As the modern railway construction continues to mature, now the laying of the continuously welded rail track has become an important part of the construction and development of the modern industry of the railway. The ...As the modern railway construction continues to mature, now the laying of the continuously welded rail track has become an important part of the construction and development of the modern industry of the railway. The study and evaluation of the stability of the continuously welded rail track will better play the values and roles of the continuously welded rail track. At the same time, through the analysis of the specific factors affecting the stability of the CWR track, especially with the combination of the data simulation, we can thus carry out the more accurate the application of the continuously welded rail track. This paper will explore the construction and application background of the continuously welded rail track, and combine the cognition of the specific factors that affect the stability of the continuously welded rail track, so as to accurately analyze and evaluate the stability of the continuously welded rail track.展开更多
Polyethylene material has some specification that makes very difficult any kind of inspection based on ultrasonic. The acoustic impedance and sound velocity in this kind of material are near to the materials commonly ...Polyethylene material has some specification that makes very difficult any kind of inspection based on ultrasonic. The acoustic impedance and sound velocity in this kind of material are near to the materials commonly used in ultrasonic wedges. Also this kind of materials are highly attenuative materials for ultrasound. To inspection of polyethylene circumferential but welds and overcome to all the problems mentioned, the especial technique of TOFD （Time of Flight Diffraction） method which employs low frequency probe and concentrate on the inspection area that longitudinal waves turn into transverse waves has been used. The purpose of inspection is determining the exact location of surface and internal welding defects. For this purpose, two separate polyethylene pipes with 10 inch in diameter, 15 mm thickness and also 25 inch diameter, 28 mm thickness, were selected. In total 40 artificial defects which involve 28 side drill holes in deferent depths and 12 surface and sub-surface notches were created. All artificially created defects were detected with very good accuracy. Unlike the conventional TOFD method which have 2 to 3 mm dead zone, by using the above method even surface notch with 0.5 mm has been detected.展开更多
文摘As the modern railway construction continues to mature, now the laying of the continuously welded rail track has become an important part of the construction and development of the modern industry of the railway. The study and evaluation of the stability of the continuously welded rail track will better play the values and roles of the continuously welded rail track. At the same time, through the analysis of the specific factors affecting the stability of the CWR track, especially with the combination of the data simulation, we can thus carry out the more accurate the application of the continuously welded rail track. This paper will explore the construction and application background of the continuously welded rail track, and combine the cognition of the specific factors that affect the stability of the continuously welded rail track, so as to accurately analyze and evaluate the stability of the continuously welded rail track.
文摘Polyethylene material has some specification that makes very difficult any kind of inspection based on ultrasonic. The acoustic impedance and sound velocity in this kind of material are near to the materials commonly used in ultrasonic wedges. Also this kind of materials are highly attenuative materials for ultrasound. To inspection of polyethylene circumferential but welds and overcome to all the problems mentioned, the especial technique of TOFD （Time of Flight Diffraction） method which employs low frequency probe and concentrate on the inspection area that longitudinal waves turn into transverse waves has been used. The purpose of inspection is determining the exact location of surface and internal welding defects. For this purpose, two separate polyethylene pipes with 10 inch in diameter, 15 mm thickness and also 25 inch diameter, 28 mm thickness, were selected. In total 40 artificial defects which involve 28 side drill holes in deferent depths and 12 surface and sub-surface notches were created. All artificially created defects were detected with very good accuracy. Unlike the conventional TOFD method which have 2 to 3 mm dead zone, by using the above method even surface notch with 0.5 mm has been detected.
