基于小波分析的复合材料层间损伤声发射行为

ACOUSTIC EMISSION BEHAVIOR ON INTERLAMINAR DAMAGE OF COMPOSITE BASED ON WAVELET ANALYSIS

通过实时监测含分层复合材料加载破坏下缺陷演化的声发射信号,应用VBScript将波形数据串联成数据流进行分析,获取复合材料层间破坏的声发射响应特征。结果表明,复合材料Ⅰ型层间开裂过程中伴随有纤维损伤,而Ⅱ型只有基体开裂,从而导致Ⅰ型、Ⅱ型分层扩展过程中的声发射能量有很大差异;频谱分布图中,Ⅰ型破坏过程出现了两个波峰,两峰所对应的频率值即为树脂和纤维受载破坏的主要频率,Ⅱ型只有一个峰值。可以利用该结论为风电叶片复合材料分层破坏形式的识别提供借鉴。

Acoustic emission （AE） testing technology was used to monitor defect evolutions of wind turbine blade composite with delamination under loading in real time.In order to obtain the acoustic emission response characteristics of interlaminar failure,the waveform data-flow cascaded by VBScript was analyzed.The results showed that during the interlaminar cracking process of mode Ⅰ the fiber was damaged,but to the mode Ⅱ,only matrix was damaged,which caused great differences of acoustic emission energy between mode Ⅰ and mode Ⅱ during the delamination growth.The frequency spectrum of mode Ⅰ has two wave crests,while mode Ⅱ has only one.The frequencies corresponding to the two wave crests were the main frequencies to the damaged resin and fibers.This conclusion can provide a basis for identifying the delamination damage mode of wind turbine blade composite.