首页/文章/ 详情

【新文速递】2024年2月22日复合材料SCI期刊最新文章

21天前浏览405

   

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 3 篇,Composites Science and Technology 1 篇

Composite Structures

Prediction and optimization of global temperature field of composite materials under multiple heat sources

Sen Yang, Wen Yao, Lin-Feng Zhu, Richard-Kwok-Kit Yuen, Liao-Liang Ke

doi:10.1016/j.compstruct.2024.117974

多热源下复合材料全局温度场的预测与优化

The property measurement and structure optimization of composite materials are difficult topics due to the diversity of combinations of composite constituents and complexity of their application environments. The distribution of composite constituents and heat sources can cause heat aggregation phenomenon which may lead to failure of materials. In this paper, we first propose a deep learning-based surrogate model (DLBSM) which can quickly and accurately achieve the end-to-end prediction between the layout of composite materials under multiple heat sources and its temperature field. The prediction result depicts that the coefficient of determination for the maximum and average temperature of all cases exceeds 0.996. Then, the layout optimization is transformed into a combinatorial optimization problem, and the DLBSM is combined with optimization algorithm to optimize the maximum temperature, temperature gradient, and uniformity of the temperature field. The optimized maximum temperature and temperature gradient are significantly reduced, while the temperature uniformity is improved. These enhancements effectively reduce the probability of failure in composites. This approach can significantly improve the efficiency of thermal behavior prediction of composite and its layout optimization compared with finite element method (FEM).

由于复合材料成分组合的多样性及其应用环境的复杂性,复合材料的性能测量和结构优化是一个难题。复合材料成分和热源的分布会造成热聚集现象,从而导致材料失效。本文首先提出了一种基于深度学习的代用模型(DLBSM),可以快速准确地实现复合材料在多热源下的布局与温度场之间的端到端预测。预测结果表明,所有情况下最高温度和平均温度的判定系数均超过 0.996。然后,将布局优化转化为组合优化问题,并将 DLBSM 与优化算法相结合,优化温度场的最高温度、温度梯度和均匀性。优化后的最高温度和温度梯度明显降低,温度均匀性得到改善。这些改进有效降低了复合材料的失效概率。与有限元法(FEM)相比,这种方法可以大大提高复合材料热行为预测及其布局优化的效率。


Composites Part A: Applied Science and Manufacturing

Thermomechanical characterisation of a thermoplastic polymer and its short glass fibre reinforced composite: Influence of fibre, fibre orientation, strain rates and temperatures

Peihao Song, David J. Chapman, Aaron M. Graham, Bratislav Lukić, Alexander Rack, Clive R. Siviour

doi:10.1016/j.compositesa.2024.108099

热塑性聚合物及其短玻璃纤维增强复合材料的热力学特性:纤维、纤维取向、应变率和温度的影响

Polycarbonate composites are widely used in products exposed to high strain rate deformation. This paper investigates the thermomechanical properties of polycarbonate and 20 wt% glass fibre reinforced polycarbonate to provide characterisation data and improved mechanistic understanding of the response to load, supported by Dynamic Mechanical Analysis and time–temperature superposition. Compressive behaviour is characterised from 0.001 to 5000 s−1 at room temperature and from −60 to 120 °C at 0.01 s−1; and a thermal imaging camera used to obtain temperature rise data. Quasi-static tensile experiments were also performed in different orientations relative to the injection flow direction. High-rate compression experiments are performed with X-ray imaging. As well as information about rate dependence of yield stresses and softening in the two materials, these data show how adiabatic shear band formation can cause significant softening in the composite. These data will enhance application of these polymers and facilitate development of advanced thermo-mechanical models.

聚碳酸酯复合材料广泛应用于承受高应变率变形的产品中。本文研究了聚碳酸酯和 20 wt%玻璃纤维增强聚碳酸酯的热机械特性,通过动态机械分析和时间-温度叠加,提供特性数据并提高对负载响应的机械理解。在室温条件下,以 0.001 至 5000 s-1 的速度对压缩行为进行表征;在 -60 至 120 °C 的条件下,以 0.01 s-1 的速度对压缩行为进行表征;并使用热像仪获取温升数据。此外,还在相对于注入流动方向的不同方向上进行了准静态拉伸实验。利用 X 射线成像技术进行了高速压缩实验。除了两种材料屈服应力和软化的速率依赖性信息外,这些数据还显示了绝热剪切带的形成如何导致复合材料的显著软化。这些数据将促进这些聚合物的应用,并有助于开发先进的热机械模型。


Composites Part B: Engineering

Physical and mechanical properties of nano-modified polybenzoxazine nanocomposite laminates: Pre-flight tests before exposure to low Earth orbit

Kyungil Kong, Joseph Gargiuli, Konstantina Kanari, Mayra Yadira Rivera Lopez, James Thomas, George Worden, Lucas Lu, Sean Cooper, Stuart Donovan-Holmes, Alexander Mathers, Nick Hewlings, Agnieszka Suliga, Johanna Wessing, Sebastien Vincent-Bonnieu, Katharine Robson Brown, Ian Hamerton

doi:10.1016/j.compositesb.2024.111311

 

纳米改性聚苯并恶嗪纳米复合材料层压板的物理和机械性能:暴露于低地球轨道前的飞行前测试

Polybenzoxazine (PBZ) formulations based on commercial components and modified with polyhedral oligomeric silsesquioxanes (POSS, 5 wt.% and 10 wt.%) have been scaled up for industrialisation, and their processing characteristics determined using thermal analysis and rheometry. The ultimate glass transition temperatures for the cured PBZ resins are increased by catalysis and by the incorporation of POSS. Carbon fibre reinforced polymer (CFRP) laminates (500 mm × 500 mm x 3 mm) were manufactured using resin transfer moulding and subjected to a suite of mechanical tests. The addition of 5 wt.% POSS to the PBZ formulation leads to substantial improvements in both strength (tensile, flexural, short beam shear, and compression) and modulus (tensile, flexural, and compression). The CFRP specimens were subjected to a suite of pre-flight qualification tests prior to deployment in low Earth orbit. When the CFRP laminates were exposed to <1 × 10−5 mbar and 125 °C, the total mass loss recorded for each sample was <1 wt.%. The introduction of POSS at both levels of incorporation improves erosion yield following exposure to high atomic oxygen flux and the ratio of solar absorptance (α) to emittance (ε) remained constant following simulated solar exposure. The outcome was that the three PBZ CFRP samples passed their pre-flight tests.

以商用成分为基础并用多面体低聚硅倍半氧烷(POSS,5 wt.% 和 10 wt.%)改性的聚苯并恶嗪(PBZ)配方已按比例进行了工业化生产,并使用热分析和流变仪确定了其加工特性。通过催化和加入 POSS,固化 PBZ 树脂的最终玻璃化转变温度得到了提高。使用树脂传递模塑法制造了碳纤维增强聚合物(CFRP)层压板(500 毫米 × 500 毫米 × 3 毫米),并对其进行了一系列机械测试。在 PBZ 配方中添加 5 wt.% 的 POSS 后,强度(拉伸、弯曲、短梁剪切和压缩)和模量(拉伸、弯曲和压缩)均有大幅提高。在低地球轨道部署之前,CFRP 试样接受了一系列飞行前鉴定测试。当 CFRP 层压板暴露在 <1 × 10-5 mbar 和 125 °C 的环境中时,每个试样记录到的总质量损失均小于 1 wt.%。在两个添加水平上引入 POSS 可提高暴露于高原子氧通量后的侵蚀产量,并且在模拟太阳暴露后,太阳吸收率(α)与发射率(ε)之比保持不变。结果表明,三种 PBZ CFRP 样品均通过了飞行前测试。


Optimisation of ultrasonic welding process of carbon/epoxy composites using Nylon-based or PES thermoplastic interlayers

L. Calabrese, G. Cicala, G. Di Bella, E. Proverbio, C. Tosto, L. Saitta

doi:10.1016/j.compositesb.2024.111318

优化使用尼龙基或聚醚砜热塑性夹层的碳/环氧树脂复合材料的超声波焊接工艺

The aim of this study is to investigate ultrasonic welding in carbon fibre-reinforced thermosetting composites by optimizing process parameters, specifically sonotrode pressure and ultrasound application time. Joining is accomplished by incorporating electrospun veils, consisting of either polyether sulfone or nylon, into the outer layers of the composite laminates. Single lap shear tests were conducted to evaluate the mechanical strength of the joints and identify failure mechanisms. The results highlight a significant influence of the thermoplastic interlayer. Polyether Sulfone ensures consistently lower mechanical properties, while Nylon contributes to higher strength. In both scenarios, these joints show promising applications, particularly in sports automotive contexts where rapid and reliable part welding is crucial.

本研究旨在通过优化工艺参数,特别是超声电极压力和超声应用时间,研究碳纤维增强热固性复合材料的超声波焊接。通过在复合材料层压板的外层加入由聚醚砜或尼龙组成的电纺纱来实现接合。为评估接合处的机械强度并确定失效机制,进行了单搭接剪切试验。测试结果表明,热塑性夹层具有重大影响。聚醚砜确保了持续较低的机械性能,而尼龙则有助于提高强度。在这两种情况下,这些接头都显示出良好的应用前景,尤其是在运动型汽车领域,快速可靠的零件焊接至关重要。


The impacts of CaCO3 deposition in natural wood on its viscoelastic properties

Hyunjun Choi, Laura E. Dalton, Ilona Peszlen, Moe Pourghaz

doi:10.1016/j.compositesb.2024.111324

天然木材中 CaCO3 沉积对其粘弹性能的影响

In this study, we discuss the methods used for depositing calcium carbonate (CaCO3) and the resulting 2D and 3D particle distributions of CaCO3 in two types of wood, which were quantified using scanning electron microscopy (SEM) and X-ray computed tomography (CT). We also present the results of dynamic mechanical analysis (DMA), which was used to measure the impact of CaCO3 deposition on the viscoelastic properties of the wood. X-ray CT scanning showed that CaCO3 deposits inside the wood scaffold with increased amounts as the deposition cycles were iterated. However, DMA results did not indicate significant improvement in storage moduli (E′) of CaCO3 deposited wood. SEM images revealed that the particles did not fill all the voids to provide stress transfer between the wood scaffold and the particles, indicating a lack of composite action between the wood and CaCO3 components. To address this issue, we hypothesized that heat-pressing would lead to a mechanical bond between the particles and the matrix. After heat-pressing, DMA results showed a dramatic increase in E′ not only in CaCO3 deposited wood samples but also in control wood samples. In other words, the densification of the structure led to significant increases in E′, primarily due to densification, while the impact of the presence of CaCO3 particles was minimal. This is mainly because the volume fraction of the deposited CaCO3 particles is small as compared to the total volume of the composite.

在本研究中,我们讨论了沉积碳酸钙 (CaCO3) 的方法以及两种木材中 CaCO3 的二维和三维颗粒分布,并使用扫描电子显微镜 (SEM) 和 X 射线计算机断层扫描 (CT) 对其进行了量化。我们还介绍了动态机械分析 (DMA) 的结果,该分析用于测量 CaCO3 沉积对木材粘弹性能的影响。X 射线 CT 扫描显示,随着沉积周期的反复进行,CaCO3 在木材支架内的沉积量不断增加。然而,DMA 结果表明,沉积 CaCO3 的木材的存储模量(E′)并没有明显改善。SEM 图像显示,颗粒没有填满所有空隙,无法在木材支架和颗粒之间提供应力传递,这表明木材和 CaCO3 成分之间缺乏复合作用。为了解决这个问题,我们假设热压将导致颗粒和基质之间的机械结合。热压后,DMA 结果表明,不仅 CaCO3 沉积木材样品的 E′显著增加,而且对照木材样品的 E′也显著增加。换句话说,结构致密化导致 E′显著增加,主要原因是致密化,而 CaCO3 颗粒的存在影响很小。这主要是因为沉积 CaCO3 颗粒的体积分数与复合材料的总体积相比很小。


Composites Science and Technology

The investigation and fabrication of novel ballistic composites with checkerboard-shaped lay-up design to improve ballistic performances

Feilong Han, Chenghao Wang, Ya Zhang, Ziyu Wang, Hangyu Yue, Lishuai Zong, Jinyan Wang, Xigao Jian

doi:10.1016/j.compscitech.2024.110511

 

研究和制造采用棋盘格形铺层设计的新型弹道复合材料,以提高弹道性能

High-performance and lightweight ballistic composites prepared through layer-by-layer lay-up of matrix and fabric have attracted significant interest. However, the traditional full-coverage lay-up design constrains the energy absorption of the composites during ballistic impact. Therefore, novel ballistic composites configured with checkerboard-shaped lay-up design were studied, using checkerboard-shaped polycarbonate (PC) films and aramid plain-woven fabrics. The effect of the size and cross-layered distribution of the checkerboard-shaped PC films was investigated. Compared with the full-coverage lay-up design, the checkerboard-shaped lay-up design can effectively improve the ballistic performance. For checkerboard-shaped lay-up design ballistic composites, the ballistic performances exhibited minor variation when impacting PC regions but gradually increased with the size of the fabric regions when impacting aramid fabric regions. The ballistic performance of interval cross-layered checkerboard-shaped PC films also increased with the number of interval layers. When impacting PC regions, the primary ballistic mechanisms were compression/shear and shear/tensile failures; however, when delamination and stress waves propagated into the regions without PC films, the checkerboard lay-up design allowing for effective energy absorption through tensile failure by fabrics. When impacting aramid fabric regions, the primary ballistic mechanisms were shear/tensile failure and tensile failure. However, when the size of aramid fabric region was insufficient, the near PC region can restrict transverse deformation of the fabrics, which did not benefit the ballistic performance.

通过逐层铺设基体和织物制备的高性能轻质弹道复合材料引起了人们的极大兴趣。然而,传统的全覆盖铺层设计限制了复合材料在弹道冲击中的能量吸收。因此,研究人员使用棋盘格状聚碳酸酯(PC)薄膜和芳纶平纹织物,研究了采用棋盘格状铺层设计的新型弹道复合材料。研究了棋盘状 PC 薄膜的尺寸和交叉层分布的影响。与全覆盖铺层设计相比,棋盘格状铺层设计能有效提高弹道性能。对于棋盘格形铺层设计的防弹复合材料,在撞击 PC 区域时,防弹性能变化不大,但在撞击芳纶纤维区域时,防弹性能随纤维区域的大小而逐渐增加。间隔交叉层棋盘状 PC 薄膜的防弹性能也随着间隔层数的增加而提高。在撞击 PC 区域时,主要的弹道机制是压缩/剪切和剪切/拉伸破坏;然而,当分层和应力波传播到没有 PC 薄膜的区域时,棋盘式层叠设计允许织物通过拉伸破坏有效吸收能量。在冲击芳纶织物区域时,主要的弹道机制是剪切/拉伸破坏和拉伸破坏。然而,当芳纶织物区域的尺寸不足时,靠近 PC 的区域会限制织物的横向变形,这不利于弹道性能的提高。



来源:复合材料力学仿真Composites FEM
ACTMechanicalFluxDeform复合材料汽车电子ADS焊接材料试验
著作权归作者所有,欢迎分享,未经许可,不得转载
首次发布时间:2024-11-06
最近编辑:21天前
Tansu
签名征集中
获赞 6粉丝 0文章 776课程 0
点赞
收藏
作者推荐

【新文速递】2024年2月26日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 3 篇Composite StructuresA modified equally-spaced method (MEQS) for fibre placement in additive manufacturing of topology-optimised continuous carbon fibre-reinforced polymer composite structuresShuai Wang, Haoqi Zhang, Aonan Li, Junaid Ahmad Abdul Qayyum, Yongxing Wang, Zhelong He, Jie Liu, Dongmin Yangdoi:10.1016/j.compstruct.2024.117998拓扑优化连续碳纤维增强聚合物复合材料结构增材制造中纤维铺放的改良等距法 (MEQS)This study proposes a modified equally-spaced (MEQS) method for the path design of continuous fibres in additive manufacturing (AM) of topologically optimised composite structures. The MEQS method addresses the low fibre infill rate issue of the traditional Equally-Spaced (EQS) method by utilising the Offset method to generate looped printing paths around the internal cavities and gaps between continuous fibre paths. The developed MEQS method was first illustrated against EQS and Offset methods using an open-hole composite plate in which topology and material orientation were simultaneously optimised using the discrete–continuous parameterisation (DCP) method. Actual printing path-based finite element modelling showed that the MEQS method achieves a 25.32% increase in stiffness compared to the Offset method. Experimental testing of the additively manufactured open-hole composite plates showed that the MEQS method improves the stiffness and strength by 15.52% and 27.38%, respectively, compared to the Offset method. The proposed MEQS was further demonstrated through two other case studies by finite element modelling, showing that the stiffness of MEQS has increased by an average of 66.71% and 14.95% compared to EQS and Offset, respectively.本研究提出了一种改进的等间距(MEQS)方法,用于拓扑优化复合材料结构的增材制造(AM)中连续纤维的路径设计。MEQS 方法利用 &quot;偏移 &quot;方法在内部空腔和连续纤维路径之间的间隙周围生成循环打印路径,从而解决了传统等间距 (EQS) 方法中纤维填充率低的问题。开发的 MEQS 方法首先使用开孔复合板与 EQS 和偏移法进行了对比,其中拓扑结构和材料取向同时使用离散连续参数化 (DCP) 方法进行了优化。基于实际印刷路径的有限元建模显示,与偏移法相比,MEQS 法的刚度提高了 25.32%。对添加制造的开孔复合板进行的实验测试表明,与偏移法相比,MEQS 法的刚度和强度分别提高了 15.52% 和 27.38%。通过有限元建模进行的另外两个案例研究进一步证明了所提出的 MEQS,结果表明,与 EQS 和偏移法相比,MEQS 的刚度平均分别提高了 66.71% 和 14.95%。Composites Part A: Applied Science and ManufacturingDamage failure analysis of flexible-oriented three dimensional woven composites with void defects: An experimental and numerical studyHao Huang, Zhongde Shan, Jianhua Liu, Zitong Guo, Zheng Sun, Dong Wang, Chenchen Tan, Juncheng Luodoi:10.1016/j.compositesa.2024.108106具有空隙缺陷的柔性导向三维编织复合材料的损伤失效分析:实验和数值研究Three-dimensional woven structures have garnered significant interest due to their enhanced mechanical properties and structural integrity. This study delves into a detailed analysis of progressive damage failure in multi-structured, flexible-oriented three-dimensional woven composites (FO3DWC), with a specific focus on the effects of voids. Employing the flexible-oriented three-dimensional woven process (FO3DWP), four distinct structures were fabricated and subjected to uniaxial tensile tests. The study integrates an progressive damage failure model coupled with a random element selection method to investigate the effects of void defects on mechanical properties. The results show that significant variations occur in the strength of the L45135 structure due to the void defects, with a maximum decrease of up to 4.37% when the porosity is 5%. This research provides a quantitative understanding of how voids impact the mechanical performance of FO3DWC, offering valuable guidance for material design and application in various engineering fields.三维编织结构因其更高的机械性能和结构完整性而备受关注。本研究详细分析了多结构柔性导向三维编织复合材料(FO3DWC)的渐进破坏失效,重点关注空隙的影响。采用柔性导向三维编织工艺(FO3DWP)制造了四种不同的结构,并对其进行了单轴拉伸试验。该研究将渐进式损伤失效模型与随机元素选择方法相结合,研究了空隙缺陷对机械性能的影响。结果表明,由于空隙缺陷,L45135 结构的强度发生了显著变化,当孔隙率为 5%时,强度最大下降达 4.37%。这项研究提供了对空隙如何影响 FO3DWC 机械性能的定量理解,为各种工程领域的材料设计和应用提供了宝贵的指导。Composites Part B: EngineeringA comprehensive review of hydrogen-induced swelling in rubber compositesChilou Zhou, Xianhui Liu, Yiran Zheng, Zhengli Huadoi:10.1016/j.compositesb.2024.111342 橡胶复合材料中氢诱导溶胀的综合评述Rubber sealing components are crucial and highly vulnerable parts in high-pressure hydrogen systems, which represent the weakest link where seal failure becomes the crucial factor limiting the increase in working pressure of hydrogen energy equipment. Prolonged exposure to hydrogen environments causes rubber materials to experience volumetric expansion, resulting in decreased sealing reliability and durability, posing significant safety risks. This review focuses on rubber sealing materials used in hydrogen energy equipment. Firstly, the current mainstream mechanisms of hydrogen-induced swelling are introduced, covering the hydrogen exposure and decompression stages. Subsequently, the impact of hydrogen-induced swelling on the micromorphology damage, mechanical performance deterioration and sealing performance reduction of rubber is elucidated. Furthermore, the primary influencing factors of rubber hydrogen-induced swelling are explored and summarized. Based on the analysis of the current state of researches, several recommendations are proposed for the study of hydrogen-induced swelling of rubber sealing materials, including broadening the influencing factors and constructing the correlations between hydrogen-induced swelling and other damages such as frictional wear to contributing the safe application of rubber seal in high-pressure hydrogen systems.在高压氢气系统中,橡胶密封部件是非常脆弱的关键部件,是最薄弱的环节,密封失效成为限制氢能设备工作压力提高的关键因素。长期暴露在氢气环境中会导致橡胶材料发生体积膨胀,从而降低密封可靠性和耐用性,带来重大安全风险。本综述侧重于氢能设备中使用的橡胶密封材料。首先,介绍当前氢气诱导膨胀的主流机制,包括氢气暴露阶段和减压阶段。随后,阐明了氢致膨胀对橡胶微观形貌损伤、机械性能恶化和密封性能降低的影响。此外,还探讨并总结了橡胶氢致溶胀的主要影响因素。在分析研究现状的基础上,对橡胶密封材料的氢致溶胀研究提出了若干建议,包括拓宽影响因素,构建氢致溶胀与摩擦磨损等其他损伤之间的相关性,以促进橡胶密封在高压氢气系统中的安全应用。Fabrication of hollow Ni/NiO/C/MnO2@polypyrrole core-shell structures for high-performance electromagnetic wave absorptionShixuan Feng, Haowen Wang, Jian Ma, Zhongtai Lin, Chuanjin Wang, Xue Li, Mingliang Ma, Tingxi Li, Yong Madoi:10.1016/j.compositesb.2024.111344 制备用于高性能电磁波吸收的中空 Ni/NiO/C/MnO2@polypyrrole 核壳结构In response to the increasingly serious problem of electromagnetic wave pollution, there is a growing demand for materials capable of absorbing electromagnetic waves. A crucial strategy involves optimizing the microstructure and composition of these materials. In this study, the Ni/NiO/C/MnO2@PPy (NCMP) composites are successfully fabricated through the combination of hydrothermal method, high-temperature calcination process, chemical method and in situ polymerization. Due to the strong synergistic effect of the dielectric and magnetic components, and good impedance match, the NCMP-40 exhibits excellent electromagnetic wave absorption properties, with an optimal reflection loss (RLmin) of −56.23 dB at a thickness of 3.87 mm, and a high effective absorption bandwidth (EAB) of 6.86 GHz (10.68–17.54 GHz) at a thickness of 1.97 mm covering the entire Ku-band part of the X-band. Moreover, the radar cross section (RCS) attenuation is obtained through a simulation procedure. Compared to the sole perfect electrically conductive (PEC) layer, the PEC layer coated with NCMP-40 achieves an RCS value consistently below −10 dB m2 in the range of −60° &lt; θ &lt; 60°, and an RCS value is −22.0 dB m2 at θ = 0°. The prepared NCMP-40 presented herein shows excellent electromagnetic wave absorption performances. And this study provides a new method for the structural design of electromagnetic wave absorption materials.为了应对日益严重的电磁波污染问题,人们对能够吸收电磁波的材料的需求与日俱增。其中一项重要策略就是优化这些材料的微观结构和成分。本研究结合水热法、高温煅烧法、化学法和原位聚合法,成功制备了 Ni/NiO/C/MnO2@PPy (NCMP)复合材料。由于介电成分和磁性成分的强协同效应以及良好的阻抗匹配,NCMP-40 表现出优异的电磁波吸收特性,在厚度为 3.87 毫米时的最佳反射损耗(RLmin)为 -56.23 dB,在厚度为 1.97 毫米时的有效吸收带宽(EAB)为 6.86 GHz(10.68-17.54 GHz),覆盖了整个 Ku 波段的 X 波段部分。此外,还通过模拟程序获得了雷达截面(RCS)衰减。与唯一的完美导电 (PEC) 层相比,涂有 NCMP-40 的 PEC 层在 -60° &lt; θ &lt; 60° 范围内的 RCS 值始终低于 -10 dB m2,在 θ = 0° 时的 RCS 值为 -22.0 dB m2。本文介绍的制备的 NCMP-40 具有优异的电磁波吸收性能。这项研究为电磁波吸收材料的结构设计提供了一种新方法。Composites Science and TechnologyImpact behaviour of bio-inspired sandwich panels integrally manufactured from 3D printed continuous carbon fibre reinforced polyamideI. Sukia, A. Esnaola, B. Erice, J. Aurrekoetxeadoi:10.1016/j.compscitech.2024.110515 用 3D 打印连续碳纤维增强聚酰胺整体制造的生物启发夹层板的冲击性能This paper studies the effect of several design parameters on the impact performance of fully 3D printed sandwich panels with a core cell unit inspired by the trabecular structure of the forewing of a beetle. The key finding is that the asymmetric sandwich panel, which featured a thicker face sheet at the back and a core with a variating cell wall thickness of weak-to-strong, exhibited the highest impact energy dissipation. Specifically, 98.1 J was dissipated with 6970 N of peak load. This surpassed the performance of the sandwich panel with homogeneous cell wall thickness and asymmetric face sheets, which dissipated only 72.1 J and failed at 5406 N. In general, asymmetric configurations were found to dissipate greater energy than symmetric face sheets, and for sandwich plates with homogenous cores, the configuration with the thickest back face sheet proved more resistant to damage than the opposite asymmetric configuration.本文研究了几个设计参数对全三维打印夹层板冲击性能的影响,夹层板的核心单元灵感来自甲虫前翅的小梁结构。研究的主要发现是,非对称夹层板(背面面层较厚,核心单元壁厚由弱到强不断变化)的冲击能量耗散最高。具体来说,6970 牛顿的峰值载荷可耗散 98.1 焦耳的能量。总体而言,非对称结构比对称结构能耗散更大的能量,而对于具有同质芯材的夹芯板来说,具有最厚背面面板的结构比相反的非对称结构更能抵抗破坏。The chemistry, properties and performance of flame-retardant rubber composites: Collecting, analyzing, categorizing, machine learning modeling, and visualizingPaulina Wiśniewska, Elnaz Movahedifar, Krzysztof Formela, M.Z. Naser, Henri Vahabi, Mohammad Reza Saebdoi:10.1016/j.compscitech.2024.110517 阻燃橡胶复合材料的化学性质、特性和性能:收集、分析、分类、机器学习建模和可视化Rubbers combine the flexibility with mechanical strength, supporting myriad applications, but suffer from inherent flammability. Development of flame-retardant rubber composites (FRRCs) has intensively practiced over years, but not comprehensively reviewed, which outlined collecting, analyzing, screening, classifying, and interpreting the literature aimed at classification of FRRCs. Herein, we quantify and visualize flame retardancy of natural and synthetic FRRCs by grouping FRRCs based on flame retardants (FRs) used among green, mineral, phosphorus-based, nitrogen-based, carbonaceous, and hybrids of two or more types. Available data on cone calorimetry, limited oxygen index (LOI), and UL-94 of FRRCs were carefully extracted and plotted. Flame Retardancy Index (FRI) specified the Poor, Good, or Excellent classes of flame retardancy in association with the chemistry and amount of FRs to broaden future innovation avenues. Machine Learning (ML) modeling further enabled to visualize flame retardancy landscapes of natural and synthetic rubbers per FRs chemistry and amount. Moreover, a downward trend in mechanical properties of FRRCS versus FR content and type was explored. Overall, this study proposed a general guideline for recognizing gaps in previous investigations and mechanics interpretations. In conclusion, the future FRRCs should take advantage of hybridizing FRs to meet fire safety requirements inspired by the innovative colorful checkered flame retardancy chart presented in this survey.橡胶兼具柔韧性和机械强度,可支持多种应用,但也存在固有的易燃性问题。多年来,阻燃橡胶复合材料(FRRCs)的开发得到了深入实践,但并未得到全面回顾,其中包括收集、分析、筛选、分类和解释旨在对 FRRCs 进行分类的文献。在此,我们根据绿色、矿物、磷基、氮基、碳基以及两种或两种以上类型的混合物所使用的阻燃剂(FRs),对天然和合成 FRRCs 的阻燃性能进行了量化和可视化分组。我们仔细提取并绘制了有关 FRRC 的锥形量热仪、限氧指数(LOI)和 UL-94 的现有数据。阻燃指数(FRI)与阻燃剂的化学性质和数量相关联,规定了阻燃性的差、好或优等级,以拓宽未来的创新途径。通过机器学习(ML)建模,还可以根据阻燃剂的化学性质和用量直观地了解天然橡胶和合成橡胶的阻燃性。此外,还探讨了 FRRCS 机械性能随 FR 含量和类型的下降趋势。总之,本研究提出了一个总体指导原则,用于识别以往研究和力学解释中的不足之处。总之,未来的 FRRC 应利用混合 FR 的优势,以满足本次调查中提出的创新彩色方格阻燃图所激发的防火安全要求。Bionic hierarchical metalized thermally responsive dynamic daytime passive radiative cooling nanocompositesJunbao Yan, Mingyue Han, Liangbo Zhu, Xinyu Zhang, Mei Xu, Mengting She, Yuhan Cai, Xueyang Liu, Hua Wang, Siwei Xiong, Luoxin Wangdoi:10.1016/j.compscitech.2024.110518 仿生分层金属化热响应动态日间被动辐射冷却纳米复合材料Passive heat management technology holds significant promise in mitigating the fossil energy crisis. However, most current passive radiative cooling textiles merely reflect sunlight, causing unnecessary cooling in cold regions during winter and lacking dynamic control. Herein, we were inspired by chameleons to develop a temperature-sensitive passive heat management nanocomposite using a multi-layered assembly strategy. This nanocomposite consisted of the core layer of metal-coated fabric and the surface layer composed of polydimethylsiloxane (PDMS), hexagonal boron nitride (h-BN), and organic temperature-variable material (OTM). When the nanocomposite contained 15 wt% OTM, the average reflectance in the cold (15 °C) and hot (30 °C) modes was 47.66% and 80.92%, respectively. Additionally, the average emissivity was found to be 91.64% and 91.31% in the cold and hot modes, respectively. Significantly, the nanocomposite demonstrated cyclic stability in multiple temperature response tests. In practical experiments, it effectively reduced the temperature within a car and a small wooden house model by 14.0 and 7.1 °C, respectively. Moreover, the nanocomposite facilitated the accelerated ice melting at a rate of 10.85 ± 0.3 g within 1 h. Additionally, the presence of a copper metal layer in the 15 wt% OTM nanocomposite was found to contribute to antimicrobial efficiencies of 56% and 38% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. This nanocomposite possesses the potential to stimulate inventive designs in the forthcoming era of functional nanocomposites, owing to its dynamic radiative cooling, solar heating capabilities, and scalability.被动式热管理技术在缓解化石能源危机方面大有可为。然而,目前大多数被动辐射降温纺织品只是反射太阳光,在冬季寒冷地区会造成不必要的降温,而且缺乏动态控制。在此,我们受到变色龙的启发,利用多层组装策略开发出一种温度敏感型被动热管理纳米复合材料。这种纳米复合材料的核心层是金属涂层织物,表层由聚二甲基硅氧烷(PDMS)、六方氮化硼(h-BN)和有机变温材料(OTM)组成。当纳米复合材料含有 15 wt% 的 OTM 时,在冷(15 °C)和热(30 °C)模式下的平均反射率分别为 47.66% 和 80.92%。此外,冷模式和热模式下的平均发射率分别为 91.64% 和 91.31%。值得注意的是,纳米复合材料在多重温度响应测试中表现出了周期稳定性。在实际实验中,它能有效地将汽车和小木屋模型内的温度分别降低 14.0 ℃ 和 7.1 ℃。此外,该纳米复合材料还能在 1 小时内以 10.85 ± 0.3 g 的速率促进冰的加速融化。此外,15 wt% OTM 纳米复合材料中的金属铜层对大肠杆菌(E. coli)和金黄色葡萄球菌(S. aureus)的抗菌效率分别为 56% 和 38%。这种纳米复合材料具有动态辐射冷却、太阳能加热功能和可扩展性,有望在即将到来的功能纳米复合材料时代激发创新设计。来源:复合材料力学仿真Composites FEM

未登录
还没有评论
课程
培训
服务
行家
VIP会员 学习 福利任务 兑换礼品
下载APP
联系我们
帮助与反馈