Abstract: A delay line is configured to acoustically couple a phased array transducer to a workpiece. The delay line includes a delay line bottom portion, a delay line end portion, and a delay line top portion. The delay line bottom portion has a delay line flat surface. The delay line end portion is contiguous with the delay line bottom portion and has a delay line curved surface extending upwardly from the delay line flat surface at a delay line transition point between the delay line curved surface and the delay line flat surface. The delay line top portion has an array mounting surface configured to support a phased array transducer in a manner such that ultrasonic waves emitted by the phased array transducer pass through the delay line and exit along the delay line flat surface at least up to the delay line transition point.

Abstract: The present disclosure provides for a multiple channel laser ultrasonic system using a single detection laser and a single generation laser for inspecting internal structures. An example system includes a laser generator configured to emit generation laser light, a laser detector configured to emit detection laser light, and a scanning apparatus. The scanning apparatus is configured to receive the generation laser light and the detection laser light, direct the generation laser light and the detection laser light onto a surface of a structure via a plurality of laser ultrasonic channels, and collect reflections of the detection laser light from the surface of the structure via the plurality of laser ultrasonic channels. The system also includes a controller configured to characterize an internal feature of the structure based on the reflections.

Abstract: A system for inspecting a structure includes a laser ultrasound device configured to direct laser light onto a surface of the structure that generates ultrasonic waves within the structure and to generate an array of ultrasound data representative of the ultrasonic waves. The system includes a robotic arm configured to move the laser light across the surface. The system includes a multiplex controller configured to trigger generation of the ultrasonic waves within the structure at an inspection location and to receive the array of ultrasound data for the inspection location. The system includes a computer system that includes a motion-control module configured to control movement of the laser light relative to the surface of the structure, a motion-tracking module configured determine when the laser light is at the inspection location, and an inspection module configured to process the array of ultrasound data to inspect the structure at the inspection location.

Abstract: Described herein is a system for determining structural characteristics of an object, the system including a first laser, a second laser, one or more processors, and a computer readable medium storing instructions that, when executed by the one or more processors, cause the system to perform functions. The functions include illuminating, by the first laser, a surface region of an object with an incident light pulse, thereby causing the object to exhibit vibrations; illuminating, by the second laser, the surface region with an incident light beam, thereby generating responsive light that is indicative of the vibrations; detecting the responsive light and determining a difference between a characteristic of the responsive light and a reference characteristic that corresponds to the surface region; determining a position of the surface region within a three-dimensional space; and displaying the surface region such that the difference is indicated at the position of the surface region.

Abstract: Multi-centric radius focusing is used to inspect a radiused surface of a radiused part having a varying radius without mechanically adjusting the array sensor. A plurality of focal laws are designed to electronically steer and focus ultrasound at respective focal points corresponding to centers of curvature of a simulated radiused surface having a varying radius. The mechanical probe that carries the array sensor is located to two physical places that are outside of the radiused area and have a spatial relationship that varies less than the radius of the radiused surface varies. As the probe is moved along the radiused part, the probe maintains the array sensor at a constant location relative to the radiused part. As the array sensor scans the radiused part, the array sensor is electronically adjusted to focus at the respective focal points in sequence.

Abstract: A system for inspecting a structure includes a laser ultrasound device configured to direct laser light onto a surface of the structure that generates ultrasonic waves within the structure and to generate an array of ultrasound data representative of the ultrasonic waves. The system includes a robotic arm configured to move the laser light across the surface. The system includes a multiplex controller configured to trigger generation of the ultrasonic waves within the structure at an inspection location and to receive the array of ultrasound data for the inspection location. The system includes a computer system that includes a motion-control module configured to control movement of the laser light relative to the surface of the structure, a motion-tracking module configured determine when the laser light is at the inspection location, and an inspection module configured to process the array of ultrasound data to inspect the structure at the inspection location.

Abstract: A method for testing a structure includes steps of: identifying a three-dimensional position of a surface of the structure relative to a reference frame; transmitting laser light from an output of a transmitter onto the surface of the structure to form ultrasonic waves in the structure and to detect a response to the ultrasonic waves; based on the three-dimensional position of the surface, moving the laser light over the structure along a scan path so that the output of the transmitter is located at a constant offset distance from the surface and that the laser light, transmitted from the output of the transmitter, is directed onto the surface at a constant angle of projection; and based on the response to the ultrasonic waves, determining whether an inconsistency is present in the structure.

Abstract: Methods that provide wrinkle characterization and performance prediction for wrinkled composite structures using automated structural analysis. In accordance with some embodiments, the method combines the use of B-scan ultrasound data, automated optical measurement of wrinkles and geometry of cross-sections, and finite element analysis of wrinkled composite structure to provide the ability to assess the actual significance of a detected wrinkle relative to the intended performance of the structure. The disclosed method uses an ultrasonic inspection system that has been calibrated by correlating ultrasonic B-scan data acquired from reference standards with measurements of optical cross sections (e.g., micrographs) of those reference standards.

Abstract: The present disclosure provides for characterizing internal structures via ultrasound by inducing an ultrasonic test wave in a component; developing a test signature based on measured propagation of the ultrasonic test wave through the component; characterizing an internal feature of the component based a comparison between the test signature and a baseline signature for the component; and providing an indication of the internal feature as characterized. In some aspects, the ultrasonic test wave is induced by a laser inducer and/or received by a laser interferometer. The test signature includes one or more of: frequency responses, amplitude responses, and times of flight. The test signature can be used to identify changes in a component over time, verify similarity between different components, monitor thermal processes, and verify an identify of a component.

Abstract: Multi-centric radius focusing is used to inspect a radiused surface of a radiused part having a varying radius without mechanically adjusting the array sensor. A plurality of focal laws are designed to electronically steer and focus ultrasound at respective focal points corresponding to centers of curvature of a simulated radiused surface having a varying radius. The mechanical probe that carries the array sensor is located to two physical places that are outside of the radiused area and have a spatial relationship that varies less than the radius of the radiused surface varies. As the probe is moved along the radiused part, the probe maintains the array sensor at a constant location relative to the radiused part. As the array sensor scans the radiused part, the array sensor is electronically adjusted to focus at the respective focal points in sequence.

Abstract: A method for testing a structure using laser ultrasound includes steps of: (1) directing positioning light on a surface of the structure; (2) determining a spatial location and a spatial orientation of the surface from an evaluation of the positioning light reflected back from the surface; (3) directing pump light onto the surface to generate ultrasonic waves in the structure; (4) selectively locating a probe-light focal point of probe light on the surface, based on the spatial location determined for the surface; (5) selectively angularly orienting the probe light normal to the surface, based on the spatial orientation determined for the surface; and (6) directing the probe light onto the surface to detect a response to the ultrasonic waves.

Abstract: Described herein is an apparatus, for shielding light generated by a laser during non-destructive inspection of an object. The apparatus includes a light shield at least partially enveloping the laser and defining a first opening through which light generated by the laser passes from the laser to the object. The light shield is opaque and includes at least one first biasing mechanism. The apparatus also includes at least one first light seal coupled to the light shield about the first opening of the light shield. The at least one first biasing mechanism is configured to urge resilient deformation of the at least one first light seal against the object. When the at least one first light seal is resiliently deformed against the object, light generated by the laser is constrained within a light containment space defined between the light shield, the at least one first light seal, and the object.

Abstract: Described herein is a system for determining structural characteristics of an object, the system including a first laser, a second laser, one or more processors, and a computer readable medium storing instructions that, when executed by the one or more processors, cause the system to perform functions. The functions include illuminating, by the first laser, a surface region of an object with an incident light pulse, thereby causing the object to exhibit vibrations; illuminating, by the second laser, the surface region with an incident light beam, thereby generating responsive light that is indicative of the vibrations; detecting the responsive light and determining a difference between a characteristic of the responsive light and a reference characteristic that corresponds to the surface region; determining a position of the surface region within a three-dimensional space; and displaying the surface region such that the difference is indicated at the position of the surface region.

Abstract: A method for testing a structure using laser ultrasound includes steps of: (1) directing positioning light on a surface of the structure; (2) determining a spatial location and a spatial orientation of the surface from an evaluation of the positioning light reflected back from the surface; (3) directing pump light onto the surface to generate ultrasonic waves in the structure; (4) selectively locating a probe-light focal point of probe light on the surface, based on the spatial location determined for the surface; (5) selectively angularly orienting the probe light normal to the surface, based on the spatial orientation determined for the surface; and (6) directing the probe light onto the surface to detect a response to the ultrasonic waves.

Abstract: Methods for measuring out-of-plane wrinkles in composite laminates are described. An example method includes scanning a first side of a composite laminate with an ultrasonic transducer. The method further includes locating an out-of-plane wrinkle of the composite laminate on a B-scan ultrasound image generated in response to the scanning of the first side of the composite laminate. The method further includes associating a first marker with the B-scan ultrasound image, the first marker determined based on a location of a crest of the out-of-plane wrinkle on the B-scan ultrasound image. The method further includes associating a second marker with the B-scan ultrasound image, the second marker determined based on a location of a trough focal point of the out-of-plane wrinkle on the B-scan ultrasound image. The method further includes determining an amplitude of the out-of-plane wrinkle based on a distance between the first marker and the second marker.

Abstract: A method for testing a structure includes steps of: identifying a three-dimensional position of a surface of the structure relative to a reference frame; transmitting laser light from an output of a transmitter onto the surface of the structure to form ultrasonic waves in the structure and to detect a response to the ultrasonic waves; based on the three-dimensional position of the surface, moving the laser light over the structure along a scan path so that the output of the transmitter is located at a constant offset distance from the surface and that the laser light, transmitted from the output of the transmitter, is directed onto the surface at a constant angle of projection; and based on the response to the ultrasonic waves, determining whether an inconsistency is present in the structure.

Abstract: Methods for measuring out-of-plane wrinkles in composite laminates are described. An example method includes scanning a first side of a composite laminate with an ultrasonic transducer. The method further includes locating an out-of-plane wrinkle of the composite laminate on a B-scan ultrasound image generated in response to the scanning of the first side of the composite laminate. The method further includes associating a first marker with the B-scan ultrasound image, the first marker determined based on a location of a crest of the out-of-plane wrinkle on the B-scan ultrasound image. The method further includes associating a second marker with the B-scan ultrasound image, the second marker determined based on a location of a trough focal point of the out-of-plane wrinkle on the B-scan ultrasound image. The method further includes determining an amplitude of the out-of-plane wrinkle based on a distance between the first marker and the second marker.

Abstract: Described herein is an apparatus, for shielding light generated by a laser during non-destructive inspection of an object. The apparatus includes a light shield at least partially enveloping the laser and defining a first opening through which light generated by the laser passes from the laser to the object. The light shield is opaque and includes at least one first biasing mechanism. The apparatus also includes at least one first light seal coupled to the light shield about the first opening of the light shield. The at least one first biasing mechanism is configured to urge resilient deformation of the at least one first light seal against the object. When the at least one first light seal is resiliently deformed against the object, light generated by the laser is constrained within a light containment space defined between the light shield, the at least one first light seal, and the object.

Abstract: Method and apparatus for detecting defects in a composite is provided. After a ply of material for a workpiece is positioned, thermal energy is applied to a top surface of the ply of material, and a digital thermographic camera captures images of the top surface. A computer processor determines heat characteristics of the top surface to identify regions of the top surface with different heat characteristics. Such different areas are identified as regions that include a defect. The defect regions can be repaired prior to disposing additional plies of material over previously-applied plies.

Abstract: Described herein is an apparatus, for shielding light generated by a laser during non-destructive inspection of an object. The apparatus includes a light shield at least partially enveloping the laser and defining a first opening through which light generated by the laser passes from the laser to the object. The light shield is opaque and includes at least one first biasing mechanism. The apparatus also includes at least one first light seal coupled to the light shield about the first opening of the light shield. The at least one first biasing mechanism is configured to urge resilient deformation of the at least one first light seal against the object. When the at least one first light seal is resiliently deformed against the object, light generated by the laser is constrained within a light containment space defined between the light shield, the at least one first light seal, and the object.