Time-of-flight diffraction ultrasonics

About: Time-of-flight diffraction ultrasonics is a research topic. Over the lifetime, 544 publications have been published within this topic receiving 3189 citations.

Ultrasonic detection fast adjustment and calibration method through diffraction time difference process

Abstract: The invention discloses an ultrasonic detection fast adjustment and calibration method through the diffraction time difference process. The method comprises the following steps: adjusting a detection mode, data and the like through certain fixed steps according to detection needs, combining items which are originally dispersed in all menus and need to be adjusted together, regulating step by step according to a certain sequence, using TOFD (time of flight diffraction) for multi-channel data acquisition, turning to the connection with an instrument system, performing setting of parameters and setting of a scanner, meeting the need of calibrating sensitivity, well setting the parameters of an instrument, adjusting the sensitivity, then turning to scanning of a workpiece, further performing flaw detection on the workpiece and then saving and analyzing the data after the flaw detection, thereby enabling a person which is not clear about the items adjusted by the TOFD to be capable of completing the setting of the parameters through guidance, simplifying the steps of an operation project, being capable of fast performing operation setting, being very convenient to operate and greatly reducing cost of the whole items.

TOFD ultrasonic non-destructive testing self-positioning fixture of welded rotor

Abstract: The invention belongs to the field of testing robots and in particular relates to a TOFD ultrasonic non-destructive testing self-positioning fixture of a welded rotor. The fixture comprises an adsorption type mobile platform, a positioning system, a fixture slideway and a self-adaption fixture. The TOFD ultrasonic non-destructive testing self-positioning fixture of the welded rotor is used for clamping a TOFD ultrasonic non-destructive testing wedge block and a probe, the wedge block automatically adapts to surface angle of the welded rotor through two rotational degrees of freedom of the tail end of the fixture and spring force and is tightly pasted with the welded rotor, and axial positioning between the fixture and the welded rotor can be realized under action of the positioning system so that the welded block can accurately aim at a welded joint.

Special flexible track for TOFD (time of flight diffraction) ultrasonic testing

Abstract: The utility model provides a special flexible track for TOFD (time of flight diffraction) ultrasonic testing The special flexible track is connected with a scanning mechanism by a connecting mechanism in a rigid mode, and comprises a drive mechanism, a lock mechanism, a tensioning mechanism, a crawling trolley, a movable chain and a connecting mechanism, wherein the crawling trolley is fixed on a pipeline; a vertical rod and the crawling trolley are fixed perpendicularly; the tensioning mechanism, the lock mechanism and the drive mechanism are fixed on the vertical rod; the tensioning mechanism comprises an adjusting screw, a compression spring and an adjusting nut; the lock mechanism comprises a gear engagement mechanism and an engaged gear; the drive mechanism comprises a rocking handle, a chain gear, a turbine screw and a turbine gear The scanning with high peripheral walking precision, stable running, balanced pressure and favorable probe coupling for the TOFD scanning mechanism is realized; moreover, the mechanism is applicable to TOFD scanning requirements for pipelines with different diameters by increasing and reducing chain buckles; the special flexible track is portable in installation, is high in detection speed, and guarantees the continuity, stability, clearness and reliability of TOFD scanned images

Using of tofd technology in the development of spc “echo +”

Abstract: Since the creation of SPC «ECHO +», special attention has been paid to ultrasonic testing methods that provide visualization of defect images and measurement of their sizes. Due to its high sensitivity and high accuracy, diffraction methods in many cases make it possible to solve the problem of identifying, classifying, and determining the parameters of defects. A review of the capabilities of equipment and software developed by SPC «ECHO +» for the implementation of TOFD technology is presented.

Synthetic Aperture Focusing Technique 3D-CAD-SAFT

Abstract: Till the 80’s ultrasonic holography has been used as an analyzing technique, a procedure which has been replaced by the Synthetic Aperture Focusing Technique “SAFT.” This technique has been applied on metallic components in different power plants, mostly on pipe systems on pressure vessels or on specimen made of composite or concrete material. SAFT exists in different versions, either in 2D or 3D, for plane or arbitrarily shaped surfaces, for pulse echo or pitch- and catch arrangements. The defect sizes ranged from 100 μm in turbine shafts till fractures of meters in research pressure vessels. The paper covers the lastest results of the SAFT-reconstruction technique under Windows NT which has been guided by the experience obtained in the field. It contributes to the currently discussed question of the possible benefit using TOFD—techniques versus pulse echo techniques; the target has been a fatigue crack in a pipe segment which was investigated by different insonification angles, wave modes and probe arrangements. The results are evaluated with respect to signal-to-noise ratio improvement; problems of TOFD are demonstrated using an animation procedure which allows to walk through the weld in three orthogonal directions. A special example will be shown from a bore hole inspection of water power station valves where the reconstruction procedure follows the radial axial insonification planes. The multi-line SAFT images can be cut according to the situation of the crack position and orientation.