今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 3 篇
Machine learning-based prediction of bond performance of FRP composites in concrete for marine composite structures
Chiara Machello, Mohammad Rahmati, Milad Bazli, Ali Rajabipour, Mehrdad Arashpour, Reza Hassanli, Milad Shakiba
doi:10.1016/j.compstruct.2025.119401
基于机器学习的海洋复合材料结构混凝土 FRP 复合材料粘结性能预测
The bond between Fibre Reinforced Polymer (FRP) bars and concrete degrades under seawater, compromising the structural integrity of FRP-reinforced concrete structures in marine environments. Accurate modelling of this bond behaviour is important for ensuring the reliability of such structures. The objective of this study is to develop and evaluate advanced tree-based machine learning (ML) models, including Extreme Gradient Boosting (XGBoost), M5P, and Random Forest, to accurately predict the bond strength retention and failure modes of FRP-reinforced concrete exposed to seawater. A database of 658 experimental results was collected, considering 14 influential parameters, and used to train and test the models. Despite the inherent variability in durability results, the developed models achieved satisfactory predictive accuracy. Feature contribution analysis identified concrete compressive strength as the most significant factor, followed by conditioning duration and bar surface condition. Lesser contributions came from concrete type, conditioning temperature, bar tensile strength, concrete cover, bar elastic modulus, bar diameter, and fibre type, with minimal impact from sustained load, resin type, bond length, and test type. Compared to Fib Bulletin 40 predictions, the ML models showed good accuracy within the range of available conditioning durations. However, accuracy diminished for marginal durations like 365 days due to limited data, indicating lower extrapolation capability and the need for longer-duration experimental results to enhance predictive performance.
纤维增强聚合物(FRP)钢筋和混凝土之间的粘结力在海水中会发生退化,从而影响海洋环境中 FRP 加固混凝土结构的结构完整性。这种粘结行为的精确建模对于确保此类结构的可靠性非常重要。本研究的目的是开发和评估先进的基于树的机器学习(ML)模型,包括极端梯度提升(XGBoost)、M5P 和随机森林,以准确预测暴露在海水中的 FRP 加固混凝土的粘结强度保持和失效模式。考虑到 14 个影响参数,收集了 658 个实验结果数据库,用于训练和测试模型。尽管耐久性结果存在固有的变异性,但所开发的模型仍达到了令人满意的预测精度。特征贡献分析表明,混凝土抗压强度是最重要的因素,其次是养护时间和钢筋表面状况。混凝土类型、养护温度、钢筋抗拉强度、混凝土覆盖层、钢筋弹性模量、钢筋直径和纤维类型的影响较小,而持续荷载、树脂类型、粘结长度和测试类型的影响最小。与 Fib Bulletin 40 预测相比,ML 模型在可用的调节持续时间范围内显示出良好的准确性。然而,由于数据有限,对于 365 天等边缘持续时间,准确性有所降低,这表明外推能力较低,需要更长时间的实验结果来提高预测性能。
Compressive behaviour of uni-directional carbon fibre-reinforced pultruded profiles with manufacturing-induced fuzz ball defects
O.V. Ferguson, J. Rifai, M.R. Wisnom, J.B. Jørgensen, L.P. Mikkelsen
doi:10.1016/j.compositesa.2025.109059
制造过程中产生毛球缺陷的单向碳纤维增强拉挤型材的抗压性能
In this study, we quantify the detrimental effects of manufacturing-induced defects in pultruded profiles intended for the manufacture of wind turbine spar caps. An artificial fuzz ball defect is used as a case study for embedded defects causing severe localised fibre misalignments in the profile. The impact of embedded defects on the fibre structure is characterised from micrographs. Fibre volume fraction and orientation distributions are determined using segmentation techniques and the structure tensor method, respectively. We characterise the compressive strain to failure for the pristine- and defected material using a four-point bending test. A sandwich beam design is proposed to obtain compressive strain across the profile thickness and to mitigate the risk of load introduction failure when testing thick carbon fibre-reinforced pultruded profiles. The artificial fuzz ball defects are positioned near the surface of the profile; however, parts of the defect are submerged, effectively splitting the material into thin and thick sections with through-thickness fibre misalignments up to 15°. Furthermore, the embedded defect pushes surrounding fibres aside, resulting in a 20% increase in local fibre volume fractions. All pristine beams fail due to load introduction challenges, while beams with embedded artificial fuzz ball defects fail in the gauge area, where failure is associated with fibre splitting and kink band failure. A 71% reduction in the compressive strain to failure at the surface of the beam is reported between the pristine- and defected material. Thus, a significant impact of the artificial fuzz ball defect in carbon fibre-reinforced pultruded profiles is evident.
在这项研究中,我们量化了用于制造风力涡轮机撑杆帽的拉挤型材中由制造引起的缺陷的有害影响。我们以人造毛刺球缺陷为例,研究了嵌入式缺陷对型材造成的严重局部纤维错位。嵌入缺陷对纤维结构的影响可通过显微照片来描述。使用分割技术和结构张量法分别确定了纤维的体积分数和取向分布。我们使用四点弯曲试验表征了棱柱材料和缺陷材料的压缩破坏应变。我们提出了一种夹心梁设计,以获得整个型材厚度的压缩应变,并在测试厚碳纤维增强拉挤型材时降低载荷引入失效的风险。人工绒毛球缺陷位于型材表面附近,但部分缺陷被淹没,从而有效地将材料分割成薄层和厚层,通厚纤维错位高达 15°。此外,嵌入的缺陷将周围的纤维挤到一边,导致局部纤维体积分数增加 20%。所有原始横梁都因荷载引入难题而失效,而嵌入人造绒毛球缺陷的横梁则在轨距区域失效,失效与纤维分裂和扭结带失效有关。据报告,棱柱材料和缺陷材料的梁表面压缩应变到失效时减少了 71%。由此可见,人工绒毛球缺陷对碳纤维增强拉挤型材的重大影响。
Enhanced Impregnation Quality, Interfacial Bonding, and Mechanical Performance of Cementitious Mineral-Impregnated Carbon Fiber Reinforcements through Tailored Fiber Sizing
Jitong Zhao, Phan van Tai, Ali Bashiri Rezaie, Borong Fan, Marco Liebscher, Viktor Mechtcherine
doi:10.1016/j.compositesb.2025.112707
通过定制纤维尺寸提高水泥基矿物浸渍碳纤维加固材料的浸渍质量、界面粘接和机械性能
The rising demand for sustainable and high-performance materials in construction has driven the advancement of mineral-impregnated carbon fiber composites, offering an innovative alternative to traditional fiber-reinforced polymer systems. This study evaluates the role of fiber sizing agents—thermoplastic, epoxy, and vinyl ester—on the interfacial properties, impregnation efficiency, and mechanical performance of cement based mineral-impregnated carbon fibers. Using an automated pultrusion process, carbon rovings were impregnated with a cementitious matrix and analyzed through multiscale characterization techniques, including wettability assessments, interfacial shear strength measurements, morphological analysis, and comprehensive mechanical testing. Vinyl ester-sized fibers exhibited superior wettability with water and cementitious materials, along with enhanced impregnation efficiency, resulting in a 62% improvement in flexural strength and a 14% increase in tensile strength compared to unsized fibers. In contrast, unsized fibers demonstrated limited wettability, higher porosity, and weak interfacial adhesion, leading to lower mechanical performance and greater variability. Thermoplastic- and epoxy-sized fibers produced intermediate results, highlighting the importance of optimized sizing formulations. Statistical modeling using Weibull analysis confirmed the enhanced reliability and consistency of mineral-impregnated, differently sized carbon fibers. This work underscores the pivotal role of fiber sizing in improving the performance and scalability of mineral-impregnated carbon fibers, establishing a foundation for the development of sustainable, high-performance materials for modern construction applications.
建筑业对可持续高性能材料的需求不断增长,推动了矿物浸渍碳纤维复合材料的发展,为传统的纤维增强聚合物系统提供了一种创新的替代方案。本研究评估了纤维上浆剂(热塑性塑料、环氧树脂和乙烯基酯)对水泥基矿物浸渍碳纤维的界面特性、浸渍效率和机械性能的影响。利用自动拉挤工艺,碳纤维粗纱被浸渍在水泥基质中,并通过多尺度表征技术进行分析,包括润湿性评估、界面剪切强度测量、形态分析和综合机械测试。乙烯基酯大小的纤维在水和水泥基材料中表现出优异的润湿性,同时提高了浸渍效率,与无尺寸纤维相比,抗弯强度提高了 62%,抗拉强度提高了 14%。相比之下,未定型纤维的润湿性有限,孔隙率较高,界面附着力较弱,因此机械性能较低,变异性较大。热塑性纤维和环氧树脂纤维的结果介于两者之间,突出了优化施胶配方的重要性。使用 Weibull 分析法建立的统计模型证实,不同尺寸的矿物浸渍碳纤维具有更高的可靠性和一致性。这项工作强调了纤维施胶在提高矿物浸渍碳纤维的性能和可扩展性方面的关键作用,为现代建筑应用领域开发可持续的高性能材料奠定了基础。
Exploring the Potential of Aramid Nanofibers in Advancing Green-Engineered Cementitious Composites
Huayang Sun, Yan Wan, Zhichao Xu, Yanlin Huo, Minjie Jia, Yingzi Yang
doi:10.1016/j.compositesb.2025.112724
探索芳纶纳米纤维在推进绿色工程水泥基复合材料中的潜力
This study developed an environmentally friendly engineered cementitious composite (ECC) reinforced with aramid nanofibers (ANFs) derived from recycled aramid fibers. ANFs were incorporated into ECC containing high-volume fly ash to improve their strength and ductility. Results showed that adding 0.05 wt. % ANFs increased the compressive strength, tensile strength, and tensile strain of ECC by 46.71%, 46.23%, and 51.45%, respectively. The mechanisms through which ANFs enhance the mechanical properties of ECC were investigated through single-fiber pull-out tests, micromechanical analysis, and microstructural analysis. ANFs contributed to filling the pores within the matrix, reducing the matrix porosity and inhibiting crack propagation, which consequently enhanced the compressive properties of ECC. Furthermore, ANFs significantly narrowed the interfacial transition zone (ITZ) at the fiber/matrix interface, thereby improving the frictional bond strength and pull-out energy, ultimately enhancing the tensile ductility of ECC. This study demonstrates the potential of ANFs-reinforced ECC as a sustainable and high-performance material.
本研究开发了一种环境友好型工程水泥基复合材料(ECC),该复合材料使用从回收的芳纶纤维中提取的芳纶纳米纤维(ANFs)进行增强。在含有大量粉煤灰的 ECC 中加入 ANFs 可提高其强度和延展性。结果表明,添加 0.05 wt. % 的 ANFs 可使 ECC 的抗压强度、抗拉强度和拉伸应变分别提高 46.71%、46.23% 和 51.45%。通过单纤维拉出试验、微机械分析和微结构分析,研究了ANFs提高ECC机械性能的机制。ANFs有助于填充基体中的孔隙,降低基体孔隙率并抑制裂纹扩展,从而增强了ECC的抗压性能。此外,ANFs 还大大缩小了纤维/基体界面的界面过渡区 (ITZ),从而提高了摩擦结合强度和拉拔能量,最终增强了 ECC 的拉伸延展性。这项研究证明了 ANFs 增强 ECC 作为一种可持续高性能材料的潜力。
Residual burst pressure prediction of COPVs after long-term seawater immersion subjected to internal pressure
Yifan Li, Huiming Ding, Wenzhu Peng, Zhengli Hua, Jinyang Zheng
doi:10.1016/j.compositesb.2025.112725
COPV 长期浸泡在海水中并承受内压后的残余爆破压力预测
Composite overwrapped pressure vessels (COPVs) play a vital role in the development of lightweight energy equipment. Once deployed in seawater environments, their load-bearing performance inevitably deteriorates. Currently, most existing researches focus on the degradation of mechanical properties of composite laminates, while limited research has been conducted specifically on COPVs. In this paper, both experimental and numerical methods were conducted to evaluate the load-bearing performance and damage evolution process of COPVs after seawater immersion. Hydraulic burst test results indicated that the burst pressure of COPVs decreased by 10% after immersion in artificial seawater at 60°C for 200 days. As immersion time increased, the adhesion between fibers and matrix weakened, leading to fiber scattering. Additionally, the simulation results demonstrated high reliability in predicting the moisture absorption process and burst pressure. The residual burst pressure after long-term seawater immersion was predicted by the validated numerical method combined with the Arrhenius theory. The damage analysis results showed that moisture primarily reduced the burst pressure by exacerbating fiber tensile damage and reducing the initial internal pressure of matrix tensile damage. Due to the moisture gradient along the thickness of the winding layers during the moisture absorption process, the initial location of fiber and matrix damage shifted from the inner to the outer layers. Once this process reached saturation, the initial locations returned to the inner layer. This method provides a powerful tool for the design and burst pressure prediction of COPVs in marine environments.
复合材料包覆压力容器(COPV)在轻型能源设备的开发中发挥着至关重要的作用。一旦部署在海水环境中,其承载性能不可避免地会下降。目前,大多数现有研究都集中在复合材料层压板机械性能的退化方面,而专门针对 COPV 的研究还很有限。本文采用实验和数值方法评估了 COPV 在海水浸泡后的承载性能和损伤演变过程。水压爆破试验结果表明,COPV 在 60°C 人工海水中浸泡 200 天后,爆破压力降低了 10%。随着浸泡时间的延长,纤维与基体之间的粘附力减弱,导致纤维散射。此外,模拟结果表明在预测吸湿过程和爆破压力方面具有很高的可靠性。经过验证的数值方法结合阿伦尼乌斯理论预测了长期海水浸泡后的残余爆破压力。损伤分析结果表明,湿气主要通过加剧纤维拉伸损伤和降低基体拉伸损伤的初始内压来降低爆破压力。由于在吸湿过程中沿着缠绕层厚度的湿度梯度,纤维和基体损伤的初始位置从内层转移到了外层。一旦这一过程达到饱和,初始位置就会回到内层。这种方法为海洋环境中 COPV 的设计和爆破压力预测提供了强有力的工具。