A system, method and apparatus that includes two or more sensor nodes that obtain sensed data from a structure. A controller receives the sensed data from the sensor nodes, via a network formed by the sensor nodes and the controller. The controller controls functionality of each of the sensor nodes, controls time synchronization among the sensor nodes, detects information collected by the sensor nodes, and communicates, utilizing an M-ary time-reversal based protocol, the detected information using a planar surface of the structure as the transmission medium for elastic waves.

An ultrasonic method and system for simultaneously measuring lubrication film thickness and liner wear of sliding bearings. The method includes: installing an ultrasonic sensor on a bearing bush; sending, by a processor, signals to an ultrasonic pulser-receiver to generate voltage pulses to excite the ultrasonic sensor to generate ultrasonic pulses; collecting an echo signal of an unworn liner-air interface as a reference signal B.sub.a(f); collecting an echo signal of worn liner-lubrication film interface as to-be-measured signal B.sub.ow(f); obtaining an amplitude spectrum |B.sub.a(f)| and a phase spectrum Φ.sub.B.sub.aof B.sub.a(f), an amplitude spectrum |B.sub.ow(f)| and a phase spectrum Φ.sub.B.sub.ow(f) of B.sub.ow(f) by FFT; calculating an amplitude spectrum |R.sub.w(f)|, and a phase spectrum Φ.sub.R.sub.w(f) of a reflection coefficient; based on |R.sub.w(f)|, calculating lubrication film thickness d via a resonance model or a spring model; and based on Φ.sub.R.sub.w(f), calculating liner worn thickness via wear model under different film thicknesses.

Detection, identification, and monitoring of various composite-damage types such as impact damage, delaminations, etc. using angle-beam coupled guided waves and methods and systems that permit excitation with angle-beam techniques of certain composite-material guided-wave modes that cannot be excited in isotropic metals with angle-beam methods.

A transmission probe for transmitting guided waves propagating in the longitudinal direction of a long member and a reception probe for receiving guided waves derived from the guided waves reflected from a predetermined portion of the long member are set on the long member. The guided waves received by the reception probe include a guided wave serving as a second signal that is noise of a desired first signal. The guided wave serving as the second signal having nodes in a circumferential direction distribution of displacement in a specific direction in the circumferential surface of the long member, and the guided waves transmitted by the transmission probe are formed such that the displacement of the guided wave serving as the second signal in the specific direction becomes zero at a specific circumferential surface position of the long member. A probe setting method comprising the steps of: setting the transmission probe for transmitting the guided waves on the circumferential surface of the long member; and setting the reception probe at a position at which the displacement of the guided wave serving as the second signal in the specific direction becomes zero on the circumferential surface of the long member.

Techniques for non-invasive diagnosis and/or monitoring of corrosion in high temperature systems using specialized sensors that produce multi-mode acoustic signals in situ for accurate determination of wall loss and/or physical property changes for a vessel in contact with a high temperature, highly corrosive substance are disclosed. Sensitivity of a few microns (or about 0.1%) of wall loss, detection of changes in physical properties of vessel contents (e.g., approximately 1%), or both, at temperatures of 500° C., 600° C., or higher may be realized. Corrosion may be identified and/or monitored using time domain, frequency domain, or mixed time domain and frequency domain analysis of signal characteristics, signal delay, or both, for relatively short circumferential acoustic wave propagation (e.g., a few inches), as well as relatively long axial acoustic wave propagation (e.g., tens of feet).

Methods for measuring mechanical properties of an object or subject under examination with an ultrasound system and using unfocused ultrasound energy are provided. Shear waves that propagate in the object or subject are produced by applying unfocused ultrasound energy to the object or subject, and measurement data is acquired by applying focused or unfocused ultrasound energy to at least one location in the object or subject at which shear waves are present Mechanical properties are then calculated from the acquired measurement data.

Systems and methods to measure states of charge of a battery may include an ultrasonic sensor and a control system. For example, the control system may instruct the ultrasonic sensor to emit ultrasonic waves toward a battery, and may instruct the ultrasonic sensor to receive echoes of the emitted ultrasonic waves reflected back from the battery. In addition, the control system may process data associated with the emitted waves and received echoes, including properties associated with the waves and echoes, such as a time of flight, frequency, amplitude, wavelength, phase, duration, or others. Based on the properties of the received echoes, and by comparison with expected properties, various physical, mechanical, chemical, and/or material characteristics of the battery may be determined, based on which a state of charge and/or a state of health of the battery may further be determined.

A method for examining a sample (50) including the steps of exciting a propagating mechanical deformation (2) in the sample (50) using a fluidic oscillator (10), and determining a characteristic of the mechanical deformation (2).

Described here are systems and methods for phase velocity imaging using an imaging system, such as an ultrasound system, an optical imaging system (e.g., an optical coherence tomography system), or a magnetic resonance imaging system. In general, systems and methods for constructing phase velocity images (e.g., 2D images, 3D images) from propagating mechanical wave motion data are described. The systems and methods described in the present disclosure operate in the frequency domain and can be implemented using a single frequency or a band of selected frequencies. If there are multiple mechanical wave sources within the field-of-view, directional filtering may be performed to separate mechanical waves propagating in different directions. The reconstructions described below can be performed for each of these directionally filtered components.

Systems and methods for beam profile imaging by emitting a ray into one or more media; receiving a first signal corresponding to the ray at a first point; encoding a first matrix based at least in part on one or more of a location of the first point, a direction of the ray at the first point, and a first perturbation effect; receiving a second signal corresponding to the ray at a second point; encoding a second matrix based at least in part on one or more of a location of the second point, a direction of the ray at the second point, and a second perturbation effect; and calculating the value of the acoustic property of one or more media based at least in part on a comparison between the first matrix and the second matrix.