An acoustic device for inspection of an object. The device includes an ultrasonic source including a snap-through buckling actuator. The device may be used for non-destructive testing of objects. The device may be carried by a platform, such as a coordinate measuring machine, to allow inspection of objects or it may be embedded within an object for life cycle monitoring purposes.

The present invention relates to a structural health monitoring system, for example a system used in the non-destructive evaluation of an aircraft structure. The present invention provides a method and apparatus for evaluating one or more anomalies within a structure using a structural health monitoring system that includes at least three transducers arranged in operative contact with the structure such that no two transducers are aligned to be parallel. A transducer excites an elastic wave that propagates through the structure, and reflections from any anomalies within the structure are collected by the three transducers. These collected signals are analyzed to identify an anomaly within the structure. Time of flight techniques are used to determine the location of the anomaly.

Systems and methods of determining a tension of an anchor embedded in a dam are described. A dynamic impulse response of the dam is empirically obtained in such that a portion of the empirical dynamic impulse response is dominated by a dynamic behavior of the anchor. Furthermore, a set of modeled impulse responses that map to a set of tension values for the anchor are obtained. Next, a closest matching modeled impulse response from the set of modeled impulse responses that is a closest match to the portion of the empirical dynamic impulse response that is dominated by the dynamic behavior of the anchor is determined. Finally, a tension value from the set of tension values is selected, which is the closest match to the portion of the dynamic impulse response dominated by the dynamic behavior of the anchor. As such, the tension value of the anchor can be determined.

An acoustic bidirectional reflectance distribution function (BRDF) measurement system utilizing metamaterials and compressive sensing for measuring scattering acoustic profiles (e.g., over large angular regions, such as hemispherical scattering/emitting into two π steradians or even spherical scattering/emitting over four π steradians). The measurement system includes one or more acoustic waveguides having a curved receiving surface and made from an acoustic metamaterial configured to encode as a sound signal a frequency and directionality of a sound input received from a sample. Each acoustic waveguide includes an acoustic sensor for detecting the encoded sound signal from the metamaterial.

Disclosed herein are acoustic spectrometers with broadband actuators and advanced system identification techniques for modeling the characteristic response of a gas. Benefits of the spectrometer devices and methods disclosed herein, which can include speed of sound measurements (or combined therewith), provide for more robust and less expensive solutions than previous technologies.

An acoustic bidirectional reflectance distribution function (BRDF) measurement system utilizing metamaterials and compressive sensing for measuring scattering acoustic profiles (e.g., over large angular regions, such as hemispherical scattering/emitting into two π steradians or even spherical scattering/emitting over four π steradians). The measurement system includes one or more acoustic waveguides having a curved receiving surface and made from an acoustic metamaterial configured to encode as a sound signal a frequency and directionality of a sound input received from a sample. Each acoustic waveguide includes an acoustic sensor for detecting the encoded sound signal from the metamaterial.

In general, according to one embodiment, a sound inspection apparatus includes: at least three microphones, a removing unit, and an estimation unit; the removing unit calculates an impulse response based on a sound pressure of a radiation sound collected via reference microphone and a first microphone, calculate an impulse response based on the sound pressure of the radiation sound collected via the reference microphone and a second microphone, and remove a component corresponding to the vibration sound from the calculated impulse response; the intensity calculation unit calculates an intensity of the radiation sound based on the impulse response from which the vibration sound is removed; the estimation unit estimates, based on the calculated intensity, a site where an abnormality in the inspection target object has occurred.

A method for quantitative analysis of a cavity at the top of a concrete-filled steel tube is disclosed. By substitution of the determined inner radius of the steel tube, the thickness of the steel tube wall and the propagation speed of ultrasonic waves in the steel tube and in the concrete, the propagation time of the ultrasonic wave between the top and the bottom of the concrete-filled steel tube enables calculation of the height of the cavity. The method can be used to quantify the cavity height at the top of the concrete-filled steel tube, with small relative errors and high accuracy.

Methods, systems, and apparatuses are provided for detecting conditions associated with a fluid conduit. An apparatus includes an insert having an internal conduit to connect with the fluid conduit and a plenum volume, and a detection device including a housing connected to the insert within the plenum volume, an acoustic sensor to receive acoustic signals, an acoustic exciter to apply acoustic signals to the housing, and a controller. The controller is electrically connected to the acoustic sensor and the acoustic exciter. The controller is configured to cause the acoustic exciter to apply an input acoustic signal to the housing, receive the acoustic signals from the housing using the acoustic sensor, analyze the received acoustic signals to determine a pipe condition of a pipe defining the fluid conduit or fluidically connected to the fluid conduit, and cause data representative of the pipe condition to be transmitted to an external device.

A method and system for inspecting a rail by guided waves, the rail being instrumented by sensors. The method comprises the steps of receiving elastic wave measurements from one or more sensors, as a train passes, releasing energy as guided waves into the rail; and of determining a function representative of the impulse response of the rail and the sensors. Developments describe how to determine the existence, position and characterisation of a defect in the rail (e.g. fracture, incipient fracture, etc.), the use of inter-correlation analyses, correlation of the coda of correlations, Passive Inverse Filter, imaging techniques. Other aspects are described for exploring rail defects: sensor position and movement, acquisition time, sampling frequency, frequency filters, amplifications, techniques for learning during successive train passes, signal injection by transducers. Software aspects are described.