Study On Real-time Monitoring System Of Specimen Crack Growing In Autoclave

In an autoclave simulating the high temperature water working environment of nuclear power equipment,it is crucial for studying the rational selection and safety evalu.ation of key structures materials to monitor the crack growing in fracture specimens of nuclear power structural materials.Due to the particularity of autoclave environment,Direct Current Potential Drop method(DCPD)is widely applied for real-time monitoring of specimens crack propagation in experiment.In this dissertation,the finite element numerical simulation method is used to simulate the potential field of the standard fracture specimen,the influencing factors of crack monitoring were analyzed by DCPD method.The real-time monitoring system for crack propagation of fracture specimens based on DCPD is researched and built.The main contents are as follows(1)The working principle of the crack propagation monitoring system for tensile test of fracture specimens in autoclave was analyzed.Based on the crack propagation monitoring requirements and the DCPD method,the requirements of this system were studied.According to the system requirements,the system hardware and software solutions are designed(2)Based on the monitoring principle,the sample potential drop monitoring model was established by ABACUS to find out the influence of various factors on monitoring.The influencing factors of crack propagation monitoring were studied from the cracking potential drop monitoring section and the production process.According to the results of simulation analysis,the formula of crack length and potential drop is fitted by least squares method(3)According to the system design and analysis of the influencing factors of crack potential drop monitoring,a real-time monitoring system for crack propagation is designed.A highly stable constant current source is selected,and a potential drop signal acquisition device is designed and fabricated;According to the system software function scheme,each functional module of the software is designed,including human-machine interface,communication module,and signal noise reduction,et al(4)After the system design is completed,the system is verified by function and propagation monitoring experiments;According to the experimental data,the accuracy of the noise reduction algorithm is analyzed.