碳纤维复合材料层合板面内压缩损伤及声发射特征分析

针对碳纤维复合材料层合板面内压缩损伤问题,基于声发射技术分析不同损伤阶段的声发射信号特征。根据加载过程中时间–载荷曲线以及试样破坏断面微观形貌,将损伤过程分为三个阶段:初始损伤阶段主要产生少量基体开裂与纤维–基体界面脱粘,裂纹迅速扩展阶段开始产生纤维剪断以及失稳变形,平稳损伤阶段主要产生失稳变形以及分层裂纹扩展。结合声发射信号的振幅、振铃计数研究损伤过程,并基于小波变换进行损伤信号的时频分析,发现不同损伤类型可通过声发射振幅及频率特征有效识别。

Analysis of Internal Compressive Damage and Acoustic Emission Characteristics of Carbon Fiber Composite Laminates

The interlaminar compression damage of carbon/expoxy composite laminates was studied based on acoustic emission technique and acoustic emission characteristics of different types of damage were analyzed. The time load curve of the loading process and the microscopic morphology of the specimen failure section were analyzed,damage evolution was divided into three stages :a small amount of matrix cracking and fiber-matrix debonding was produced in the initial damage stage;in rapid failure stage,fiber-matrix debonding and shear fracture was produced;in stable damage stage,fiber instability deformation and crack propagation of delamination was produced. The process of damage evolution combined with the acoustic emission signal amplitude,counts and time frequency relationship obtained by wavelet transform were analyzed. It was found that different damage types can be identified by the amplitude and frequency characteristics of acoustic emission.