Design And Implementation Of A Multi-Channel Active One-Shot Multi-Receiver Ultrasonic Guided Wave Monitoring System For Large-scale Structures

Ultrasonic guided wave technology has been widely used in online monitoring of important equipment structures such as mechanical engineering,aerospace engineering and vehicle engineering.At present,there are fewer integrated and minimized structural health monitoring systems on the market,most of them are platforms built by independent laboratories in the laboratory,and most of them are working in Pitch-Catch mode which is inefficient and difficult to meet the needs of large-scale structural health monitoring.Therefore,based on ultrasonic guided wave technology,this paper designs and implements a multi-channel active structural health monitoring system(including hardware and software),which aims to improve the monitoring efficiency of large structures.The main work of this paper is summarized as follows:(1)From the overall design point of view,according to the basic principle of ultrasonic guided wave damage monitoring,the key technologies that need to be solved for the application of ultrasonic guided wave monitoring technology in large-scale structure are analyzed,and the hardware of active structural health monitoring system based on ultrasonic guided wave is summarized.Based on the basic requirements of software design,the basic hardware and software architecture of multi-channel multi-channel active monitoring system is proposed.(2)From the perspective of hardware integration,according to the performance requirements and overall architecture design of the active ultrasonic guided wave damage monitoring system,the PC-based PXI architecture is equipped with a signal generator board,a matrix switch card,and an oscilloscope board.The aforementioned hardware system has been selected and designed,and the hardware system integration design has been completed,which realizes the excitation and acquisition functions of the multi-received ultrasonic guided wave signal.The design of low-noise multi-channel charge amplifier is completed,and it is divided into power supply c:ircuit and signal amplification circuit.The power supply circuit steps down the input voltage and converts it into positive and negative voltage.After the voltage regulation filter meets the low noise requirement,it is the signal amplification.The circuit is powered,and the signal amplifying circuit adopts a two-stage amplification design to achieve low-noise signal amplification.(3)From the perspective of software integration,according to the principle of friendly and efficient operation of human-machine interface,the interface and function design of ultrasonic guided wave damage monitoring software system are completed,including structural modeling,sensing path setting,signal acquisition parameter setting,sweep,signal display and UI design,and implement FFT and Hilbert signal processing methods,and achieve human-computer interaction with a good interface,while operating through the touch screen.The algorithms of various damage imaging are compared and analyzed,and the damage imaging algorithm based on probability weighted distribution is integrated into the software system.(4)From the perspective of technical verification and system integration,several key technologies and prototypes proposed in this paper are verified respectively.The feasibility and stability of the structural health monitoring system based on ultrasonic guided wave technology are verified by experiments.The damage location and imaging accuracy of the system achieves a multi-receiving work mode and improves the efficiency of large-scale structural damage monitoring.