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
A multi-linear constitutive relation considering the temperature effect on quasi-static mode I delamination in UD/MD laminates
Luohuan Zou, Yu Gong, Dingli Tian, Yuting Gao, Jianyu Zhang, Libin Zhao, Ning Hu
doi: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。
Combination of in-/and ex-situ damage detection methods to investigate the forming behavior of fiber-metal-laminates
Florian Thum, Marco Korkisch, Anna Trauth, Markus G.R. Sause
doi: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 arrangement
Guang Zhang, Jiahao Luo, Min Sun, Yang Yu, Jiong Wang, Bo Chen, Qing Ouyang, Ye Qiu, Guinan Chen, Teng Shen, Zheng Zhang
doi: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。
Scalable production of robust and creep resistant ultra-high filled wood-plastic composites
An Yang, Zhengyu Liao, Zesheng Xu, Tian Liu, Yiqun Fang, Weihong Wang, Min Xu, Yongming Song, Qingwen Wang, Yao Li
doi: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。
Open source tool for Micro-CT aided meso-scale modeling and meshing of complex textile composite structures
Bin Yang, Yuwei Feng, Cédric Béguin, Philippe Causse, Jihui Wang
doi: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 route
Wei Wang, Chong Ren, Jiaxin Zheng, He Huang, Can Wu, Xiangyu Jin, Changqing Hong, Xinghong Zhang
doi: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 screening
Kening Yan, Lin Qiu, Haimo Li, Ning Cao, Yanhui Feng
doi: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 composites
Lulu Lei, Yiqiao Zhao, Zefei Cheng, Jieyu Chen, Sixian Yang, Tao Yu, Jinhong Fan, Yan Li, Jianzhuang Xiao
doi: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 manufacturing
Xianhe Cheng, Qigang Han, Yuzhang Huang, Mingdi Shi, Hexuan Shi, Mengxue Ji, Chuncai Yang
doi: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。