This application relates to an apparatus and method for detecting a microcrack using orthogonality analysis of a mode shape vector and a principal plane in a resonance point. The apparatus may include a measurement unit comprising multiple sensors and configured to measure whether a crack exists at a measurement target, and an analysis unit configured to determine whether a crack exists, on the basis of measurement values of the respective sensors. The measurement unit includes a fixing jig configured to fix the measurement target, an excitation means configured to apply a predetermined impact to the measurement target, and multiple acceleration sensors attached at predetermined locations on the measurement target. The analysis unit may further calculate frequency responses of the measurement target to the impact applied by the excitation means, and determine whether a crack exists by analyzing the number of resonance points and independence of the resonance points.

The present application provides a pipeline structural fault diagnosis apparatus and a diagnosis method. The pipeline structural fault diagnosis apparatus includes a signal generating apparatus configured to generate an acoustic wave signal by knocking a pipeline; a signal collecting apparatus configured to collect the acoustic wave signal; a signal storage apparatus configured to store the acoustic wave signal for a signal processing and analyzing apparatus to analyze and determine a fault type, a fault degree, and a fault position. The acoustic wave signal after being generated by the signal generating apparatus is collected by the signal collecting apparatus and stored in the signal storage apparatus. The signal processing and analyzing apparatus extracts the acoustic wave signal in the signal storage apparatus, and performs processing and analysis to determine the fault type, the fault degree, and the fault position of the pipeline structure.

Disclosed is a sensor for monitoring a composite structure. The sensor includes multiple sensing elements of different sizes, each configured for different respective monitoring tasks. Also disclosed are methods of fabricating the sensor, designing and manufacturing the sensor, and attaching the sensor to the composite structure.

Disclosed are non-destructive evaluation systems and method thereof for detecting delamination, overlay debonding, spalling and detecting and differentiating between sound and delaminated patches in concrete structures. The non-destructive evaluation method for detecting delamination in concrete structures includes obtaining a plurality of acoustic waves, storing the plurality of acoustic waves, calculating a short-term Fourier transform (STFT) spectrum for each of the plurality of acoustic waves, wherein each STFT spectrum comprises a plurality of window discrete Fourier transforms, and detecting the delamination based on the STFT spectrum.

Disclosed is a structure analyzing device and a structure analyzing method which can analyze a state change of a structure, which is caused before the structure is destroyed, such as a state change of degradation of the structure or the like. A structure analyzing device (10) includes a vibration detecting unit (11) which detects a vibration of a structure, and an analysis unit (12) which analyzes an output signal of the vibration detecting unit (11). The analysis unit (12) analyzes a state change of the structure by comparing a value of resonant sharpness Q, which is measured by use of the following formula (1) in a state existing when carrying out analysis, with a value of resonant sharpness Q which is measured by use of the following formula (1) in a standard state.

A process for determining the quality of a laser weld-seam, whereby a welded plate and a geometrically equivalent non-welded plate are subjected to a physical impact to generate a natural vibration frequency. The natural vibration frequency of the welded plate and the non-welded plate is then measured with an accelerometer and compared. The uniformity of the weld is then determined by the similarity between the natural vibration frequency of the welded plate and the geometrically equivalent non-welded plate.

A system for non-destructive testing of a bond condition of concrete beams reinforced by steel rods is described. The system includes a transducing transmitter, a transducing receiver, and an ultrasonic pulse generator configured to generate drive signals for the transducing transmitter and receive a plurality vibrational waves at the transducing receiver. The system further includes a computing device including a measurement circuit configured to record a transit time for each vibrational wave and divide a distance between the transducing transmitter and the transducing receiver by the transit time to determine a pulse velocity of each vibrational wave, a comparison circuit configured to identify a highest pulse velocity of the vibrational waves and compare each highest pulse velocity to a first reference pulse velocity, and a decision circuit including an artificial neural network configured to identify a compromised bond condition around a steel rod.

According to an embodiment, a structure evaluation system includes a plurality of sensors, a position locator, and an evaluator. The sensors detect an elastic wave generated from a structure. The position locator derives a source distribution of the elastic waves generated from the structure, caused by an impact on the structure. The evaluator evaluates a state of deterioration of the structure from characteristic parameters of the elastic waves in the source distribution.

A system includes: an acoustic exciter; a compliant material applied to the acoustic exciter to configure the acoustic exciter for triggering acoustic excitation of at least part of a substrate; a sensor configured to receive an acoustic response of the acoustic excitation; and circuitry configured to determine at least one characteristic of the substrate using the acoustic response.

Kits, apparatuses, and methods are provided for measuring acoustic properties of a surface. In an implementation, a kit may be provided. The kit may comprise an elongated pin; a tube having first and second ends, the tube having at least one pair of diametrically opposing holes, the at least one pair of diametrically opposing holes operable to support the elongated pin therethrough; a mass adapted to be received through the first and second ends of the tube; wherein placement of the elongated pin through a first pair of the at least one pair of diametrically opposing holes may prevent movement of the mass through the tube; and wherein removal of the elongated pin through the first pair of the at least one pair of diametrically opposing holes may allow passage of the mass through the tube.