【作者】 陈建军； 章德； 毛一葳；

【Author】 Jian-jun CHEN,De ZHANG,Yi-wei MAO The Institute of Acoustics,Nanjing University,Nanjing 210093,China

【机构】 江苏省南京市南京大学声学研究所；

【摘要】 随着多层复合材料在材料工业(如碳纤维材料、玻璃纤维等)、航空工业、医疗事业及其他民用工业的大量应用,为保证材料使用的长期性与安全性,对复合材料进行无损检测成了必不可少的重要的工作。而复合材料的可靠性主要取决于黏结界面的质量,因此研究声波在复合材料中传播的特性,尤其是研究声波通过黏结界面时所产生的接触声非线性现象,可以为界面黏接状态的评估提供特殊的信息。所谓的接触声非线性就是当纵声波传播经过固体中间隙时,由于间隙的两面在声波的作用下振动,相互碰撞,产生大量的高次谐波。如果我们仔细观测复合材料的黏结界面,黏结层与固体之间存在着许多微小的裂纹,这些裂纹是黏结层固化过程中形成的,或者复合材料使用了一段时间后,黏结层中也会出现裂纹,这些裂纹直接影响到黏结状态。同时这些裂纹的存在也使得纵声波经过黏结界面时会产生接触声非线性现象。本文中定义的接触声非线性参数对界面黏结状态非常敏感,我们可用它来获得界面黏结状态信息。本文最后还介绍了一个实验,用聚焦纵波换能器扫描界面黏结状态,结果表明接触声非线性参数能清楚的用来描述黏结界面黏结状态的分布情况。更多还原

【Abstract】 Due to the massive applications of multilayered composite materials(for example carbon fiber material,glass fiber material etc.) in material industry,aviation industry,medical enterprise and other consumer industries,it becomes an important work to carry on the non-destructive evaluation to the long-term characteristic and the security of the composite materials in use.The reliability of a composite material is mainly decided by the quality of its bonded interfaces.In the bonded interface,the weak bonding region is possibly the initial spot of the entire equipment’s failure. Therefore the examination technology of the bonding state at the interface becomes the hot spot of the current research and application.Actually,in the bonded interface,micro-cracks or micro-flaws will be formed during the solidification of bonding material or after the composite material have been used for a period of time.When a longitudinal acoustic wave propagates through the interface with micro-cracks,it will drive the two surfaces of the micro-cracks to pop each other and the contact acoustic nonlinearity(CAN) phenomenon will happen.In this paper,we analysis the CAN phenomenon in the interface and propose a CAN parameter to describe the bonding state.Also an experiment is stated in the paper to scan the bonding state at the interface using the CAN parameter.The results show that the region with weak bonding strength can be easily distinguished from the scanning contour.更多还原