Optimization of Ultrasound C-SCAN System and Wave Identification of Defects in Copper-steel Welding Joint
In this dissertation, Optimization has been made on the ultrasound C-SCAN system which developed independently. Appropriate operational parameter was set on the servo electrical machineries. Electrical machinery noise and the “Zero floats” phenomenon on motors were solved. A new water tank has been designed and installed. Designed the location-limited device to the ultrasonic detector and corrected the motor drive proportion.In view of the Disturbance made by motors during the date acquire process, Analysis has been done, characteristics of this disturbance have been summed up. The methods of hardware isolation and Filtering in Matlab studios were successfully used to improve SNR of this system.Welding joint characteristics have been analyzed. The ultrasonic testing and destructive examination were both used to definite the types of the defects in copper-steel re-melt welding joint.Technique was designed to product normal samples within defects. Some normal samples and samples within man-made defects have been made.Through a large number of inspection trails, reflection waves caused by all kinds of defects have been collected, the features of them were researched to identify the natures of defects. Six parameters were defined to help establish the mode of “defect auto- recognition”, such as position, shape, characters, maximum of defect wave, back wave, and interface wave. The mode was based on the thought of “max probability” and implemented by computers online.Operate the system. Ultrasonic C-SCAN test was carried on theΦ122mm copper-steel welding joint. The Results were provided and analyzed.Against some shorts in the system, some views were displayed to help others to go on improve the system. The time domain of different defects has been withdrawn. New thought was provided to develop the mode of “defects auto- recognition”.