Research On Ultrasonic Nondestructive Testing By Combining LabVIEW

In recent years, the nondestructive testing(NDT) has been developing rapidly in industry.The Ultrasonic Testing(UT) which is one of the NDT is widely used in the fields of mechanical manufacturing, petrochemical industry, railway transportation and other industry,because it is no damage to materials, easy to operate, highly reliable and harmless to people.However, the traditional UT system usually adopts SCM, DSP, or ARM+DSP architecture.With the improving demands of high quality materials, the traditional design of ultrasonic nondestructive testing method is hard to meet the needs of the modern detecting technology to the detect process, which are real-time, sensitivity and automation. The thesis puts forward a kind of ‘LabVIEW + IPC' system architecture which is based on the traditional UT by virtual instrument technology. This method not only can achieve the basic function of the UT but also increases efficiency and precision of the UT. The main works and originalities are as follows.Firstly, the thesis proposed a scheme that the UT is combing with the virtual instrumental technology. There are many disadvantages in NDT equipment, such as high maintenance cost,long cycle developing and single function. This system which adopts the technology of the virtual instrument not only can solve the above problems but also can be fit for different testing requirements.Secondly, based on the traditional UT device the thesis proposed a hardware system constituted with the ultrasonic sensors, industrial personal computer, ultrasonic pulser/receiver card. The system is designed with modules which are ultrasonic nondestructive testing module, data processing module, communication interface and the modules are coordination controlled by the powerful function of the virtual instrument.Thirdly, system software design is completed by LabVIEW virtual instrument development tools. It not only can control the transmitting and receiving of the ultrasonic, but also can fulfill the function of the ultrasonic data acquisition, threshold detection, distance amplitude correction, real-time waveform display and data transmission on PCs. A friendly and powerful ultrasonic testing interface is built after repeated debugging and modification.Finally, the system is tested. Through the concrete water leaching and thickness experiment, the results show that the system can fulfill the function of the defects intelligent recognition and thickness accurately measurement and reach the design goals.