基于近似熵谱的碳纤维复合材料层压板拉伸损伤声发射分析

采用近似熵理论分析了碳纤维环氧树脂层压板在拉伸过程中产生的三种典型声发射信号。研究 表明基体开裂、脱胶以及纤维断裂这三种信号的近似熵谱特征不同,结合经验模式分解方法解释了三种损伤破 坏机制。此外,在经验模式分解的基础上考察了三种声发射信号本征模函数的频谱分布,进一步说明了近似熵 在本质上是衡量信号发生新振动模式产生的概率以及在复合材料声发射检测与损伤识别中使用近似熵谱分析 的有效性。

Acoustic Emission Analysis for Carbon Fiber Composite Materials in Tensile Damage Based on Approximate Entropy Spectrum

Three typical acoustic emission signals for carbon fiber epoxy laminate in tensile damage are investigated by approximate entropy theory. The computed results show matrix cracking, debonding and fiber breaking own some different characteristics of approximate entropy spectrum which is construed by empirical mode decomposition (EMD) method. In addition, spectral distribution of intrinsic mode functions for the three kinds of acoustic emission signals is analyzed which further illustrate approximate entropy in essence is measuring the probability of new vibration mode in signal, and demonstrate the effectiveness of using approximate entropy spectrum analysis in acoustic emission detection for composite material.