今日更新:Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 1 篇
Surface topography sensing and defect location prediction during CFRTP 3D printing process
Issei Ogawa, Gen Watanabe, Hiroshi Ikaida, Mitsuo Matsunaga, Yutaro Arai, Ryosuke Matsuzaki
doi:10.1016/j.compositesa.2025.109262
CFRTP 3D打印过程中表面形貌传感与缺陷定位预测
Molding using fused filament fabrication (FFF) 3D printing has emerged as a promising method for manufacturing continuous fiber-reinforced thermoplastic composites (CFRTP). However, internal voids may further contribute to strength degradation and the relatively low strength in the stacking direction. Therefore, this study proposes integrating CFRTP printing and sensing using a tool-changing 3D printer. We performed CFRTP layer stacking and surface shape sensing of each layer during printing using a laser displacement sensor. Additionally, we captured internal voids by subjecting the fabricated specimens to X-ray CT scanning. After appropriately processing the surface shape and X-ray CT data, a machine learning model is developed to predict images of voids from surface shape images, using X-ray CT images as ground truth labels. U-Net was employed for machine learning, and validation was conducted by varying the network depth and the number of epochs. The prediction accuracy was evaluated using the F1-score, the harmonic mean of precision and recall. By addressing some issues that arose, the maximum F1 score achieved was 0.631. This demonstrates that predicting voids from surface shape data is feasible.
使用熔丝成型(FFF) 3D打印已经成为制造连续纤维增强热塑性复合材料(CFRTP)的一种有前途的方法。然而,内部空洞可能会进一步导致强度退化,并且在堆积方向上强度相对较低。因此,本研究提出使用可更换工具的3D打印机将CFRTP打印和传感集成在一起。我们使用激光位移传感器在打印过程中进行了CFRTP层的堆叠和每层的表面形状感知。此外,我们通过对制作的标本进行x射线CT扫描来捕获内部空隙。在对表面形状和x射线CT数据进行适当处理后,开发了一种机器学习模型,以x射线CT图像作为地面真值标签,从表面形状图像中预测空洞图像。采用U-Net进行机器学习,通过改变网络深度和epoch数进行验证。采用f1分数、准确率和召回率的调和平均值对预测精度进行评价。通过解决出现的一些问题,获得的最高F1分数为0.631。这表明从表面形状数据预测空洞是可行的。
Carbon fiber reinforced SiBCN composite with broadband and tunable microwave absorption performance
Qihong Wei, Kaili Zhang, Yuefeng Yan, Changtao Shao, Dechang Jia, Xiaoxiao Huang, Yu Zhou
doi:10.1016/j.compositesa.2025.109268
具有宽带可调微波吸收性能的碳纤维增强SiBCN复合材料
Polymer-derived ceramics (PDCs) have demonstrated significant application potential in the microwave absorption field due to the remarkable high temperature stability, low density and tunable dielectric properties. However, the single PDCs microwave absorption performance is limited due to low dielectric loss ability. In this study, a novel SiBCN/carbon fibers (SiBCN/CF) composite was fabricated using PDCs and mechanical mixing processes. The conductivity, dielectric properties and microwave absorption performance of the SiBCN/CF composite could be controlled by regulating the content of CF. The impedance matching and attenuation property of SiBCN/CF have been improved due to the synergy loss of the conductive network structure of the CF, multiple phase interfaces (BN, Si3N4 and SiC) in the SiBCN ceramic and defects. The experimental results showed that the SiBCN/CF exhibits efficient microwave absorption performance with a filling content of 15 wt%. The minimum reflection loss (RLmin) value is −46.16 dB (2.5 mm), the maximum effective absorption bandwidth (EABmax) achieves 7.87 GHz (10.13–18 GHz) at 2.39 mm and the radar cross section (RCS) value is 4.18 dB·m2 at 0°. This research provides a valuable strategy for developing novel lightweight, broadband and strong microwave absorption materials.
聚合物衍生陶瓷(PDCs)由于其优异的高温稳定性、低密度和可调谐的介电特性,在微波吸收领域显示出巨大的应用潜力。然而,由于介质损耗能力较低,单个PDCs的微波吸收性能受到限制。在本研究中,采用PDCs和机械混合工艺制备了一种新型的SiBCN/CF复合材料。通过调节CF的含量,可以控制SiBCN/CF复合材料的电导率、介电性能和微波吸收性能。由于CF的导电网络结构与SiBCN陶瓷中的多相界面(BN、Si3N4和SiC)以及缺陷的协同损失,提高了SiBCN/CF的阻抗匹配和衰减性能。实验结果表明,填充量为15 wt%时,SiBCN/CF具有良好的微波吸收性能。最小反射损耗(RLmin)值为- 46.16 dB (2.5 mm),最大有效吸收带宽(EABmax)在2.39 mm处达到7.87 GHz (10.13-18 GHz), 0°处雷达截面(RCS)值为4.18 dB·m2。该研究为开发新型轻质、宽带、强微波吸收材料提供了有价值的策略。
Cryogenic damage mechanis m of CFRP laminates under bending load via in-situ fiber-optic acoustic emission and mode decomposition
Yi-fan Su, Sai-nan Wang, Lian-hua Ma, Hong Gao, Hong-shuai Lei, Wei Zhou
doi:10.1016/j.composites b.2025.112994
基于原位光纤声发射和模态分解的CFRP复合材料在弯曲载荷下的低温损伤机理研究
The mechanical performance of composite materials under cryogenic environments presents significant challenges to structural reliability. Current limitations in in-situ characterization techniques hinder the comprehensive understanding of damage evolution mechanis ms under cryogenic bending loads. To address this, flexural damage behavior of carbon fiber reinforced polymer laminates at temperatures as low as 123 K was systematically investigated using in-situ fiber-optic acoustic emission (AE) testing. A refined damage mode identification method, integrating mode decomposition an alysis and a novel deep learning algorithm, was adopted to elucidate the cryogenic damage mechanis ms. Results reveal that cryogenic environments significantly reduce the damage initiation strain threshold and compress the temporal intervals between damage modes, thereby promoting homogenization of damage development and the dissipation of mechanical energy. Although cryogenic temperatures strengthen the resin matrix and the bonding at the matrix-fiber interface, matrix embrittlement at 123 K markedly decreases the delamination resistance, serving as the key contributing factor to strength degradation. Notably, the refined damage identification methodology achieves over 99% classification accuracy in identifying four critical damage modes across different temperature conditions while effectively recovering hidden information related to fiber/matrix debonding and fiber breakage. This study advances the understanding of cryogenic damage mechanis ms in composite materials and establishes a robust framework for real-time damage assess ment in cryogenic engineering applications.
低温环境下复合材料的力学性能对结构可靠性提出了重大挑战。目前原位表征技术的局限性阻碍了对低温弯曲载荷下损伤演化机制的全面理解。为了解决这个问题,使用原位光纤声发射(AE)测试系统地研究了碳纤维增强聚合物层压板在低至123 K温度下的弯曲损伤行为。结合模态分解分析和一种新的深度学习算法,采用一种改进的损伤模式识别方法来阐明低温损伤机理。结果表明,低温环境显著降低了损伤起裂应变阈值,压缩了损伤模式间的时间间隔,从而促进了损伤发展的均匀化和机械能的耗散。虽然低温增强了树脂基体和基体-纤维界面的结合,但123 K时基体脆化明显降低了抗分层能力,是导致强度下降的关键因素。值得注意的是,改进的损伤识别方法在识别不同温度条件下的四种关键损伤模式时达到了99%以上的分类准确率,同时有效地恢复了与纤维/基体脱粘和纤维断裂相关的隐藏信息。该研究促进了对复合材料低温损伤机制的理解,并为低温工程应用中的实时损伤评估建立了一个强大的框架。