针对交流电磁场检测(alternating current field measurement,ACFM)技术教学实验的需要,借助LabVIEW构建服务器和远程客户端之间一对多通信的ACFM网络实验平台,设计含服务器程序和客户端程序的TCP网络通信模块,以通信端口和IP地址为标示,服务器循环监听客户端连接请求,对通过请求的每个客户端逐个发送信号,实现ACFM检测信号的网络传输。采用真实缺陷ACFM检测实验进行实验验证,实验结果表明:该实验平台能够完成服务器端ACFM缺陷检测信号数据的网络发布以及远程客户端的实时信号接收和通信,接收信号与原信号一致,能满足实验教学要求。
This article studies the application of the alternating current field measurement （ACFM） method in defect detection for underwater structures. Numerical model of the ACFM system is built for structure surface defect detection in seawater environment. Finite element simulation is performed to investigate rules and characteristics of the electromagnetic signal distribution in the defected area. In respect of the simulation results, underwater artificial crack detection experiments are designed and conducted for the ACFM system. The experiment results show that the ACFM system can detect cracks in underwater structures and the detection accuracy is higher than 85%. This can meet the engineering requirement of underwater structure defect detection. The results in this article can be applied to establish technical foundation for the optimization and development of ACFM based underwater structure defects detection system.
