今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
A review of extrusion-based additive manufacturing of multi-materials-based polymeric laminated structures
Imran Khan, Imad Barsoum, Muhammad Abas, Ans Al Rashid, Muammer Koç, Muhammad Tariq
doi:10.1016/j.compstruct.2024.118490
多材料基聚合物层合结构的挤出增材制造研究进展
Additive Manufacturing (AM) techniques have garnered significant attention for their applicability in fabricating intricate and complex geometries, end-user products, expediting prototyping processes, creating functional devices, sensors, and metamaterial structures for various applications. A relatively nascent area of exploration within this realm is using Extrusion-based Additive Manufacturing (EbAM) to produce multi-materials-based laminated, clad, or panel-based polymer composite structures. This study delves into recent advancements in clad, laminated, or panel-based polymer composite fabrication through EbAM, offering a comprehensive review of relevant literature. The examination encompasses a brief literature review, exploring potential applications for the fabricated composites, scrutinizing 3-dimensional printing (3DP) conditions, identifying optimum 3DP parameters, and assessing the resultant mechanical and functional properties. Furthermore, the article addresses the drawbacks and deficiencies found in existing studies, highlighting areas requiring attention in future research endeavours. A culmination of the review involves discussing the identified future research gaps in the fabrication of laminated composites via EbAM. By synthesizing insights from recent works and elucidating accomplishments and limitations, this article contributes to the collective understanding of the evolving landscape of EbAM techniques for multi-materials-based polymer laminated composite structure (LCS) and lattice structures fabrication.
增材制造(AM)技术因其在制造复杂几何形状、最终用户产品、加速原型制作过程、创建功能器件、传感器和各种应用的超材料结构方面的适用性而受到广泛关注。在这一领域中,一个相对新兴的探索领域是使用基于挤压的增材制造(EbAM)来生产基于多材料的层压、覆层或基于面板的聚合物复合材料结构。本研究通过EbAM深入研究了覆层、层压或板基聚合物复合材料制造的最新进展,并对相关文献进行了全面的回顾。该研究包括简要的文献综述,探索制造复合材料的潜在应用,仔细检查三维打印(3DP)条件,确定最佳的3DP参数,并评估由此产生的机械和功能特性。此外,本文还指出了现有研究中的缺陷和不足,强调了未来研究工作中需要注意的领域。回顾的高 潮包括讨论通过EbAM制造层压复合材料确定的未来研究差距。通过对近期研究成果的综合分析,以及对研究成果和局限性的阐述,本文有助于对基于多材料的聚合物层压复合材料结构(LCS)和晶格结构制造的EbAM技术的发展前景进行集体理解。
Interaction of multiple micro-defects on the strength and failure mechanism of UD composites by computational micromechanics
Chenyang Xie, Yaowei Meng, Junzhen Chen, Zhiyong Zhao, Junbiao Wang, Jianjun Jiang, Yujun Li
doi:10.1016/j.compstruct.2024.118492
多个微缺陷相互作用对UD复合材料强度及破坏机制的计算细观力学研究
The mechanical properties of unidirectional fiber-reinforced plastic (UD-FRP) are affected by a variety of micro-defects, such as random fiber arrangement, fiber misalignment and micro-voids. This study aims to investigate how these multiple micro-defects interact with each other and how they affect the strength and failure mechanisms of UD-FRP by means of computational micromechanics. The composite behavior was simulated by the finite element analysis of a representative volume element of the composite microstructure in which the random distribution of fibers, the micro-voids, and the fiber misalignment are explicitly included. Both matrix and interface failure were considered for the loadings of transverse tension/compression, longitudinal compression, transverse/ longitudinal shear, and their combination. It was found that these three micro-defects significantly weakened the compressive strength of UD-FRP along the longitudinal direction. Especially, the fiber misalignment magnified the effect of fiber arrangement, while the micro-voids reduce the effect. Besides, the fiber arrangement and micro-voids significantly weakened the tensile and compressive strength of UD-FRP along the transverse direction, but their interaction effect was not obvious. Moreover, transverse and longitudinal shear strength are significantly affected by micro-voids, but only longitudinal shear is affected by geometric fiber arrangement, and this effect is also weakened by micro-voids. Finally, the damage envelope under the combined longitudinal compression and transverse loads was obtained and compared with the Tsai-Wu failure criterion. The results showed that the Tsai-Wu criteria can provide an effective estimation for the failure locus under this biaxial loading condition
单向纤维增强塑料(UD-FRP)的力学性能受到多种微缺陷的影响,如纤维无序排列、纤维错位和微孔洞。本研究旨在通过计算细观力学的方法研究这些多个微缺陷如何相互作用,以及它们如何影响UD-FRP的强度和破坏机制。采用具有代表性的复合材料微观结构体积元进行有限元分析,明确考虑了纤维的随机分布、微空隙和纤维的错位等因素,模拟了复合材料的性能。横向拉伸/压缩、纵向压缩、横向/纵向剪切及其组合荷载均考虑基体破坏和界面破坏。结果表明,这3个微缺陷沿纵向显著削弱UD-FRP的抗压强度。其中,光纤错位放大了光纤排列的效果,而微孔的存在则降低了光纤排列的效果。此外,纤维排列和微孔沿横向显著削弱UD-FRP的抗拉和抗压强度,但它们的相互作用不明显。此外,微孔洞对横向和纵向抗剪强度均有显著影响,但纤维几何排列只对纵向抗剪强度有影响,微孔洞也削弱了这种影响。最后,得到了纵向压缩和横向荷载联合作用下的损伤包络线,并与Tsai-Wu破坏准则进行了比较。结果表明,Tsai-Wu准则可以有效地估计双轴加载条件下的破坏轨迹
Quasi-brittle fracture criterion of CFRP with shallow surface scratch based on boundary effect model
Pingping Luo, Wei Shen, Lifeng Chen, Qian Li, Zijia Yao, Lvtao Zhu
doi:10.1016/j.compstruct.2024.118464
基于边界效应模型的CFRP浅表面划伤准脆性断裂准则
This study investigates the quasi-brittle fracture parameters of carbon fiber composites with shallow surface scratches by considering single-layer prepreg thickness as the characteristic composite microstructure. Three-point bending fracture tests were conducted on single-edge notched specimens of various-sized carbon fiber composites. The boundary effect model was employed to establish the relationship between the microstructure and macroscopic mechanical characteristics of carbon fiber composites. The maximum fracture load was used to determine the quasi-brittle fracture characteristics. By employing normal distribution analysis, the tensile strength and fracture toughness of each specimens were determined as ft = 453.28 MPa and KIC= 22.2 MPa√m, respectively. The analysis results exhibited an error of only 0.39 % compared to the least-squares fit, and encompassed almost all discrete points of the specimens within a 95 % reliability range. Using standard laboratory dimensions, fracture intervals for different notched depths at the same thickness can be predicted. Furthermore, the fracture parameters demonstrated an increasing trend within a certain range as the crack-thickness ratio increases, which aligns with the theoretical findings.
本研究将单层预浸料厚度视为复合材料微观结构的特征,研究了表面有浅划痕的碳纤维复合材料的准脆性断裂参数。对不同尺寸碳纤维复合材料的单边缺口试样进行了三点弯曲断裂试验。采用边界效应模型建立了碳纤维复合材料微观结构与宏观力学特性之间的关系。最大断裂载荷用于确定准脆性断裂特征。通过正态分布分析,确定每个试样的抗拉强度和断裂韧性分别为 ft = 453.28 MPa 和 KIC= 22.2 MPa√m。与最小二乘法拟合相比,分析结果的误差仅为 0.39%,几乎涵盖了试样的所有离散点,可靠度在 95% 的范围内。利用标准实验室尺寸,可以预测相同厚度下不同缺口深度的断裂区间。此外,随着裂纹厚度比的增加,断裂参数在一定范围内呈上升趋势,这与理论研究结果一致。
Ultimate strength prediction of composite laminates containing straight-sided holes, scarfed holes, and bonded repairs
Stephen Daynes, Raj Das
doi:10.1016/j.compstruct.2024.118512
包含直边孔、斜切孔和粘合修补的复合材料层压板的极限强度预测
Scarfed repairs are well suited to load carrying aerospace structures because they can improve the strength of a damaged composite laminate while maintaining a smooth aerodynamic profile. However, the strength prediction of such composite repairs is challenging, with strength depending upon the size and shape of the geometric features causing stress concentrations and the laminate stacking sequence. New semi-analytical and finite element analysis strength models are presented along with experimental verification for laminates containing circular and elliptically shaped straight-sided holes, scarfed holes, and adhesively bonded repairs. The new semi-analytical model for open hole ultimate strength is an extension of the point stress criterion. The model can estimate the characteristic damage length based on material properties, stacking sequence, hole shape, and hole size. Strength predictions for adhesively bonded repairs are also presented. The semi-analytical models are comparable in accuracy to the more computationally expensive continuum damage finite element models for the wide range of panels tested, and both model predictions are in close correlation with experimental results.
斜切修复非常适合于承载载荷的航空航天结构,因为它们可以在保持光滑气动外形的同时提高受损复合材料层压板的强度。然而,这种复合材料修复的强度预测具有挑战性,其强度取决于引起应力集中的几何特征的大小和形状以及层压板的堆叠顺序。提出了新的半解析和有限元分析强度模型,并对含有圆形和椭圆形直边孔、斜切孔和粘接修复的层合板进行了实验验证。新的裸眼极限强度半解析模型是对点应力准则的扩展。该模型可以根据材料特性、堆积顺序、孔洞形状和孔洞尺寸来估计特征损伤长度。粘接修复的强度预测也被提出。半解析模型在精度上可与计算成本较高的连续损伤有限元模型相媲美,并且两种模型的预测结果与实验结果密切相关。
Damage evolution analysis of C/SiC screwed/bonded hybrid joints based on in-situ micro-CT technique
Bingyao Li, Jingran Ge, Zhenqiang Wu, Xiaodong Liu, Binbin Zhang, Shuwei Zhao, Zengwen Wu, Jun Liang
doi:10.1016/j.compositesa.2024.108417
基于原位微ct技术的C/SiC螺纹/粘结复合接头损伤演化分析
Due to own good high temperature mechanical properties, the C/SiC screwed/bonded hybrid joints are considered as an important development direction of vehicle connection structures. However, the difficulty of directly monitoring the interior of the hybrid joints during the bearing presents a potential challenge to the structural damage assessment. In this study, the damage process of the hybrid joints subjected to tensile loading was monitored and characterized based on the in-situ micro-CT technique. The intrinsic relationship between the mechanical responses of the hybrid joints and the local damage evolution was elucidated by observing the variation of the deposited SiC void volume at the overlap interface. The dual inhomogeneity of SiC bonding layer was quantitatively characterized utilizing the average failure rate and determination coefficient. The coupling influence mechanism of prefabricated bottom hole size and online connection process on the final assembly clearance was revealed.
C/SiC螺纹/粘接混合接头由于具有良好的高温力学性能,被认为是汽车连接结构的重要发展方向。然而,在承载过程中对混合接头内部进行直接监测的难度给结构损伤评估带来了潜在的挑战。本研究基于原位微ct技术对复合接头在拉伸载荷作用下的损伤过程进行了监测和表征。通过观察叠合界面沉积SiC空洞体积的变化,阐明了杂化接头的力学响应与局部损伤演化之间的内在关系。利用平均失效率和确定系数定量表征了碳化硅键合层的双重不均匀性。揭示了预制井底尺寸与在线连接工艺对最终装配间隙的耦合影响机理。
Asymmetric electrical-magnetic composite foams with oriented cells fabricated by supercritical CO2 foaming and thermal stretching for efficient absorption dominated electromagnetic interference shielding
Jinghao Qian, Haiying Zhan, Hao-Yang Mi, Xiao Li, Weipeng Zhong, Xinchao Wang, Chuntai Liu, Changyu Shen
doi:10.1016/j.compositesa.2024.108428
采用超临界CO2发泡和热拉伸技术制备具有定向孔的非对称电磁复合泡沫材料,用于高效吸收为主的电磁干扰屏蔽
Asymmetric composite foams (TCFAs) based on thermoplastic polyurethane (TPU) containing carbon nanotubes (CNTs) and Fe3O4-decorated reduced graphene oxide (Fe3O4@rGO) electrical-magnetic dual networks with oriented cell structures and a silver layer were fabricated through supercritical carbon dioxide foaming, thermal stretching and a knife coating process. The oriented cells prolonged the electromagnetic (EM) wave transmission path and induced more multiple reflections, and the asymmetric silver layer enabled a special “absorption-reflection-reabsorption” mechanism, which contributed to a high electromagnetic interference (EMI) shielding effectiveness (SE) of 89.5 dB with an A value of 0.748 at a relatively low total filler content of 1.784 vol%. By regulating the oriented cell structure and the incorporation of asymmetric design, the TCFA-1 achieved 10 times improvement in EMI SET with a low EMI SER of 1.27 dB. This work offers new insights into the design and fabrication strategies for high performance absorption-dominated EMI shielding foams.
采用超临界二氧化碳发泡、热拉伸和刀涂工艺制备了以碳纳米管(CNTs)和fe3o4修饰的还原性氧化石墨烯(Fe3O4@rGO)为基体的热塑性聚氨酯(TPU)为基体的非对称复合泡沫材料(TCFAs)。定向电池延长了电磁波的传输路径,引起了更多的多次反射,不对称银层实现了特殊的“吸收-反射-重吸收”机制,这使得在相对较低的填料含量为1.784 vol%的情况下,电磁干扰屏蔽效率(SE)达到89.5 dB, a值为0.748。通过调节定向单元结构和非对称设计,TCFA-1的EMI SET性能提高了10倍,EMI SER低至1.27 dB。这项工作为高性能吸收型电磁干扰屏蔽泡沫的设计和制造策略提供了新的见解。
Tailored thermoelectric performance of poly(phenylene butadiynylene)s/carbon nanotubes nanocomposites towards wearable thermoelectric generator application
Wei-Chen Shih, Megumi Matsuda, Kazuki Konno, Po-Shen Lin, Tomoya Higashihara, Cheng-Liang Liu
doi:10.1016/j.compositesb.2024.111779
面向可穿戴热电发电机应用的聚苯丁二烯/碳纳米管纳米复合材料的热电性能
In this study, two conjugated polymers (CPs) featuring poly(phenylene butadiynylene) (PPB) were meticulously synthesized and composited with single-walled carbon nanotubes (SWCNTs) to investigate their thermoelectric properties and fabricate wearable thermoelectric generators (TEGs). These CPs, designated as P1 and P2, were tailored with distinct side chain configurations by incorporating 2-butyloctyloxy and 6-(methyldioctylsilyl)hexyloxy groups, respectively. Notably, P2, characterized by longer side chains with branchpoints farther from the backbone, exhibited planar backbone structure and enhanced solubility, consequently engendering stronger π–π interaction with SWCNTs and facilitating the disperse of SWCNTs through polymer wrapping at bundle surface. Such characteristics therefore contributed to the superior thermoelectric performances of the P2/SWCNTs nanocomposite, yielding a higher power factor (PF) of 216.5 μW m−1 K−2 for the spin-coated film. Furthermore, the corresponding wearable TEGs, which were constructed through spray-coating with 14 legs, resulted in an output power of approximately 49.6 nW under a temperature difference of 25 K, exhibiting successful harvesting of waste heat. Further applications also demonstrated operational efficacy under diverse conditions. These findings not only underscored the significance of side chain engineering in tailoring the thermoelectric properties of CP/SWCNTs nanocomposites but also demonstrated the feasibility of fabricating high-performance wearable thermoelectric devices applicable in versatile contexts.
在本研究中,精心合成了两种具有聚苯丁二炔(PPB)特征的共轭聚合物(CPs),并将其与单壁碳纳米管(SWCNTs)复合,以研究其热电性能并制造可穿戴热电发生器(teg)。这些CPs分别被命名为P1和P2,它们分别含有2-丁基氧基和6-(甲基二辛基硅基)己氧基,具有不同的侧链构型。值得注意的是,侧链较长且支点离主链较远的P2具有平面主链结构,其溶解性增强,从而与SWCNTs产生更强的π -π相互作用,促进SWCNTs通过束表面的聚合物包裹分散。因此,这些特性有助于P2/SWCNTs纳米复合材料的优越热电性能,使自旋涂层薄膜的功率因数(PF)达到216.5 μW m−1 K−2。此外,相应的可穿戴teg通过喷涂构建,具有14条腿,在温差为25 K的情况下,输出功率约为49.6 nW,成功地收集了废热。进一步的应用也证明了在不同条件下的运行效率。这些发现不仅强调了侧链工程在调整CP/SWCNTs纳米复合材料热电性能方面的重要性,而且证明了制造适用于多种环境的高性能可穿戴热电器件的可行性。
Ultrahigh absorption dominant EMI shielding polyimide composites with enhanced piezoelectric property
Hui Li, Jianwei Li, Wei Chu, Jun Lin, Pengfei He, Wei Fan, Qiangli Zhao
doi:10.1016/j.compscitech.2024.110820
增强压电性能的超高吸收优势屏蔽聚酰亚胺复合材料
Piezoelectric sensors have been widely used in wearable electronic devices with improved integration, which is prone to cause electromagnetic interference (EMI) pollution and affects its operation stability. How to design the materials with integrated piezoelectric sensing and EMI shielding performance is of great significance. In this paper, the Fe3O4@PPy/PINF (FPN) composite film was prepared by depositing pyrrole (Py) on the surface of Fe3O4 nanoparticles and combining it with polyimide (PI) nanofibrous membrane via vacuum-assisted suction filtration. In addition, after encapsulation with a highly soluble fluorine-containing polyimide (FPI) resin, a structurally stable FPI-Fe3O4@PPy/PINF (PFPN) composite film was obtained. The prepared PFPN composites show excellent EMI shielding effectiveness (44.58 dB) through the secondary reflection and multiple absorption effects. Remarkably, the value of the absorption coefficient A can reach 0.74, showing outstanding absorption characteristics. In addition, PFPN composite film also shows unexpected piezoelectric properties with high sensitivity of S = 0.8, short response (25 ms) and recovery (45 ms) time. Its piezoelectric output can reach 4.2 V with stable cyclic output property (> 15000 times). This kind of composite film with ultra-low reflection characteristics and favorable piezoelectricity presents a wide range of potential applications in the self-powered wearable electronic fields.
压电传感器广泛应用于集成度较高的可穿戴电子器件中,易产生电磁干扰污染,影响其工作稳定性。如何设计集压电传感和电磁干扰屏蔽性能于一体的材料具有重要意义。本文将吡咯(Py)沉积在Fe3O4纳米颗粒表面,并通过真空辅助吸滤将其与聚酰亚胺(PI)纳米纤维膜结合,制备了Fe3O4@PPy/PINF (FPN)复合膜。此外,用高溶性含氟聚酰亚胺(FPI)树脂包封后,获得了结构稳定的FPI-Fe3O4@PPy/ PFPN复合膜。通过二次反射和多次吸收效应,制备的PFPN复合材料具有良好的电磁干扰屏蔽效果(44.58 dB)。值得注意的是,其吸收系数A可达0.74,表现出优异的吸收特性。此外,PFPN复合膜还表现出意想不到的压电性能,具有S = 0.8的高灵敏度、短响应(25 ms)和45 ms的恢复时间。其压电输出可达4.2 V,循环输出性能稳定(> 15000次)。这种复合薄膜具有超低反射特性和良好的压电性,在自供电可穿戴电子领域具有广泛的应用前景。