Application Research Of Weak Magnetic Technology In Detection Of Honeycomb Composites

With the rapid development of materials,honeycomb composites have developed rapidly because of their excellent performances and become one of the indispensable materials in modern society.However,human factors in the process of fabrication and curing of honeycomb composites lead to the instability of process quality,which makes the quality of honeycomb composite components random and the existence of defects inevitable.The main defects in honeycomb composites include debonding,delamination and inclusions,which conventional non-destructive testing exposes some shortcomings when dealing with,such as detecting blind spots,low detection efficiency and inability to visually display test results.Therefore,it is extremely necessary to adopt a new non-destructive testing technology.Based on the above problems,a new honeycomb composite material detection system based on weak magnetic detection has been designed in this paper.We have discussed the feasibility of weak magnetic detection technology in the detection of honeycomb composites mainly from four perspectives,including the magnetic properties of materials,the geomagnetic field,the magnetic properties of the honeycomb composite,and weak magnetic detection principle.According to the design requirements of the honeycomb composite testing system,the detection system is divided into two parts: hardware and software.The hardware includes the MIO board usage method,the fluxgate sensor,and the parameter design of the array magnetic sensor,etc.Among them,the array magnetic sensor parameter design is mainly for sensor spacing,on which five sets of spacing tests are designed to compare detection results and then select the optimal detection spacing.And the software includes data acquisition system design,data imaging system design,data processing system design,and the last one,signal processing system design,which includes signal smoothing processing,defect signal extraction,and defect signal interpolation processing.Through the Visual Studio development platform,we have designed the software operation interface and software processing interface.Finally,the software and hardware are combined to form a complete detection system.Four sets of test are performed for the honeycomb composite test piece,which include the honeycomb plate weak magnetic detection test,weak magnetic detectiontest of honeycomb composite bonding surface,air-coupled ultrasonic testing of honeycomb panel,defect-free weak magnetic detection test of honeycomb panel.We have located the defects in the test specimen with the honeycomb composite weak magnetic detection system,and also we have analyzed the difference between the test results and the actual defects via quantitative analysis.At the same time,we have studied the relationship between defect area and magnetic induction intensity.To sum up,our detection system has the advantages of simple operation,high defect detection rate and intuitionistic display of detection results,thus obviously it meets the expected design requirements in the engineering application of paper honeycomb composites and aluminum honeycomb composites.