三维编织复合材料拉伸微变形的测量与损伤破坏声发射监测  

Micro-deformation measurement and acoustic emission monitoring of three-dimensional braided composites under tensile loading

作　　者：张燕南 周伟[1] 商雅静 赵文政 ZHANG Yannan;ZHOU Wei;SHANG Yajing;ZHAO Wenzheng(College of Quality and Technical Supervision,Hebei University,Baoding,Hebei 071002,China)

机构地区：[1]河北大学质量技术监督学院

出　　处：《纺织学报》2019年第8期55-63,共9页Journal of Textile Research

基　　金：国家自然科学基金项目(11502064);河北省教育厅重点项目(ZD2016097)

摘　　要：为监测三维四向编织复合材料拉伸过程中的变形与损伤破坏行为,采用声发射(AE)与数字图像相关互补技术,有效获取复合材料表面局部微变形信息和内部损伤源动态演变特征。结果表明:当复合材料拉伸应变值增加到0.45%左右时,纱线交织区域开始出现明显应变集中;随应变水平进一步提高,应变集中分别向纱线横向、纵向扩展,伴随较多AE信号,出现刚度下降;在应变水平接近1.13%时,表面应变场形成以纱线为受载主体的锯齿形应变集中带;基于K-means聚类分析表明,复合材料基体开裂、纤维/基体脱黏和纤维断裂对应的AE幅度分别为40~60、55~100、40~90dB;随编织厚度增加,复合材料皮芯结构外部区域占比降低,导致材料抗拉强度下降,但AE峰值幅度和频率无明显变化。In order to monitor the deformation and damage behavior of three-dimensional four-directional braided composites under tensile loading, the acoustic emission (AE) and digital image correlation method complementary techniques were adopted, and the surface local micro-deformation information and the dynamic characteristics of internal damage sources of the composites were effectively acquired. The results show that the obvious tensile strain concentration can be observed at the interweaving area of the yarns while the tensile strain value of the composite increases up to about 0.45%. The propagation of the strain concentrations along the transverse and longitudinal braiding yarns are induced as the strain level increases gradually. At the same time, more AE signals are generated,and the stiffnesses of the composite specimens are decreased. As the strain level increases up to about 1.13%, the yarns carry the main loads, and the strain band in shape of zigzag are obtained in the surface of the composite specimens. Based on the K-means cluster analysis, AE amplitudes of the main damage modes such as matrix cracking, fiber/matrix debonding and fiber breakage are 40-60, 55-100 and 40-90 dB, respectively. With the increase of the weaving thickness, the proportion of the surface region in the skin-core structures of the composite specimen decreases, resulting in the decrease of tensile strength. The peak amplitude and frequency of AE signals have no significant change.

关 键 词：三维编织复合材料 声发射检测 数字图像相关 损伤演化 拉伸变形 

分 类 号：TB332[一般工业技术—材料科学与工程]