General Electric Company

Manohar Bashyam

Richard L Trantow

David Charles Copley

A method of non-destructively evaluating or validating a processed area of an object such as a metallic laser shock peened surface by determining Rayleigh wave angles at various positions on the surface. The Rayleigh wave angle is determined by: (a) directing incident beams of ultrasonic waves onto at least one point of a surface at a plurality of incident angles; (b) simultaneously measuring intensity of a combination of corresponding directly reflected and re-radiated beams at a plurality of corresponding reflected angles equal in magnitude to the incident angles with respect to a line normal to the surface; (c) generating a null angle profile of data indicating intensity versus corresponding incident angles from measured intensities in step (b); (d) determining an intensity curve by applying a polynomial curve fit to a low intensity portion of the null angle profile; and (e) determining the effective critical angle for the corresponding Rayleigh wave by determining a substantially minimum point on the curve. The polynomial curve fit may be a second order polynomial fit and the plurality of incident angles and corresponding reflected angles are predetermined and in close proximity to a predetermined critical angle.

Determination of Rayleigh wave critical angle

An apparatus for aiming an ultrasonic beam to nondestructively test an object has an ultrasonic transducer for generating the ultrasonic beam having a beam axis and impinging the ultrasonic beam upon the object. The apparatus includes a laser aiming apparatus for directing at least one laser beam having a laser sight line substantially coaxial with the ultrasonic beam axis. The laser aiming apparatus, in one embodiment of the invention, includes a cross-hair apparatus for generating a laser beam cross-hair having a center along the laser sight line. Another embodiment of the present invention provides an ultrasonic mirror apparatus for bending the ultrasonic beam and which has a mirror made of a material that is substantially transparent to the laser beam. A mounting apparatus is used for initially directing a single laser beam and the ultrasonic beam along two different co-planar axes on opposite sides of the mirror and to set the mirror to bend the ultrasonic beam and align its axis with the laser beam axis so that the laser beam and ultrasonic beam axes are substantially coaxial at the object.

Laser beam aiming apparatus for ultrasonic inspection

A light weight hand held ultrasonic scanner for ultrasonic flaw detection systems utilizes an omnidirectional rolling ball element which drive optical encoders for X-Y coordinate position location of flaws. The rolling ball element is mounted in a body for rolling contact with a surface to be inspected. An ultrasonic transducer is mounted at one end of a second hollow body attached to the first body. An ultrasound reflector is provided in the hollow body to reflect an ultrasound beam transversely out of the second body.

Manual ultrasonic scanner for complex surfaces

A transducer device for an ultrasonic flaw detection system comprises a right angle rectangular block with one longitudinal edge being shaped to accurately conform to the curvature of the surface to be inspected. An ultrasonic sound wave beam in the block is reflected 90.degree. by a rotating mirror to cut a 360.degree. arc path through the surface to be inspected.

Ultrasonic flange radii inspection transducer device

A method for locating and identifying defects in a variable geometry workpiece using first and second transceivers positioned of a preselected distance apart adjacent opposite surfaces of the workpiece and aligned to direct ultrasonic signals toward each other through the workpiece. An ultrasound signal is transmitted from each transceiver toward the workpiece. Signal reflections from each adjacent workpiece surface are detected and used to compute workpiece thickness. Signals from one transceiver are detected at the other transceiver and their intensity determined. The signal intensity is normalized in proportion to the obtained workpiece thickness to establish a signal intensity independent of workpiece thickness. In one form, at least three signal processing paths, each having a different preselected gain, provide three signals of different amplified intensities for each measurement point. The one of the signals having the greatest amplitude not exceeding an established maximum processable signal intensity is selected and the actual intensity of the signal passing through the workpiece is computed by correlating the amplitude of the selected one of the three signals with the gain of the channel from which the signal is selected. A signal intensity corresponding to the actual intensity is displayed on an intensity responsive display for each measurement point after the actual intensity is adjusted for workpiece thickness.

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Mason, OH, United States of America

Manohar Bashyam