-BBPs nanocomposite film with 1.5 wt% MWCNTs loading exhibits high tensile strength (up to 80.6 % increase), exceptional elongation at break (up to 380 % increase), and superior toughness (up to 976 % increase) in comparison with the neat CS. This study represents a new strategy for designing interface-strengthened nanocomposites with exceptional performance and holding great promise in a wide range of applications.含有分层结构纳米填料的纳米复合材料为生成高性能人工材料创造了巨大的机遇。然而,由于纳米填料和基体之间的内在不匹配,合理设计聚合物基体内界面的化学和结构仍具有挑战性。在此,我们报告了一种制造壳聚糖(CS)基纳米复合材料的有效方法,这种复合材料具有综合高强度和韧性,其界面由蝌蚪状底丛聚合物(BBPs)修饰的多壁碳纳米管(MWCNTs)进行化学调制。蝌蚪状 PCL-b-(PCL-g-PGMA) BBPs 含有一个蝌蚪状的聚(ε-己内酯)-聚(甲基丙烯酸缩水甘油酯)(PCL-g-PGMA) 主体和一个线性软 PCL 尾部,作为连接 MWCNT 和 CS 基质的桥梁、从而在 CS/MWCNTs-BBPs 纳米复合薄膜的界面上形成了柔软的内层(PCL 尾部)和可拉伸的交联外层(PCL-g-PGMA 主体)。值得注意的是,与传统嵌段共聚物(BCPs)在有限拉伸间距下的增韧不同,PCL-g-PGMA 主体中拉伸的 PGMA 刷子和柔软的 PCL 主干的耦合使 MWCNTs-BBPs 在 MWCNTs 承受拉伸力时具有可拉伸的界面空间距离。与纯 CS 相比,含有 1.5 wt% MWCNTs 的 CS/MWCNTs-BBPs 纳米复合薄膜具有较高的拉伸强度(可提高 80.6%)、优异的断裂伸长率(可提高 380%)和卓越的韧性(可提高 976%)。这项研究为设计具有优异性能的界面增强型纳米复合材料提供了一种新策略,在广泛的应用领域中大有可为。Composites Science and TechnologyMultiphase radiation mechanism based dual-scale ablation model for woven thermal protection materialsHaoran Liang, Weijie Li, Xiaoyan Liang, Mengdie Zhu, Zhongwei Zhang, Ying Lidoi:10.1016/j.compscitech.2024.110467 基于多相辐射机制的编织热防护材料双尺度烧蚀模型Deep space exploration is a significant focus in the aerospace field, encompassing missions to celestial bodies such as Mars, Venus, and beyond. During exploration, the thermal protection system (TPS) of detectors must endure extreme environmental conditions, characterized by high temperatures, pressures, and diverse atmospheric compositions, as exemplified by Venus (97 % CO2, 92 bar). Accurately predicting the TPS material response is crucial for mission success. Based on ‘multiphase radiation’ mechanism, this paper introduces a dual-scale material response model for woven composites. Following validation through oxyacetylene ablation tests, simulations are performed on two different woven structures — 2.5D shallow cross-linked and 3D orthogonal — at various flow conditions. The study reveals that the surface emission power is composed of three main components: the intrinsic emissivity of the solid phase, the morphology of the mesostructure, and the spectral radiative properties of the mixed gas on the surface. The results demonstrate that mesostructure enhancements lead to respective increases in emissivity of 9.6 % and 18.3 % for the two structures. The enthalpy value has a negligible effect on the enhancement of surface emissivity, while pressure has a significant impact on the 2.5D structure. At 10 atm pressure, there is a 9.85 % enhancement over the mesostructure, and at 50 atm, there is a 28 % increase. Pressure has a minimal impact on the 3D structure.深空探索是航空航天领域的一个重要焦点,包括前往火星、金星等天体的任务。在探索过程中,探测器的热保护系统(TPS)必须承受极端的环境条件,如金星(97 % CO2,92 bar)的高温、高压和不同的大气成分。准确预测 TPS 材料的反应对于任务的成功至关重要。基于 &quot;多相辐射 &quot;机制,本文介绍了编织复合材料的双尺度材料响应模型。通过氧乙炔烧蚀试验进行验证后,在各种流动条件下对两种不同的编织结构--2.5D 浅交联和 3D 正交--进行了模拟。研究表明,表面发射功率主要由三部分组成:固相的固有发射率、中间结构的形态以及表面混合气体的光谱辐射特性。结果表明,介观结构的增强使两种结构的发射率分别提高了 9.6% 和 18.3%。焓值对提高表面发射率的影响可以忽略不计,而压力对 2.5D 结构的影响很大。在 10 atm 的压力下,比中间结构提高了 9.85%,而在 50 atm 的压力下,提高了 28%。压力对三维结构的影响微乎其微。Maintaining electromagnetic interference shielding and flame-retardant performance of recycled carbon fiber-reinforced composites under multiple pyrolysis recyclesKaifeng Wang, Wenshuang Chu, Yujie Chen, Hua Li, Hezhou Liudoi:10.1016/j.compscitech.2024.110470 在多次热解循环中保持再生碳纤维增强复合材料的电磁干扰屏蔽和阻燃性能The widespread usage of carbon fiber-reinforced polymer composites imposes serious challenges in disposing of end-of-life and wasted products. Pyrolysis recycling has become an efficient strategy to decompose the resin matrix and extract the fiber, while the bottleneck lies in maintaining the structural integrity and physicochemical properties of the recycled fibers, along with reconstructing corresponding composites with performance efficiency. In this work, a two-step pyrolysis strategy is demonstrated to decompose the resin matrix and remove the carbon residues without damaging the internal structure of the recycled carbon fiber felts (rCFFs), followed by surface modification to facilitate the reconstruction of rCFFs-reinforced phenolic resin composites. The composites achieve remarkable electromagnetic interference (EMI) shielding performance in the X band with maximum EMI shielding effectiveness value of 70.5 dB, along with impressive flame-retardant performance under a high heat flux of 50 kW/m2. Besides, more than 80 % EMI shielding effectiveness is maintained after 10 pyrolyzing cycles by optimizing the pyrolysis parameters. Catering to maintaining the intrinsic properties of the recycled carbon fibers by proposing comprehensive recycling strategy, the synthesis of rCFFs-based materials is of great significance for promoting the substitution of pristine EMI shielding counterparts and the practical reutilization of carbon fiber resources.碳纤维增强聚合物复合材料的广泛使用给报废产品的处理带来了严峻挑战。热解回收已成为分解树脂基体和提取纤维的有效策略,而瓶颈在于如何保持回收纤维的结构完整性和物理化学特性,以及如何重建相应的复合材料并提高其性能效率。本研究采用两步热解策略,在不破坏再生碳纤维毡(rCFF)内部结构的前提下分解树脂基体并去除残碳,然后进行表面改性,以促进再生碳纤维毡增强酚醛树脂复合材料的重构。这种复合材料在 X 波段具有显著的电磁干扰(EMI)屏蔽性能,最大 EMI 屏蔽效果值为 70.5 dB,同时在 50 kW/m2 的高热通量下具有出色的阻燃性能。此外,通过优化热解参数,在 10 次热解循环后仍能保持 80% 以上的 EMI 屏蔽效果。通过提出全面的回收策略来保持回收碳纤维的固有特性,合成基于 rCFFs 的材料对于促进原始 EMI 屏蔽材料的替代和碳纤维资源的实际再利用具有重要意义。A direct prediction method for 3D woven composites bending properties based on unit-cell finite element modelZengfei Liu, Jingran Ge, Chunwang He, Chen Liu, Binbin Zhang, Kai Liu, Jun Liangdoi:10.1016/j.compscitech.2024.110474 基于单元有限元模型的三维编织复合材料弯曲性能直接预测方法The deformation distribution along the thickness direction of 3D woven composites under bending loading is inhomogeneous, and hence there is difficulty in numerically predicting the bending behavior of woven composites. This paper aims to propose a direct mesoscopic method for predicting the bending behavior of woven composites using the unit-cell finite element model. Firstly, four-point bending tests were conducted in the warp and weft directions, respectively. Then, the periodic boundary conditions are established for the unit-cell model with non-uniformly distributed deformations under pure bending loading. Finally, the bending properties and damage accumulation process of the woven composites are analyzed based on the elasto-plastic damage model with different mechanical properties in tension and compression. The simulated moment-curvature curves and failure modes are in good agreement with the experimental results. It is shown that the developed unit-cell finite element model can accurately predict the bending behavior of woven composites.三维编织复合材料在弯曲荷载作用下沿厚度方向的变形分布是不均匀的,因此难以对编织复合材料的弯曲行为进行数值预测。本文旨在提出一种利用单元单元有限元模型预测编织复合材料弯曲行为的直接介观方法。首先,分别在经向和纬向进行了四点弯曲试验。然后,在纯弯曲载荷下,为非均匀分布变形的单元单元模型建立周期性边界条件。最后,基于弹塑性损伤模型,分析了编织复合材料在拉伸和压缩时的不同力学性能和损伤累积过程。模拟的弯矩-曲率曲线和破坏模式与实验结果十分吻合。结果表明,所开发的单元单元有限元模型可以准确预测编织复合材料的弯曲行为。High sensitivity self-sensing damage of thick carbon fiber 3D woven angle-interlock composites with oblique currentChaofeng Han, Zhenyu Wang, Yijie Peng, Junhao Liu, Jinchao Li, Xianhua Zhang, Jie Liudoi:10.1016/j.compscitech.2024.110472 用斜电流对厚碳纤维三维编织角交错复合材料进行高灵敏度自感破坏The electrical potential distribution and current spreading depth significantly influence the sensitivity and resolution of self-sensing damage in thick 3D woven angle-interlock (AI) composites. Herein, we report the potential distributions along the thickness and surface in-plane directions of thick 3D woven AI composites under different current strategies. The damage mechanisms of the composites subjected to multiple low-velocity impacts were investigated. Micro-CT and Ultrasound C-scan techniques were used to analyze the microscopic damage morphology and macroscopic damage area, respectively, to demonstrate the effectiveness of the electrical potential self-sensing method. We found that the current completely spreads through the entire thickness of the thick composite plate under oblique injection mode. The potential values between −5.2 and 2.0 mV measured on the impact back surface of the composite plate are at least twice that of the in-plane current mode (−1.0-1.0 mV). The potential damage envelope mapping under oblique current mode coincides with the micro-CT profile, and is much larger than the ultrasound C-scan outline. It achieved the highest detection sensitivity, resolution and flexibility compared to the current in-plane introduction. A three-dimensional orthogonal potential model was developed to determine the spatial potential distribution. The theoretical results agree well with the experimental data. A quantitative relationship between the effective current penetration δ and electrode spacing an of 3D woven composites under in-plane current was established: δ≥ 0.5, a≤46.6 mm. The electrical potential method with oblique current injection offers a highly sensitive, cost-effective, and non-destructive solution for accurate structural health monitoring in aircraft.电势分布和电流扩散深度对厚三维编织角交错(AI)复合材料自感损伤的灵敏度和分辨率有很大影响。在此,我们报告了不同电流策略下厚三维编织 AI 复合材料沿厚度和表面平面方向的电势分布。我们还研究了复合材料在多次低速冲击下的损伤机理。采用显微 CT 和超声 C 扫描技术分别分析了微观损伤形态和宏观损伤面积,以证明电势自感方法的有效性。我们发现,在斜向注入模式下,电流完全通过厚复合板的整个厚度。在复合板的冲击背面测量到的 -5.2 至 2.0 mV 之间的电位值至少是平面内电流模式(-1.0 至 1.0 mV)的两倍。在斜电流模式下绘制的潜在损伤包络线与显微 CT 轮廓相吻合,并且比超声 C 扫描轮廓大得多。与电流面内导入相比,它实现了最高的检测灵敏度、分辨率和灵活性。建立了一个三维正交电位模型来确定空间电位分布。理论结果与实验数据十分吻合。建立了面内电流下三维编织复合材料的有效电流穿透率δ和电极间距 an 之间的定量关系:δ≥ 0.5,a≤46.6 mm。带有斜向电流注入的电势法为飞机结构健康的精确监测提供了一种高灵敏度、高成本效益和非破坏性的解决方案。来源:复合材料力学仿真Composites FEM

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