Peng Chaoyong

Phased array ultrasonic probe simulation and designing for railway axle inspection

When the solid axle is detected by the conventional ultrasonic probes, the inspecting coverage of axle is very limited, especially for the press-fit part of axle where the signal-to-noise ratio of detection is very low, and the echoes are difficult to distinguish, which easily leads to false judgment or missing judgment. In view of this phenomenon, a kind of dedicated phased array ultrasonic probe is introduced in this paper. Based on the advantages of phased array ultrasonic technology, relative theoretical analysis and simulation comparison are conducted. Finally, this probe is proved to have superior detection ability of railway axle inspection by comparison test.

Way-side wheel crack detecting using arrayed ultrasonic probes

Wheelset is one of the vital components of the train. Normally, the wheels are regularly detected by using ultrasonic technology to check cracks, especially in wheel rim. In order to eliminate the failure risks of wheels, daily dynamic wheelset inspecting system is needed during the light maintenance period. A way-side arrayed ultrasonic technology is described in this paper to detect wheel cracks. By using a specially designed track structure, the arrayed ultrasonic probes are arranged between the double-track for wheel rim inspection. From the testing results, Φ3mm side drill hole in the wheel rim can be well detected at the running speed of 30∼40km/h. The noise is effectively suppressed by filtering algorithm, thus to improve the signal to noise ratio and the positive alarming rates. At present, the technology has been successfully used in Chinese high-speed train maintenance centers, rolling stocks and locomotive maintenance depots.

Solid axle defect detection technique based on phased array ultrasonics

The quality of train axles is especially important for the safety of railway transportation. A technique and system based on the newest Olympus phased array ultrasonic instrument, the FOCUS PX, for the detection of defects in on-train solid axles is presented in this paper. Advanced phased array ultrasonic technology, the ultrasonic transmitting and receiving principle, and the ultrasonic testing method for solid axle defect detection are explained in detail. With this technique, transverse defects in axles can be detected by coupling from the end face of solid axles. There is no need to dismount wheel-sets from the train or remove coating for ultrasonic inspection. A real inspection system based on this technique, named the LZM In-Service Automatic Ultrasonic Inspection System for Solid Axles (hereinafter referred to as “LZM system”), which has a high level of efficiency and reliability, is described in detail. Half of the axle can be covered by ultrasonic beams from each side, and ultrasonic data can be acquired in 20 seconds. The inspection results are displayed in A-scans and B-scans for correlative data analysis, and all inspection data are recorded.