碳纤维复合材料拉伸损伤声发射信号MC-ApEn分析

MC-ApEn analysis of acoustic emission signals of carbon fiber composite materials during tensile damage

采用滑动移除近似熵(MC-ApEn)分析碳纤维环氧树脂复合材料拉伸损伤过程中产生的声发射信号。从信号的无序性、复杂性及动力学平衡角度描述基体开裂、纤维/基体脱胶及纤维断裂三种典型声发射信号的近似熵谱特征并给出相应解释。用MC-ApEn分析载荷、计数、声发射能量与时间的相关曲线。由不同趋势间过渡引起的近似熵突变发现,拉伸断裂过程被两结构突变时间点划分为三个不同阶段,并据其演进特点推荐复合材料拉伸失效的临界载荷。

Acoustic emission signals of carbon fiber composite materials during tensile damage was analyzed by the method of moving cut data approximate entropy （MC-ApEn ）.From the view points of disorder and complexity of AE signals and dynamics equilibrium,the characteristics of approximate entropy spectra of matrix cracking,fiber/matrix debonding and fiber breaking were described and explained.In addition,the time correlation curves between AE energy, counts and load were also investigated by MC-ApEn.Because the transition between different trends will cause the mutation of ApEn,the results show the tensile fracture process of CFPR is divided into three different stages by two structure sudden change points and according to the evolution features of stages,the critical load of tensile failure for composite materials was recommended.