Study on Precision Measurement Technique for Cableway Tube of High Tower Column

In cableway tube of cable-stayed bridge construction, the precise location and loft cableway be installation accuracy an important part of construction. How fast, accurate the cableway tube precision positioning is the key to the construction of cable-stayed bridge tower column. In this paper, the actual project as an example, Creatively put forward based on the space linear equation and the method of measuring the elevation of Resemble-leveling method, Coordinates measured coordinates with the theoretical calculation coordinates difference. Through the cableway tube naturalization adjust, coordinate difference is zero, To determine the location of the installation of cableway tube. Thereby cableway tube positioning precision and speed of construction to improve.

Analysis of Characteristic of Metal Vapor Plume during High-Power Disc Laser Welding

Metal vapor plume which induced during high power disc laser welding contains lots of information that related to the welding quality. Stainless steel 304 was taken as the experiment object for the high power disc laser welding experiment. A high-speed camera was used to capture the ultraviolet band and visible light band metal vapor plume images in the laser welding process. Image processing techniques such as median filtering, Wiener filtering, gray level threshold and image binarization were applied to get the images that only metal vapor plume was included. The ratio of the absolute value of coordinate difference between the centroid of plume and welding point was taken as the characteristic parameter. Welding experimental results and analysis of the changing of the ratio of the absolute value of coordinate difference between the centroid of plume and welding point confirmed that the welding quality could be monitored by the metal vapor plume during high power disc laser welding.