【新文速递】2024年5月25日复合材料SCI期刊最新文章

   

今日更新：Composite Structures 2 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 2 篇

Composite Structures

FCA-based efficient prediction of effective properties for 3D braided composites considering the effect of strain rate

Yangxuan Zhu, Chunwang He, Tian Zhao, Ying Li

doi:10.1016/j.compstruct.2024.118232

考虑应变速率影响的基于fca的三维编织复合材料有效性能预测

The existing fast concurrency algorithms are difficult to predict the dynamic mechanical performance of three-dimensional (3D) braided composites from different scales. A modified Finite Element Method Cluster Analysis (FCA) method is employed to address this challenge. The modified FCA method is consisted of an offline and an online stage. In the offline stage, the high-fidelity Representative Unit Cell (RUC) is compressed to form a cluster-based RUC via the k-means method. Additionally, the cluster interaction matrix is calculated. In the online stage, the cluster interaction matrix is updated according to the strain rate levels for predicting the stress–strain curves for the RUC. Based upon the comparison with the data obtained from the Split Hopkinson Pressure Bar (SHPB) experiments, it is found that the modified FCA method can accurately predict the stress–strain curves under different strain rates for RUCs. Additionally, the modified FCA method provides a great improvement on computing efficiency when predicting the dynamic behavior of 3D braided composites.

现有的快速并发算法难以从不同尺度预测三维编织复合材料的动态力学性能。采用一种改进的有限元聚类分析(FCA)方法来解决这一挑战。改进的FCA方法由离线和在线两个阶段组成。在离线阶段，通过k-means方法将高保真代表性单元单元(RUC)压缩成基于聚类的RUC。此外，还计算了聚类相互作用矩阵。在在线阶段，根据应变率水平更新聚类相互作用矩阵，用于预测RUC的应力-应变曲线。通过与分离式霍普金森压杆(Split Hopkinson Pressure Bar, SHPB)试验数据的对比，发现改进的FCA方法能够准确预测不同应变率下的混凝土应力-应变曲线。此外，改进的FCA方法在预测三维编织复合材料的动态行为时大大提高了计算效率。

Interactive inverse design of periodic non-uniform/inhomogeneous rod structures based on q-learning method

Chun Bao, Y.Q. Guo, Y.J. Wang

doi:10.1016/j.compstruct.2024.118233

基于q-学习方法的周期非均匀/非均匀杆结构交互逆设计

The existing researches on controlling the longitudinal waves through periodic rods with frequency bands mainly focus on the analysis of band structures together with their influences by various geometrical/material parameters and on the corresponding forward design via passive/active modulations. This paper originally proposes the interactive inverse design method by virtue of the Q-Learning algorithm for catering required objectives with introducing the cross-sectional nonuniformity and material inhomogeneity to the constituent components in periodic rods. Firstly, theoretically analyzing the frequency bands of periodic non-uniform/inhomogeneous rods with linear variations to the cross-sectional area and to the Young’s modulus and material density, is presented using transfer matrix method (TMM). After verifying the analysis method by comparing it with the finite element method (FEM) for obtaining band structures in three kinds of exemplified periodic rods with non-uniform/inhomogeneous components, the effects of non-uniformity and inhomogeneity of components on the frequency bands are discussed. These effects provide qualitative judgment criteria to the results of inverse design. Secondly, the inverse design method by the Q-learning algorithm for periodic non-uniform/inhomogeneous rods is proposed as the optimization objective is the maximum of the first bandgap width. The optimization results of the periodic rods with only non-uniformity, with only inhomogeneity or with both non-uniformity and inhomogeneity are provided to validate the accuracy and efficiency of the proposed Q-Learning algorithm that has the advantages of obtaining the optimal result from any initial states and giving the evolutionary path along the gradient to the objective. It should be pointed out that our proposed inverse design method can actually be extended for other optimization objectives and to other kinds of periodic structures for controlling diversified elastic waves.

现有的带频带周期棒控制纵波的研究主要集中在分析带结构及其受各种几何/材料参数的影响，并通过无源/有源调制进行相应的正演设计。本文首先提出了一种基于Q-Learning算法的交互式逆设计方法，通过引入周期棒组成部件的截面非均匀性和材料非均匀性来满足要求的目标。首先，利用传递矩阵法(TMM)从理论上分析了周期性非均匀/非均匀棒的横截面积、杨氏模量和材料密度随线性变化的频带;通过与有限元法对三种非均匀/非均匀构件周期棒的频带结构进行验证，讨论了构件的非均匀性和非均匀性对频带结构的影响。这些影响为反设计的结果提供了定性的判断标准。其次，以第一带隙宽度最大为优化目标，提出了周期非均匀/非均匀棒的q -学习反设计方法;通过只存在非均匀性、只存在非均匀性或同时存在非均匀性和非均匀性的周期棒的优化结果，验证了所提Q-Learning算法的准确性和效率，该算法具有从任意初始状态获得最优结果并给出沿梯度到达目标的进化路径的优点。需要指出的是，我们提出的反设计方法实际上可以推广到其他优化目标和其他类型的周期结构，以控制多样化的弹性波。

Composites Part B: Engineering

Failsafe layer for wind turbine blades: Erosion protection of glass fiber composite through nanodiamond-treated flax composite top layer

Carsten Hinzmann, Nicolai Frost-Jensen Johansen, Charlotte Bay Hasager, Bodil Holst

doi:10.1016/j.compositesb.2024.111584

 

风力涡轮机叶片的故障保护层:通过纳米金刚石处理的亚麻复合材料顶层，保护玻璃纤维复合材料的侵蚀

Wind turbine blades are mainly made from E-glass fiber (GF) epoxy composites, because of their good ratio of strength to weight and costs. With the increase in blade length and tip speed, the problem of leading edge erosion is becoming more severe, reducing annual energy production and raising maintenance cost. It was recently shown that nanodiamond-treated flax fiber (FF ND ) composites have significantly less erosion than GF composites and could be an alternative for GF in the turbine blade aeroshells. However, FF ND alone might not be suitable for manufacturing turbine blades at the large scale of modern wind turbines. Here, we show that a hybrid composite with a thin layer of only 1.5 mm of FF ND on a GF base, can achieve the same superior results as bulk material FF ND composite. In addition, we show and explain why aramid fibers, that are known for impact resistance, do not perform well as erosion protection. Our research shows the great potential of this technology to be implemented as a low-cost, lightweight skin layer on the leading edge. Acting as damage-tolerant failsafe layer, negligible ∼ 0.04 % extra weight of the FF ND could increase the blade’s base erosion resistance by a factor of 60±20 compared to plain GF, expanding the repair window, reducing costs, and enhancing reliability.

风力涡轮机叶片主要由e -玻璃纤维(GF)环氧复合材料制成，因为它们具有良好的强度重量比和成本。随着叶片长度和叶尖速度的增加，前缘侵蚀问题日益严重，降低了年发电量，提高了维修成本。最近的研究表明，纳米金刚石处理亚麻纤维(FF ND)复合材料比GF复合材料具有更小的腐蚀，可以作为GF在涡轮叶片壳体中的替代品。然而，单独使用FF ND可能不适合大规模制造现代风力涡轮机的涡轮叶片。在这里，我们证明了在GF基上仅覆盖1.5 mm的FF ND薄层的杂化复合材料可以达到与块状材料FF ND复合材料相同的优异效果。此外，我们还展示并解释了为什么以抗冲击而闻名的芳纶纤维不能很好地发挥侵蚀保护作用。我们的研究表明，这项技术具有巨大的潜力，可以作为一种低成本、轻质的前沿皮肤层来实现。作为容损故障安全层，与普通GF相比，可忽略不计的~ 0.04%的额外重量可将叶片基部抗侵蚀能力提高60±20倍，从而扩大了维修窗口，降低了成本，提高了可靠性。

Composites Science and Technology

Thermal Conductive Network Construction and Enhanced Thermal Conductivity in Mica Tape Composites for Large Generator Insulation

Zhonghua Zhang, Yu Feng, Dongyue Wang, Liang Liang, Zhanyi Wang, Kailun Yang, Xuesong Chen, Qingguo Chen

doi:10.1016/j.compscitech.2024.110671

 

大型发电机绝缘用云母带复合材料导热网络的构建及导热性能的提高

The rapid development of large generators to high voltage and large capacity calls for high thermal conductivity and excellent insulation for their insulation. In this work, an hexagonal boron nitride (h-BN) thermal conductive network is firstly constructed. The thermal conductivity network in mica paper exhibits a three-dimensional structure, and mica tape composites was prepared with glass fabric, epoxy and mica paper above. Accordingly, a typical mica paper and mica tape have thermal conductivities of 1.07 W/(m·K) and 0.416 W/(m·K), respectively, which are 157.21% and 75.53% higher than those without filling. A modified thermal conductivity model (LN-SSS model) is proposed to analyze the thermal conductivity of the mica tape composites, which is found to fit the mica tape's experiment value and tendency accurately, and the mica tape composites have excellent insulation properties. The design approach in this paper also provides new ideas for insulating materials and structures with high thermal conductivity.

大型发电机向高压、大容量的快速发展，要求其绝缘具有高导热性和优良的绝缘性能。本文首次构建了六方氮化硼(h-BN)导热网络。云母纸中的导热网络呈现出三维结构，并将玻璃织物、环氧树脂和云母纸制备成云母带复合材料。因此，典型云母纸和云母带的导热系数分别为1.07 W/(m·K)和0.416 W/(m·K)，比未填充云母纸和云母带的导热系数分别提高了157.21%和75.53%。提出了一种改进的导热系数模型(LN-SSS模型)来分析云母带复合材料的导热系数，发现该模型能较好地拟合云母带的实验值和趋势，并且云母带复合材料具有优异的绝缘性能。本文的设计方法也为高导热绝缘材料和结构提供了新的思路。

Effects of yarn interlacement in diamond triaxial braid on its patterns and tensile properties

Wonki Kim, Ha Eun Lee, Woe Tae Kim, Hyeonseong Jo, Seong Su Kim

doi:10.1016/j.compscitech.2024.110678

 

金刚石三轴编织中纱线交织对其花型和拉伸性能的影响

Braiding is a preform technique involving the use of interweaving yarns. In the braiding process, manufacturing parameters dictate the resulting braided structures. Although numerous models based on braided architectures have been presented to predict patterns and mechanical properties, a comprehensive braided model that considers in-plane yarn interference in braiding is yet to be established. This study introduces a pioneering predictive model for triaxial braided patterns, considering yarn interlacing during braiding. Because of yarn interference, basic and deformed patterns were fabricated within the diamond triaxial braided structure. The cover factor of each pattern and the bent axial yarns in deformed patterns were predicted using a cover-factor equation and bending discriminant. To validate the analytical model and examine the effects of the patterns on the mechanical properties, various braided preforms and composites with three different braiding angles were fabricated. The analytical model and experimental results for cover factors indicated a discrepancy of less than 6%. Based on tensile tests, the deformed pattern exhibited inferior mechanical properties compared with the basic pattern, primarily due to its bent axial yarn and larger resin-rich area. This study provides a sophisticated method for predicting triaxial braided patterns, which are applicable to braided product design and modeling.

编织是一种使用交织纱线的预成型技术。在编织过程中，制造参数决定了最终的编织结构。尽管已经提出了许多基于编织结构的模型来预测图案和力学性能，但尚未建立一个考虑编织过程中面内纱线干涉的综合编织模型。本文介绍了一种开创性的三轴编织花型预测模型，该模型考虑了编织过程中纱线的交织。由于纱线的干涉，在金刚石三轴编织结构中产生了基本图案和变形图案。利用复盖系数方程和弯曲判别法预测了各花型的复盖系数和变形花型中轴向纱的弯曲。为了验证分析模型的有效性，研究了图案对力学性能的影响，制作了三种不同编织角度的编织预制体和复合材料。覆盖因子分析模型与试验结果的差异小于6%。拉伸试验表明，变形花型的力学性能较基本花型差，主要是由于其轴向纱弯曲和富树脂面积较大。本研究提供了一种完善的三轴编织图案预测方法，可用于编织产品的设计和建模。