一种金属结构裂纹监测的薄膜传感器设计

针对金属结构服役过程中裂纹实时监测的需求,设计了一种基于电位法原理的裂纹监测薄膜传感器。首先,建立了该薄膜传感器的有限元模型并对传感器输出特性进行了仿真分析。仿真结果表明:通过分析各监测点之间的电位差变化可以判断裂纹扩展方向和长度。其次,应用离子镀技术在铝合金中心孔试件表面制备了薄膜传感器,薄膜传感器与基体表面结合良好。最后,进行了基于薄膜传感器的裂纹监测试验。实验结果表明:通过分析相邻两次监测数据的变化程度可以判断裂纹所处的扩展阶段。

Film Sensor Design for Metallic Structure Crack Monitoring

According to the real-time crack monitoring demand of metalli c structures during their service, a film sensor is presented to monitor the met al structure crack based on the electric potential method. Firstly, the correspo ndin g finite element model(FEM) of the film sensor is established, and the output c harac teristics of the sensor are analyzed by FEM. The results indicate that the exte nsion direction and the length of crack can be obtained through analyzing the el ectr ic potential differences between monitoring points. And then the film sensor is prepared on the surface of the 2A12 aluminum alloy specimen by ion plating techn ology, which can integrate with metal surface firmly. Finally, crack monitoring experiments are carried out with the film sensor. Experimental results show tha t the structural crack propagation stage can be learned through analyzing the ch ange extent of the adjacent monitoring data of the film sensor.