摘要
不同时间影响下玻璃纤维增强复合材料(GFRP)的热老化效应亟待研究。本文采用声发射(AE)与数字图像相关技术(DIC)相结合的互补无损检测技术,分别对热老化0、4、8、16 d后三点弯曲试样的损伤过程进行实时监测,并进一步分析预制缺陷对热老化后复合材料的纤维与基体界面间性能的影响。对AE信号进行K-means聚类分析同时通过DIC进行全局应变场测量,表征了预制缺陷和热老化时间对GFRP力学行为和变形损伤机理的影响。结果表明:声发射信号可以对各类损伤进行分类,通过分析脱粘信号发现,在层合板内部交联时,脱粘信号减少且分布在失效载荷后;随着热老化进展至水分挥发阶段,脱粘信号增多并均匀分布在断裂前期与后期。对于预制纤维断裂的层合板,交联现象会使层合板加载过程中纤维断裂信号数量减少且幅度降低,最大应变值减小,有效地提升了层合板承载能力。声发射聚类分析和数字图像相关技术结合可以较好地描述不同热老化条件下GFRP的损伤演化过程,有助于进一步揭示缺陷和热老化时间对GFRP内部损伤机理的影响规律。
The thermal aging effect of glass fiber reinforced composites(GFRP) under the influence of different time needs to be studied urgently. In this paper, the complementary nondestructive testing technology which combines acoustic emission(AE) and digital image correlation(DIC) technologies was used to monitor the damage process of three-point bending specimens after thermal aging at 0, 4, 8 and 16 days respectively. Finally, the effect of prefabrication defects on the fiber-matrix interface properties of composites after thermal aging was analyzed. K-means cluster analysis was performed on the AE signals and global strain field measurements were performed by DIC to characterize the effects of prefabrication defects and thermal aging time on the mechanical behavior and deformation damage process of GFRP. Acoustic emission signals can classify various types of damage, and through the analysis of debonding signals, it was found that when crosslinking inside the laminate, the debonding signal was reduced and distributed after the failure load;as the thermal aging progresses to the stage of moisture volatilization, the debonding signal increased and was evenly distributed in the pre-fracture and post-fracture stages. For prefabricated fiber fractured laminates, the crosslinking phenomenon will reduce the number and amplitude of fiber fracture signals during laminate loading, and the maximum strain value will be reduced, which will effectively improve the carrying capacity of the laminate. The combination of acoustic emission clustering analysis and digital image correlation technology can better describe the damage evolution of fiber-reinforced composites under different thermal aging conditions, which is helpful to further reveal the influence of defects and thermal aging time on internal damage mechanism.
作者
郭雪吟
周伟
马连华
刘佳
姬晓龙
Guo Xueyin;Zhou Wei;Ma Lianhua;Liu Ja;Ji Xiaolong(College of Quality and Technical Supervision,Hebei University,Baoding 071002,China;National&Local Joint Engineering Research Center of Metrology Instrument and System,Hebei University,Baoding 071002,China;Hebei Key Laboratory of Energy Metering and Safety Testing Technology,Hebei University,Baoding 071002,China)
出处
《电子测量技术》
北大核心
2022年第14期172-178,共7页
Electronic Measurement Technology
基金
国家自然科学基金(12172117)
河北大学高层次人才科研启动项目(521000981417)资助。
关键词
预制缺陷
声发射
热老化时间
K均值聚类
损伤机理
thermal ageing
acoustic emission
thermal aging time
K-means clustering
damage mechanism
