Experimental System Design Of Concrete Defects Ultrasonic Detection

Concrete is very important structural material in engineering construction. The quality ofconcrete is directly related to the safety and durability of building structures. Therefore, it isparticularly important to detect and control of concrete structures. Starting from the physicalbasis of ultrasonic testing, the characteristics of ultrasonic in concrete detection are analyzed,and the detection methods and data judgment methods of concrete defects ultrasonic detectionare discussed. On this basis, with the combination of electronic technology, signal processingtechnology, virtual instrument technology and computer technology, a set of concrete defectsultrasonic detection system is designed.The thesis has completed the software and hardware circuit design and commissioning ofthe concrete defects ultrasonic detection system. The hardware mainly includes ultrasonicemitting circuit, signal receiving and adjusting circuit, A/D conversion circuit, and serialcommunication, pulse triggering, FIFO, FIR filter based on FPGA. The software parts mainlydesign the upper computer software based on LabVIEW. The functions of digital filter,frequency spectrum analysis, acoustic parameters measurement, waveform display, testingdata report and storage, automatic threshold detection and manual testing are realized.Finally, the test system is checked in accordance with the relevant technical regulationsin the air, the sound velocity relative error is0.29%, meet the specification which require ofplus or minus0.5percent. And then we take a concrete block of400mm×200mm×200mm asexperimental object, ultrasonic transducers with resonant frequency of50kHz and200kHz areused to detect the concrete structure by transmission method, and achieved satisfactory results,the feasibility of this system could be verified.