作者：张鹏飞, 商雅静, 周伟, 赵文政

作者单位：河北大学无损检测研究所, 河北 保定 071002

关键词：碳纤维编织复合材料;四点弯曲;声发射;数字图像相关

摘要：

为研究碳纤维编织复合材料的弯曲损伤与破坏行为，结合声发射（AE）与数字图像相关（DIC）方法互补实验技术，对复合材料在四点弯曲载荷作用下的失效过程进行监测，动态获取AE特征信号和对应的散斑图像，并根据DIC算法得到复合材料在加载过程中的全场变形和应变。结果表明：AE信号在碳纤维编织复合材料中近似呈指数衰减，与谐振式AE传感器相比，宽频带式AE传感器表现出更好的测量性能；复合材料弯曲加载前期，无明显损伤出现，AE信号较少，对应的位移场和应变场变化平稳；复合材料弯曲破坏对应较高持续时间、幅度和相对能量的AE信号。复合材料损伤演化过程的AE响应行为及对应位移场、应变场的变化反映复合材料的变形与损伤破坏过程，为碳纤维编织复合材料的无损评价、健康监测与失效分析提供借鉴。

Acoustic emission monitoring for carbon fiber braided composites under bending damage and failure condition
ZHANG Pengfei, SHANG Yajing, ZHOU Wei, ZHAO Wenzheng
Non-destructive Testing Laboratory, Hebei University, Baoding 071002, China
Abstract: In order to study the bending damage and failure behavior of carbon fiber braided composites, combined with the experimental techniques of (AE) and digital image correlation (DIC) method, the failure process of composites under four-point bending load was monitored and dynamically acquired AE characteristic signals and corresponding speckle images. According to the digital image correlation algorithm, the full field deformation and strain of the composite during the loading process are obtained. The results show that AE signal attenuates approximately exponentially in the carbon fiber braided composites, and the broadband AE sensor show better performance than the resonant AE sensor. In the early stage of bending loading, the composite material showed no obvious damage, and the AE signal was less, and the corresponding displacement field and strain field were stable. The composite material is bent to destroy AE signals corresponding to higher duration, amplitude and relative energy. The deformation and damage process of composite materials are reflected by the AE response behavior of the damage evolution process of composite materials and the corresponding changes of displacement field and strain field, which provide reference for the nondestructive evaluation, health monitoring and failure analysis of composites.
Keywords: carbon fiber braided composite;four-point bending;acoustic emission;digital image correlation
2019, 45(5):47-53  收稿日期: 2018-04-05;收到修改稿日期: 2018-05-09
基金项目: 国家自然科学基金（11502064）；河北省自然科学基金（E2016201019）
作者简介: 张鹏飞(1994-),男,河北石家庄市人,硕士研究生,专业方向为复合材料声发射检测
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