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【新文速递】2024年11月4日复合材料SCI期刊最新文章

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今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 3 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 2 篇

Composite Structures

A rotating triangular auxetic perforated plate: Structural design and characteristic analysis

Tao Xue, Wei Zhong Jiang, Yi Zhang, Nian Ci Du, Jun Wen Shi, Yi Chao Qu, Xin Ren

doi:10.1016/j.compstruct.2024.118684

旋转三角形补孔板:结构设计与特性分析

Auxetic metamaterials have garnered extensive attention over the past few decades due to their exceptional and superior mechanical properties. However, owing to their unique porous structure, it is challenging to ensure that structures possess strong energy absorption capabilities while exhibiting excellent auxetic characteristics. This study introduces a rotating triangular auxetic metamaterial (RTAM) by perforating traditional rigid rotating triangles. Quasi-static compression tests and numerical simulations are conducted on the new structure to investigate the effects of wall thickness and re-entrant angle of the triangular perforated plate on mechanical properties and Poisson’s ratio. The plateau stress and specific energy absorption (SEA) of RTAM are 4 and 10 times higher than that of traditional trichiral auxetic metamaterials (TCAM), respectively. With an increase in wall thickness, both plateau stress and SEA of the structure are improved significantly. As the re-entrant angle increases, the SEA of the structure initially decreases and then increases. RTAM achieves both lightweight structure and ideal mechanical performance, providing an approach for manufacturing lightweight and high-strength auxetic metamaterials, with significant potential applications in the field of energy absorption.

在过去的几十年里,增塑型超材料由于其优异的机械性能而引起了广泛的关注。然而,由于其独特的多孔结构,在保证结构具有强大的吸能能力的同时又具有良好的减振特性是一项挑战。通过对传统的刚性旋转三角形进行射孔,研制了一种旋转三角形补强超材料(RTAM)。对新型结构进行了准静态压缩试验和数值模拟,研究了三角形穿孔板壁厚和入角对力学性能和泊松比的影响。RTAM的平台应力和比能吸收(SEA)分别是传统三手性增塑型超材料(TCAM)的4倍和10倍。随着壁厚的增加,结构的平台应力和SEA均有显著提高。随着再入角的增大,结构的SEA先减小后增大。RTAM既实现了轻量化结构,又实现了理想的力学性能,为制造轻量化、高强度的形变超材料提供了途径,在能量吸收领域具有重要的应用潜力。


Hybrid composite-metal structure response to post-impact compression – Experimental and numerical study

Piotr Podolak, Patryk Jakubczak, Jarosław Bieniaś

doi:10.1016/j.compstruct.2024.118685

混合复合金属结构对冲击后压缩的响应。实验和数值研究

Numerical analysis of the post-impact damage propagation process during CAI tests on titanium-based fibre metal laminates was conducted, and the model was validated by collation of mechanical parameters predicted by it with experimental results. Delaminations induced by the impact were claimed as the hotspot for other modes propagation in most of studied cases and intensively propagated shortly before reaching peak compressive force. Metal – composite interfaces away from impact surface were locations of most intensive delamination propagation during CAI, constituting 63.5 % of overall damage area for titanium-carbon laminate and 81.6 % for titanium-glass laminate. Similarly to delaminations, damage due to fibre and matrix compression propagated from impact point and lead to significant load-carrying ability loss even in low volumes. Propagation of fibre and matrix tension was connected more to buckling progression, than post-impact damage and had the highest volumetric share in composite layers damage modes (max 13.5 % for titanium-carbon laminate and 8.3 % for titanium-glass laminate).

对钛基金属纤维层合板CAI试验中冲击后损伤传播过程进行了数值分析,并将模型预测的力学参数与实验结果进行比对,对模型进行了验证。在大多数研究案例中,由冲击引起的分层被认为是其他模态传播的热点,并且在达到峰值压缩力前不久集中传播。在CAI过程中,远离冲击面的金属-复合材料界面是分层扩展最密集的位置,占钛-碳层合板整体损伤面积的63.5 %,占钛-玻璃层合板整体损伤面积的81.6 %。与分层类似,纤维和基体压缩造成的损伤从撞击点开始传播,即使在小体积下也会导致严重的承载能力损失。与冲击后损伤相比,纤维和基体张力的传播更多地与屈曲过程有关,并且在复合材料层的损伤模式中具有最高的体积份额(钛-碳层压板最大13.5 %,钛-玻璃层压板最大8.3 %)。


Extension of the crack equivalent method applied to mode II fracture of thermoplastic composites bonded joints using the ENF test

J.P. Reis, M.F.S.F. de Moura, R.D.F. Moreira

doi:10.1016/j.compstruct.2024.118687

 

裂纹等效法在热塑性复合材料粘结接头II型断裂中的扩展

Thermoplastic based composites (TPC) have emerged as a new generation of eco-friendly materials with tougher matrices capable of overcoming the major weaknesses of the thermoset counterparts related with poor resistance to delamination and recycling difficulties. Although TPC materials present low surface energy, adhesive bonding is still effective when the requirements for fusion bonding procedures are not met. Recent advances in adhesive technology have unveiled two-part acrylic adhesive specifically designed for low energy surfaces, characteristic of TPC materials. In this work, unidirectional carbon-reinforced polyamide 6 (CF/PA6) bonded joint was characterized under pure mode II loading using end-notched flexure (ENF) test. The experimental fracture tests revealed unstable crack propagation and a data reduction scheme based on the equivalent crack concept was developed to obtain the strain energy release rate distribution along the crack front for the specimen’s length beyond the actuator central loading point. The proposed procedure was successfully validated using a finite element analysis including a cohesive zone modelling and applied to the experimental results. The obtained Resistance-curves showed that this adhesive is capable to provide a significant bonding resistance in pure mode II loading even in low energy surfaces characteristic of TPC materials.

热塑性复合材料(TPC)已成为新一代环保材料,具有更坚固的基体,能够克服热固性材料的主要弱点,即抗分层性差和回收困难。虽然TPC材料表面能较低,但在不满足熔合工艺要求的情况下,胶粘剂粘合仍然有效。粘合剂技术的最新进展已经推出了专为低能量表面设计的两组分丙烯酸粘合剂,具有TPC材料的特点。采用端缺口挠曲(ENF)试验对单向碳增强聚酰胺6 (CF/PA6)键合接头在纯II型载荷下的特性进行了研究。基于等效裂纹概念,提出了一种基于等效裂纹概念的数据约简方案,得到了执行器中心加载点以外试件长度沿裂纹前沿的应变能释放率分布。采用有限元分析(包括内聚区建模)成功验证了所提出的程序,并将其应用于实验结果。得到的电阻曲线表明,即使在TPC材料的低能量表面,该粘合剂也能够在纯II型加载下提供显著的粘接电阻。


Composites Part A: Applied Science and Manufacturing

Arrest behavior of local resonators connected by nonlocal interaction in elastic wave metamaterials with machine learning prediction

Xuan Zhang, Yi-Ze Wang

doi:10.1016/j.compositesa.2024.108571

弹性波超材料中由非局部相互作用连接的局部谐振器的捕获行为与机器学习预测

In this study, the arrest behaviors of elastic wave metamaterials are analyzed in which the interconnected local resonators are considered. The influence of structural parameters on arrest performance is discussed to show good arrest properties. In order to support the theoretical calculation, both finite element simulation and fracture experiment are performed. Results show that additional energy barriers are generated in the higher subsonic range and the crack propagation resistance can be significantly improved by proper nonlocal interaction. Finally, based on the machine learning method, the energy release ratio G0/G of the elastic wave metamaterial is predicted. Comparing with the theoretical and predicted values, they are basically consistent in the stable range of energy release ratio.

在本研究中,考虑了相互连接的局部谐振器的弹性波金属材料的捕获行为进行了分析。讨论了结构参数对捕获性能的影响,以显示良好的捕获特性。为了支持理论计算,进行了有限元模拟和断裂实验。结果表明,在较高亚声波范围内会产生额外的能量障碍,通过适当的非局部相互作用可以显著提高裂纹扩展阻力。最后,基于机器学习方法,预测了弹性波金属材料的能量释放比率G0/G。将理论和预测值与稳定能量释放比率范围进行比较,它们基本一致。


Remaining useful life prediction of flax fibre biocomposites under creep load by acoustic emission and deep learning

Jianqun Hao, Matthias Rupp, Stepan V. Lomov, Carlos Fuentes Rojas, Aart Willem Van Vuure

doi:10.1016/j.compositesa.2024.108572

基于声发射和深度学习的亚麻纤维生物复合材料蠕变载荷剩余使用寿命预测

Natural fibre composites are increasingly explored for structural applications due to improvements in mechanical performance. For this, damage prognostics are crucial. We integrate acoustic emission (AE) and deep learning techniques to predict the remaining useful life of a flax fibre composite under long-term creep load. Derivatives of cumulative AE features with respect to time, such as cumulative hit and count rates, are introduced to reflect the performance degradation rate of the materials. These proposed features seem more relevant for creep lifespan than traditional AE features. Long short-term memory networks and temporal convolutional networks are adopted to estimate the composite’s remaining useful life. The two model’s normalized root mean square errors are below 0.11, less than 20% of the error of a statistical Weibull-distribution benchmark model. Our study demonstrates that AE-based data-driven models can predict the performance degradation of composite materials subject to sustained load.

由于机械性能的提高,天然纤维复合材料越来越多地用于结构应用。为此,损害预测至关重要。我们整合了声发射(AE)和深度学习技术来预测亚麻纤维复合材料在长期蠕变载荷下的剩余使用寿命。累积声发射特征对时间的导数,如累积命中率和计数率,被引入来反映材料的性能退化率。与传统声发射特征相比,这些特征似乎与蠕变寿命更相关。采用长短期记忆网络和时间卷积网络估计复合材料的剩余使用寿命。两个模型的归一化均方根误差均小于0.11,小于统计威布尔分布基准模型误差的20%。我们的研究表明,基于ae的数据驱动模型可以预测复合材料在持续载荷作用下的性能退化。


Toughening of thick bonded interfaces through architected crack-arresting features

Dharun Vadugappatty Srinivasan, Anastasios P. Vassilopoulos

doi:10.1016/j.compositesa.2024.108575

 

通过结构裂纹止裂特性对厚粘结界面进行增韧

This research investigates the application of additively manufactured crack-arresting features (CAFs), designed from tough and soft polymers, in enhancing the performance of thick glass fiber-reinforced polymer composite-epoxy adhesive joints found in wind turbine rotor blades. Mode I fracture and fatigue behaviors of these joints are assessed through double-cantilever beam experiments and compared against pristine joints. In pristine joints, cracks consistently deviate from the adhesive bondline into the composite adherend, causing a sudden increase in strain energy release rate. Finite element models based on linear elastic fracture mechanics are employed to provide insight into this behavior. Experimental results demonstrate that joints with architected CAFs achieved higher strain energy release rates, more stable failure mechanisms, and minimized damage to the composite adherend. Under fatigue loading, joints featuring tough CAF material exhibit slower fatigue crack growth compared to both pristine joints and those with soft CAF material.

本研究研究了增材制造的裂纹止裂特征(CAFs)的应用,由坚韧和柔软的聚合物设计,以提高风力涡轮机转子叶片中厚玻璃纤维增强聚合物复合环氧胶粘接接头的性能。通过双悬臂梁试验评估了这些节点的I型断裂和疲劳行为,并与原始节点进行了比较。在原始接头中,裂纹不断偏离胶粘剂结合线进入复合材料粘附面,导致应变能释放率突然增加。采用基于线弹性断裂力学的有限元模型来深入了解这种行为。实验结果表明,具有结构的碳纤维接头具有更高的应变能释放率,更稳定的破坏机制,并且对复合材料粘附体的损伤最小。在疲劳载荷下,与原始接头和软CAF接头相比,具有坚韧CAF材料的接头表现出较慢的疲劳裂纹扩展。


Composites Part B: Engineering

One-step green synthesis of multi-morphological carbon nanotube forests for superior microwave absorption and electrocatalysis

Rong Ding, Fu-Rong Zeng, Hai-Bo Zhao, Hao Chen, Yu-Chuan Zhang, Bo-Wen Liu

doi:10.1016/j.compositesb.2024.111932

 

具有优异微波吸收和电催化性能的多形态碳纳米管森林一步绿色合成

Porous carbon materials with multiscale distinctive morphologies hold significant promise in electromagnetic wave stealth/protection and catalysis; however, formidable challenges are highly verbose and resource/time-consuming fabrication processes. Here, we report a one-step solvent/template-free self-expanding carbonization strategy for rapidly fabricating porous carbon foams (Ni/CNT) with zero-dimensional (0D) nanoparticles, one-dimensional (1D) nanotube forests, and three-dimensional (3D) hollow microvesicles. Owing to the multi-morphological structure and low-density feature, the resulting porous carbon foam Ni/CNT-800 achieves a minimum reflection loss of −56.48 dB and an effective bandwidth of 5.44 GHz at a low filler loading of only 9 wt%. Moreover, altering the electronic structure and surface chemistry of carbon foam by phosphorus doping enables a highly reduced durable overpotential (η) of 275 mV for oxygen evolution reaction. This work emphasizes a straightforward strategy for the facile design and efficient fabrication of carbon-based materials with unique multiscale porous morphologies, customizable functions, and various applications.

多孔碳材料具有独特的多尺度形态,在电磁波隐身/保护和催化方面具有重要的应用前景。然而,巨大的挑战是非常冗长和资源/耗时的制造过程。在这里,我们报告了一种无溶剂/模板的一步自膨胀碳化策略,用于快速制造具有零维(0D)纳米颗粒、一维(1D)纳米管森林和三维(3D)空心微泡的多孔碳泡沫(Ni/CNT)。由于多孔泡沫碳Ni/CNT-800的多形态结构和低密度特性,在低填充量为9 wt%的情况下,其反射损耗最小为- 56.48 dB,有效带宽为5.44 GHz。此外,通过磷掺杂改变泡沫碳的电子结构和表面化学性质,可以使析氧反应的持久过电位(η)大幅降低至275 mV。这项工作强调了碳基材料的简单设计和高效制造的直接策略,具有独特的多尺度多孔形态,可定制的功能和各种应用。


Electrospun green fluorescent-highly anisotropic conductive Janus-type nanoribbon hydrogel array film for multiple stimulus response sensors

Haina Qi, Xuelian Jing, Yaolin Hu, Ping Wu, Xuejian Zhang, Yongtao Li, Hongkai Zhao, Qianli Ma, Xiangting Dong, C.K. Mahadevan

doi:10.1016/j.compositesb.2024.111933

 

用于多刺 激响应传感器的电纺绿色荧光高各向异性导电janus型纳米带水凝胶阵列薄膜

A new strategy aimed at significantly enhancing the anisotropic conductivity of hydrogel materials, along with a simple construction technology and design concept, are proposed. Anisotropic conductive hydrogel materials have attracted much attention from researchers in the field of flexible electronics for their inherent excellent properties. However, the anisotropic conductivity of the existing conductive hydrogels is not high and the preparation methods are complex. Herein, fluorescent-highly conductive anisotropic Janus-type nanoribbon hydrogel array film (named JNHAF) is successfully prepared using a combination of parallel electrospinning and post-polymerization as an example of the study. Highly oriented [2,7-dibromo-9-fluorenone (DF)/gelatin (GE)]//[carbon black (CB)/GE] Janus-type nanoribbon is used as the building block. The composition as well as the arrangement of Janus-type nanoribbons are microscopically designed and regulated to effectively separate the conductive and insulating materials, so that the samples can achieve highly anisotropic conductivity and obvious green fluorescence. When the mass ratio of GE to CB is 1:0.1, the conductive anisotropy ratio of JNHAF can reach 1.12 × 105. The degree of anisotropic conductivity of JNHAF is significantly improved compared with existing reported anisotropic conductive hydrogels, and the preparation method is simple. JNHAF responds quickly to light, tensile strain, and temperature, making it suitable for assembling multi-stimulus responsive sensors. JNHAF has excellent flexibility, degradability, mechanical properties and a certain degree of sensitivity (gauge factor of 4.29), and is used for human joint motion detection with an obvious response signal. The design idea and construction technology of this hydrogel breaks through the technical bottleneck of the low degree of anisotropy of conductive hydrogels, which will lead and expand the scientific frontiers of anisotropic conductive hydrogel materials, and provide novel design ideas and theoretical values for new hydrogel materials.

提出了一种旨在显著提高水凝胶材料各向异性电导率的新策略,以及一种简单的施工技术和设计理念。各向异性导电水凝胶材料以其固有的优异性能受到柔性电子领域研究人员的广泛关注。但现有导电水凝胶的各向异性电导率不高,制备方法复杂。本文以采用平行静电纺丝和后聚合相结合的方法成功制备荧光高导电性各向异性janus型纳米带水凝胶阵列膜(命名为JNHAF)为例。高取向的[2,7-二溴-9-芴酮(DF)/明胶(GE)]//[炭黑(CB)/GE] janus型纳米带被用作构建块。通过对janus型纳米带的组成和排列进行微观设计和调控,有效分离导电材料和绝缘材料,使样品具有高度的各向异性电导率和明显的绿色荧光。当GE与CB的质量比为1:0.1时,JNHAF的导电各向异性比可达1.12 × 105。与已有报道的各向异性导电水凝胶相比,JNHAF的各向异性导电程度显著提高,且制备方法简单。JNHAF对光、拉伸应变和温度反应迅速,适合组装多刺 激响应传感器。JNHAF具有优良的柔韧性、可降解性、力学性能和一定的灵敏度(测量因子为4.29),用于人体关节运动检测,响应信号明显。该水凝胶的设计思路和施工技术突破了导电水凝胶各向异性程度低的技术瓶颈,将引领和拓展各向异性导电水凝胶材料的科学前沿,为新型水凝胶材料提供新颖的设计思路和理论价值。


Composites Science and Technology

Room-Temperature Ionic Liquid Electrolytes for Carbon Fiber Anodes in Structural Batteries

Lakshmi Surag Singavarapu, Paul Gilmore, Jun Wei Yap, Yehia Khalifa, Umesh Gandhi, Timothy S. Arthur, Jay Sayre, Jung-Hyun Kim

doi:10.1016/j.compscitech.2024.110952

 

结构电池碳纤维阳极用室温离子液体电解质

Structural batteries require thermally stable electrolytes paired with carbon fibers (CFs), which offer advantages of lightweight, high mechanical strength, and good electrical conductivity. This work evaluated various room-temperature ionic-liquid (RTIL) as compatible electrolytes for CF anodes and LiFePO4 (LFP) cathodes on CFs. This LFP/CF full-cell design eliminates Cu and Al current-collectors, potentially enhancing gravimetric energy and reducing costs. Among various RTILs, LiTFSI in N-propyl-N-methylpyrrolidinium (PYR13) – bis(fluorosulfonyl)imide (FSI) offered promising LFP/CF full-cell performances, attributed to the formation of solid electrolyte interface (SEI) on the CF anode with components such as Li2Sx, Li2S-SO3, LiF, LixFy and F-SO2, identified through X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) analyses further confirmed the electrochemical stability of the SEI layer on CF anodes. The LFP/CF cell delivered an initial capacity of 119 mAh/g and relatively high Coulombic efficiency when using the 1 M LiTFSI in PYR13-FSI. CF cycled in different electrolytes exhibit varying mechanical properties with up to 10.08% loss in tensile strength, which may be related to CF surface degradation mechanisms during repeated cycling. Furthermore, the 1 M LiTFSI in PYR13-FSI is non-flammable, offering a significant thermal safety. This work successfully demonstrated the significant potential of 1 M LiTFSI in PYR13-FSI LTILs, which enables the use of CF as both an anode active material and cathode current collector for structural battery applications.

结构电池需要热稳定的电解质与碳纤维(CFs)配合使用,这种材料具有重量轻、机械强度高和导电性好的优点。本研究评估了不同室温离子液体(RTIL)作为CF阳极和LiFePO4 (LFP)阴极的相容电解质。这种LFP/CF全电池设计消除了Cu和Al集流器,潜在地提高了重力能量并降低了成本。在各种RTILs中,n -丙基- n -甲基吡啶鎓(PYR13) -双(氟磺酰基)亚胺(FSI)中的LiTFSI具有很好的LFP/CF全电池性能,这是由于在CF阳极上与Li2Sx、Li2S-SO3、LiF、LixFy和F-SO2等组分形成固体电解质界面(SEI),通过x射线光电子能谱(XPS)和扫描电子显微镜(SEM)进行了鉴定。电化学阻抗谱(EIS)和弛豫时间分布(DRT)分析进一步证实了SEI层在CF阳极上的电化学稳定性。当在PYR13-FSI中使用1m LiTFSI时,LFP/CF电池提供了119 mAh/g的初始容量和相对较高的库仑效率。在不同的电解液中循环的CF表现出不同的力学性能,拉伸强度损失高达10.08%,这可能与重复循环过程中CF表面降解机制有关。此外,PYR13-FSI中的1m LiTFSI是不可燃的,提供了显著的热安全性。这项工作成功地证明了1 M LiTFSI在PYR13-FSI ltls中的巨大潜力,这使得CF既可以作为结构电池应用的阳极活性材料,也可以作为阴极集流器。


Three-dimensional cohesive finite element simulations coupled with machine learning to predict mechanical properties of polymer-bonded explosives

Daokun Lu, Bingru Zhang, Liu Liu, Haitao Zhang, Luoxia Cao, Yang Zhou

doi:10.1016/j.compscitech.2024.110947

 

三维内聚有限元模拟结合机器学习预测聚合物粘结炸药的力学性能

Developing multifactorial predictive models for the design of polymer-bonded explosives (PBXs) is of importance for their further application in insensitive munition fields. As a popular method, finite element simulations can provide a reliable prediction, but are laborious and expensive if considering the extensive design parameter space. In light of this challenge, we proposed a coupled strategy that includes machine learning (ML) and three-dimensional cohesive finite element simulation for effciently predicting the mechanical properties of PBXs. The strain rate, particle volume fraction, interface strength, fracture energy, and the binders are considered as the main factors of tailoring the tensile strength of PBXs. To improve the prediction performance, an augmented database of 2500 data sets utilizing GANs neural network were established and then processed to train and test six ML models. The results show the accuracy and generalizability of the low-computational-cost ML models in predicting the mechanical properties of PBX composites. The predicted values from these models are in good agreement with the experimental ones. Feature contribution analysis demonstrates that the tensile modulus and failure strain are most affected by the binders, while the tensile strength are most affected by the fracture energy. Using the above conclusions as design guidelines, we can develop the new PBX formulations according to different mechanical property requirements for their optimal use across insensitive ammunitions. This strategy can be a viable machine-learning-assisted solution to designing PBXs.

建立多因素预测模型用于聚合物粘结炸药的设计,对其在不敏感弹药领域的进一步应用具有重要意义。有限元模拟作为一种常用的方法,虽然可以提供可靠的预测,但由于设计参数空间太大,计算难度大,成本高。鉴于这一挑战,我们提出了一种包括机器学习(ML)和三维内聚有限元模拟的耦合策略,以有效预测pbx的力学性能。应变速率、颗粒体积分数、界面强度、断裂能和粘结剂是影响PBXs抗拉强度的主要因素。为了提高预测性能,利用gan神经网络建立了2500个数据集的增强数据库,并对6个ML模型进行了训练和测试。结果表明,低计算成本的机器学习模型在预测PBX复合材料力学性能方面具有准确性和通用性。模型的预测值与实验值吻合较好。特征贡献分析表明,粘结剂对拉伸模量和破坏应变影响最大,而断裂能对拉伸强度影响最大。利用上述结论作为设计指导,我们可以根据不同的机械性能要求开发新的PBX配方,以优化其在不敏感弹药中的使用。该策略可以作为设计pbx的一种可行的机器学习辅助解决方案。




来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveMAGNET疲劳断裂复合材料化学隐身通用电子增材UGECAD裂纹理论材料
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首次发布时间:2024-11-16
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【新文速递】2024年11月6日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 5 篇Composite StructuresA multi-linear constitutive relation considering the temperature effect on quasi-static mode I delamination in UD/MD laminatesLuohuan Zou, Yu Gong, Dingli Tian, Yuting Gao, Jianyu Zhang, Libin Zhao, Ning Hudoi:10.1016/j.compstruct.2024.118691考虑温度对UD/MD层合板准静态I型分层影响的多线性本构关系In this study, a multi-linear constitutive relation taking into account temperature and fiber bridging is proposed for characterizing delamination behavior in composite laminates under various temperature conditions. An approach combining analytical solution and J-integral is also established for determining the cohesive parameters in the multi-linear constitutive relation. To validate the proposed constitutive relation, mode I quasi-static delamination experiments of unidirectional (UD) and multidirectional (MD) carbon/bismaleimide laminates are carried out at 25 ℃ (room temperature), 80 °C and 130 ℃. The experimental results show that the increasing temperature resulted in a monotonic increase in the fracture toughness of the UD laminates while affect the fracture toughness of MD laminates slightly. A FE model is established with the implementation of the proposed multi-linear constitutive relation using UMAT subroutine. Good agreements between the experimental and simulated results demonstrate the validity of the proposed constitutive relation, with the relative difference of peak load between predicted and experimental values less than 8.2 % and the relative difference of initial and steady-state fracture toughness between predicted and tested results less than 15 %. This study provides the possibility to numerically study the temperature effect on the delamination behavior of laminates and has promising applications in the damage tolerance design of composite structures.在这项研究中,提出了考虑温度和纤维桥接的多线性本构关系来表征复合材料层合板在不同温度条件下的分层行为。建立了解析解与j积分相结合的方法来确定多线性本构关系中的内聚参数。为了验证所提出的本构关系,在25℃(室温)、80 ℃和130℃下,对单向(UD)和多向(MD)碳/双马来酰亚胺层叠板进行了I型准静态分层实验。实验结果表明,温度升高导致UD层合板的断裂韧性单调增加,而对MD层合板的断裂韧性影响较小。利用UMAT子程序实现所提出的多线性本构关系,建立了有限元模型。试验结果与模拟结果吻合较好,验证了本构关系的有效性,峰值荷载预测值与试验值的相对差值小于8.2 %,初始断裂韧性和稳态断裂韧性预测值与试验值的相对差值小于15 %。该研究为数值研究温度对层合板分层行为的影响提供了可能,在复合材料结构的损伤容限设计中具有很好的应用前景。Composites Part A: Applied Science and ManufacturingCombination of in-/and ex-situ damage detection methods to investigate the forming behavior of fiber-metal-laminatesFlorian Thum, Marco Korkisch, Anna Trauth, Markus G.R. Sausedoi:10.1016/j.compositesa.2024.108562结合原位和非原位损伤检测方法研究金属纤维层合板的成形行为In this study, the forming behavior of fiber-metal laminates (FML) is investigated by a combination of different (in- and ex-situ) measurement techniques. Using FML-samples consisting of aluminum and carbon fiber reinforced polyamide-6, deep-drawing tests were employed at high temperatures. It can be concluded a conventional approach based on the forming limit curve (FLC) is not suitable to predict the failure initiated in the multi-material setup as principal strains cannot differentiate the strain in aluminum and CFRP and lack sensitivity to detect other relevant failure modes, such as debonding as well as debonding in between layers. To better understand the failure behavior due to forming of FML, an experimental setup, that based on the Nakajima-test, was developed, using in-situ acoustic emission testing, 3D digital image correlation as well as ex-situ X-ray computed tomography. The combined results from all methods helped to gain a deeper insight into how thermoplastic FML behave during deep drawing at elevated temperatures especially focusing on evolving damage inside the hybrid material在本研究中,通过不同(原位和非原位)测量技术的组合,研究了纤维-金属层压板(FML)的成形行为。采用由铝和碳纤维增强聚酰胺-6组成的fml样品,在高温下进行深拉试验。结果表明,基于成形极限曲线(FLC)的传统方法不适合预测多材料结构中引发的破坏,因为主应变不能区分铝和碳纤维布的应变,并且缺乏检测其他相关破坏模式(如脱粘和层间脱粘)的灵敏度。为了更好地了解FML形成的破坏行为,基于nakajima试验,开发了一种实验装置,使用原位声发射测试,3D数字图像相关以及非原位x射线计算机断层扫描。所有方法的综合结果有助于更深入地了解热塑性FML在高温深拉伸过程中的行为,特别是关注混合材料内部的演变损伤Effect of soft magnetic particles content on multi-physics field of magnetorheological composite gel clutch with complex flow channel excited by Halbach array arrangementGuang Zhang, Jiahao Luo, Min Sun, Yang Yu, Jiong Wang, Bo Chen, Qing Ouyang, Ye Qiu, Guinan Chen, Teng Shen, Zheng Zhangdoi:10.1016/j.compositesa.2024.108576软磁颗粒含量对Halbach阵列激发复杂流道磁流变复合凝胶离合器多物理场的影响In this paper we investigate the influence of soft magnetic particle mass fraction on the multi-physics field of proposed magnetorheological (MR) gel clutch. A novel MR gel clutch with complex cup-shaped gap is described, whose performance is based on the relative placement between Halbach array arrangement and MR gel. Smart MR gel with 40 wt%, 50 wt%, 60 wt%, 70 wt% and 80 wt% of soft magnetic particles used as the transfer medium and Halbach array is adopted as magnetic excitation system. Its magnetic/mechanical analysis is carried out based on Bingham-plastics model using COMSOL Multiphysics software, which takes into account the variation of dynamic viscosity with magnetic flux density. The distribution of the magnetic flux density, shear yield stress, post-yield viscosity, shear stress and torque in the four flow channels during the transition from engagement state to disengagement state are obtained and analyzed in detail. Multi-physics field characteristics of proposed MR gel clutch with five kinds of MR gels are studied and compared in order to give some useful suggestions in the design phase. Finally, the dynamic torque of the MR clutch with different MR gel is experimentally evaluated.本文研究了软磁颗粒质量分数对磁流变(MR)凝胶离合器多物理场的影响。介绍了一种新型的具有复杂杯状间隙的磁流变凝胶离合器,其性能基于哈尔巴赫阵列与磁流变凝胶的相对位置。采用40 wt%、50 wt%、60 wt%、70 wt%和80 wt%软磁颗粒的智能磁共振凝胶作为传递介质,采用Halbach阵列作为磁激励系统。采用COMSOL Multiphysics软件基于bingham -plastic模型对其进行了磁/力学分析,考虑了动态粘度随磁通密度的变化。得到并详细分析了从接合状态到脱离状态过渡过程中四个流道的磁通密度、剪切屈服应力、后屈服粘度、剪切应力和转矩的分布。对所提出的5种MR凝胶离合器的多物理场特性进行了研究和比较,以期在设计阶段提供一些有用的建议。最后,对不同磁流变凝胶的磁流变离合器的动态转矩进行了实验评估。Composites Part B: EngineeringScalable production of robust and creep resistant ultra-high filled wood-plastic compositesAn Yang, Zhengyu Liao, Zesheng Xu, Tian Liu, Yiqun Fang, Weihong Wang, Min Xu, Yongming Song, Qingwen Wang, Yao Lidoi:10.1016/j.compositesb.2024.111937 可扩展生产的坚固和抗蠕变超高填充木塑复合材料With the widespread use of wood-based materials in human life, the availability of wood resources has gradually decreased. The use of low-value wood that does not require chemical adhesives can address the depletion of wood resources used to prepare wood-based composites. However, the development of high-strength, low-cost, scalable wood-based composites from low-value wood is challenging. In this study, high-performance ultra-high filled wood-plastic composites (UFWPC) composed of up to 95 wt.% wood flour were prepared through cell wall densification and the construction of multiple cross-linked networks via deep cross-fusion. The UFWPC exhibited excellent mechanical properties, with a flexural strength that was 5.9 times higher than that of commercial particleboard, 2.1 times higher than commercial fiberboard, and 2.6 times higher than commercial wood-plastic composites. UFWPC also demonstrated excellent creep resistance, with a creep strain 76.79% lower than that of commercial wood-plastic composites. Finally, a customizable large-scale commercial continuous flat-pressing system was established to produce UFWPC. The highly efficient preparation of UFWPC makes it an excellent alternative to commercial wood-plastic composites, particleboard, and fiberboard. This approach provides a promising valorization and sustainability method for recycling plastics and low-value wood.随着木质材料在人类生活中的广泛应用,木材资源的可用性逐渐减少。使用不需要化学粘合剂的低价值木材可以解决用于制备木基复合材料的木材资源枯竭的问题。然而,从低价值木材中开发高强度、低成本、可扩展的木基复合材料具有挑战性。在本研究中,通过细胞壁致密化和深度交叉融合构建多个交联网络,制备了由高达95% wt.%的木粉组成的高性能超高填充木塑复合材料(UFWPC)。UFWPC具有优异的力学性能,其抗弯强度比商用刨花板高5.9倍,比商用纤维板高2.1倍,比商用木塑复合材料高2.6倍。UFWPC还表现出优异的抗蠕变性能,其蠕变应变比商用木塑复合材料低76.79%。最后,建立了一套可定制的大型商用平压系统来生产UFWPC。UFWPC的高效制备使其成为商用木塑复合材料、刨花板和纤维板的优良替代品。这种方法为回收塑料和低价值木材提供了一种有前途的增值和可持续性方法。Composites Science and TechnologyOpen source tool for Micro-CT aided meso-scale modeling and meshing of complex textile composite structuresBin Yang, Yuwei Feng, Cédric Béguin, Philippe Causse, Jihui Wangdoi:10.1016/j.compscitech.2024.110940 Micro-CT辅助复杂纺织复合材料结构细观建模和网格划分的开源工具Volumetric image-based modeling of textile reinforcements and composites is favored over ideal geometric modeling because of its ability to represent complex structures in sufficient detail. Although several approaches were devised, there is still a scarcity of dedicated tools capable of effectively transferring pertinent information from images to high-fidelity models. This work presents the open source project, PolyTex, a Python-based object-oriented application that establishes a streamlined and reproducible workflow for such tasks. Dual kriging serves as the foundational theory for the parametric approach developed to represent, simplify, and approximate the morphology and topology of fiber tows. The code takes two types of input, either an explicit representation of tow geometry using point clouds or implicit representations, such as image masks representing fiber tows separately with grayscale values. Tailored APIs allow for smooth integration between PolyTex’s modeling capabilities and the simulation environments offered by OpenFOAM and Abaqus. Case studies on virtual testing of textile permeability were presented to demonstrate this capability. The modular and object-oriented design makes PolyTex a highly reusable and extensible tool that allows users to create a customized pipeline.基于体积图像的纺织增强材料和复合材料建模比理想的几何建模更受青睐,因为它能够足够详细地表示复杂的结构。虽然设计了几种方法,但仍然缺乏能够有效地将相关信息从图像传输到高保真模型的专用工具。本文介绍了开源项目PolyTex,这是一个基于python的面向对象应用程序,它为此类任务建立了一个流线型和可重复的工作流。双克里格是用来表示、简化和近似纤维束形态和拓扑的参数化方法的基础理论。代码接受两种类型的输入,一种是使用点云来显式表示纤维束的几何形状,另一种是隐式表示,比如用灰度值分别表示纤维束的图像掩模。定制的api允许PolyTex的建模功能与OpenFOAM和Abaqus提供的仿真环境之间的平滑集成。以纺织品透气性的虚拟测试为例,说明了该方法的可行性。模块化和面向对象的设计使PolyTex成为一个高度可重用和可扩展的工具,允许用户创建定制的管道。Ultra-high strength and flame retardant carbon aerogel composites with efficient electromagnetic interference shielding and superior thermal insulation via nano-repairing routeWei Wang, Chong Ren, Jiaxin Zheng, He Huang, Can Wu, Xiangyu Jin, Changqing Hong, Xinghong Zhangdoi:10.1016/j.compscitech.2024.110949 通过纳米修复途径,具有高效电磁干扰屏蔽和优异隔热性能的超高强度阻燃碳气凝胶复合材料Carbon aerogel composites (CAs) have received numerous attention for protection of aircraft due to their unique properties. However, the shrinkage mismatch between rigid fibers and carbon sources during carbonization dramatically weakens the performance of CAs, and no significant breakthroughs have been made. We propose a vacuum impregnation assisted nano-repairing (VINR) strategy to fabricate crack-free carbon fiber reinforced carbon aerogel (Cf/CA) composites with high strength, electromagnetic interference shielding and thermal insulation. The cross-confined, overlapping nano-CA particles greatly limits the shrinkage of the carbon source, conferring excellent mechanical properties to Cf/CA, and its compressive strength and modulus reaches 3.93 MPa and 69.96 MPa in XY direction and 2.03 MPa and 40.67 MPa in Z direction, respectively, at 5% strain. In addition, Cf/CA exhibits significant thermal insulation (0.054 W/(m·K) at 25 °C under air condition) and superior electromagnetic interference shielding properties (EMI SE is ∼48.52 dB at a thickness of ∼2 mm). Herein, the structurally optimized Cf/CA provides a promising solution for multi-effect protection for critical electronic devices of aircraft in special service environments.碳气凝胶复合材料(CAs)由于其独特的性能在飞机防护方面受到了广泛的关注。然而,碳化过程中刚性纤维与碳源之间的收缩失配严重削弱了碳纤维的性能,目前还没有取得重大突破。提出了一种真空浸渍辅助纳米修复(VINR)方法,制备具有高强度、屏蔽电磁干扰和隔热性能的无裂纹碳纤维增强碳气凝胶(Cf/CA)复合材料。交叉约束、重叠的纳米CA颗粒极大地限制了碳源的收缩,赋予Cf/CA优异的力学性能,在5%应变下,其抗压强度和模量在XY方向分别达到3.93 MPa和69.96 MPa,在Z方向分别达到2.03 MPa和40.67 MPa。此外,Cf/CA具有显著的隔热性能(25°C空调条件下0.054 W/(m·K))和优异的电磁干扰屏蔽性能(EMI SE为~ 48.52 dB,厚度为~ 2mm)。因此,结构优化后的Cf/CA为特殊服役环境下飞机关键电子设备的多效保护提供了一种很有前景的解决方案。Expanded graphite encapsulation of nitrates for enhanced thermal transport: mechanism insight and component screeningKening Yan, Lin Qiu, Haimo Li, Ning Cao, Yanhui Fengdoi:10.1016/j.compscitech.2024.110957 硝酸盐的膨胀石墨封装增强热传输:机制的洞察力和成分筛选The efficient improvement of the heat transfer capability of high-temperature molten salts and the accurate measurement within the operating temperature range is vital for improving the efficiency of concentrating solar power devices. Through theoretical investigation, this paper explores different thermal properties including thermal conductivity, phase transition properties and interfacial interactions using a range of expanded graphite/nitrates (EG/nitrates). Molecular dynamics simulations reveal that the EG/eutectic salt (ES) exhibits optimal comprehensive properties. Experimentally prepared EG/ES composite phase change materials (PCMs), coupled with theoretical predictions, demonstrate exceptional thermal conductivity (2.2 W·m-1·K-1) and a significant latent heat of phase change (>80 J·g-1). The calculation results of the interaction energy between the host-guest indicate that the strong interaction of the EG to ES restricts the molecule movement, leading to a weak temperature dependence of the thermal conductivity of the EG/ES composite PCM. This contrasts with the conventional understanding of PCM thermal conductivity, which typically exhibits a sharp change during the phase transition from solid state to liquid state. Additionally, the thermal response of 15 wt% EG/ES is increased by 27.2% compared to pure ES, which effectively helps alleviate local overheating in practical applications. The progress made so far sheds light on the mechanism behind the improved heat transfer and storage performance of nitrate from a microscopic view, offering valuable theoretical insight for developing high-efficient nitrate PCMs in solar thermal power generation systems.有效提高高温熔盐的传热能力和在工作温度范围内的精确测量是提高聚光太阳能发电装置效率的关键。本文通过理论研究,探讨了一系列膨胀石墨/硝酸盐(EG/nitrates)的不同热性能,包括导热系数、相变性能和界面相互作用。分子动力学模拟表明,EG/共晶盐(ES)具有最佳的综合性能。实验制备的EG/ES复合相变材料(PCMs),结合理论预测,表现出优异的导热系数(2.2 W·m-1·K-1)和显著的相变潜热(>80 J·g-1)。主客体相互作用能的计算结果表明,EG与ES的强相互作用限制了分子的运动,导致EG/ES复合PCM的导热系数对温度的依赖性较弱。这与传统的对PCM热导率的理解形成了对比,传统的理解是PCM热导率在从固态到液态的相变过程中通常表现出急剧的变化。此外,与纯ES相比,15 wt% EG/ES的热响应提高了27.2%,有效地缓解了实际应用中的局部过热。目前所取得的进展从微观角度揭示了硝酸盐传热和储存性能改善背后的机制,为开发太阳能热发电系统中高效的硝酸盐pcm提供了有价值的理论见解。The critical role of size effect on internal damage and mechanical properties of flax fiber reinforced compositesLulu Lei, Yiqiao Zhao, Zefei Cheng, Jieyu Chen, Sixian Yang, Tao Yu, Jinhong Fan, Yan Li, Jianzhuang Xiaodoi:10.1016/j.compscitech.2024.110958 尺寸效应对亚麻纤维增强复合材料内部损伤及力学性能的影响The effect of the size on the strength of laminated artificial fiber reinforced composites has been extensive discussed during the design of large composites structure. With the trial as the structures in aerospace, civil engineering, automobile industry, the scaling of the properties of plant fiber reinforced composite should be studied. In this paper, the size effect and failure mechanism of tensile and impact properties of flax fiber reinforced composites were valuated. The effects of different area, thickness and volume on the tensile properties of composites were explored. Additionally, the failure mechanism of size effect on tensile specimens was proposed through the damage morphologies of composites. It is found that the twist of fiber bundle plays an important role in the size effect of composite thickness. Besides, the relationship between impact properties and size effect of composites was conducted, including the size of hammer, different impact energy and sample size. The curves of different types of impact samples were normalized to verify the linear rule in response stage. The crack length after impact was measured and the size effect of crack length was discussed. The size effect of crack area was studied by calculating the crack area with ultrasonic C-scan. Different “size effects” between flax fibers and artificial fibers were explored. The results are expected to provide a theoretical basis for the structural design of plant fiber reinforced composites.在大型复合材料结构设计中,广泛讨论了尺寸对层合人工纤维增强复合材料强度的影响。随着植物纤维增强复合材料在航空航天、土木工程、汽车工业等领域的应用,对其性能的影响问题进行了深入的研究。研究了亚麻纤维增强复合材料拉伸和冲击性能的尺寸效应及其破坏机理。探讨了不同面积、厚度和体积对复合材料拉伸性能的影响。此外,通过复合材料的损伤形态分析,提出了尺寸效应对拉伸试样的破坏机理。研究发现,纤维束捻度对复合材料厚度的尺寸效应有重要影响。此外,还分析了复合材料的冲击性能与尺寸效应之间的关系,包括锤头尺寸、不同冲击能和试样尺寸。对不同类型冲击试样的曲线进行归一化,验证了响应阶段的线性规律。测量了冲击后的裂纹长度,并讨论了裂纹长度的尺寸效应。通过超声c扫描计算裂纹面积,研究了裂纹面积的尺寸效应。探讨了亚麻纤维与人造纤维的不同“尺寸效应”。研究结果有望为植物纤维增强复合材料的结构设计提供理论依据。Bioinspired ultra-fine hybrid nanocoating for improving strength and damage tolerance of composite fan blades in flexible manufacturingXianhe Cheng, Qigang Han, Yuzhang Huang, Mingdi Shi, Hexuan Shi, Mengxue Ji, Chuncai Yangdoi:10.1016/j.compscitech.2024.110956 柔性制造中提高复合材料风扇叶片强度和损伤容忍度的仿生超细混合纳米涂层The ultrafine mineral bridges/bio-polymer hybrid structure inspired by nacreous is applied to the interface structure design of composite, aiming to address the high brittleness and low damage tolerance problems of carbon fiber composite fan blades (CFCFB). Herein, we present a simple and efficient approach, called the "cationic copolymer-mono micelle-mediated" method, to translate the nacre-inspired structure for developing micelles/ZnO hybrid nanocoating. The hybrid nanocoating was demonstrated to have remarkable characteristics such as ultrafine ZnO sizes, monodispersity, uniformity, and core-shell structure (diameters: ≈45 nm). Additionally, the coating process is simple, solvent-free, and seamlessly integrates with scalable carbon fiber manufacturing. Based on the nacre-inspired interface structure, the CFCFB exhibits high interlaminar strength (99.3 MPa), high stiffness (79 GPa), and high toughness (41.2 MPa m1/2). This study provides a blueprint for bioinspired ultrafine nanostructure design in composites and inspires advanced manufacturing strategies for other promising engineering materials.将珠蚌启发的超细矿物桥/生物聚合物杂化结构应用于复合材料界面结构设计,旨在解决碳纤维复合材料风扇叶片(CFCFB)的高脆性和低损伤容限问题。在此,我们提出了一种简单有效的方法,称为“阳离子共聚物-单胶束介导”的方法,来翻译纳米结构,以开发胶束/ZnO杂化纳米涂层。该杂化纳米涂层具有ZnO尺寸超细、单分散性、均匀性和核壳结构(直径≈45 nm)等显著特性。此外,涂层过程简单,无溶剂,并与可扩展的碳纤维制造无缝集成。基于珠核界面结构,CFCFB具有高层间强度(99.3 MPa)、高刚度(79 GPa)和高韧性(41.2 MPa m1/2)。该研究为仿生超细纳米复合材料的设计提供了蓝图,并为其他有前途的工程材料的先进制造策略提供了灵感。来源:复合材料力学仿真Composites FEM

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