Welding Defect Ultrasonic Test And Idetification Based On LabVIEW

Virtual Instrument Technology is a kind of brand-new instrumental systematic concept.With the development of computer and software technology, virtual instrument is graduallybecoming the development direction in measurement field. With the increasing improvement ofautomatic manufacture degree and enterprises'attention on the quality of products, thetechnology of ultrasonic testing has gained the extended applications. In the existing virtualultrasonic testing system, instruments and their functions are single. The existing measuringplatform has disadvantages in several aspects such as versatile, visualization, openness and soon, and itsstructure is complicated. In order to overcome these disadvantages above mentioned,a new platform has been developed by use of LabVIEW (product of America NationalInstruments corporation), and a signal processing system of data acquisition card has beenestablished. The platform with the signal processing system can control data acquisition,analysis, processing,feature extractionand idetificationwith the help of software. Taking the adhesive strength of inner defects of circular weld for different walls ofmental cartridge as the research object, the general principles for ultrasonic testing designsuch as design theory, processing methods for various defects and feature extraction methods,were reviewed. The key technologies in testing the adhesive strength of inner defects ofcircular weld for different walls of mental cartridge were described in length using thetechnology of ultrasonic testing, laying the foundation guidance for testing on-line anddiagnosing the defects of various workpieces in industry application. The following were the major research work: III中北大学学位论文 1,Use the new ultrasonic testing method named as orthogonal scanning that is differentfrom the tranditional method. 2,Use the fast hardware extraction of defect feature being applied in high fast on-linetesting system. 3,Applied defect indetificaion technology based on D-S principle and illegibilityintegration in the welding defect qualitation analysis.By this way, the error ratio is decreasedand testing reliability id increased. 4,Discussed the application of virtual instruments technology in ultrasonic testing byexperiments. The simulations and experiments proved that the functions above can meet the need ofproject field.