For Flaw Or Discontinuity Detection Patents (Class 73/598)
  • Patent number: 6367328
    Abstract: Ultrasonic energy in the form of guided waves is launched into the wall of a fluid-filled container. The guided wave propagates around the circumference of the container from a transmitting transducer to a receiving transducer. Part of the guide wave energy leaks into the fluid in the form of bulk waves, reflects off the inner wall on the other side and enters back to the receiving transducer trailing the direct wave. Analysis of the received waves determines the presence of corrosion pitting and MIC nodules on the container inner wall, and fluid level. In addition, it determines whether foreign objects are inside the container. The guided waves are created with wideband transducers excited at certain frequencies that depend on the material and geometry of the part being measured. The leakage energy is maximized with a shaped tone burst pulse at the specified frequency.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: April 9, 2002
    Assignee: Digital Wave Corporation
    Inventors: Michael R. Gorman, Steven M. Ziola, Wei Huang
  • Patent number: 6367330
    Abstract: The invention describes a method and system for detecting anomalies in a material. The method comprises the steps of transmitting waves through the object, receiving the waves after passage through the object, determining more than one reference characteristic, measuring more than one characteristic of the received wave, comparing a first reference characteristic with a first characteristic of the received wave to create a first factor, comparing a second reference characteristic with a second characteristic of the received wave to create a second factor, combining the first factor with the second factor to create a defect index, and identifying a location of one or more anomalies in the object using the defect index. The step of determining the reference characteristics may comprise transmitting another wave of known characteristics through a material free of anomalies to produce a standard wave, and measuring one or more characteristics of the standard wave.
    Type: Grant
    Filed: August 17, 2000
    Date of Patent: April 9, 2002
    Assignee: Perceptron, Inc.
    Inventor: Mark E. Schafer
  • Patent number: 6363787
    Abstract: An apparatus and method for measuring the thickness of a coating adhered to a substrate. An electromagnetic acoustic transducer is used to induce surface waves into the coating. The surface waves have a selected frequency and a fixed wavelength. Interpolation is used to determine the frequency of surface waves that propagate through the coating with the least attenuation. The phase velocity of the surface waves having this frequency is then calculated. The phase velocity is compared to known phase velocity/thickness tables to determine the thickness of the coating.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: April 2, 2002
    Assignee: Bechtel BWXT Idaho LLC
    Inventors: Nancy M. Carlson, John A. Johnson, David M. Tow, John B Walter
  • Patent number: 6363788
    Abstract: Ultrasonic energy in the form of guided waves (plate waves or Lamb waves) is launched into the wall of a container. The guided wave propagates around the circumference of the container from a transmitting transducer to a receiving transducer. Analysis of the received waves determines the presence of corrosion pitting and MIC nodules on the container inner wall, as well as the existence of foreign objects in intimate contact with the container wall. The guided waves are created with wideband transducers excited at certain frequencies that depend on the material and geometry of the part being measured. The guided wave ultrasonic energy is maximized with a shaped tone burst pulse at the specified frequency rather than an electrical spike commonly used to excite transducers in standard ultrasonic search units.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: April 2, 2002
    Assignee: Digital Wave Corporation
    Inventors: Michael R. Gorman, Steven M. Ziola
  • Patent number: 6357297
    Abstract: A method for easily and effectively preventing shattered-rim fracture in a railway wheel. Generally, the method comprises the steps of providing a railway wheel, measuring the maximum defect size within the rim of the railway wheel, and determining whether the maximum defect size is less than a predetermined maximum permissible defect size, the maximum permissible defect size being determined based on an analysis of the likelihood of Mode II crack propagation from the defect when the railway wheel has been subjected to the load. The disclosed invention also encompasses a method for grading railway wheels for maximum load suitability.
    Type: Grant
    Filed: June 1, 2000
    Date of Patent: March 19, 2002
    Assignee: Sumitomo Metal Industries, Inc.
    Inventors: Taizo Makino, Takashi Fujimura
  • Patent number: 6347551
    Abstract: An ultrasonic computed tomography tree or log scanner has a plurality of ultrasonic transceivers carried on a belt (102) sized to encircle a tree (100). The belt includes an apparatus for engaging is tightly around the tree (104). The transceivers are strapped around the tree, and their mutual relative distances are known. Electronic circuitry energizes the transmitters in a known sequence. The signals received at each of the receivers are also collected and analyzed. Computed tomographic techniques analyze the time of arrival of the acoustic pulse that is first to arrive at each receiver. A signal processor generates a two-dimensional image of a slice of the tree (110) at the locus of the belt.
    Type: Grant
    Filed: November 6, 2000
    Date of Patent: February 19, 2002
    Assignees: University of Alaska, Massachusetts Institute of Technology
    Inventors: Roger M. Turpening, Zhenya Zhu, Joseph R. Matarese, Carol E. Lewis
  • Patent number: 6347550
    Abstract: An ultrasonic test process and device intended for testing a preferably cylindrical specimen (2), such as railway wheel, which is capable of displacement along a support, such as a rail (10). The ultrasonic test device comprises at least one ultrasonic probe (14) disposed in the support (10) which emits acoustic waves in the direction of the specimen. The acoustic waves are reflected by defects in the specimen (2) and received again by a probe. The test device is designed to reliably and non-destructively test the volume and surface of the specimen (2) as it rolls over the support (10). In the process of the invention a number (m) of probes (14) are controlled so that the ultrasonic waves have a preferably horizontal polarization and are emitted into the specimen (2) at a predetermined angle (66) relative to the running surface (8) of the rail (10).
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: February 19, 2002
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der Angewandtzen Forschung E.V.
    Inventors: Michael Kroening, Juergen Salzburger, Friedhelm Waite
  • Publication number: 20020000125
    Abstract: An aircraft has several ultrasonic phased arrays acoustically bonded to parts of its structure to be monitored. The arrays are energized to produce an ultrasonic beam that scans the structure in two planes. A monitor receives the output from the arrays produced by reflection of energy from discontinuities within the structure. When there is a change in these outputs, the monitor signals a pilot display unit and a flight control system such that the aircraft flight envelope can be restricted to minimize damage.
    Type: Application
    Filed: April 1, 1999
    Publication date: January 3, 2002
    Inventor: GEOFFREY BEARDMORE
  • Patent number: 6332361
    Abstract: A method for evaluating bonding properties of a metallic pipe, the method comprises steps of measuring, in advance of a pipe expansion operation, at least one selected from a degree of shape discontinuity, a degree of defect at a bonding portion, and a degree of change in crystal structure, and comparing a measurement value with a predetermined threshold value to evaluate suitability of the bonding properties for applying pipe expansion.
    Type: Grant
    Filed: October 13, 1999
    Date of Patent: December 25, 2001
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Ryuzo Yamada, Hirotsugu Horio, Takao Shimizu
  • Publication number: 20010052264
    Abstract: A method for the concurrent ultrasonic inspection of partially completed welds is disclosed and which includes providing a pair of transducers which are individually positioned on the opposite sides of a partially completed weld to be inspected; moving the transducers along the length of and laterally inwardly and outwardly relative to the partially completed weld; pulsing the respective transducers to produce an ultrasonic signal which passes through or is reflected from the partially completed weld; receiving from the respective transducers ultrasonic signals which pass through or are reflected from the partially completed welds; and analyzing the ultrasonic signal which has passed through or is reflected from the partially completed weld to determine the presence of any weld defects.
    Type: Application
    Filed: December 19, 2000
    Publication date: December 20, 2001
    Applicant: Bechtel BWXT Idaho, LLC
    Inventors: John A. Johnson, Eric D. Larsen, Karen S. Miller, Herschel B. Smartt, Timothy R. McJunkin
  • Patent number: 6327910
    Abstract: Disclosed are an apparatus and a monitoring system and various methods for use in the drying of lumber that use disclosed apparatus. During drying lumber is arranged in multiple courses stacked one on top of the other with multiple wooden stickers substantially evenly spaced from each other between courses and extending across the full width of said stack. The present invention includes a special sticker for inclusion in place of one of the wooden stickers to monitor the AE from the stack and to ultrasonically excite the stack for other measurements. The special sticker in the simplest form, includes a body portion and an acoustic sensor with the body portion constructed of an acoustically conductive material that is sized similarly to a wooden sticker. Also disclosed is a monitoring system which includes a special sticker and signal processing and control electronics coupled to receive an AE signal from the special sticker for monitoring and controlling the drying cycle of the lumber.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: December 11, 2001
    Inventor: Frank C. Beall
  • Patent number: 6324901
    Abstract: A process and device are disclosed for recognizing foreign bodies in viscous or fluid masses with lumpy foodstuffs. The mass to be checked runs through a measurement section, in which, pulsed ultrasonic signals are emitted through the mass, are reflected after passing through the mass, and after passing again through the mass they are received and compared with the ultrasonic echo of the reflection surface. When the changes of the received signals exceed a predetermined threshold value, a warning or actuating signal is generated to interrupt mass advance. The parameters to be evaluated for the signal may be their amplitudes, as well as the speed of change of their amplitudes or the propagation times.
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: December 4, 2001
    Inventors: Gerd Flüh, Wolfgang Katten, Josef Krieger, Manfred Rost
  • Publication number: 20010015104
    Abstract: A flaw detection system using acoustic Doppler effect for detecting flaws in a medium wherein there is relative motion between the medium and system includes a transducer, spaced from the medium to be inspected, for introducing to and sensing from the medium an acoustic signal that propagates in the medium at a predetermined frequency; and a detector, responsive to the sensed propagating acoustic signal, for detecting in the sensed acoustic signal the Doppler shifted frequency representative of a flaw in the medium.
    Type: Application
    Filed: February 24, 1998
    Publication date: August 23, 2001
    Inventor: SHI-CHANG WOOH
  • Patent number: 6276209
    Abstract: A system and method of detecting anomalies and/or grain variations in a wooden member. At least one ultrasonic transmitter applies an ultrasound waveform into a surface of a wooden member so as to generate a multiplicity of ultrasonic waves including, e.g., longitudinal and shear ultrasonic waves. These ultrasonic waves are measured after propagation through the wooden member by at least one ultrasonic receiver disposed on the same surface of the wooden member. At least one ultrasonic receiver may also be placed opposite the ultrasonic transmitter so as to detect radial transmission of the longitudinal ultrasonic wave at a point across from the wooden member. The received ultrasonic waves are processed to determine anomalies and/or grain variations in the wooden member at positions of the wooden member between the ultrasonic transmitter and the ultrasonic receiver(s). The ultrasonic transmitters and receivers may be placed in rollers to facilitate high-speed, in-line processing of wooden members.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: August 21, 2001
    Assignees: Perceptron, Inc., The United States of America as represented by the Secretary of Agriculture
    Inventors: Mark E. Schafer, Robert J. Ross, John R. Erickson, Rodney C. DeGroot
  • Patent number: 6266994
    Abstract: Stress wave measuring apparatus includes a Hopkinson bar or pressure bar bundle system comprising an input bar bundle having input bars, and an output bar bundle having output bars 104a. A brittle test specimen is positioned in between the input and output bar bundles. Means is provided to induce a one dimensional compression force into the bar bundles. Instrumentation is introduced onto the input and output bars for measuring values of shear wave or crack propagation. The specimen may be placed under different stress conditions measured by appropriate instrumentation on the bar bundles. In one embodiment, a rod gauge is glued to a rock massive and arranged to measure wave effects generated in the rock massive. Other arrangements provide amplification of the wave effects prior to measurement by instrumentation on the gauge 500.
    Type: Grant
    Filed: September 16, 1999
    Date of Patent: July 31, 2001
    Assignee: European Atomic Energy Community
    Inventors: Carlo Albertini, Mikhail Mogilevsky
  • Patent number: 6263941
    Abstract: A cleaving tool provides pressurized gas to the edge of a substrate in combination with a sharpened edge to cleave the substrate at a selected interface. The edge of the tool is tapped against the perimeter of a substrate, such as a bonded substrate, and a burst of gas pressure is then applied at approximately the point of contact with the edge of the tool. The combination of mechanical force and gas pressure separates the substrate into two halves at a selected interface, such as a weakened layer in a donor wafer.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: July 24, 2001
    Assignee: Silicon Genesis Corporation
    Inventors: Michael A. Bryan, James K. Kai
  • Patent number: 6257064
    Abstract: An impact test method excites a bridge by an impact hammer at an impact point to create impact waves traveling through the bridge toward distal and proximal ends of the bridge where transient responses are measured in time reference to impact excitation. Time delays from an impact trigger time referenced to the reception of the transient responses over respective distances traveled by the impact wave provide wave speed indices that can be used to indicate structural change or damage of the bridge when compared to pre-damaged wave speed indices.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: July 10, 2001
    Assignee: The Aerospace Corporation
    Inventor: Ziyad H. Durón
  • Patent number: 6195624
    Abstract: A system (10) and method (42,44,46,48,52,54) for generating an index (38,132,40,134) commensurate with the degree to which a tube array degrades over a period of time due to corrosion in a particular operating environment. A data array (62,114) is created defining the number of tubes in the tube array, a plurality of time points defining time intervals during which the degradation is to be assessed, and operating conditions that induce corrosion during each time interval. The expected degradation value of the array is computed over each of a plurality of time points using a deterministic failure model (88) having at least one parameter (102,104,106) that is assumed constant at each time point. For each time point and at least one parameter, a plurality of values of the parameter (108,110) that deviate from the assumed constant value, are generated.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: February 27, 2001
    Assignee: Combustion Engineering, Inc.
    Inventors: Brian Wilder Woodman, John F. Hall
  • Patent number: 6186006
    Abstract: A method for nondestructive, three-dimensional detection of structural elements in structures, especially those made of concrete or similar materials, allows an area to be investigated to be scanned areawise using ultrasound and by recording high-frequency, travel-time-dependent data for the individual points. In an imaging method, the respective volume image of the area being investigated is determined. This method is improved in such fashion that the accuracy of the location of structures is improved. It is proposed that the area to be investigated be scanned by both ultrasound and radar and that a structural representation of the area investigated be performed both on the basis of data acquired using sound and on the basis of data acquired using radar, with these two representations being calibrated.
    Type: Grant
    Filed: January 13, 1999
    Date of Patent: February 13, 2001
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung e.V.
    Inventors: Volker Schmitz, Herbert Wiggen-Hauser, Martin Krause, Christiane Maierhofer
  • Patent number: 6178819
    Abstract: An inspection apparatus for evaluating a partially completed weld is described and which is utilized in combination with an automated movable welder which moves across a supporting surface, and wherein the inspection apparatus includes a coupling member mounted on the welder; a frame member mounted on the coupling member; an ultrasonic sensor mounted on the frame member and disposed in ultrasonic sound transmitting relation relative to the partially completed weld; and a drive assembly for adjusting the position of the ultrasonic sensor relative to the partially completed weld.
    Type: Grant
    Filed: November 19, 1998
    Date of Patent: January 30, 2001
    Assignee: Bechtel BWXT Idaho, LLC
    Inventors: Herschel B. Smartt, Eric D. Larsen, Jonn A. Johnson
  • Patent number: 6164137
    Abstract: An EMAT testing device for nondestructively testing tubes for surface defects and displaying the results has a EMAT transmitter arranged collinear with a pair of EMAT receivers. The EMAT receivers each receive a pair of oppositely propagating circumferential acoustic surface waves from the transmitter at different times and the relative amplitudes of the received waves are compared to located defects adjacent the receivers in the tube.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: December 26, 2000
    Assignee: McDermott Technology, Inc.
    Inventors: Jimmy W. Hancock, Daniel T. MacLauchlan
  • Patent number: 6158285
    Abstract: A method for inspecting welds uses a single EMAT tranducer operated in pulse-echo mode that sends and receives Rayleigh waves to detect defects in a weld between sheet plates of dissimilar thicknesses.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: December 12, 2000
    Assignee: McDermott Technology, Inc.
    Inventors: Paul J. Latimer, Daniel T. MacLauchlan
  • Patent number: 6138514
    Abstract: A tube flaw detecting method detects a flaw portion in a heat exchanger tube constituting a boiler furnace wall using two probes, enabling one to carry out appropriate inspection work with a high efficiency. A transmitter probe and a receiver probe are juxtaposed in a circumferential direction, and an ultrasonic wave is transmitted from the transmitter probe to propagate. Repeated reflections occur at a tube inner surface and tube outer surface, and the wave is reflected at a crack extending in the circumferential direction to return, propagating likewise to be received by the receiver probe so that existence of the crack is confirmed. Thus, inspection work for a crack can be done with certainty with a simple arrangement.
    Type: Grant
    Filed: June 16, 1998
    Date of Patent: October 31, 2000
    Assignees: Mitsubishi Heavy Industries, Ltd., Shin-Nippon Nondestructive Inspection Co., Kyusyugiken Co., Ltd.
    Inventors: Keiichi Iwamoto, Kiyotaka Aoki, Hironori Ishii, Shinichi Tsuji, Kinjiro Kobayashi
  • Patent number: 6125703
    Abstract: A method of detecting damage in a ferromagnetic workpiece such as a boiler tube positions a pair of EMAT coils adjacent to the workpiece at a non-zero angle with respect to one another. A spike pulse is applied to one of the EMAT coils for generating a horizontally polarized shear wave in the workpiece which is capable of being reflected by a flaw, and the amplitude of a reflected wave from any flaw is received at the other EMAT coil and analyzed and compared to a predetermined percent of an amplitude of a calibration standard flaw to establish the presence of the flaw.
    Type: Grant
    Filed: June 26, 1998
    Date of Patent: October 3, 2000
    Assignee: McDermott Technology, Inc.
    Inventors: Daniel T. Mac Lauchlan, Paul J. Latimer
  • Patent number: 6125705
    Abstract: An apparatus for the concurrent nondestructive evaluation of partially completed welds is described and which is used in combination with an automated welder and which includes an ultrasonic signal generator mounted on the welder and which generates an ultrasonic signal which is directed toward one side of the partially completed welds; an ultrasonic signal receiver mounted on the automated welder for detecting ultrasonic signals which are transmitted by the ultrasonic signal generator and which are reflected or diffracted from one side of the partially completed weld or which passes through a given region of the partially completed weld; and an analysis assembly coupled with the ultrasonic signal receiver and which processes the ultrasonic signals received by the ultrasonic signal receiver to identify welding flaws in the partially completed weld.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: October 3, 2000
    Assignee: Bechtel BWXT Idaho, LLC
    Inventor: John A. Johnson
  • Patent number: 6105430
    Abstract: An acoustic travel time tomography system enables determining of physical properties of a dam, or a like concrete mass. The system includes a plurality of acoustic sensors, positioned on the dam at a plurality of spaced sensor locations which are known relative to each other, for producing output data responsive to the detection thereby of acoustic waves generated in the dam. An impact source produces an impact at an impact location which is known relative to the sensor locations so as to generate acoustic waves in the dam for detection by the sensors. A data processing unit acquires output data from the sensors produced responsive to acoustic waves generated by the impact source and analyzes this output data, together with data related to the relative locations of the sensors and the impact source, to determine physical properties of the dam.
    Type: Grant
    Filed: July 2, 1998
    Date of Patent: August 22, 2000
    Assignee: The United States of America as represented by the Secretary of the Interior
    Inventors: William F. Kepler, Leonard J. Bond
  • Patent number: 6092418
    Abstract: Ultrasonic techniques are applied to the measurement of wooden members to identify splits in wooden members. Multiple angularly displaced measurements allow detection of splits at arbitrary angles.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: July 25, 2000
    Assignees: Perceptron, Inc., The United States of America as represented by the Secretary of Agriculture
    Inventors: Mark E. Schafer, Robert J. Ross
  • Patent number: 6085592
    Abstract: A short ring is mounted onto a back part of a housing of an ultrasonic sensor so that the short ring is coaxial with the housing. The width of the short ring along the axial direction of the housing is set such that it shields the back part of the housing including a transformer of a processor. The short ring is made up of an excellent metal conductor and is coaxial with the coils of the transformer.
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: July 11, 2000
    Assignee: Denso Corporation
    Inventor: Yasuhiro Kawashima
  • Patent number: 6038925
    Abstract: A focusing electromagnetic acoustic transducer is provided which comprises a pair of meander coils, three insulation sheets and a magnet. The meander coils are formed on both surfaces of one of the insulation sheets to be positioned such that the meander coils are coincident with each other, and they are covered with the other insulation sheets. Each of the meander coils comprises a plurality of coil segments wherein intervals between adjacent coil segments sequentially are varied from one end to the other end. The magnet is positioned above the layers consisting the meander coils and insulation sheets. The coil segments of each meander coil are straight lines in parallel with each others, sector shapes on respective circulars having the same center point, or generally circular shapes having the same center point.
    Type: Grant
    Filed: March 20, 1998
    Date of Patent: March 21, 2000
    Assignee: Ebara Corporation
    Inventors: Toshihiro Ohtani, Hirotsugu Ogi, Masahiko Hirao
  • Patent number: 6029522
    Abstract: Ultrasonic techniques are applied to the measurement of wooden members to identify localized anomalies internal to the wooden members substantially smaller than the full width of the ultrasonic beam. Multiple spatially displaced measurements allow generation of comprehensive maps of the wooden members to aid in computer cutting and grading of the wooden members.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: February 29, 2000
    Assignees: Perceptron, Inc., The United States of America as represented by the Department of Agriculture
    Inventors: Mark E. Schafer, Robert J. Ross
  • Patent number: 6023976
    Abstract: A detector for detecting detonatable devices such as land mines has a a search head with a probe having a tip for placing beneath the surface of the ground. The probe tip ultrasonically provides an indication of the presence of a metal or plastic material. A force sensor coupled to the probe time provides an indication of force at the tip as it is placed beneath the ground surface. Therefore, before too much force is applied to the tip, a user is warned and accidental detonation may be prevented.
    Type: Grant
    Filed: October 14, 1998
    Date of Patent: February 15, 2000
    Assignee: DEW Engineering and Development limited
    Inventors: Michael A. Borza, Patrick J. Gallagher
  • Patent number: 5996413
    Abstract: A method is provided for testing prestressed concrete pipe. In the method, elastic waves are serially induced at at least three different inducing locations along the surface of the conduit. The shear wave component of each induced elastic wave is detected by at least one, and preferably two, acoustic sensors disposed at fixed sensing sites along the conduit. The relationship between at least one parameter of each induced shear wave and the distance between each inducing location and the acoustic sensor(s), are correlated and compared with standard correlations to identify structural discontinuities in the conduit. In a typical example of the method, elastic waves are induced using a mechanical hammer at multiple inducing sites around a multiplicity of annuli along the length of the conduit. Each annulus is separated from adjoining annuli by 2-4 feet.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: December 7, 1999
    Assignee: The Metropolitan Water District of Southern California
    Inventors: Subramanian T. M. Iyer, Harvey O. Webster, III
  • Patent number: 5974886
    Abstract: An exemplary apparatus for determining the thicknesses of individual layers in a multilayer article comprises an ultrasonic transducer coupled to the multilayer article with a buffer rod of similar acoustic properties, a pulser-receiver-amplifier which generates ultrasonic waves to produce discernible, time resolved pulse echoes, a digitizing oscilloscope which may be used to view the received pulse echoes, and a computer for controlling data acquisition and analysis.
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: November 2, 1999
    Assignee: General Electric Company
    Inventors: James Jorgly Carroll, John Broddus Deaton, Jr., Ram Kumar Upadhyay, Robert Snee Gilmore, Robert Stanley Thayer
  • Patent number: 5969253
    Abstract: A multilayer object having multiple layers arranged in a stacking direction is evaluated for imperfections such as voids, delaminations and microcracks. First, an acoustic wave is transmitted into the object in the stacking direction via an appropriate transducer/waveguide combination. The wave propagates through the multilayer object and is received by another transducer/waveguide combination preferably located on the same surface as the transmitting combination. The received acoustic wave is correlated with the presence or absence of imperfections by, e.g., generating pulse echo signals indicative of the received acoustic wave, wherein the successive signals form distinct groups over time. The respective peak amplitudes of each group are sampled and curve fit to an exponential curve, wherein a substantial fit of approximately 80-90% indicates an absence of imperfections and a significant deviation indicates the presence of imperfections.
    Type: Grant
    Filed: June 9, 1997
    Date of Patent: October 19, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Adminstration
    Inventors: Joseph S. Heyman, Md. Nurul Abedin, Kuen J. Sun
  • Patent number: 5965818
    Abstract: This invention is a new inspection technique using ultrasonic Lamb waves to measure reduction of pipe wall thickness due to localized corrosion at pipe supports. The technique uses two transducers in a pitch-catch mode to send and receive a selected Lamb wave. The wave travels along the pipe wall in the circumferential direction. The reduction of the pipe wall thickness at the pipe support changes the time-of-flight between the two transducers. By comparing time-of-flight data measured from the pipe support area and from areas adjacent to the pipe support, one can quantify the change of time-of-flight due to the pipe corrosion wall loss at the support. A mathematical model, a sizing algorithm and a PC program have been developed to quantitatively relate in time-of-flight to the minimum remaining wall thickness. With them, one can quantify the minimum remaining pipe wall thickness at a pipe support by simply measuring the change in the time-of-flight.
    Type: Grant
    Filed: January 15, 1998
    Date of Patent: October 12, 1999
    Assignee: Shell Oil Company
    Inventor: Weicheng David Wang
  • Patent number: 5942689
    Abstract: In this invention there is disclosed a system and method for predicting web breaks in a paper machine. In particular, this invention uses a neural network to predict web break tendencies from sensor measurements taken from the paper machine. Also, an induction tree model is used to isolate the root cause of the predicted web break tendencies.
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: August 24, 1999
    Assignee: General Electric Company
    Inventors: Piero Patrone Bonissone, Yu-To Chen, Pratap Shankar Khedkar
  • Patent number: 5942688
    Abstract: A detecting device for detecting a physical quantity of an object, which includes a transmission signals generating device for generating first and second transmission signals of different frequencies, an ultrasonic wave transmission device that is excited by the first and the second transmission signal, for transmitting ultrasonic pulses corresponding to the first and the second transmission signal to an object, and a signal processing device for carrying out a signal processing process on the first and the second echo. The signal processing process is such that it detects phases of the first and second echo corresponding to the first and second transmission signal, which are received by the ultrasonic wave receiving device. An indeterminacy integer times as large as 2.pi.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: August 24, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tomonori Kimura, Shusou Wadaka, Koichiro Misu, Tsutomu Nagatsuka, Mitsuhiro Koike
  • Patent number: 5922945
    Abstract: An apparatus for analyzing a liquid product. The apparatus includes a conveyor assembly having a conveyor belt and an agitator. The conveyor belt is constructed to deliver a unit of liquid product from the agitator to an analysis position. The agitator is constructed to impart motion to a unit of liquid product. The apparatus further includes an ultrasound transmissive pad assembly having a pad defining a chamber therein. A liquid acoustical couplant is contained in the chamber. The ultrasound transmissive pad assembly further includes an ultrasonic transducer in ultrasonic contact with the liquid acoustical couplant. The pad is positioned to contact a unit of liquid product at the analysis position. The pad has an upper portion and a lower portion and is orientated such that the upper portion contacts a unit of liquid product delivered to the analysis position before the lower portion contacts the unit of liquid product delivered to the analysis position.
    Type: Grant
    Filed: April 16, 1997
    Date of Patent: July 13, 1999
    Assignee: Abbott Laboratories
    Inventors: Brian J. Allmaras, Elwood L. Stokesbury, Jianjun Wang
  • Patent number: 5895791
    Abstract: In a method for obtaining near-surface characteristics of a material, a series of single frequency ultrasonic Rayleigh waves are generated, with a generating system, in the material. The Rayleigh waves are detected with a detection system remote from the generating system. Velocities of the detected Rayleigh waves are determined at the selected frequencies. A depth profile of one or more characteristics of the material is prepared based on the determined Rayleigh wave velocities.
    Type: Grant
    Filed: January 6, 1998
    Date of Patent: April 20, 1999
    Assignee: Industrial Quality, Inc.
    Inventors: Eric A. Lindgren, Moshe Rosen, Harold Berger
  • Patent number: 5894092
    Abstract: In a method for obtaining near-surface characteristics of a material, a series of single frequency ultrasonic Rayleigh waves are generated, with a generating system, in the material. The Rayleigh waves are detected with a detection system remote from the generating system. Velocities of the detected Rayleigh waves are determined at the selected frequencies. A depth profile of one or more characteristics of the material is prepared based on the determined Rayleigh wave velocities.
    Type: Grant
    Filed: January 6, 1998
    Date of Patent: April 13, 1999
    Assignee: Industrial Quality, Inc.
    Inventors: Eric A. Lindgren, Moshe Rosen, Harold Berger
  • Patent number: 5874677
    Abstract: A device for the detection of smooth surface lesions of dental caries on a tooth crown surface, having an ultrasonic transducer for transmitting ultrasonic waves and receiving ultrasonic wave reflections produced by lesions present on the surface, and an interface operatively connected to the transducer. The interface has a contact surface forming an angle .alpha. with a longitudinal axis of the ultrasonic transducer, where .alpha. is substantially different from 90.degree.. When the contact surface is in at least partial contact with a tooth crown surface at the longitudinal axis, ultrasonic waves generated by the ultrasonic transducer are imparted by the interface onto the tooth crown surface as surface ultrasonic waves which migrate along the tooth crown surface. Any lesions present on the tooth crown surface are then identifiable as surface ultrasonic wave reflections produced thereat.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: February 23, 1999
    Assignee: Novadent Ltd.
    Inventors: Itai Bab, Osnat Feuerstein
  • Patent number: 5866820
    Abstract: A EMAT inspection system is utiliized on sheet metal prior to it being formed or rolled to identify surface defects and sub-surface defects such as pencil pipe inclusions by using ultrasonic Lamb waves with the results being displayed on a remote screen of a display and control system which also records the inspection results and controls the EMAT system.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: February 2, 1999
    Inventors: Kenneth R. Camplin, Dennis D. Lang, Darrel P. Kohlhorst, Daniel P. Geier, Gary D. Novak, Sean M. Fitzpatrick, Glenn E. McNeelege, Bradley E. Cox, Richard C. Brewer, Thomas A. Artman, Mark A. Hooker
  • Patent number: 5864065
    Abstract: A railroad wheel test apparatus for sensing and mapping the subsurface of a railroad wheel tread face has a housing assembly with a holding device, a wheel transfer arrangement, a transducer assembly, a positioning and moving table for the transducer and a control apparatus for receiving evaluation signals from the transducer and also for communicating control signals to the positioning table and wheel transfer devices as well as a drive apparatus, where the wheel is positioned in a fluid bath and while the wheel is rotated the transducer imposes an ultrasonic signal on the tread face and receives the response signal therefrom to provide a map of the tread-face subsurface structure.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: January 26, 1999
    Assignee: Amsted Industries Incorporated
    Inventors: Raymond F. Prorok, Christopher J. Kuznieski, William J. Kucera
  • Patent number: 5861548
    Abstract: A method for analyzing the internal pressure of a closed container includes inducing vibration in a surface of the container; detecting sound resulting from the vibration; deriving information representing the detecting sound; and determining whether this information corresponds to a predetermined spectral frequency condition and a predetermined spectral amplitude condition. To ensure that the test results are not affected by modulating distortion which may be present in the information, the information is tested for the presence of a modulating distortion, and if so processed to compensate for the effects of this modulating distortion, prior to being tested against the predetermined spectral conditions.
    Type: Grant
    Filed: May 1, 1998
    Date of Patent: January 19, 1999
    Assignee: Benthos, Inc.
    Inventors: Robert G. Melvin, II, Robert J. Ryan
  • Patent number: 5824908
    Abstract: A system for the non-contact inspection and characterization of an object in which wideband (40 kHz to approximately 2 MHz) air/gas coupled ultrasonic transducers are used. The system of the present invention enables a single set of transducers to be used in an inspection/defect detection arrangement to characterize materials having a wide range of through-thickness, and other resonances. For example, the through-thickness fundamental resonance of 11 mm thick plywood is 44 kHz, 723 kHz for 2 mm thick carbon fiber, and 1.47 kHz for 0.75 mm thick polystyrene, all of which are measurable in the same system. The system is used in a method to characterize a defect by being able to operate at or near the resonant frequency of the normal material and at or near the resonant frequency of the material in a defect region to improve the accuracy of detecting specific types of defects including inclusions, material thinning, delamination and pitting by monitoring changes of various attributes (e.g.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: October 20, 1998
    Assignee: Queen's University at Kingston
    Inventors: David W. Schindel, David A. Hutchins
  • Patent number: 5804728
    Abstract: A method and apparatus for detecting internal bio-deterioration in round wood used in various applications (e.g. utility poles, pier pilings, round wood beams, posts and poles in structures, and living trees). The method includes the steps of securing a pulsing transducer adjacent one point on the surface of the round wood and securing a receiving transducer substantially diametrically opposite to the pulsing transducer. The pulsing transducer transmits ultrasonic signals through the round wood, which propagate through possibly deteriorated areas within the round wood. The receiving transducer receives the propagating ultrasonic signals, and a plurality of acousto-ultrasonic parameters contained in the received ultrasonic signals are processed and analyzed. The processing step includes the step of storing the averaged signals, and processing the stored signals on a real time basis to determine the acousto-ultrasonic parameters in the time and frequency domains.
    Type: Grant
    Filed: September 7, 1994
    Date of Patent: September 8, 1998
    Assignee: The Regents of the University of California
    Inventors: Frank Carroll Beall, Richard Len Lemaster, Jacek Marek Biernacki
  • Patent number: 5777891
    Abstract: An ultrasonic real-time inspection method which is user-friendly in an interactive environment to provide ease of operation, as well as a combination of consistency, thoroughness, and speed of operation in flaw detection not achievable by other methods. The method offers significantly increased pattern recognition capability, which provides greater automation potential and reduced missed detection and false alarm rates.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: July 7, 1998
    Assignee: Dapco Industries Inc
    Inventors: Dominick Pagano, Brian Mackay, James Norris
  • Patent number: 5760308
    Abstract: A method and apparatus for detecting internal bio-deterioration in round wood used in various applications (e.g. utility poles, pier pilings, round wood beams, posts and poles in structures, and living trees). The method includes the steps of securing a pulsing transducer adjacent one point on the surface of the round wood and securing a receiving transducer substantially diametrically opposite to the pulsing transducer. The pulsing transducer transmits ultrasonic signals through the round wood, which propagate through possibly deteriorated areas within the round wood. The receiving transducer receives the propagating ultrasonic signals, and a plurality of acousto-ultrasonic parameters contained in the received ultrasonic signals are processed and analyzed. The processing step includes the step of storing the averaged signals, and processing the stored signals on a real time basis to determine the acousto-ultrasonic parameters in the time and frequency domains.
    Type: Grant
    Filed: April 18, 1997
    Date of Patent: June 2, 1998
    Assignee: The Regents of the University of California
    Inventors: Frank Carroll Beall, Richard Len Lemaster, Jacek Marek Biernacki
  • Patent number: 5760307
    Abstract: A method and apparatus of inspecting for flaws in a specular reflector, where the flaws having an expected length and the reflector is electrically conductive. The method includes directing a beam of an electromagnetic acoustic transmitting transducer along a beam axis toward the specular reflector for producing a reflected electromagnetic acoustic beam. The transmitted beam has side lobes with zero points therebetween, at least some of the side lobes being major side lobes. The reflected beam is received using an electromagnetic acoustic receiving transmitter set at an angle to the beam axis, the angle being selected to be at one of the zero points and past all of the major lobes of the transmitted beam to eliminate root and crown signals of the weld, in the reflected signal.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: June 2, 1998
    Inventors: Paul J. Latimer, Daniel T. MacLauchlan
  • Patent number: 5714688
    Abstract: A method of examining a ductile iron casting to determine a percent of nodularity present in the casting uses an electromagnetic acoustic transducer (EMAT) system to determine a time-of-flight of an ultrasonic shear wave pulse transmitted through the casting at a selected location, from which a velocity of sound in the casting can be determined. The ultrasonic shear wave pulse created and sent through the casting experiences several internal reflections within the casting, and the absolute delay time for both second, T.sub.DELAY1, and third, T.sub.DELAY2, multiple reflections are used to determine the time, T.sub.DELTA, required for the ultrasonic pulse to travel through twice the thickness, t, of the casting at said location. The velocity, V.sub.SHEAR, of the ultrasonic shear wave pulse through the casting is calculated from T.sub.DELTA and a measurement of the thickness, t, of the casting at the location being inspected.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: February 3, 1998
    Assignee: The Babcock & Wilcox Company
    Inventors: Jonathan David Buttram, Wayne Meredith Latham