2D-C/SiC拉伸损伤的声发射信号聚类分析

CLUSTER ANALYSIS OF ACOUSTIC EMISSION SIGNALS OF 2D-C/SiC UNDER TENSILE LOADING

对2D-C/SiC复合材料进行常温拉伸试验,利用声发射(AE)仪在线监测其损伤过程.应用K-均值聚类算法对AE信号进行模式识别,结合扫描电镜观察,发现2D-C/SiC复合材料拉伸过程的损伤模式包括基体开裂、界面层脱粘、层间剥离、纤维断裂以及纤维束断裂等,并得到了各种损伤模式AE信号参数的中心值.通过对不同损伤模式AE累积事件数和累积能量随时间变化的统计分析,描述了2D-C/SiC复合材料拉伸损伤演化过程.

Static tensile test of two dimensional C/SiC composite material was carried out at room temperature and the damage processes was on line monitored by an acoustic emission instrument. From the SEM observation,five damage modes were found during the tension,which are matrix cracking,interracial debonding, delamination, individual fiber breakage, and fiber bundle breakage. Acoustic Emission （AE） sig- nals were analyzed by using K-means cluster method to identify these five classes of damage modes and to determine the center value of the AE parameters of these five kinds of damage modes. Then damage evolu tion is described by analyzing the cumulative count of AE events and cumulative energy change with load ing time.