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【新文速递】2023年12月18日复合材料SCI期刊最新文章

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今日更新:Composite Structures 6 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 6 篇,Composites Science and Technology 1 篇

Composite Structures

CNTs/PVA Composite Aerogel for Efficient Microwave and Acoustic Absorption

Xu Cao, Yong Liu, Qiong Sun, Tian Che, Cao Wu, Yong Yang

doi:10.1016/j.compstruct.2023.117805

高效微波声吸收的CNTs/PVA复合气凝胶

The lightweight three-dimensional (3D) carbon nanotubes (CNTs) aerogel has garnered significant interest due to their exceptional characteristics, including high porosity, large specific surface area, and a 3D conductive network. These characteristics make it as a promising candidate for various applications in microwave absorption. However, to construct a multifunctional framework, that can swiftly adapt to complex real-world environments, remains a large challenge. In this study, we fabricated a multifunctional CNTs/polyvinyl alcohol composite aerogel (CPA). Integrating polyvinyl alcohol (PVA) into CNTs aerogel could effectively prevent CNTs aggregation, thus obtaining the remarkable electromagnetic absorption, acoustic, mechanical, and thermal properties. The minimum reflection loss (RL) of CPA achieved an outstanding value of -39.77 dB, measured with a thickness of 2 mm. In addition, CPA showed excellent sound absorption performance, with the highest sound absorption coefficient (SAC) of 0.981. Sound transmission loss (STL) could be improved by adjusting the ratio of CPA, the improvement of STL was 5-8 dB at the mid-high frequencies. Finally, CPA also exhibited excellent thermal insulation performance with the lowest thermal conductivity of 0.0297 W/m·k. The multifunctional capabilities of CPA position it as a highly promising material for various applications, such as microwave absorption, noise reduction, and heat preservation.

轻质三维(3D)碳纳米管(CNTs)气凝胶由于其独特的特性(包括高孔隙率、大比表面积和3D导电网络)而引起了人们的极大兴趣。这些特性使其在微波吸收领域具有广阔的应用前景。然而,构建一个能够快速适应复杂现实环境的多功能框架仍然是一个巨大的挑战。在这项研究中,我们制备了一种多功能CNTs/聚乙烯醇复合气凝胶(CPA)。将聚乙烯醇(PVA)加入到CNTs气凝胶中,可以有效地防止CNTs聚集,从而获得优异的电磁吸收、声学、力学和热性能。在厚度为2mm时,CPA的最小反射损耗(RL)达到了-39.77 dB的显著值。此外,CPA具有优异的吸声性能,吸声系数(SAC)最高,为0.981。通过调节CPA的比值可以提高声传输损耗(STL),在中高频时,STL的改善幅度为5 ~ 8 dB。最后,CPA也表现出优异的保温性能,最低导热系数为0.0297 W/m·k。CPA的多功能特性使其在微波吸收、降噪和保温等方面具有很高的应用前景。


Analyzing free vibration and buckling of heated laminated plate with cutouts: A Nitsche-based isogeometric approach

Yuan Wang, Chaofeng Pan, Chao Zhang, Wangfan Zhou, Xiaobo Liu, Kaibo Xia, Jiangping Xu

doi:10.1016/j.compstruct.2023.117812

 

热切割层合板的自由振动和屈曲分析:一种基于nitsche的等几何方法

In this research, a comprehensive Nitsche-based isogeometric analysis framework is presented for studying the free vibration and buckling characteristics of laminated plates with cutouts under uniform and non-uniform thermal loads. The approach utilizes non-overlapping non-uniform rational B-Splines patches to discretize the perforated plate and seamlessly connects them using the Nitsche method. The technique is then applied to investigate the free vibration and buckling behaviors of laminated plates with cutouts under varying thermal conditions. Three tests with different element sizes are used to analyze composite plate under uniform thermal load, demonstrating good convergence and accuracy of the present method. Rectangular laminated plates without cutouts, considering various boundary conditions, fiber orientations, and temperature variations under uniform or non-uniform thermal loads are analyzed. The natural frequencies and critical buckling temperatures are found to be in excellent agreement with existing literature. Additionally, the analysis is expanded for laminated plates with cutouts under diverse boundary conditions, considering variations in fiber orientations, cutout shapes and numbers, and types of thermal loads. Thorough investigations are carried out to understand the influence of these factors on the vibrational and buckling behaviors of the plates. Moreover, numerical study with non-conforming mesh demonstrates strong capability of the proposed method.

在本研究中,提出了一种基于nitsche的综合等几何分析框架,用于研究带切口层合板在均匀和非均匀热载荷下的自由振动和屈曲特性。该方法利用非重叠非均匀有理b样条块将穿孔板离散化,并使用Nitsche方法将它们无缝连接。然后应用该技术研究了带切口层合板在不同热条件下的自由振动和屈曲行为。采用三种不同单元尺寸的试验对复合材料薄板进行了均匀热载荷分析,结果表明该方法具有较好的收敛性和准确性。在均匀热载荷和非均匀热载荷作用下,对考虑不同边界条件、纤维取向和温度变化的无切口矩形层合板进行了分析。固有频率和临界屈曲温度与现有文献非常吻合。此外,考虑到纤维方向、切口形状和数量以及热载荷类型的变化,对不同边界条件下带切口的层合板进行了扩展分析。对这些因素对板的振动和屈曲行为的影响进行了深入的研究。此外,对非一致性网格的数值研究也证明了该方法的有效性。


Strain Rate-Dependent Failure Modelling of Impact Damage in Laminated CFRP Structures

D. Ivančević, J. Ratković, E. Giannaros

doi:10.1016/j.compstruct.2023.117817

基于应变率的CFRP层合结构冲击损伤失效模型

This work focuses on the development, implementation, and validation of a constitutive model for unidirectional composites, aiming to numerically simulate impact damage in laminated structures. The model incorporates a failure criterion that accounts for the influence of strain rate on failure initiation and distinguishes between four failure modes. Failure initiation criteria are 3D phenomenological-based criteria according to the previous work of Puck and Schürmann (1998) and Pinho (2006). Additionally, a mesh-objective damage propagation model is implemented to simulate the impact damage. The impact simulations are performed using Abaqus/Explicit, with the constitutive model implemented through the user subroutine VUMAT. Validation of the strain rate effects on failure initiation is performed using strain rate-dependent bi-axial failure curves for IM7/8552 and AS-4/3506. The analyses indicate that the properties governing the strain rate dependence of failure initiation are consistent. Therefore, the hypothesis was tested in which the same strain rate scaling approach could be used for CFRP materials for which only static properties are available. This hypothesis was tested in high and low-velocity impact simulations at laminated IMS60/977-2 CFRP plates. The results demonstrate that the model accurately replicates the experimentally observed impact-induced contact forces and effectively captures the damaged state in the impacted plate.

这项工作的重点是开发、实施和验证单向复合材料的本构模型,旨在数值模拟层压结构的冲击损伤。该模型纳入了考虑应变速率对破坏起始影响的破坏准则,并区分了四种破坏模式。根据Puck和sch<s:1> rmann(1998)和Pinho(2006)之前的工作,失效启动标准是基于三维现象学的标准。此外,还建立了网格目标损伤传播模型来模拟冲击损伤。采用Abaqus/Explicit进行冲击仿真,本构模型通过用户子程序VUMAT实现。使用应变率相关的IM7/8552和as /3506双轴失效曲线验证了应变率对失效启动的影响。分析表明,控制破坏起始的应变速率依赖特性是一致的。因此,假设进行了测试,其中相同的应变率缩放方法可以用于CFRP材料,只有静态性能可用。这一假设在IMS60/977-2 CFRP叠层板的高速和低速冲击模拟中得到了验证。结果表明,该模型准确地复 制了实验观察到的冲击接触力,有效地捕捉了冲击板的损伤状态。


Fatigue Damage Mechanisms and Evolution of Residual Tensile Strength in CFRP Composites: Stacking Sequence Effect

Zuxiang Lei, Rui Pan, Weikang Sun, Yawei Dong, Yun Wan, Binbin Yin

doi:10.1016/j.compstruct.2023.117818

CFRP复合材料疲劳损伤机理及残余抗拉强度演化:堆叠顺序效应

This study explores the effect of fiber orientation on the fatigue resistance of carbon fiber reinforced polymer composite laminates. First, fatigue damage mechanisms of composite laminates with different stacking sequences at various stress levels are analyzed by utilizing digital image correlation (DIC) and scanning electron microscope (SEM) techniques. The findings highlight that the fiber orientation of the laminate has a significant effect on the fatigue life of the specimens. Prior to final fatigue failure, laminates with 0° fiber orientation experience only a 30% reduction, while laminates with ±45° fiber orientation show up to 93% stiffness reduction. The fracture modes of laminates with a 0° fiber orientation vary depending on stress levels. Microscopic observations confirm that in the case of laminates with ±45° fiber orientations under compressive loading, fiber flexion, and delamination are the predominant failure mechanisms. Further, the post-fatigue tensile tests reveal that the residual tensile strength of the laminates with ±45° fiber orientations increases by 6.3% after 15% of the total cycles (7.2×104) at a 30% stress level. The contribution of this study provides vital insights into the structural design of laminates and offers a pathway for improving their fatigue performance.

研究了纤维取向对碳纤维增强聚合物复合材料层合板抗疲劳性能的影响。首先,利用数字图像相关(DIC)和扫描电镜(SEM)技术,分析了不同叠层顺序的复合材料层板在不同应力水平下的疲劳损伤机理。结果表明,层合板的纤维取向对试件的疲劳寿命有显著影响。在最终疲劳失效之前,纤维取向为0°的层压板刚度仅降低30%,而纤维取向为±45°的层压板刚度降低高达93%。纤维取向为0°的层压板的断裂模式随应力水平的变化而变化。微观观察证实,在压缩载荷下纤维取向为±45°的层压板的情况下,纤维弯曲和分层是主要的破坏机制。此外,疲劳后拉伸试验表明,在30%的应力水平下,经过15%的总循环(7.2×104),纤维取向为±45°的层合板的残余拉伸强度增加了6.3%。本研究为层合板的结构设计提供了重要的见解,并为提高层合板的疲劳性能提供了途径。


Investigation on interference and damage behaviours of electromagnetic riveted double-sided countersunk 30CrMnSiA/CFRP joints

Minghao Zhang, Zengqiang Cao, Yuejie Cao, Guo Zheng, Chengxiang Guo, Yuehaoxuan Wang

doi:10.1016/j.compstruct.2023.117824

电磁铆接30CrMnSiA/CFRP双面沉头接头干扰及损伤行为研究

Carbon fibre reinforced polymer (CFRP) structures benefit from electromagnetic riveting (EMR). However, incorrect riveting parameters could result in damages in CFRP structures during the EMR process. Excessive interference size may introduce initial damages to the joints. As a result, in this paper, the damage behaviours and the interference characteristics of the 30CrMnSiA/CFRP double-sided countersunk electromagnetic riveted joints are investigated. The riveting damage experiment was conducted, with the regular pressing riveting (RPR) process as a comparison. Moreover, a progressive damage FE model considering multiple typical damage modes of CFRP was developed for EMR damage prediction. The results show that when the rivet-hole diameter increases by 5% (4.08mm to 4.28mm), the average interference size of the joint under EMR and RPR processes decreases by 41% and 53%, respectively. Double-sided countersunk riveted joint interference size along the rivet axial distribution is not uniform, the CFRP sheet side of the interference size is relatively small. The EMR achieves a tighter, more uniform interference fit, while causing more severe riveting damages to the CFRP structure. Initial riveting damage exhibits a variety of modes, with delamination damage showing most significant sensitivity to rivet hole clearance.

碳纤维增强聚合物(CFRP)结构受益于电磁铆接(EMR)。然而,在EMR过程中,不正确的铆接参数可能导致CFRP结构的损伤。过大的干涉尺寸会对接头造成初始损伤。为此,本文对30CrMnSiA/CFRP双面埋头电磁铆接接头的损伤行为和干扰特性进行了研究。进行了铆接损伤实验,并与常规冲压铆接(RPR)工艺进行了对比。此外,建立了考虑碳纤维布多种典型损伤模式的渐进损伤有限元模型,用于EMR损伤预测。结果表明:当铆钉孔直径增加5% (4.08mm ~ 4.28mm)时,EMR和RPR工艺下接头的平均干涉尺寸分别减小41%和53%;双面沉铆接头过干涉尺寸沿铆钉轴向分布不均匀,CFRP片材侧的过干涉尺寸相对较小。EMR实现了更紧密、更均匀的过盈配合,同时对CFRP结构造成更严重的铆接损伤。初始铆接损伤表现出多种模式,分层损伤对铆钉孔间隙的敏感性最大。


The numerical simulation of Particulate Reinforced Composites by using a two-dimensional VCFEM formulated with plastic, thermal, and creep strain

Jie Rao, Ran Guo, Rui Zhang

doi:10.1016/j.compstruct.2023.117825

采用含塑性、热应变和蠕变应变的二维VCFEM对颗粒增强复合材料进行了数值模拟

The working environment of industrial fields where the Particulate Reinforced Composites (PRCs) are commonly used is complex. In these harsh environments, PRCs produce some nonlinear strains, such as plastic, thermal, and creep strains, which affect the performance of PRCs to some extent. In addition, the actual structure of PRCs contains a massive amount of inclusions, and the number of inclusions could reach the magnitude of millions or even tens of millions. For the large-scale numerical simulation of PRCs, ordinary displacement finite element requires a large number of meshes, which increases their computational complexity and unsolvability. For real PRCs with random particle distribution, homogenisation theory does not accurately capture the true state of stress concentration in PRCs. The Voronoi cell finite element method (VCFEM) can be a good solution to the drawbacks of the above two numerical simulation methods. The subject of the present work explores a modified complementary energy generalized function that takes the constitutive relationship of nonlinear strain into account, proposing a two-dimensional VCFEM, formulated with plastic, thermal, and creep strain. The simulation results are compared with the computed results of a commercial finite element software Marc to verify the validity and accuracy of the VCFEM. Results of the comparison show that the VCFEM has the advantages of simple meshing and faster computation under the same precision. The VCFEM, considering plastic, thermal, and creep strains proposed in this paper, lays the foundation for future large-scale numerical simulations of PRCs containing a large quantity of inclusion structures and can realistically capture the stress concentration state of PRCs. At the end of the article, the impact of the order of stress function on the calculation results is discussed.

颗粒增强复合材料(prc)在工业领域的工作环境是复杂的。在这些恶劣的环境中,prc会产生一些非线性应变,如塑性应变、热应变和蠕变应变,这些都在一定程度上影响了prc的性能。此外,prc的实际结构中含有大量的包裹体,包裹体的数量可以达到数百万甚至数千万个量级。普通位移有限元在大尺度数值模拟中需要大量的网格,这增加了有限元的计算复杂度和不可解性。对于具有随机颗粒分布的真实prc,均质化理论不能准确地捕捉prc中应力集中的真实状态。Voronoi单元有限元法(VCFEM)可以很好地解决上述两种数值模拟方法的不足。本工作的主题探讨了一个改进的互补能量广义函数,该函数考虑了非线性应变的本构关系,提出了一个二维VCFEM,包含塑性、热应变和蠕变应变。仿真结果与商用有限元软件Marc的计算结果进行了比较,验证了VCFEM的有效性和准确性。对比结果表明,在相同精度下,VCFEM具有网格划分简单、计算速度快的优点。本文提出的VCFEM考虑了塑性应变、热应变和蠕变应变,为今后对含有大量夹杂物结构的复合材料进行大规模数值模拟奠定了基础,可以真实地捕捉复合材料的应力集中状态。最后讨论了应力函数阶数对计算结果的影响。


Composites Part A: Applied Science and Manufacturing

Modeling and experimental identification of thermo-kinetic and visco-hyperelastic coupling for semicrystalline thermoplastic continuous fiber composites subjected to processing temperatures

Nicolas Bigot, Nahiène Hamila, Philippe Chaudet, Shihe Xin, M’hamed Boutaous

doi:10.1016/j.compositesa.2023.107967

加工温度下半结晶热塑性连续纤维复合材料热动力学和粘弹性耦合的建模与实验鉴定

This paper presents a visco-hyperelastic constitutive model to characterize the temperature-dependent mechanical deformation of composite materials during thermoforming. The material of interest was a unidirectional or woven fibrous reinforcement filled with a semi-crystalline thermoplastic matrix. Based on the two laws of thermodynamics, the mechanical model was coupled with the heat equation and a crystallization kinetics model. As a result, the viscoelastic effects and exothermicity of the crystallization reaction, characteristic of the presence of the semicrystalline thermoplastic matrix, constituted internal heat sources taken into account by the heat equation. These were the first steps towards establishing a thermo-chemical–mechanical coupling. In order to validate and parameterize the present law, a thermomechanical characterization of in-plane shear was put forward.

本文提出了一种粘-超弹性本构模型来表征复合材料在热成形过程中随温度变化的力学变形。感兴趣的材料是一种单向或编织纤维增强填充半结晶热塑性基质。基于热力学两定律,将力学模型与热方程和结晶动力学模型相结合。因此,结晶反应的粘弹性效应和放热性,以及半结晶性热塑性基体的存在,构成了热方程考虑的内部热源。这是建立热-化学-机械耦合的第一步。为了验证和参数化这一规律,提出了面内剪切的热力学表征。


Composites Part B: Engineering

Significantly enhanced fatigue resistance and mechanisms of hypoeutectic Al-Si composite calibrated using trace in-situ nanocrystals

Tian-Shu Liu, Lin Zhu, Hong-Yu Yang, Hong-Yu Cui, Jia Meng, Feng Qiu, Bai-Xin Dong, Shi-Li Shu, Qi-Chuan Jiang, Lai-Chang Zhang

doi:10.1016/j.compositesb.2023.111138

 

利用微量原位纳米晶对亚共晶Al-Si复合材料的抗疲劳性能和机制进行了显著增强

Fatigue resistance under extreme stress conditions is an important indicator to evaluate industrial application potential of Al-Si-Mg alloys, but their fatigue resistance is inherently weakened by large grain size, long-needle Si phases and coarse precipitates. This work reports significantly optimized microstructure configuration and fatigue resistance of hypoeutectic Al-Si composite optimized by the nanocrystallization products of a NiNbTi metallic glass. It was proved the in-situ NiTi (B2) nanocrystals can serve as the heterogeneous nucleation sites of α-Al and β-Mg2Si and the growth retarder of eutectic Si. Particularly, the optimized composite exhibited nearly 5 times and 6 times longer fatigue life than the unoptimized alloy at 120 MPa and 60 Hz and at 240MPa and 20 Hz, respectively. The fatigue strength (N = 107) was increased by 21.7 % and 25.9 % at 60 Hz and 20 Hz, respectively. The α-Al refinement enhanced the resistance to fatigue crack initiation. The refinement and spheroidization of eutectic Si phases reduced stress concentration. Also, the austenite-martensite phase transformation of NiTi afforded more energy for precipitation. Refined β-Mg2Si and β'' phases were facilitated to interact with dislocations, improving the resistance to dislocation slip during cyclic strain through the dislocation shearing effect. This work provides a theoretical basis for the future development of Al-Si alloys and composites with excellent fatigue resistance for expanding their industrial application scope.

极端应力条件下的抗疲劳性能是评价Al-Si-Mg合金工业应用潜力的重要指标,但晶粒尺寸大、Si相长针状、析出物粗大等因素削弱了Al-Si-Mg合金的抗疲劳性能。本文报道了利用纳米化产物优化的镍钛金属玻璃的亚共晶铝硅复合材料的微观结构和抗疲劳性能。结果表明,原位NiTi (B2)纳米晶可以作为α-Al和β-Mg2Si的非均相成核位点和共晶Si的生长缓凝剂。特别是,在120 MPa和60 Hz、240MPa和20 Hz下,优化后的复合材料的疲劳寿命分别比未优化的合金长近5倍和6倍。在60 Hz和20 Hz下,合金的疲劳强度(N = 107)分别提高了21.7% %和25.9% %。α-Al的细化增强了材料抗疲劳裂纹萌生的能力。共晶Si相的细化和球化降低了应力浓度。同时,NiTi的奥氏体-马氏体相变为析出提供了更多的能量。细化的β- mg2si和β”相与位错相互作用,通过位错剪切效应提高了循环应变过程中对位错滑移的抵抗能力。本工作为今后开发具有优异抗疲劳性能的铝硅合金及复合材料,扩大其工业应用范围提供了理论基础。


Individualized bio-scaffold encapsulating siPTEN-loaded exosomes for promoting neuronal regeneration in spinal cord injury

Zehan Shang, Zihao Liu, Min Han, Hao Fan, Dongxiao Lu, Zijian Zhou, Zhihai Wang, Yuming Li, Xiaofeng Wang, Bingcheng Wang, Baogeng Huai, Youqiang Cui, Huitang Xia, Shan Wang, Tao Xin

doi:10.1016/j.compositesb.2023.111146

包裹载sipten外泌体的个别化生物支架促进脊髓损伤神经元再生

Biological scaffold implants loaded with exosomes were acknowledged as a promising strategy for the treatment of spinal cord injury. In this study, we constructed an individualized biomimetic scaffold based on combination of multimodal imaging and 3D printing technology, featuring sustained release, biodegradability, and strongly biocompatibility. The scaffold incorporated mesenchymal stem cell-derived exosomes to alleviate inflammatory response in microenvironment and reduce scar formation of ECM molecule deposition. Furthermore, to effectively enhance neuronal repair and regeneration, siRNAs targeting PTEN were introduced into exosomes. The engineered exosomes within scaffold induced endogenous neuronal regeneration and enhanced axonal growth through PTEN/PI3K/AKT/mTOR signaling pathway. Additionally, implantation of scaffold could bridge the severed ends, thus providing spatial signals to modulate the organization of neural cells, facilitating the reconstruction of complex neural networks, and restoring nerve conduction. Collectively, the individualized 3D printed bio-scaffold encapsulated siPTEN-loaded exosomes could offer great promise for the prospective clinical translation in spinal cord injury therapy.

装载外泌体的生物支架植入物被认为是治疗脊髓损伤的一种有前途的策略。在本研究中,我们基于多模态成像和3D打印技术的结合构建了个体化仿生支架,具有缓释、可生物降解、强生物相容性的特点。支架加入间充质干细胞来源的外泌体,减轻微环境下的炎症反应,减少ECM分子沉积的瘢痕形成。此外,为了有效地促进神经元的修复和再生,将靶向PTEN的sirna引入外泌体。支架内工程化外泌体通过PTEN/PI3K/AKT/mTOR信号通路诱导内源性神经元再生,促进轴突生长。此外,支架的植入可以桥接断端,从而提供空间信号来调节神经细胞的组织,促进复杂神经网络的重建,恢复神经传导。综上所述,这种封装了sipten负载外泌体的个性化3D打印生物支架在脊髓损伤治疗的前瞻性临床转化中具有很大的前景。


Electromagnetic oscillation induced graphene-based aerogel microspheres with dual-chamber achieving high-performance broadband microwave absorption

Wenting Deng, Dandan Zhi, Jinzhe Li, Tian Li, Qian Liu, Jiatong Li, Jiang Zhu, Fanbin Meng

doi:10.1016/j.compositesb.2023.111149

电磁振荡诱导石墨烯基双腔气凝胶微球实现了高性能宽带微波吸收

Graphene-based aerogels have indeed generated significant interest in manufacturing microwave absorbers with ultra-low density and high efficiency. Nevertheless, unitary loss mechanism and impedance mismatch hinder corresponding application. Furthermore, it is essential to address the challenges related to structure control strategy and explanation of the loss mechanism. Dual-chamber graphene-based aerogel microspheres (AMs) with heterogeneous interfaces were fabricated through electrospinning-freeze drying and subsequent calcination. Significant differences are observed in reflecting and scattering of shell and dual-chamber structure against electromagnetic wave (EMW), enabling electromagnetic oscillation, sequential absorption and multi-level coupling of EMW. In addition, the dual-chamber construction is a pivotal role in optimizing impedance matching. In this regard, dual-chamber structure graphene-based AMs with 5 wt% loading were synthesized and exhibited excellent loss ability to EMW in the range of 5∼18 GHz, which manifest −28.12 dB at 15.62 GHz, and accordingly, the fE is 6.0 GHz at 2.2 mm thickness, achieving full coverage dissipation of Ku-band. The results demonstrate that the dual-chamber graphene-based AMs achieve the effect of multi-frequency compatible and broadband microwave absorption at low thickness. The integration of the ideation of heterogeneous dual-chamber AMs with electromagnetic-oscillation and sequential loss provides a unique and innovative strategy for modulating lightweight and broadband efficiency absorbers.

基于石墨烯的气凝胶在制造超低密度和高效率的微波吸收剂方面确实引起了极大的兴趣。然而,单一的损耗机制和阻抗失配阻碍了相应的应用。此外,必须解决与结构控制策略和解释损失机制相关的挑战。采用电纺丝-冷冻干燥-煅烧法制备了具有非均相界面的双腔石墨烯基气凝胶微球。壳体结构和双腔结构对电磁波的反射和散射存在显著差异,从而实现电磁波的电磁振荡、顺序吸收和多级耦合。此外,双腔结构在优化阻抗匹配中起着关键作用。在这方面,合成了负载为5 wt%的双腔结构石墨烯基AMs,并在5 ~ 18 GHz范围内表现出优异的EMW损耗能力,在15.62 GHz时表现为−28.12 dB,因此fE为6.0 GHz,厚度为2.2 mm,实现ku波段全覆盖损耗。结果表明,双腔石墨烯基AMs在低厚度下实现了多频兼容和宽带微波吸收的效果。结合电磁振荡和时序损耗的非均质双腔AMs的思想,为调制轻量级和宽带效率吸收器提供了一种独特而创新的策略。


Aramid nanofiber-based functional composite materials: Preparations, applications and perspectives

Hui Zhang, Meiyun Zhang, Jinbao Li, Bin Yang, Syed Comail Abbas, Chenglong Fu, Ting Chen, Yuanyuan Xia, Jiawei Liu, Xiaoyun Du, Zhibin He, Yonghao Ni

doi:10.1016/j.compositesb.2023.111151

   

芳纶纳米纤维基功能复合材料的制备、应用与展望

Aramid Nanofibers (ANFs), akin to PPTA Poly (p-phenylene terephthalamide), stand at the forefront of cutting-edge nanomaterials, boasting exceptional properties like high tensile strength, modulus of elasticity, high temperature stability, and chemical stability. Their remarkable advantages have already paved the way for diverse applications in composite materials, energy devices, protection, adsorption, and groundbreaking medical products. Due to the unique properties of ANFs, there has been strong interests in the research community on the functional ANF- based composites and their applications in cutting-edge fields, there has been a lack of comprehensive reviews on the fundamental development and practical applications of ANFs regarding these most recent results (e.g., the last three years). This review aims to fill that void by thoroughly exploring the potential of ANFs. We delve into the preparation methods, uncovering techniques for preparing ANFs with specific properties and morphologies. Additionally, we critically evaluate the fascinating mechanisms driving these extraordinary properties, which stem from their nanoscale dimensions and high aspect ratio. Furthermore, we closely examine the distinct characteristics of ANFs-based composites in various forms, i.e., 1D, 2D, and 3D structure, especially in relevance to their specific applications. Also, this paper discusses the major challenges and future prospects of ANFs composites. This comprehensive review and outlook will inspire readers to gain a better understanding of the latest development status and future research directions of ANFs and ANFs-based materials.

芳纶纳米纤维(ANFs),类似于PPTA聚对苯基对苯二甲酰胺,站在尖端纳米材料的最前沿,具有优异的性能,如高抗拉强度、弹性模量、高温稳定性和化学稳定性。它们的显著优势已经为复合材料、能源设备、保护、吸附和突破性医疗产品的各种应用铺平了道路。由于ANF的独特性质,研究界对功能性ANF基复合材料及其在前沿领域的应用产生了浓厚的兴趣,但关于这些最新成果(例如,最近三年),对ANF的基本发展和实际应用缺乏全面的综述。本文旨在通过深入探索ANFs的潜力来填补这一空白。我们深入研究了制备方法,揭示了制备具有特定性质和形态的ANFs的技术。此外,我们批判性地评估了驱动这些非凡特性的迷人机制,这些特性源于它们的纳米级尺寸和高纵横比。此外,我们仔细研究了各种形式的基于anfs的复合材料的独特特征,即1D, 2D和3D结构,特别是与它们的特定应用相关。同时,本文还讨论了ANFs复合材料的主要挑战和未来的发展前景。这篇综述和展望将有助于读者更好地了解纳米纤维和纳米纤维基材料的最新发展现状和未来研究方向。


Low velocity impact and compression-after-impact response of hybrid pseudo-woven meso-architectured carbon/epoxy composite laminates manufactured via automated fiber placement

Karan Kodagali, Cyrus Vakili Rad, Subramani Sockalingam, Zafer Gurdal, Eileen Miller

doi:10.1016/j.compositesb.2023.111154

自动化纤维铺放复合假编织细观结构碳/环氧复合材料层合板低速冲击及冲击后压缩响应

An experimental study is presented on the low velocity impact (LVI) and compression after impact (CAI) response of T800-SC carbon/epoxy laminates manufactured via automated fiber (AFP) placement manufacturing. Two hybrid laminate configurations consisting of unidirectional and pseudo-woven meso-architectured composite (MAC) sub-laminates are compared against a traditional quasi-isotropic control laminate. MAC sub-laminates are manufactured via a modified AFP process implementing tow skips. The MAC architecture is macroscopically heterogeneous with discontinuous and spatially varying fiber orientations both in-plane and through thickness resulting in multiple interfaces and an expanded design space. The laminates are tested under LVI energies of 15–55 J using a 25.4 mm diameter hemispherical projectile according to ASTM D7136. The results show similar load-displacement responses but significant difference in the LVI damage profiles and CAI strengths for the different configurations. The hybrid laminate configurations exhibit increased damage resistance with up to 37% higher critical delamination load and increased damage tolerance with 26% higher residual compressive strength after an impact of 55 J compared to control laminate.

对自动化纤维铺层制造的T800-SC碳/环氧复合材料的低速冲击(LVI)和冲击后压缩(CAI)响应进行了实验研究。比较了两种由单向和伪编织细观结构复合材料(MAC)子层压板组成的混合层压板结构与传统的准各向同性控制层压板结构。MAC亚层压板是通过改进的AFP工艺制造的,实现了两个跳过。MAC结构在宏观上是不均匀的,在平面内和厚度上的光纤方向是不连续和空间变化的,导致了多个接口和扩展的设计空间。根据ASTM D7136,在LVI能量为15-55 J的情况下,使用直径25.4 mm的半球形弹丸对层压板进行测试。结果表明,不同结构下的荷载-位移响应相似,但LVI损伤曲线和CAI强度存在显著差异。与对照层压板相比,混合层压板的抗损伤能力提高了37%,临界分层载荷提高了37%,在55 J的冲击后,其损伤容忍度提高了26%。


The multi-objective optimization framework: A step towards minimizing life-cycle costs and energy consumption of carbon fibre automotive structures

Kaushik Iyer, Mathilda Karlsson Hagnell, Malin Åkermo

doi:10.1016/j.compositesb.2023.111158

多目标优化框架:朝着最小化碳纤维汽车结构生命周期成本和能源消耗迈出的一步

Design of a sustainable and economical composite structure is challenging due to the often contradicting design drivers such as energy consumption and cost. Therefore, predicting the environmental and economic impact in the early stages of product design results in the significant reduction of energy consumption and cost. Consequently, the impact of contrasting objectives on an optimized carbon fibre reinforced polymer (CFRP) demonstrator is evaluated in this study. This evaluation is performed by integrating a predictive life-cycle assessment and costing framework in a multi-objective optimization methodology. The varying design configurations include designs with and without stiffeners. Furthermore, the impact of end-of-life allocation on the optimized design is also evaluated in this study. The results show a marked difference between the energy consumption of the various optimized designs with energy optimization producing the most efficient solution. However, the mass of the demonstrator increases by 7–9 kg across the different design configurations when the closed loop allocation model is implemented. Consequently, the results show the importance of selecting an appropriate EOL allocation methodology in evaluating the energy consumption of a products. The results also show that the parameters driving the energy consumption (mass and material configuration) and cost (complexity and manufacturability) are varied and often contrasting. The differences in mass, cost, and energy optimized designs further reinforces the importance of coupling cost and energy evaluation in design of sustainable products. Finally, the study demonstrates the need for a holistic life-cycle based assessment in early stage sustainable product design.

由于能源消耗和成本等相互矛盾的设计驱动因素,设计可持续和经济的复合材料结构具有挑战性。因此,在产品设计的早期阶段预测环境和经济影响可以显著降低能耗和成本。因此,对比目标对优化的碳纤维增强聚合物(CFRP)演示器的影响在本研究中进行了评估。这种评估是通过在多目标优化方法中集成预测性生命周期评估和成本框架来执行的。不同的设计配置包括有和没有加强筋的设计。此外,本研究还评估了寿命末端分配对优化设计的影响。结果表明,各种优化设计的能耗存在显著差异,能量优化产生最有效的解决方案。然而,当实现闭环分配模型时,演示器的质量在不同的设计配置中增加了7-9 kg。因此,结果表明选择适当的EOL分配方法在评估产品的能源消耗的重要性。结果还表明,驱动能耗(质量和材料配置)和成本(复杂性和可制造性)的参数是多种多样的,并且经常形成对比。质量、成本和能源优化设计的差异进一步强化了可持续产品设计中耦合成本和能源评估的重要性。最后,研究证明了在早期可持续产品设计中需要一个基于整体生命周期的评估。


Composites Science and Technology

Manufacturing multifunctional vascularized composites by through-thickness frontal polymerization and depolymerization: A numerical study on the impact of sacrificial fiber configurations

Zhuoting Chen, Xiang Zhang

doi:10.1016/j.compscitech.2023.110394

   

通过厚度正面聚合和解聚制备多功能血管化复合材料:牺牲纤维构型影响的数值研究

Concurrent through-thickness frontal polymerization and vascularization (FP-VaSC) is emerging as a promising alternative to conventional multi-step fabrication approaches for vascularized thermoset polymers and composites. This method relies on a localized and self-propagating exothermic polymerization reaction front of the polymer matrix, to simultaneously cure the matrix, and depolymerize pre-embedded sacrificial templates. It delivers fully cured thermoset polymers and composites rapidly and energy-efficiently with the desired vascular system in a single step. While previous studies demonstrated the capability of this method for making woven laminates with a single vascular channel created by embedding a single straight sacrificial fiber, it is desirable to explore the potential of this method for making composites with multiple channels for more practical applications. We employ a previously validated thermo-chemical model from our prior study, to systematically investigate the reaction process with the presence of multiple sacrificial fibers. Two sacrificial fiber configurations are considered, namely, inline and staggered fiber configurations. Within each configuration, we consider a range of horizontal and vertical fiber spacing, which also lead to different sacrificial fiber volume fractions. This study reveals the interactions between the sacrificial fiber and the reactions, identifies the working window of this method for different sacrificial fiber configurations, and provides guidance for manufacturing laminates with multiple vascular channels. We also propose an analytical model that can quickly approximate the maximum sacrificial fiber volume fraction that can lead to successful FP-VaSC for a given carbon fiber volume fraction and compare the results with those from the thermo-chemical modeling.

同时通过厚度正面聚合和血管化(FP-VaSC)正在成为血管化热固性聚合物和复合材料的传统多步骤制造方法的有前途的替代方法。该方法依靠聚合物基体的局部自扩散放热聚合反应,同时固化基体,解聚预嵌牺牲模板。它可以在一个步骤中快速、高效地提供完全固化的热固性聚合物和复合材料,并提供所需的血管系统。虽然之前的研究表明,这种方法可以通过嵌入一根笔直的牺牲纤维来制造具有单一血管通道的编织层叠板,但为了更实际的应用,探索这种方法在制造具有多通道的复合材料方面的潜力是可取的。我们采用先前研究中验证过的热化学模型,系统地研究了存在多个牺牲纤维的反应过程。考虑了两种牺牲光纤结构,即嵌线光纤结构和交错光纤结构。在每种配置中,我们考虑了水平和垂直纤维间距的范围,这也导致了不同的牺牲纤维体积分数。本研究揭示了牺牲纤维与反应之间的相互作用,确定了该方法在不同牺牲纤维构型下的工作窗口,为制造多血管通道层叠板提供了指导。我们还提出了一个分析模型,该模型可以快速近似最大牺牲纤维体积分数,从而在给定的碳纤维体积分数下成功实现FP-VaSC,并将结果与热化学模型的结果进行比较。





来源:复合材料力学仿真Composites FEM
MeshingACTMechanicalSystemInspire振动疲劳断裂复合材料非线性化学汽车裂纹理论材料仿生
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【新文速递】2023年12月9日复合材料SCI期刊最新文章

今日更新:Composite Structures 5 篇,Composites Part A: Applied Science and Manufacturing 3 篇,Composites Science and Technology 2 篇Composite StructuresMemeplex-based memetic algorithm for the multi-objective optimal design of composite structuresCarlos Conceição Antóniodoi:10.1016/j.compstruct.2023.117789基于 Memeplex 的复合结构多目标优化设计记忆算法Hybrid construction is proposed to decrease costs in lightweight structures using fiber-reinforced plastics (FRP) composite materials. Minimum weight, minimum strain energy (stiffness), and minimum energy variability of the structural system response are the objectives of the robust design optimization approach applied to composite shell structures with stiffeners. The trade-off depends on given stress, displacement, and buckling constraints imposed on composite structures considering non-linear geometric behavior. The design variables are ply angles and ply thicknesses of shell laminates, the cross-section dimensions of stiffeners, and the variables related to the selection of materials and their distribution at the laminate level and subsequently of the laminates along the structure. A Multi-Objective Memetic Algorithm (MOMA) applies multiple learning procedures exploring the synergy of different cultural transmission rules. An enlarged virtual population with a dual age-dominance nature captures and updates the Pareto curve. The concept of memeplex controls the meme selection and their propagation along the hybrid genetic and cultural evolution path. The success of memetic learning procedures is analyzed by measuring each meme&#39;s relative and absolute success events according to different approaches, depending on the reference time used in evolutionary history. Results show that MOMA is promising in multi-objective optimization of composite hybrid structures.为了降低使用纤维增强塑料(FRP)复合材料的轻质结构的成本,提出了混合结构。结构系统响应的最小重量、最小应变能(刚度)和最小能量变化是应用于带加劲件复合壳体结构的稳健设计优化方法的目标。考虑到非线性几何行为,权衡取决于对复合材料结构施加的给定应力、位移和屈曲约束。设计变量包括壳体层压板的层角和层厚、加强筋的横截面尺寸,以及与材料选择和材料在层压板上的分布有关的变量,以及层压板沿结构的分布。多目标记忆算法(MOMA)采用多种学习程序,探索不同文化传播规则的协同作用。具有双重年龄主导性质的扩大虚拟人口捕捉并更新帕累托曲线。memeplex的概念控制着meme的选择及其在遗传和文化混合进化路径上的传播。记忆学习程序的成功与否,可根据进化史中使用的参考时间,按照不同的方法测量每个记忆的相对和绝对成功事件进行分析。结果表明,MOMA 在复合混合结构的多目标优化方面大有可为。Void formation and suppression in CFRP laminate using newly designed ultrasonic vibration assisted RTM techniqueYunfei Peng, Maojun Li, Xujing Yangdoi:10.1016/j.compstruct.2023.117796利用新设计的超声波振动辅助 RTM 技术抑制 CFRP 层压板中空洞的形成和消失This study introduces an ultrasonic vibration assisted resin transfer molding (RTM) technique as an innovative approach to address the inherent challenges associated with traditional methods for producing CFRP laminates. It investigates the mechanism of void formation in CFRP composites under ultrasonic vibration using 3D X-ray microscopy. Numerical calculations and simulation analyses are also employed to validate the impact of ultrasonic vibration on mechanical properties of CFRP. The findings indicate that ultrasonic vibration results in CFRP laminates with more uniform thickness, leading to a substantial increase in fiber volume fraction up to ∼16%. Concurrently, there are significant improvements in flexural strength (∼20%) and fracture energy (∼90%). Ultrasonic vibration also effectively reduces CFRP porosity by at least 25%, resulting in a more consistent distribution of voids, primarily consisting of small circular voids. This porosity reduction is attributed to the cavitation effect and enhancing wettability, consequently improving the mechanical properties of CFRP. Moreover, simulations and numerical calculations demonstrate the significant occurrence of cavitation effect within the resin under specific process conditions. The intensity of cavitation is influenced by factors such as the initial bubble radius, acoustic pressure amplitude, and static pressure of the resin. The ultrasonic-assisted RTM process is proved as a promising method for producing CFRP laminates with superior properties.本研究介绍了一种超声波振动辅助树脂传递模塑(RTM)技术,它是一种创新方法,可解决与生产 CFRP 层压材料的传统方法相关的固有挑战。研究利用三维 X 射线显微镜研究了 CFRP 复合材料在超声波振动下形成空隙的机理。此外,还采用了数值计算和模拟分析来验证超声波振动对 CFRP 机械性能的影响。研究结果表明,超声波振动可使 CFRP 层压板的厚度更加均匀,从而使纤维体积分数大幅增加,最高可达 ∼ 16%。同时,抗弯强度(∼20%)和断裂能(∼90%)也有显著提高。超声波振动还能有效降低 CFRP 的孔隙率至少 25%,使空隙分布更加一致,主要由小圆形空隙组成。孔隙率的降低归因于空化效应和润湿性的增强,从而改善了 CFRP 的机械性能。此外,模拟和数值计算表明,在特定的工艺条件下,树脂内部会产生显著的空化效应。空化强度受初始气泡半径、声压振幅和树脂静压等因素的影响。超声波辅助 RTM 工艺被证明是生产具有优异性能的 CFRP 层压板的一种可行方法。Mechanically robustandconductive zwitter ionic polymer coated electrospun nanofibrous electrolyte membranes for wireless human motion detection and capacitor applicationsMehdihasan I. Shekh, Mintao Wang, Guangming Zhu, Florian J. Stadler, Jun Ma, Bing Dudoi:10.1016/j.compstruct.2023.117797用于无线人体运动检测和电容器应用的机械坚固性和导电性齐聚物离子聚合物涂层电纺纳米纤维电解质膜To address the limitations of poor ionic conductivity, low toughness, and high mass ratios in hydrogel-based electrolytes for flexible energy storage and wearable devices, here in a simple synthesis method of poly(ionic liquids) (PILs) based electrolyte membrane was developed. Briefly, PILs were utilized to coat electrospun PVDF-HFP nanofibrous membranes, resulting in ionically conducting composite electrolyte membranes (CPEMs) with enhanced physio-chemical properties. The obtained CPEMs exhibited an ionic conductivity of 0.056 S/m, along with a high tensile strength of 5.06 MPa and elongation to break of 156%. Furthermore, we utilized these CPEMs as the electrolyte in symmetric capacitors by sandwiching them between carbon nanotube (CNT) coated Ni-foams. The resulting capacitors demonstrated a specific capacitance of 170 F/g, an energy density of 53.41 Wh/kg, and a power density of 108.9 W/kg at an applied current of 1 mA. The suitability of these CPEMs as chemo-resistive sensors was investigated by attaching them to different body parts and monitoring changes in resistance during physical motion. The results demonstrated that the CPEMs exhibited effective gauge factors ranging from 1.85 to 6.44 and could detect movements up to 1% strains.为解决柔性储能和可穿戴设备中水凝胶基电解质离子传导性差、韧性低和质量比高等限制,本文开发了一种基于聚(离子液体)(PILs)的电解质膜的简单合成方法。简而言之,利用 PILs 包覆电纺 PVDF-HFP 纳米纤维膜,得到了物理化学性能更强的离子导电复合电解质膜(CPEMs)。获得的 CPEM 具有 0.056 S/m 的离子电导率、5.06 MPa 的高抗拉强度和 156% 的断裂伸长率。此外,我们还将这些 CPEMs 夹在碳纳米管(CNT)涂层镍泡沫之间,用作对称电容器的电解质。所制成的电容器的比电容为 170 F/g,能量密度为 53.41 Wh/kg,外加电流为 1 mA 时的功率密度为 108.9 W/kg。通过将这些 CPEM 附着在不同的身体部位并监测身体运动时的电阻变化,研究了这些 CPEM 作为化学电阻传感器的适用性。结果表明,CPEM 的有效测量系数在 1.85 到 6.44 之间,可检测到高达 1%应变的运动。Micromachined piezoelectric sensor with radial polarization for enhancing underwater acoustic measurementXingxu Zhang, Zichen Cui, Hao Wu, Jian Luo, Tao Ye, Xiaobiao Shan, Tao Xie, Binghe Madoi:10.1016/j.compstruct.2023.117798用于增强水下声学测量的径向极化微机械压电传感器This work presents an underwater acoustic sensor featuring a radial polarized piezoelectric diaphragm, which aims to work in d33 mode to enhance its performance. For the sake of accomplishing the in-plane polarization, interdigital electrodes based on semi-circular ring patterns are designed on both sides and aligned along the thickness direction of the diaphragm. Effects of electrode parameters on the polarization orientation are numerically analyzed by the conversion relationship between different coordinates. Using the Kirchhoff plate theory and Rayleigh-Ritz method, a mathematical model is developed to investigate the dynamic properties of the sensor. The results indicate that the output voltages increase with the increase of the electrode inner radius, width, and spacing but decrease with the increase of the diaphragm thickness and radius. Sensor prototypes are fabricated by the microelectromechanical system (MEMS) technology in a clean room and characterized by impedance spectrums. An underwater testing system is established to conduct the experimental verification, whose results are in good accord with those of mathematical modeling. The sensor output voltage has fine linearity with the underwater acoustic pressure and achieves a flat frequency response. Moreover, the sensor has a sensitivity of -172.7 dB (Ref. 1V/μPa) superior to the reported devices in the same categories. This work provides significant guidance for modeling radial field piezoelectric diaphragms and designing more efficient piezoelectric microsensors, which have a fine application prospect in underwater acoustic measurement.本研究提出了一种水下声学传感器,其特点是采用径向极化压电膜片,旨在以 d33 模式工作以提高其性能。为实现平面内极化,在膜片两侧设计了基于半圆环形图案的数字间电极,并沿膜片厚度方向排列。通过不同坐标之间的转换关系,对电极参数对极化方向的影响进行了数值分析。利用基尔霍夫板理论和雷利-里兹方法,建立了一个数学模型来研究传感器的动态特性。结果表明,输出电压随电极内半径、宽度和间距的增加而增加,但随膜片厚度和半径的增加而减少。传感器原型是在无尘室中利用微机电系统(MEMS)技术制造的,并通过阻抗谱进行了表征。建立了一个水下测试系统来进行实验验证,其结果与数学建模结果十分吻合。传感器输出电压与水下声压具有良好的线性关系,并实现了平坦的频率响应。此外,传感器的灵敏度为 -172.7 dB(参考值 1V/μPa),优于已报道的同类设备。这项研究为径向场压电膜片建模和设计更高效的压电微型传感器提供了重要指导,在水下声学测量领域具有广阔的应用前景。Influence of polyurea on dynamic response behaviors of cylindrical composite shells under internal explosion loadChao Tian, Sha Yang, Jiahe Feng, Qi Dongdoi:10.1016/j.compstruct.2023.117800聚脲对内部爆炸载荷下圆柱形复合材料壳体动态响应行为的影响The dynamic responses of open-ended cylindrical shells with different polyurea layers under explosion load are studied in the current paper. The influences of polyurea thickness and position on the response characteristics of the composite shell are analyzed in detailed. The results indicate that the polyurea layer has significant influence the failure mode and energy absorption of the composite shell. Both polyurea in the interlayer and on the outer layer will decrease the bending moments of the composite shells of equal mass in the initial deformation process, which is easier to make the increase of the deformation heights of metal liner of composite shells with polyurea layers. The polyurea in the interlayer will weaken the constraint of metal liner, delay the fracture of fiber and restrain the bulking phenomenon of metal liner. With increase of polyurea thickness, the bulking phenomenon becomes less obvious and the deformation height of liner decreases non-monotonously. On the contrary, the outer layer polyurea will cause the bulking phenomenon of metal liner more obviously with increase of the polyurea thickness.But the outerlayer polyurea will restrict the deformation of the inner materials and limit the scattering of fiber fragment, improving the safety distance of the explosion vessel. In the whole process of anti-explosion, both polyurea in interlayer and outer layer absorb less than 10% of total energy, but they can significantly change the energy absorption of metal liner and fiber composite.本文研究了带有不同聚脲层的开口圆柱形壳体在爆炸载荷下的动态响应。详细分析了聚脲厚度和位置对复合材料壳体响应特性的影响。结果表明,聚脲层对复合材料壳体的失效模式和能量吸收有显著影响。夹层聚脲和外层聚脲都会减小等质量复合材料壳体在初始变形过程中的弯矩,更容易使带有聚脲层的复合材料壳体金属衬里的变形高度增加。夹层中的聚脲会减弱金属内衬的约束,延缓纤维的断裂,抑制金属内衬的膨胀现象。随着聚脲厚度的增加,膨胀现象变得不那么明显,衬垫的变形高度非单调地减小。相反,随着聚脲厚度的增加,外层聚脲会使金属衬里的鼓包现象更加明显,但外层聚脲会限制内层材料的变形,限制纤维碎片的散落,提高爆炸容器的安全距离。在整个防爆过程中,夹层聚脲和外层聚脲吸收的能量均小于总能量的 10%,但它们能显著改变金属衬里和纤维复合材料的能量吸收。Composites Part A: Applied Science and ManufacturingCo-modifying geopolymer composite by nano carbon black and carbon fibers to reduce CO2 emissions in airport pavement induction heatingGonghui Gu, Tao Ma, Feng Chen, Chengjia Han, Heng Li, Fang Xudoi:10.1016/j.compositesa.2023.107951 用纳米炭黑和碳纤维共同改性土工聚合物复合材料,减少机场路面感应加热中的二氧化碳排放CO2 emissions during airport pavement induction heating for ice and snow melting are primarily determined by the electrothermal behavior of electrically conductive layer (ECL). A single type of conductive filler is difficult to significantly improve the electrothermal performance of ECL while maintaining its mechanical properties. This work introduces nano carbon black (NCB) into carbon fiber-reinforced geopolymer to prepare NCB-carbon fiber co-modified geopolymer composites (NMGC) with great potential to dramatically improve the electrothermal performance of ECL and reduce CO2 emissions during induction heating. Furthermore, in order to provide guidance support for the ECL design, the evolution mechanisms of the electrothermal and mechanical properties of NMGC were inquired through electrochemical impedance spectroscopy (EIS) analysis and geopolymerization rate characterization, respectively. Results show that introducing 1 wt.% NCB into the carbon fiber-reinforced geopolymer can effectively increase the reaction rate within NMGC and improve its electrothermal performance due to the enhanced electron transition. Indoor induction heating tests further indicate that the optimized NMGC can reduce the CO2 emissions by 13.7 kg/m2 comparing to the NMGC without NCB during 30 min of induction heating.机场路面感应加热融冰融雪过程中的二氧化碳排放主要取决于导电层(ECL)的电热行为。单一类型的导电填料很难在保持导电层机械性能的同时显著改善其电热性能。本研究在碳纤维增强土工聚合物中引入纳米炭黑(NCB),制备出纳米炭黑-碳纤维共改性土工聚合物复合材料(NMGC),有望显著改善 ECL 的电热性能,并减少感应加热过程中的二氧化碳排放。此外,为了给 ECL 的设计提供指导支持,还分别通过电化学阻抗谱(EIS)分析和土工聚合速率表征,探究了 NMGC 的电热性能和力学性能的演变机理。结果表明,在碳纤维增强土工聚合物中引入 1 wt.% 的 NCB 可有效提高 NMGC 内部的反应速率,并由于电子转变的增强而改善其电热性能。室内感应加热试验进一步表明,与不添加 NCB 的 NMGC 相比,优化后的 NMGC 在 30 分钟的感应加热过程中可减少 13.7 kg/m2 的二氧化碳排放量。Piecewise damage model for SiC/SiC composites with multilevel experimental validationDuoqi Shi, Zhenyu Wang, James Marrow, Changqi Liu, Fan Wan, Xiaoguang Yangdoi:10.1016/j.compositesa.2023.107952通过多级实验验证 SiC/SiC 复合材料的片状损伤模型Using multiscale and multidimensional data from experiments and advanced microscopic characterisation, a piecewise damage model for SiC/SiC composite structures has been proposed. First, the geometric information of the microstructure was acquired using scanning electron microscopy (SEM) and X-ray computed tomography (X-CT). High-precision and total-factor finite element models were established, and a piecewise damage model was introduced to simulate in detailing the initiation and propagation of damage. Subsequently, in-situ experiments using the digital image correlation method were conducted to capture the strain fields. After failure, the failure modes were observed and analysed by SEM and X-CT. In the piecewise damage model, observed failure modes were associated within the progressive failure analysis concretely. Combining the multisource data during and after loading, the validity and reliability of this damage model based on failure mechanisms are demonstrated in the accurate prediction of the properties, deformation and stress fields in multilevel structures of SiC/SiC composites.利用来自实验的多尺度和多维数据以及先进的微观表征技术,我们提出了一种 SiC/SiC 复合结构的片状损伤模型。首先,利用扫描电子显微镜(SEM)和 X 射线计算机断层扫描(X-CT)获取了微观结构的几何信息。建立了高精度和全因子有限元模型,并引入了片状损伤模型来详细模拟损伤的发生和传播。随后,使用数字图像相关方法进行了原位实验,以捕捉应变场。失效后,通过扫描电子显微镜和 X-CT 对失效模式进行了观察和分析。在片状破坏模型中,观察到的破坏模式与渐进破坏分析具体相关。结合加载过程中和加载后的多源数据,证明了这种基于破坏机制的破坏模型在准确预测 SiC/SiC 复合材料多层结构的性能、变形和应力场方面的有效性和可靠性。Resolving 3D microstructure evolution of ceramifiable composites at elevated temperatures using in-situ X-ray computed tomographyHuanfang Wang, Tianfei Zhao, Zheng Gong, Jiahui Gu, Yong Deng, Chao Zhang.doi:10.1016/j.compositesa.2023.107953利用原位 X 射线计算机断层扫描技术解析陶瓷复合材料在高温下的三维微观结构演变过程Ceramifiable polymer composites suffers significant microstructure change during the polymer-to-ceramic conversion as the environmental temperature increases. The present study employs in-situ X-ray computed tomography (XCT) to reveal the microstructure evolution of high-silica/boron-phenolic composites modified with B4C and talc (B4C-talc_HSF/BPR) in three dimensions as the composites is heated to 1000 °C. The cracks are classified based on their locations, and the temporal sequence of their formation is identified. The evolution of internal pore distribution is reconstructed and analyzed quantitatively. Furthermore, the 3D deformation fields of composites during in-situ heating were calculated using digital volume correlation. It is found that the equivalent strain along the thickness direction shows a multi-stage behavior corresponding to the thermal degradation and ceramization transformation processes. The findings provide a 3D visualization of crack propagation and deformation during the polymer-to-ceramic conversion process, which can provide a foundation for further developments in material design.随着环境温度的升高,在聚合物向陶瓷转化的过程中,可陶瓷聚合物复合材料的微观结构会发生显著变化。本研究采用原位 X 射线计算机断层扫描(XCT)技术,揭示了用 B4C 和滑石粉改性的高硅/硼酚醛复合材料(B4C-talc_HSF/BPR)在加热至 1000 °C 时的三维微观结构演变过程。根据裂纹的位置对裂纹进行了分类,并确定了裂纹形成的时间顺序。对内部孔隙分布的演变进行了重建和定量分析。此外,还利用数字体积相关技术计算了复合材料在原位加热过程中的三维变形场。研究发现,沿厚度方向的等效应变表现出与热降解和陶瓷化转变过程相对应的多阶段行为。研究结果提供了聚合物向陶瓷转化过程中裂纹扩展和变形的三维可视化图像,为材料设计的进一步发展奠定了基础。Composites Science and TechnologyInterphase enhanced low-velocity impact energy absorption in liquid crystal elastomer-based woven compositesBeom-Gon Cho, Jinsu Kim, Young-Bin Park, Jungwon Kim, Min Wook Lee, Woong-Ryeol Yu, Seung-Yeol Jeondoi:10.1016/j.compscitech.2023.110377 液晶弹性体基编织复合材料中相间增强的低速冲击能量吸收能力A reasonable approach to enhancing the energy absorption capability of composites is to incorporate elastomers that possess viscoelastic properties capable of enduring considerable elastic deformations and absorbing significant energy without fracturing. From this perspective, using liquid crystal elastomers (LCEs) as a matrix for fiber-reinforced composites could be an excellent option for developing impact-absorbing materials since LCEs possess an outstanding energy dissipation ability compared with amorphous elastomers. Herein, we report excellent energy-dependent impact properties of LCE composites reinforced with carbon fiber (CF) woven fabric. We discovered that the LCE/CF composite can effectively dissipate high amounts of low-velocity impact energy. The exceptional characteristics of LCE, which make it adaptable to impact energy absorption, combined with the presence of an interphase featuring a higher loss modulus compared to the individual composite components, were demonstrated to significantly enhance impact energy absorption of the composite. The developed LCE/CF composite panel is capable of absorbing up to 60 J of impact energy despite its thickness of only about 1 mm and has a substantial damping loss coefficient of about 0.1, which is two orders of magnitude higher than those of typical fiber-reinforced composites.增强复合材料能量吸收能力的一个合理方法是加入具有粘弹性能的弹性体,这种弹性体能够承受相当大的弹性变形,吸收大量能量而不会断裂。从这个角度来看,使用液晶弹性体(LCE)作为纤维增强复合材料的基体可能是开发冲击吸收材料的绝佳选择,因为与非晶弹性体相比,液晶弹性体具有出色的能量耗散能力。在此,我们报告了用碳纤维(CF)编织物增强的 LCE 复合材料的优异的能量相关冲击性能。我们发现 LCE/CF 复合材料能有效消散大量低速冲击能量。LCE 的优异特性使其能够适应冲击能量吸收,再加上与单个复合材料成分相比,中间相具有更高的损失模量,这些都证明 LCE 可显著增强复合材料的冲击能量吸收能力。所开发的 LCE/CF 复合材料板厚度仅约 1 毫米,却能吸收高达 60 焦耳的冲击能量,而且阻尼损失系数高达 0.1 左右,比典型的纤维增强复合材料高出两个数量级。Lightweight multi-layer graded pyramid folded structure based on tucked kirigami for green manufacturingHao Qiu, Yixiong Feng, Zhaoxi Hong, Yicong Gao, Jianrong Tandoi:10.1016/j.compscitech.2023.110383 基于折纸的轻质多层分级金字塔折叠结构,实现绿色制造Lightweight structures are extensively utilized in various applications that demand exceptional mechanical properties and low densities, such as aerospace, vehicles, and construction components. However, the production of lightweight structures often entails significant material consumption and the emission of pollutants during the pressing and welding processes. Additive manufacturing (AM) has been hailed as a green technology that offers superior flexibility, reduces material wastage, and enables personalized design compared to traditional approaches. In this study, we present a novel lightweight multi-layer graded pyramid folded structure (PFS) based on tucked kirigami, with a focus on green manufacturing principles. The PFSs consist of nested pyramid cells connected by flat triangular plates. By leveraging stereolithography and a two-stage curing process, we achieve AM of multi-layer PFSs with excellent mechanical properties and shaping quality. Experimental studies were conducted on two-dimensional and three-dimensional graded PFSs under lateral and vertical quasi-static compressive loading to investigate the influence of gradient types and values on the mechanical performance of 3D printed PFSs. Our findings reveal that length gradients parallel to the load induce buckling deviations from the center, negatively impacting the performance of single-layer PFSs. Conversely, a height gradient along the z-direction further enhances specific energy absorption (SEA) and compressive strength. The results of this study provide a novel and viable approach to the design and manufacturing of multi-layer graded PFSs with programmable non-uniform stiffness. These graded PFSs hold significant potential for environment-friendly lightweight engineering applications.轻质结构被广泛应用于航空航天、车辆和建筑构件等各种需要优异机械性能和低密度的应用领域。然而,轻质结构的生产往往需要消耗大量材料,并在压制和焊接过程中排放污染物。与传统方法相比,快速成型制造(AM)被誉为一种绿色技术,它具有卓越的灵活性,可减少材料浪费,并实现个性化设计。在本研究中,我们介绍了一种新型轻质多层分级金字塔折叠结构(PFS),该结构基于褶裥叽里格米(kirigami),注重绿色制造原则。金字塔折叠结构由嵌套的金字塔单元组成,单元之间用三角形平板连接。利用立体光刻技术和两阶段固化工艺,我们实现了多层折叠结构的自动机械加工,并具有优异的机械性能和成型质量。我们对横向和纵向准静态压缩载荷下的二维和三维梯度 PFS 进行了实验研究,以探讨梯度类型和数值对三维打印 PFS 机械性能的影响。我们的研究结果表明,与载荷平行的长度梯度会导致屈曲偏离中心,从而对单层 PFS 的性能产生负面影响。相反,沿 Z 方向的高度梯度可进一步增强比能量吸收(SEA)和抗压强度。这项研究成果为设计和制造具有可编程非均匀刚度的多层分级 PFS 提供了一种新颖可行的方法。这些分级 PFS 在环境友好型轻质工程应用方面具有巨大潜力。来源:复合材料力学仿真Composites FEM

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