Development Of Real-time Monitoring System For Crack Propagation Based On DCPD Method

It is one of the important tasks to test the environmental crack growth rate of the nuclear power structural materials selection and safety evaluation in the autoclave simulating the high temperature and high pressure water environment.There are relatively few means to monitor the crack growth rate in real time due to the particularity of autoclave environment.The Direct Current Potential Drop method(DCPD)is one of the most widely used and most important methods.It is expensive that imported crack monitoring instruments based on DCPD method,in a long period.In the dissertation,the integrated and localized crack growth rate real-time monitor in autoclave environment is carried out based on DCPD method and the existing instruments in our laboratory.The primary research work are as follows:(1)Analysis of basic principles and application status based on DCPD,it is main factors that affected the accuracy of monitoring crack propagation are studied,the system of a real-time crack growth rate monitor instrument are designed,and hardware module selection,circuit design,subroutine and general programming,etc,based on experiments data improve the monitoring system experimental platform with Monitor system schematic.(2)Due to the results of theoretical analysis and finite element simulation analysis,three sets of original signal generator devices simulating crack propagation were.studied,setting a reasonable experimental parameters,analyzing and collecting the original experimental data.(3)The data of developing the system of monitoring instruments in this project compare with imported general purpose instrument,studying and formulating a reasonable interference suppression technology,optimizing the result data by digital filtering technology,the data and the result is re iable and accurate.(4)The prototype and first-generation model of the crack growth rate real-time monitor based on the inverted DCPD technology were developed and tested in the laboratory.The accuracy of the first-generation machine test can reach millivolts.The crack monitoring resolution can reach to 1mm,for self-developed simulated crack signal source samples.The research content of the dissertation provides a method and mean for real-time monitoring of crack propagation,which lays a foundation for the intelligent and highly integrated crack propagation monitoring system.