今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 7 篇,Composites Science and Technology 1 篇
Investigation of elastic waves frequency converted for the piezoelectric metamaterial cylindrical shell
Ju-Wei Zhao, Ling-Yun Yao, Xiao-Dong Zhang, Hui Chen
doi:10.1016/j.compstruct.2024.118799
压电超材料圆柱壳弹性波频率转换研究
The control of elastic waves in metamaterials has predominantly focused on beam and plate structures, with relatively limited research on cylindrical shell structures. However, cylindrical shell structures are used in various applications where elastic wave modulation plays a crucial role in vibration noise control and vibration energy research. Consequently, this paper achieves frequency conversion of elastic waves in cylindrical shell structures using piezoelectric metamaterials. The study demonstrates that elastic wave frequency conversion can be accomplished through a “single-sensor-dual-actuator” approach, conventional physical law of frequency is not variable can be break by frequency conversion. This work begins with theoretical derivation of the kinetic equation for cylindrical shell structures, along with design of piezoelectric metamaterial cylindrical shells and the development of time-dependent transfer functions. Then, elastic waves frequency conversion is thoroughly analyzed by simulation on axial and circumferential cylindrical shells, these analysis results are investigated and discussed. Finally, frequency conversion function is verified through experiments which are collecting elastic wave parameters in frequency domain. The experimental results align closely with the simulation outcomes, demonstrating that frequency conversion of incident elastic waves can be successfully achieved in the range of 7 kHz to 9 kHz. Moreover, frequency conversion with different values can be realized by modifying key parameters in the transfer function. This work provides a solid experimental foundation and methodology for achieving elastic waves frequency conversion in curved shell structure, contributing to the broader understanding and application of elastic wave metamaterials.
超材料中弹性波的控制主要集中在梁和板结构上,而对柱壳结构的研究相对较少。弹性波调制在振动噪声控制和振动能量研究中起着至关重要的作用。因此,本文利用压电超材料实现了圆柱壳结构中弹性波的频率转换。研究表明,弹性波的变频可以通过“单传感器-双作动器”的方式实现,通过变频可以打破传统的频率不变的物理规律。这项工作从圆柱壳结构动力学方程的理论推导,以及压电超材料圆柱壳的设计和时变传递函数的发展开始。然后,通过轴向和周向圆柱壳的仿真,对弹性波的频率转换进行了深入的分析,并对这些分析结果进行了研究和讨论。最后,通过在频域采集弹性波参数的实验,对变频函数进行了验证。实验结果与仿真结果吻合较好,表明在7 kHz ~ 9 kHz范围内可以成功实现入射弹性波的频率转换。通过修改传递函数中的关键参数,可以实现不同值的变频。本研究为实现弯曲壳结构的弹性波频率转换提供了坚实的实验基础和方法,有助于对弹性波超材料的更广泛的理解和应用。
Shell-Beam micromechanical models to improve the efficiency of simulations of composites under longitudinal compression
D. Bikos, F. Poh, R.S. Trask, P. Robinson, S. Pimenta
doi:10.1016/j.compstruct.2024.118830
采用壳梁细观力学模型提高复合材料纵向压缩模拟效率
The variability of fibre paths in composite microstructures is a key parameter influencing their compressive behaviour; however, despite numerous developments, no micromechanical finite element simulation has represented enough fibres to be statistically representative of this variability. This paper proposes and develops a methodology which replaces the computationally-expensive continuum 3D finite elements with shells and beams (SB) to simulate explicitly the matrix and the fibres in real microstructures of composites under longitudinal compression. The SB methodology is illustrated in simulations using fibre paths from micro-computed tomography of real microstructures. The SB methodology shows a reduction in simulation time over 99.9% compared to the conventional continuum approach; the accuracy of the compressive strength and kinking direction predicted by the SB methodology were at least 94% and 97% respectively (compared to the continuum approach). This new proposed micromechanical simulation methodology can advance the state of the art by efficiently capturing the effect of microstructural imperfections on the performance of composites under longitudinal compression.
复合材料微结构中纤维路径的变化是影响其压缩性能的关键参数;然而,尽管有许多发展,没有微机械有限元模拟能够代表足够的纤维,以统计方式代表这种变异性。本文提出并发展了一种用壳梁连续三维有限元代替计算量大的连续三维有限元方法,以明确地模拟复合材料在纵向压缩下的真实微观结构中的基体和纤维。利用真实微观结构的微计算机断层扫描的纤维路径进行模拟,说明了SB方法。与传统的连续介质方法相比,SB方法的模拟时间减少了99.9%以上;与连续体方法相比,SB方法预测的抗压强度和扭结方向的准确性分别至少为94%和97%。这种新提出的微观力学模拟方法可以通过有效地捕捉微观结构缺陷对复合材料纵向压缩性能的影响来推进当前的技术水平。
Enhanced sound absorption properties of a semi-open underwater periodic acoustic metamaterial
Zihan Feng, Xiaoliang Xu, Shurui Wen, Zhijing Wu, Fengming Li
doi:10.1016/j.compstruct.2024.118831
半开放式水下周期性声学超材料的增强吸声性能
In order to enhance the underwater low-frequency sound absorption performance, a semi-open underwater periodic acoustic metamaterial (SUPAM) is proposed combining the slit and the rubber shear deformation mechanisms of the acoustic energy dissipation. According to the slit absorber theory and the complex viscosity model of viscoelastic material, the theoretical model for predicting the sound absorption performance of the SUPAM is established using the transfer matrix method, the correctness of which is validated by the well agreement of its result with that of the finite element method and experiment, respectively. The influence of the sound incidence angle, slit width, air cavity height and rubber thickness on the sound absorption property of the SUPAM is discussed. It is found that the introduction of the slit enables acoustic waves to effectively enter the SUPAM and increases the amount of sound energy dissipated by the shear deformation of the rubber damping layer. A sound absorption coefficient above 0.8 can be achieved almost across an ultra-wide frequency range of 176–5000 Hz for the SUPAM composed of metacells based on the stepped design, which shows its extraordinary low-frequency sound absorption performance.
为了提高水下低频吸声性能,提出了一种结合狭缝和橡胶剪切变形机制的半开放式水下周期声超材料(SUPAM)。根据狭缝吸声理论和粘弹性材料的复黏性模型,采用传递矩阵法建立了预测SUPAM吸声性能的理论模型,并分别与有限元法和实验结果吻合较好,验证了理论模型的正确性。讨论了声入射角、狭缝宽度、气腔高度和橡胶厚度对SUPAM吸声性能的影响。研究发现,狭缝的引入使声波能够有效地进入SUPAM,增加了橡胶阻尼层剪切变形所耗散的声能。基于阶梯式设计的元胞组成的SUPAM在176-5000 Hz的超宽频率范围内几乎可以实现0.8以上的吸声系数,显示出其非凡的低频吸声性能。
Protection concept for foamed radar-absorbing sandwich composites with high-conductive film against lightning strike impacts
Woo-Hyeok Jang, Dongjun Hong, Shanigaram Mallesh, Juhyeong Lee, Chanyeop Park, Chun-Gon Kim, Won-Ho Choi, Youngwoo Nam
doi:10.1016/j.compositesa.2024.108660
具有高导电性薄膜的泡沫雷达吸收夹层复合材料对雷击冲击的防护概念
This paper presents a foamed radar-absorbing sandwich composite using Ni-plated glass fiber, serving as a dielectric loss material and a high-conductive film for lightning strike protection (LSP). Image processing found that surface damage area was reduced by 38.7 % in high-conductive films compared to those without. Furthermore, micro-X-ray CT revealed no critical damage, such as fiber breakage, deeper than the film. Moreover, specimens without high-conductive film experienced a 37.8 % decrease in −10 dB bandwidth after the lightning strike (LS) test, while high-conductive film specimens maintained a −10 dB bandwidth. The proposed structure offers high radar-absorbing performance, effectively protecting the structure from lightning.
介绍了一种以镀镍玻璃纤维为材料,作为介质损耗材料和高导电性雷击防护膜的泡沫吸波夹层复合材料。图像处理发现,与不导电薄膜相比,高导电薄膜的表面损伤面积减少了38.7 %。此外,微x线CT未发现比膜更深的纤维断裂等严重损伤。此外,没有高导电膜的试样在雷击(LS)试验后带宽下降了37.8% %,而高导电膜试样在雷击(LS)试验后带宽保持了−10 dB。该结构具有较高的雷达吸收性能,有效地保护结构免受雷击。
BiVO4/MoO3 composites for ultra high performance energy-storing photocathodic protective coatings
Siyi Li, Bin Liu, Huayang Tian, Yujie Ning, Shuo Wu, Yihan Song, Qi Wang
doi:10.1016/j.compositesa.2024.108691
用于超高性能储能光电阴极保护涂层的BiVO4/MoO3复合材料
The practical application of photocathodic protection (PCP) technology has been hindered by its failure in darkness. In this work, The BiVO4/MoO3 composites were synthesized through a simple hydrothermal method, which were used as functional fillers, and then added to polyurethane resins to prepare energy-storing PCP coatings. This achievement enabled efficient PCP even in darkness. The 304 stainless steel coated with PCP coating (PB10M1) exhibited excellent photoelectrochemical properties as photocurrent density of 394 μA/cm2, and the corrosion potential decreased by about 350 mV. Furthermore, the cathodic protection effect of PB10M1 could last for 15 h in the dark, showing exceptional stability, superior energy-storage ability and potential application. The superior PCP performance of BiVO4/MoO3 should be attributed to the cooperative effect in heterojunction structure and electronic regulation revealed by electrochemical characterizations and DFT calculation.
光电阴极保护(PCP)技术在黑暗环境下的失效,阻碍了其实际应用。本文采用简单的水热法合成了BiVO4/MoO3复合材料,并将其作为功能填料,加入聚氨酯树脂中制备储能PCP涂料。这一成就使PCP即使在黑暗中也能有效发挥作用。涂有PCP涂层(PB10M1)的304不锈钢具有优异的光电化学性能,光电流密度为394 μA/cm2,腐蚀电位降低约350 mV。此外,PB10M1的阴极保护效果在黑暗中可以持续15 h,表现出优异的稳定性和优异的储能能力,具有潜在的应用前景。BiVO4/MoO3优异的PCP性能应归因于电化学表征和DFT计算所揭示的异质结结构和电子调节的协同效应。
Structure and performance evolutions with temperature, stress, and thermal-force coupling of the silica aerogel composite for suppressing thermal runaway propagation of LIBs
Ming Liu, Yong Kong, Jin Tang, Bangqin Zhang, Xiaodong Shen
doi:10.1016/j.compositesa.2024.108692
抑制lib热失控传播的二氧化硅气凝胶复合材料的结构和性能随温度、应力和热力耦合的演变
Silica aerogel composite (SAC) with high thermal stability up to 1200 °C for suppressing thermal runaway (TR) propagation of Li-ion batteries (LIBs) was developed via a facile base-catalyzed single-step sol–gel-impregnation process. Structure and thermal performance evolutions of the silica aerogel composite with temperature, stress, and thermal-force coupling condition were investigated firstly. Thermal conductivity of the SAC with SiC as opacifier (SAC-SiC) is 0.021–0.045 W/(m·K) at 600–1200 °C, which are lower than those of its state-of-art counterparts at 600–1200 °C or even lower temperatures. The structure and thermal insulation performance of the SAC-SiC are hardly affected by stress (0.01–0.9 MPa) under thermal-force coupling conditions. The use of SAC with a thickness of 2.35 mm suppressed the TR propagation of a commercial cell (NCM 811) in a module successfully. The resulting SAC is exceptional in thermal insulation under high temperature and thermal-force coupling conditions.
采用易碱催化的单步溶胶-凝胶-浸渍工艺,研制出了可抑制锂离子电池热失控(TR)传播的高热稳定性(高达1200 °C)硅气凝胶复合材料(SAC)。首先研究了温度、应力和热力耦合条件下二氧化硅气凝胶复合材料的结构和热性能变化规律。以SiC为混浊剂的SAC (SAC-SiC)在600-1200 °C时的导热系数为0.021-0.045 W/(m·K),低于目前先进的SAC在600-1200 °C甚至更低温度下的导热系数。在热力耦合条件下,应力(0.01 ~ 0.9 MPa)对SAC-SiC的结构和保温性能几乎没有影响。使用厚度为2.35 mm的SAC,成功地抑制了NCM 811在模块中的TR繁殖。所得SAC在高温和热力耦合条件下具有优异的隔热性能。
A semipermanently stable, photocrosslinkable graphene colloid: A fresh strategy for fabricating polymer nanocomposites
Seung Koo Park, Bong Je Park, Won Bae Cho, Eun Jin Shin, Suntak Park, Hyung Cheol Shin
doi:10.1016/j.compositesa.2024.108693
半永久稳定、可光交联的石墨烯胶体:制造聚合物纳米复合材料的新策略
It is challenging to choose a polymer matrix suitable for preparing a homogenous graphene/polymer nanocomposite due to their incompatibility. This study introduces a highly stable, photocrosslinkable graphene colloid prepared by calculating the three-dimensional (3D) distance (Δδ¯) of solubility parameters for the polymer nanocomposites with well-distributed graphene. Δδ¯between tetra(ethylene glycol)diacrylate (TEGDA) and graphene was calculated to be low, 4.29. The black ink-like graphene colloid solutions in TEGDA were formulated and stable for nearly one year. After UV irradiation, the colloid layers could be converted to transparent, robust, and thermostable polymer composite films with several tens-nano-sized graphene. Without light scattering loss, the transparency of the films with ca. 50 µm thickness showed 92 ∼ 47 % depending on the graphene content. They exhibited nonlinear optical properties. A conversion of reverse saturable into saturable absorption was unexpectedly observed in relatively high graphene concentrations. We proved that the colloids are fit for preparing graphene-well-dispersed polymer nanocomposites.
由于聚合物基质与石墨烯的不相容性,选择适合制备均匀石墨烯/聚合物纳米复合材料的聚合物基质颇具挑战性。本研究通过计算聚合物纳米复合材料中石墨烯分布均匀的三维(3D)溶解度参数距离(Δδ¯),引入了一种高度稳定且可光交联的石墨烯胶体。四乙二醇二丙烯酸酯(TEGDA)与石墨烯之间的Δδ¯值较低,为 4.29。在 TEGDA 中配制的黑色墨水状石墨烯胶体溶液稳定近一年。经过紫外线照射后,胶体层可转化为透明、坚固且耐热的聚合物复合薄膜,其中石墨烯尺寸为几十纳米。在无光散射损失的情况下,厚度约为 50 微米的薄膜透明度在 92% 至 47% 之间,取决于石墨烯含量。它们表现出非线性光学特性。在相对较高的石墨烯浓度下,意外观察到从反饱和吸收向饱和吸收的转变。我们证明了这些胶体适合制备石墨烯均匀分散的聚合物纳米复合材料。
High-performance automotive adhesives with urethane-modified and nanophase-separated epoxy systems
Kyeng-Bo Sim, Jong-Ho Back, Gi-Yeon Han, Hyun-Joong Kim
doi:10.1016/j.compositesa.2024.108652
高性能汽车胶粘剂与聚氨酯改性和纳米相分离环氧系统
Epoxy resins are extensively used across various industries due to their exceptional adhesive strength, mechanical properties, and chemical resistance. However, their inherent brittleness, low crack resistance, and limited elongation and fracture toughness restrict their standalone applications. Although numerous toughening strategies have been explored, challenges such as increased viscosity, difficulties in achieving uniform dispersion, opacity, and limited improvement in elongation remain unresolved. To address these limitations, aliphatic diols with urethane linkages were synthesized with varying diamine chain lengths (230, 400) and used as additives in epoxy systems, resulting in the formation of nano-sized domains that promote phase separation. This phase-separated structure facilitated uniform stress distribution and enhanced energy absorption, leading to an elongation of 11.5 % at 50 % A-D230. A-D400 formed larger domains, exhibiting superior performance under high impact, with an Izod impact strength of 72 J/m. Furthermore, aliphatic-modified epoxy synthesized through the thermal reaction of aliphatic diol with epichlorohydrin, when used as a reactant, acted as a flexible segment in the epoxy matrix, enhancing stress absorption and toughness. This approach also demonstrated improved thermal stability and shear strength. The toughening strategies utilizing additives and reactants in epoxy can be tailored to meet the specific performance requirements, such as adhesive strength, impact resistance, durability, and fatigue life, making these epoxy systems highly applicable for automotive adhesive formulations.
环氧树脂因其优异的粘接强度、机械性能和耐化学性而广泛应用于各个行业。然而,它们固有的脆性、低抗裂性、有限的伸长率和断裂韧性限制了它们的独立应用。尽管已经探索了许多增韧策略,但诸如粘度增加,难以实现均匀分散,不透明和延伸率有限改善等挑战仍未解决。为了解决这些限制,研究人员合成了具有不同二胺链长(230,400)的具有氨基甲酸乙酯键的脂肪族二醇,并将其用作环氧体系中的添加剂,从而形成了纳米级结构域,促进了相分离。这种相分离的结构有利于均匀的应力分布和增强的能量吸收,在50 % A-D230处伸长率为11. %。A-D400形成较大的畴,在高冲击下表现出优异的性能,Izod冲击强度达到72 J/m。此外,脂肪族二醇与环氧氯丙烷热反应合成的脂肪族改性环氧树脂,作为反应物在环氧树脂基体中充当柔性段,增强了应力吸收和韧性。该方法还证明了热稳定性和抗剪强度的提高。在环氧树脂中使用添加剂和反应物的增韧策略可以量身定制,以满足特定的性能要求,例如粘合强度,抗冲击性,耐久性和疲劳寿命,使这些环氧树脂系统非常适用于汽车粘合剂配方。
Finite element simulation of novel Polybenzoxazine-Carbon fibre composites prior to Low Earth Orbit: A comparative analysis of mechanical properties
H.Lucas Lu, Kyungil Kong, George Worden, Joseph F. Gargiuli, James Thomas, Katharine Robson Brown, Ian Hamerton
doi:10.1016/j.compositesa.2024.108670
近地轨道前新型聚苯并恶嗪-碳纤维复合材料的有限元模拟:力学性能对比分析
High-fidelity finite element (FE) models have been applied to simulate the mechanical properties of carbon fibre-reinforced polymer composites, which include a novel polybenzoxazine matrix resin designed for space applications. FE analysis was used to construct a digital model that replicates the geometry of the plain-woven fabric composite structure, employing X-ray computed tomography data to detail the quality of the composite laminate (manufactured with a thickness of 3.00 mm and fibre volume fraction of 53.0 %). The simulation results are in agreement with experimental data: the simulated tensile modulus (69.2 GPa) closely matches the experimental result (68.8 GPa), and this comparative analysis is also agreeable for the tensile strength (493 MPa simulated, 485 MPa experimental), flexural modulus (48.8 GPa simulated, 48.7 GPa experimental), flexural strength (554 MPa simulated, 526 MPa experimental), compressive modulus (4.20 GPa simulated, 4.00 GPa experimental), and compressive strength (328 MPa simulated, 335 MPa experimental).
高保真有限元(FE)模型已被应用于模拟碳纤维增强聚合物复合材料的力学性能,其中包括为空间应用而设计的新型聚苯并恶嗪基树脂。利用有限元分析构建了一个数字模型,该模型复 制了平纹织物复合材料结构的几何形状,利用x射线计算机断层扫描数据详细描述了复合材料层压板的质量(厚度为3.00 mm,纤维体积分数为53.0 %)。仿真结果与实验数据吻合较好:模拟拉伸模量(69.2 GPa)与实验结果(68.8 GPa)吻合较好,抗拉强度(493 MPa模拟,485 MPa实验)、弯曲模量(48.8 GPa模拟,48.7 GPa实验)、弯曲强度(554 MPa模拟,526 MPa实验)、压缩模量(4.20 GPa模拟,4.00 GPa实验)、抗压强度(328 MPa模拟,335 MPa实验)的对比分析也较为吻合。
Fabrication, progress and future perspective of MXene/polymeric nano composites for electromagnetic shielding application – A review
Mayank Pandey, C. Anju, B.V.S. Praveen, Ali Dashan, Raj Kumar Verma, Bahram Ramezanzadeh
doi:10.1016/j.compositesa.2024.108682
电磁屏蔽用MXene/聚合物纳米复合材料的制备、研究进展及展望
MXene is the fastest-growing 2D material with remarkable qualities including surface tunability, high conductivity, easy processibility, thermal stability, and water dispersibility. MXene also represents effective electromagnetic interference (EMI) shielding properties, which can be further enhanced by adopting it with other materials such as polymers, carbon derivatives, fibers, and metal–organic frameworks (MOF). MXene/polymer nanocomposites harness the advantageous traits of both MXenes and polymers, combining the inherent strength of MXenes with the flexibility and ease of processing of polymers. These composite materials exhibit remarkable attributes, including exceptional electromagnetic interference shielding and impressive charge storage capabilities, surpassing those of alternative nanocomposites. This comprehensive review examines the fundamental theory and mechanism of EMI shielding followed by various fabrication processes of MXene-based Polymeric nanocomposites. This paper summarizes the current state of the art, as well as the potential future developments, in the manufacturing of MXene materials for electromagnetic interference (EMI) shielding.
MXene是发展最快的2D材料,具有显著的品质,包括表面可调节性,高导电性,易加工性,热稳定性和水分散性。MXene还具有有效的电磁干扰(EMI)屏蔽性能,可以通过与其他材料(如聚合物,碳衍生物,纤维和金属有机框架(MOF))一起使用进一步增强。MXene/聚合物纳米复合材料利用了MXene和聚合物的优势特性,将MXene的固有强度与聚合物的灵活性和易加工性相结合。这些复合材料表现出非凡的特性,包括卓越的电磁干扰屏蔽和令人印象深刻的电荷存储能力,超过了其他纳米复合材料。本文综述了电磁干扰屏蔽的基本理论和机理,以及mxene基聚合物纳米复合材料的各种制备工艺。本文综述了用于电磁干扰(EMI)屏蔽的MXene材料的制造现状,以及潜在的未来发展。
Simulation of thermal degradation in a composite material using phase field method
M. Abdoussalam, A. Nait-Ali, B. Batiot, M. Calvat, D. Halm
doi:10.1016/j.compscitech.2024.111015
用相场法模拟复合材料的热降解
Carbon fibers/epoxy resin composite laminates decompose by pyrolysis when submitted to high heat fluxes under inert atmosphere. A rigorous thermodynamic approach with internal variables has been adopted to better capture the phenomenon under study. In the literature, the models used to describe this degradation generally do not take into account the influence of microstructural heterogeneity on the decomposition rate, on the degradation kinetics and, consequently, on the propagation of the thermal front decomposition. To consider the variability of the composite microstructure, simulations at the microscale were conducted, involving a strong coupling between the evolution of the thermal degradation rate (which follows an Arrhenius law) and the temperature evolution using the phase-field method. An experimental approach with cone calorimeter has been undertaken to achieve two major objectives: first, to calibrate model parameters, and then to compare the numerical results with experimental data for the purpose of model validation. This comparison will focus on the analysis of degradation kinetics as well as the evolution of mass loss.
碳纤维/环氧树脂复合层压板在惰性气氛下受到高热通量时发生热解分解。为了更好地捕捉所研究的现象,采用了带有内变量的严格热力学方法。在文献中,用于描述这种降解的模型通常没有考虑到微观结构非均质性对分解速率、降解动力学以及热锋分解传播的影响。为了考虑复合材料微观结构的可变性,在微观尺度上进行了模拟,使用相场法模拟了热降解率(遵循Arrhenius定律)的演变与温度演变之间的强耦合。采用锥形量热仪的实验方法来实现两个主要目标:一是校准模型参数,二是将数值结果与实验数据进行比较,以进行模型验证。这种比较将集中在降解动力学的分析以及质量损失的演变。