基于涂层传感器的金属结构疲劳裂纹监测

针对飞机金属结构在服役过程中的裂纹扩展实时监测需求,提出一种现代表面技术与电位法原理相结合的疲劳裂纹监测研究方案.在结构易出现裂纹的热点部位制备了一种具有绝缘隔离层、导电传感层和封装保护层3层结构的裂纹监测涂层传感器.然后进行了疲劳裂纹监测试验,结果表明:通过分析涂层传感器电阻(电位)的变化可以实现对2A12-T4铝合金连接结构多个部位的裂纹同时进行有效监测.此外,还对表面制备涂层传感器的试样与原始试样的疲劳特性进行了对比研究.结果表明:应用现代表面技术在2A12-T4铝合金表面制备涂层传感器,对其疲劳性影响甚微.

Fatigue crack monitoring of metallic structure based on coating sensor

To allow continuous crack monitoring of aircraft metallic structures during their service, a fatigue crack monitoring method was presented based on modern surface technology and electrical potential technique. A crack monitoring coating sensor, consisting of the insulated separating layer, the conductive sensing layer and the packaging protective layer, was deposited on the hot spots of the structure. Fatigue crack monitoring experiments were carried out. Experimental results show that the information about crack can be acquired through analyzing the changes of the resistance (electrical potential) values of the surface coating sensor and the crack on different spots of aluminum alloy joint structures can be monitored availably at the same time. Moreover, the fatigue property of the specimen with surface coating sensor and that of the original specimen were studied. Contrast experiment results show that there is no obvious influence on the fatigue property of the 2A12-T4 aluminum alloy to prepare the coating sensor on its surface by modern surface technology.