Abstract: A system, apparatus, and method for remotely detecting defects in a structure may proceed non-destructively. A mobile sensing platform may place sensors in a desired positioning relative to the structure. The desired position may include a non-contacting relation between the sensors and structure. The mobile sensing platform may project laser beams onto the structure and sense backscattered light via the sensors. Variations in the backscattered light may correspond to motion of the structure, such as vibrations. By calculating the frequency and amplitude of the vibrations, defects in the structure may be detected. By correcting for noise, such as that associated with acceleration of the mobile sensing platform, accuracy and precision of defect detection may be enhanced.

Abstract: A system, apparatus, and method for remotely detecting defects in a structure may proceed non-destructively. A mobile sensing platform may place sensors in a desired positioning relative to the structure. The desired position may include a non-contacting relation between the sensors and structure. The mobile sensing platform may project laser beams onto the structure and sense backscattered light via the sensors. Variations in the backscattered light may correspond to motion of the structure, such as vibrations. By calculating the frequency and amplitude of the vibrations, defects in the structure may be detected. By correcting for noise, such as that associated with acceleration of the mobile sensing platform, accuracy and precision of defect detection may be enhanced.

Abstract: A system for forming virtual beacons usable in wavefront sensing includes a first lens configured to receive light from a target and to output an image towards an input plane. The system also includes a selector positioned at the input plane. The selector includes a transparent portion that allows a portion of the image output by the first lens to pass through the selector to form a virtual beacon. The selector also includes a translucent portion to prevent another portion of the image output by the first lens from passing through the selector.

Abstract: Systems and methods for conformal imaging vibrometry capable of real-time measurements of the dynamic motions of any arbitrary two-dimensional or three-dimensional structure. The systems and methods are able to fully characterize the dynamic behavior of an object of any arbitrary geometry. The test object is illuminated with multiple laser beams whose directions conform to the local normal axis of the surface. The approach enables high-speed vibration imaging of whole-body dynamics of arbitrarily shaped structures in real-time, with no multiplexed data capture or synthesized motion reconstruction, as is currently practiced. By measuring the object's vibrations simultaneously at multiple points, the disclosed systems and methods are able to reproduce the structural behavior under operational conditions, which can then be spectrally decomposed to determine the modal, complex modal and transient nature of the true structural dynamics.

Abstract: An optical image amplifier device capable of amplifying low-intensity backscattered illumination includes an optical port having an input, an output, and a controller having an ON state and an OFF state, the controller connecting the input and the output to form an optical loop in the ON state and disconnecting the input and the output in the OFF state, and an optical relay housing the optical loop and connected to the optical port having a gain medium configured for amplifying a signal beam propagating inside the optical loop in the ON state.

Abstract: An optical image amplifier device capable of amplifying low-intensity backscattered illumination includes an optical port having an input, an output, and a controller having an ON state and an OFF state, the controller connecting the input and the output to form an optical loop in the ON state and disconnecting the input and the output in the OFF state, and an optical relay housing the optical loop and connected to the optical port having a gain medium configured for amplifying a signal beam propagating inside the optical loop in the ON state.

Abstract: A system for forming virtual beacons usable in wavefront sensing includes a first lens configured to receive light from a target and to output an image towards an input plane. The system also includes a selector positioned at the input plane. The selector includes a transparent portion that allows a portion of the image output by the first lens to pass through the selector to form a virtual beacon. The selector also includes a translucent portion to prevent another portion of the image output by the first lens from passing through the selector.

Abstract: Systems and methods for conformal imaging vibrometry capable of real-time measurements of the dynamic motions of any arbitrary two-dimensional or three-dimensional structure. The systems and methods are able to fully characterize the dynamic behavior of an object of any arbitrary geometry. The test object is illuminated with multiple laser beams whose directions conform to the local normal axis of the surface. The approach enables high-speed vibration imaging of whole-body dynamics of arbitrarily shaped structures in real-time, with no multiplexed data capture or synthesized motion reconstruction, as is currently practiced. By measuring the object's vibrations simultaneously at multiple points, the disclosed systems and methods are able to reproduce the structural behavior under operational conditions, which can then be spectrally decomposed to determine the modal, complex modal and transient nature of the true structural dynamics.

Abstract: Systems and methods for conformal imaging vibrometry capable of real-time measurements of the dynamic motions of any arbitrary two-dimensional or three-dimensional structure. The disclosed systems and methods are able to fully characterize the dynamic behavior of an object of any arbitrary geometry. The test object is illuminated with multiple laser beams whose directions conform to the local normal axis of the surface. The approach enables high-speed vibration imaging of whole-body dynamics of arbitrarily shaped structures in real-time, with no multiplexed data capture or synthesized motion reconstruction, as is currently practiced. By measuring the object's vibrations simultaneously at multiple points, the disclosed systems and methods are able to reproduce the structural behavior under operational conditions, which can then be spectrally decomposed to determine the modal, complex modal and transient nature of the true structural dynamics.

Abstract: Systems and methods for conformal imaging vibrometry capable of real-time measurements of the dynamic motions of any arbitrary two-dimensional or three-dimensional structure. The disclosed systems and methods are able to fully characterize the dynamic behavior of an object of any arbitrary geometry. The test object is illuminated with multiple laser beams whose directions conform to the local normal axis of the surface. The approach enables high-speed vibration imaging of whole-body dynamics of arbitrarily shaped structures in real-time, with no multiplexed data capture or synthesized motion reconstruction, as is currently practiced. By measuring the object's vibrations simultaneously at multiple points, the disclosed systems and methods are able to reproduce the structural behavior under operational conditions, which can then be spectrally decomposed to determine the modal, complex modal and transient nature of the true structural dynamics.

Abstract: A multi-beam heterodyne vibrometer for analyzing vibration of an object includes an optical system and a combining element. The optical system generates a plurality of object beams and a plurality of reference beams where one of the plurality of beams has a frequency that is shifted from a frequency of the other plurality of beams. The optical system focuses each of the plurality of object beams on the object and transmits the plurality of focused object beams to the object. A portion of each of the plurality of focused object beams is reflected off of a surface of the object as a modulated object beam. The optical system collects the modulated object beams. The combining element combines each of the modulated object beams with a respective one of the reference beams into a plurality of beam pairs.

Abstract: A multi-beam laser Doppler vibrometer simultaneously measures velocity, displacement, and vibration history of multiple locations on an object. A beam of coherent light is split into an object beam and a reference beam. The object beam is divided into a plurality of object beams to simultaneously illuminate multiple locations on the object under inspection. The reference beam is frequency shifted and split into a corresponding plurality of frequency-shifted reference beams. A portion of each object beam is reflected by the object as a modulated object beam. The plurality of modulated object beams are collected and respectively mixed with the plurality of frequency-shifted reference beams to provide a plurality of beam pairs. Each beam pair may be focused onto a photodetector or an optical fiber connected to a photodetector.

Abstract: A multi-beam laser Doppler vibrometer simultaneously measures velocity, displacement, and vibration history of multiple locations on an object. A beam of coherent light is split into an object beam and a reference beam. The object beam is divided into a plurality of object beams to simultaneously illuminate multiple locations on the object under inspection. The reference beam is frequency shifted and split into a corresponding plurality of frequency-shifted reference beams. A portion of each object beam is reflected by the object as a modulated object beam. The plurality of modulated object beams are collected and respectively mixed with the plurality of frequency-shifted reference beams to provide a plurality of beam pairs. Each beam pair may be focused onto a photodetector or an optical fiber connected to a photodetector.

Abstract: A system for quantifying surface characteristics detects and quantifies characteristics of a surface of an object. For example, the system may quantify changes in surface roughness without contacting the specimen and without requiring precise temporal or spatial stability. The system may also quantify the evolution or progression of a particular characteristic of a surface, such as a defect, a slipband, a crack, a microcrack, a pit, a damage feature, corrosion, a contour change, an impact crater, a change in residual stress, and so on. The system may include an energy source, a detector section, and a process section. The energy source transmits a source signal to the surface of the object. The source signal is specularly reflected and/or scattered by the surface to yield one or more received signals. The detector section receives the received signal and, in turn, provides a detector signal indicative of the received signal.

Abstract: A support and associated flexible untearable band which incorporates a plurality of energy-absorbing loops intended to destruct under the effect of an applied impact load. The energy-absorbing loops are made of an elastic elongated material and are secured on the band, and a rigid holder is provided onto which the loops are put one after another. The flexible band is a woven ribbon provided on at least one side with at least one row of woven loops made integral with the ribbon and having a width less than the width of the woven ribbon itself.

Abstract: The device comprises a flexible band, composed of two layers which are established by the band being folded back, which band is associated with an energy-absorbing member. The members are fashioned as a plurality of loops from an elastic long-sized material, which are fastened on the band between its layers. The loops of the band layers are consecutively interconnected by virtue of tricot knit in a direction from the ends of the band towards the place where it is folded back. One of the ends of the band may be connected to a stationary fixed support, while applied to the other end may be a load F directed to destruct the knit in a direction opposite to that of unknitting. The most promising practical application of the present invention lies with shock absorbers of safety belts for builders, erectors, mountaineers, as well as with automobile safety seat belts.