今日更新：Composite Structures 1 篇，Composites Part A: Applied Science and Manufacturing 2 篇，Composites Part B: Engineering 2 篇，Composites Science and Technology 2 篇Composite StructuresStudy on the effect of multi-factor compound action on long-term tensile performance of GFRP composite pipe and life prediction analysisDandan Liao, Tan Gu, Jing Yan, Zhiming Yu, Jingjie Dou, Min Hu, Fei Zhao, Jie Liu, Jun Wangdoi:10.1016/j.compstruct.2024.118478多因素复合作用对玻璃钢复合管材长期拉伸性能的影响及寿命预测分析In this work, the glass fiber reinforced plastic (GFRP) composite pipes used as sewerage pipes in oil and gas field environments were studied. The accelerated aging experiments were carried out under the simulated environments of three typical oil field media which including circulating air, simulated produced water and standard simulated oil. Scanning electron microscopy (SEM) was adopted to observe the microscopic morphology of the aged GFRP tubes under the three conditions. The microstructural characteristics of the aged tubes and the evolution process of internal defects were also analyzed and evaluated in combination with micro-CT technology. The attenuation pattern of the hoop tensile strength of the aged pipes was measured via the separation disk method, and the service life prediction was carried out based on the Arrhenius theory with the hoop strength as the life index. The results show that the accumulation of aging time and continuous heat input will aggravate the expansion of internal pores and cause the aggregation of small-volume defects into large-volume defects. Especially in the simulated oil environment, which has the highest sensitivity to defects. The maximum porosity reaching 1.5 % and the maximum volume of individual defects exceeding 106 μm3 after aging for 4000 h at 95 °C. The thermal aging process under the three environmental conditions had similar aging characteristics, and interfacial damage of the glass fibers was observed in all of them. The variability of hydrothermal aging is related to the hydrolytic behavior of the glass fibers, which is associated with the progressive dissolution damage of the SiO2 network in the glass fibers, as well as the breaking of silane bonds. Thus, the hydrothermal environment had the most significant effect on the hoop tensile strength decay. Ultimately, 75 % strength retention was taken as the end-of-life indicator. The predicted service life based on the Arrhenius model for the three environments of thermo-oxygen, hydrothermal and simulated oil were 23.5, 23.1 and 28.5 years at 20 °C, and 12.2, 4.9 and 10.3 years at 40 °C, respectively.本文对玻璃钢(GFRP)复合管道作为油气田环境污水管道进行了研究。在循环空气、模拟采出水和标准模拟油三种典型油田介质的模拟环境下进行了加速老化试验。采用扫描电镜(SEM)观察了三种条件下时效GFRP管的微观形貌。结合显微ct技术，对时效管的显微组织特征和内部缺陷的演变过程进行了分析和评价。采用分离盘法测量了老化管材的环向抗拉强度衰减规律，并基于Arrhenius理论，以环向抗拉强度为寿命指标进行了寿命预测。结果表明:时效时间的累积和持续的热输入会加剧内部气孔的膨胀，导致小体积缺陷聚集成大体积缺陷;特别是在模拟油环境中，对缺陷的敏感性最高。95 ℃时效4000 h后，最大孔隙率达到1.5 %，单个缺陷最大体积超过106 μm3。三种环境条件下的热老化过程具有相似的老化特征，均出现了玻璃纤维界面损伤。水热老化的变异性与玻璃纤维的水解行为有关，这与玻璃纤维中SiO2网络的逐渐溶解破坏以及硅烷键的断裂有关。因此，热液环境对环向拉伸强度衰减的影响最为显著。最终以75% %的强度保留率作为寿命终止指标。基于Arrhenius模型的热氧、热液和模拟油三种环境的预测寿命分别为:20 °C时的23.5、23.1和28.5 年，40 °C时的12.2、4.9和10.3 年。Composites Part A: Applied Science and ManufacturingConstructing polyimide-based nanocomposite dielectrics with superior high‐temperature energy storage performance via using ternary structure strategyAo Xu, Jinlong Zhou, Hao Tan, Hao Zhong, Liwen Deng, Hang Luo, Sheng Chendoi:10.1016/j.compositesa.2024.108405 采用三元结构策略构建具有优异高温储能性能的聚酰亚胺基纳米复合电介质To maintain low leakage current and energy storage stability of polyimide at high temperature and electric field, ternary structure strategy is used to construct polyimide-based nanocomposite dielectrics, relating to cross-linked structure, sandwich structure and inorganic filler structure. Based on synergistic effect, energy storage properties of crosslinked polyimide-based sandwich‐structured nanocomposite films is significantly improved, in which cross-linked polyimide composited layers with 2 wt% hexagonal boron nitride nanosheets are selected as two outer insulating layers and cross-linked polyimide composited layer with 1 wt% barium titanate nanoparticles is employed as central polarization layer. When volume ratio of middle polarization layer is 10 % (denoted as N-10 T-N), the maximum Ud of 11.6 J/cm3 and η of 87 % are achieved at room temperature. At 150 °C, the Ud of N-10 T-N is 5.1 J/cm3. This study provides the experience for the development of polyimide dielectrics with high capacitive properties over a wide temperature range.为了保持聚酰亚胺在高温和电场下的低漏电流和储能稳定性，采用了三元结构策略来构建聚酰亚胺基纳米复合电介质，即交联结构、夹层结构和无机填料结构。在协同效应的基础上，交联聚酰亚胺基夹层结构纳米复合薄膜的储能性能得到显著提高，其中交联聚酰亚胺复合层与 2 wt%的六方氮化硼纳米片组成两层外绝缘层，交联聚酰亚胺复合层与 1 wt%的钛酸钡纳米颗粒组成中间极化层。当中间极化层的体积比为 10%（记为 N-10 T-N）时，室温下的最大 Ud 为 11.6 J/cm3，η 为 87%。在 150 °C 时，N-10 T-N 的 Ud 为 5.1 J/cm3。这项研究为开发在宽温度范围内具有高电容特性的聚酰亚胺电介质提供了经验。Development of a novel characterization model for innovative bionic helical carbon fiber towsZ.C. He, S.H. Li, H.L. Tan, Eric Li, H. Gao, C.F. Qin, Y.B. Wangdoi:10.1016/j.compositesa.2024.108406 新型仿生螺旋碳纤维束表征模型的建立The design of bionic helical structures significantly enhances load-bearing capacity and impact resistance, demonstrating great potential for mechanical property improvement. However, there is still a lack of precise characterization models for the helical structures of carbon fibers, which constrains their potential in engineering applications. This paper successfully fabricated helical carbon fiber tows using a carbon fiber twisting technique and introduced a novel intersecting circular cross-section model to thoroughly investigate the influence of the helical structure on the mechanical properties of carbon fiber tows. Tensile test results show that at a twist angle of 5°, the helical structure increases the tensile strength and fracture toughness of carbon fiber tows by 13.6% and 34.3%, respectively. Additionally, the introduction of complex structures such as helices significantly influences the material’s modulus, and precise modulus prediction is crucial for material optimization and practical application. Based on the newly proposed model, a modulus prediction model is developed, demonstrating higher predictive accuracy than traditional models with a prediction error of 2.8%. Finite element simulations further validate the practicality and superiority of the intersecting circular cross-section model. Compared to traditional models, the predictions of the novel model are closer to experimental data, with a prediction error below 2%, emphasizing the significant impact of microstructures on macroscopic properties and offering a new perspective for modeling complex material systems. These findings provide crucial theoretical and methodological support for the design and performance optimization of carbon fiber materials.仿生螺旋结构的设计显著提高了结构的承载能力和抗冲击能力，在力学性能改善方面具有很大的潜力。然而，目前对于碳纤维螺旋结构还缺乏精确的表征模型，限制了其在工程上的应用潜力。本文采用碳纤维捻制技术成功制备了螺旋碳纤维束，并引入了一种新型的相交圆形截面模型，深入研究了螺旋结构对碳纤维束力学性能的影响。拉伸试验结果表明，当扭转角为5°时，螺旋结构可使碳纤维束的抗拉强度和断裂韧性分别提高13.6%和34.3%。此外，螺旋等复杂结构的引入会显著影响材料的模量，精确的模量预测对于材料优化和实际应用至关重要。在此基础上建立了模量预测模型，预测误差为2.8%，比传统模型具有更高的预测精度。有限元仿真进一步验证了交圆截面模型的实用性和优越性。与传统模型相比，该模型的预测更接近实验数据，预测误差在2%以下，强调了微观结构对宏观性能的重要影响，为复杂材料系统的建模提供了新的视角。这些发现为碳纤维材料的设计和性能优化提供了重要的理论和方法支持。Composites Part B: Engineering4D printing bio-inspired chiral metamaterials for flexible sensorsXiaozhou Xin, Zhicheng Wang, Chengjun Zeng, Cheng Lin, Liwu Liu, Yanju Liu, Jinsong Lengdoi:10.1016/j.compositesb.2024.111761用于柔性传感器的4D打印仿生手性超材料Chiral metamaterials were a typical metamaterial configuration, which had broad application prospects in vibration isolation, energy absorption and other fields. Although 4D-printed chiral metamaterials have been investigated by introducing stimulus-responsive materials to achieve programmable properties of metamaterials, chiral metamaterials are mostly fabricated by single materials, which limits the adjustable domains of the mechanical properties and the design freedom of metamaterials. In this work, inspired by the configuration of collagen fibers of biological tissues, the bio-inspired chiral metamaterials with wave ligaments were developed. The bi-phase (TPE@PLA-SMP) composite chiral metamaterials were fabricated by combining active phase (shape memory polylactic acid, PLA-SMP) with passive phase (thermoplastic elastomer, TPE). The influences of geometric parameters, ligament gradient forms, and TPE distribution modes on the mechanical properties of the developed metamaterials were characterized. When the TPE was distributed at 0° and 45°, the deformation of the mechanical metamaterials occurred mainly in the TPE cells, resulting in the J-shaped displacement-force curve. The programmable and reconfigurable properties of the metamaterials (including configuration, and energy absorption performance) under thermal stimulation were demonstrated. The specific energy absorption (SEA) of the metamaterial 2θ=π/2 was realized to transform between 0.92 kJ/kg and 0.38 kJ/kg by shape memory programming. Flexible sensors based on TPE@PLA-SMP composite metamaterials were developed by filling CNC-CNT@PVA composite hydrogels (minimum resistivity 8.1 Ω•m), which enabled stable output of electrical signals under repeated loads. A motion state monitor was developed and realized to monitor the wearer's movement such as running, demonstrating its potential application prospects in fields such as flexible electronics.手性超材料是一种典型的超材料构型，在隔振、吸能等领域具有广阔的应用前景。虽然通过引入刺 激响应材料来实现超材料的可编程性能，已经对4d打印的手性超材料进行了研究，但手性超材料大多是由单一材料制成的，这限制了超材料力学性能的可调域和设计自由度。本研究受生物组织胶原纤维结构的启发，开发了具有波状韧带的仿生手性超材料。将主动相(形状记忆聚乳酸，PLA-SMP)与被动相(热塑性弹性体，TPE)相结合，制备了双相(TPE@PLA-SMP)复合手性超材料。研究了几何参数、韧带梯度形式和TPE分布方式对制备的超材料力学性能的影响。当TPE分布在0°和45°时，机械超材料的变形主要发生在TPE胞内，形成j型的位移-力曲线。在热刺 激下，证明了超材料的可编程和可重构性能(包括结构和能量吸收性能)。通过形状记忆编程实现了超材料2θ=π/2的比能吸收(SEA)在0.92 kJ/kg ~ 0.38 kJ/kg之间的转换。通过填充CNC-CNT@PVA复合水凝胶(最小电阻率8.1 Ω•m)，开发了基于TPE@PLA-SMP复合超材料的柔性传感器，可在重复载荷下稳定输出电信号。开发并实现了一种运动状态监测器，用于监测佩戴者的跑步等运动，展示了其在柔性电子等领域的潜在应用前景。Experimental evaluation of the use of cruciform specimens for biaxial stability analysisM.C. Serna Moreno, S Horta Muñozdoi:10.1016/j.compositesb.2024.111764十字形试样用于双轴稳定性分析的实验评价Novel research is proposed about the suitability of cruciform specimens for estimating the stress-strain response and buckling modes of flat laminates under equibiaxial compression. The experimental challenge lies in determining whether the specimen design and test procedure can be adequate to observe geometric instability at the coupon scale with small dimensions of the tested region. Although the literature on composite buckling is extensive, the number of studies that include experimental biaxial testing of flat laminates is limited, particularly when considering strong flexural-torsional coupling. In this work the region of interest of the cruciform specimen consists of a carbon-fibre reinforced [∓45]S laminate with shape and boundary conditions close to a clamped square plate. For the first time, the buckling mode of an anisotropic laminate is observed in the central region of a cross-shaped specimen using 3D deflection surface data recorded by Digital Image Correlation. The effect of flexural-torsional coupling at the bifurcation onset is experimentally corroborated through the orientation of the buckling mode, which is analytically utilized to quantify the proportion between bending and twist moments. Non-linearities exhibited in the stress-strain evolution of the biaxially loaded region are verified to be independent of the response of the sample’s arms. Furthermore, no previous experimental investigation has shown the differences in local strain gauge measurements induced by the stress state at the ply level. Additionally, this work adapts the method for strength reduction to estimate the real critical stress of a bi-compressed laminate.对十字形试样在等双轴压缩条件下的应力应变响应和屈曲模态的适用性进行了新的研究。实验挑战在于确定试样设计和测试程序是否足以观察小尺寸测试区域的几何不稳定性。尽管关于复合材料屈曲的文献很多，但包括平面层合板双轴试验的研究数量有限，特别是在考虑强弯曲-扭转耦合的情况下。在这项工作中，十字形标本的兴趣区域由碳纤维增强的[45]S层压板组成，其形状和边界条件接近夹紧的方形板。利用数字图像相关技术记录的三维挠曲面数据，首次在十字形试样的中心区域观察到各向异性层合板的屈曲模式。通过屈曲模态的定向实验验证了分岔处弯扭耦合的影响，并利用屈曲模态的定向分析量化了弯矩与扭转矩的比例。验证了双轴加载区应力-应变演化的非线性与试样臂的响应无关。此外，没有先前的实验研究表明，在铺层水平应力状态引起的局部应变测量的差异。此外，本文采用强度折减法来估计双压缩层压板的实际临界应力。Composites Science and TechnologyMultimodal Data Fusion Enhanced Deep Learning Prediction of Crack Path Segmentation in CFRP CompositesPeng Zhang, Keke Tang, Guangxu Chen, Jiangfeng Li, Yan Lidoi:10.1016/j.compscitech.2024.110812 多模态数据融合增强CFRP复合材料裂纹路径分割深度学习预测Carbon fiber-reinforced polymer (CFRP) composites are extensively used in various engineering applications due to their superior strength-to-weight ratio and excellent mechanical properties. Predicting crack propagation paths in CFRP composites is a complex challenge due to their multiphase nature and intricate microstructural interactions. While finite element (FE) simulations possess significant capabilities for this purpose, they entail substantial computational demands and extended execution times, thereby limiting their viability in applications with high computational requirements. To address this challenge, we propose an end-to-end deep learning framework specifically for predicting crack propagation paths in two-dimensional CFRP composites. Drawing inspiration from semantic segmentation techniques, we employ EfficientNet for feature extraction, enabling the capture of hierarchical and multiscale features from both microstructure images and stress field distributions. A key aspect of our framework is the utilization of multimodal data fusion and self-attention mechanisms to effectively integrate these diverse data sources. The results demonstrate the effectiveness of our multimodal feature integration approach, producing accurate segmentations of crack path. This novel framework offers a promising approach to understanding and predicting failure mechanisms in composite materials, with significant implications for the design and maintenance of advanced composite structures.碳纤维增强聚合物(CFRP)复合材料以其优越的强度重量比和优异的力学性能被广泛应用于各种工程领域。由于CFRP复合材料的多相特性和复杂的微观结构相互作用，预测其裂纹扩展路径是一项复杂的挑战。虽然有限元(FE)模拟在这方面具有重要的能力，但它们需要大量的计算需求和延长的执行时间，从而限制了它们在具有高计算要求的应用中的可行性。为了解决这一挑战，我们提出了一个端到端深度学习框架，专门用于预测二维CFRP复合材料的裂纹扩展路径。从语义分割技术中获得灵感，我们采用高效率网络进行特征提取，从而能够从微观结构图像和应力场分布中捕获分层和多尺度特征。我们的框架的一个关键方面是利用多模态数据融合和自关注机制来有效地集成这些不同的数据源。结果证明了多模态特征集成方法的有效性，可以产生准确的裂纹路径分割。这种新框架为理解和预测复合材料的失效机制提供了一种有希望的方法，对先进复合材料结构的设计和维护具有重要意义。A Damage-related Adaptive Self-Consistent Clustering Analysis method with localized refinement capability for the damage problem of 3D woven compositesSiyang Wu, Licheng Guo, Zhixing Li, Junfeng Ding, Yue Zhuodoi:10.1016/j.compscitech.2024.110814 三维编织复合材料损伤问题的局部细化自适应聚类分析方法In this work, a Damage-related Adaptive Self-Consistent Clustering Analysis (DASCA) method is developed to achieve higher solving accuracy for 3D damage problems than Self-Consistent Clustering Analysis (SCA) method, which is applied to investigate the mesoscale damage behavior of 3D woven composites (3DWC). The developed clustering adaptivity framework is based on the characteristics of the damage problem, which consists of five fundamental stages: evaluation of the adaptivity conditions, selection criterion of potential damage clusters, online adaptive clustering analysis, update of the cluster database and adaptive rewind of the analysis process. In the second stage, the clusters with the highest potential to enter the damage state are identified and marked as adaptivity target clusters. In the solving process, the distribution of clusters can achieve problem-dependent dynamic adjustments, ensuring that clusters are concentrated on the regions of interest. Though the numerical examples of 3DWC, the DASCA solutions, using fewer clusters and less computational cost, exhibit higher prediction accuracy for macroscopic mechanical performance, first damage initiation moments and damage evolution process than the SCA solutions.本文提出了一种与损伤相关的自适应自洽聚类分析(DASCA)方法，该方法比自洽聚类分析(SCA)方法具有更高的三维损伤问题求解精度，用于研究三维编织复合材料(3DWC)的中尺度损伤行为。本文提出的聚类自适应框架主要包括五个基本阶段:自适应条件的评估、潜在损伤聚类的选择准则、在线自适应聚类分析、聚类数据库的更新和分析过程的自适应倒带。在第二阶段，识别出最有可能进入破坏状态的集群，并将其标记为自适应目标集群。在求解过程中，簇的分布可以实现与问题相关的动态调整，保证簇集中在感兴趣的区域。通过对3DWC的数值算例分析发现，与SCA相比，DASCA方法在宏观力学性能、首次损伤起爆矩和损伤演化过程的预测精度更高，且簇数更少，计算成本更低。来源：复合材料力学仿真Composites FEM
