A measurement method includes: a step of acquiring, based on observation information obtained by an observation device, first observation point information including a time point when each of a plurality of parts of a moving object passes a first observation point of a structure and a physical quantity which is a response to an action of each of the plurality of parts on the first observation point; a step of acquiring, based on the observation information, second observation point information including a time point when each of the plurality of parts passes a second observation point and a physical quantity which is a response to an action of each of the plurality of parts on the second observation point; a step of calculating, based on the first observation point information, the second observation point information, a predetermined coefficient, and an approximate expression of deflection of the structure, a deflection waveform of the structure generated by each of the plurality of parts; and a step of calculating a deflection waveform of the structure generated by the moving object by adding the deflection waveform of the structure generated by each of the plurality of parts.

A measurement method includes: a step of acquiring first observation point information including a time point when each part of a moving object passes a first observation point and a physical quantity which is a response to an action; a step of acquiring second observation point information including a time point when the each part passes a second observation point and a physical quantity which is a response to an action; a step of calculating a deflection waveform of a structure generated by the each part; a step of adding the deflection waveforms to calculate a moving object deflection waveform, and calculating a path deflection waveform based on the moving object deflection waveform; a step of calculating a displacement waveform by twice integrating an acceleration of a third observation point; and a step of calculating, based on the path deflection waveform, a value of each coefficient of a polynomial approximating an integration error, and correcting the displacement waveform based on the value of each coefficient.

A structural health monitoring system is provided comprising sensors and/or sensor modules attached to, or near to, one or more parts or regions of a structure that detect and measure data regarding physical or related features or phenomena associated with the structure before, during and after a load or other event impacting or otherwise affecting the structure. The sensor modules measure and convert the detected phenomena into digital data and transmit the data to a master station for data compilation, storage and analysis. The master station is configured to produce analytic work product based on sensed phenomena which is useful for assisting inspectors in determining what action to take with respect to a structure's health after an event.

A sensor array can differentiate acceptable tensile and flexural stresses in a beam from stress patterns that indicate a fracture in the beam. At least three strain gauges, with additional pairs of strain gauges added for redundancy, can be used. The single, central strain gauge is adhered to the beam directly over, and with the sensing elements parallel to the neutral axis of the beam. The pairs of strain gauges are adhered to the beam parallel to the sensing elements of the single strain gauge on opposite sides of and equidistant from the neutral axis. The single strain gauge senses the tensile stress in the beam. The pairs of gauges sense the bending strain in the beam. A non-zero value in the sum of the strains measured by each of the pair of strain gauges indicates a potential structural health issue with the beam.

An information processing device includes a displacement calculation means and a motion estimation means. The displacement calculation means acquires time-series images obtained by capturing images of a measurement target region of a structure supported by a supporting member. The displacement calculation means calculates a three-dimensional displacement of the measurement target region from the acquired time-series images. The motion estimation means estimates a motion of the supporting member in the structure based on the three-dimensional displacement of the measurement target region.

A measuring system for measuring the displacement of at least one point of a bridge, wherein the bridge has a resonance frequency included in the frequency band [fl, fh] where fl<fh, the measuring system including: a geophone adapted to be applied in the at least one point of the bridge, the geophone having a resonance frequency fr greater than fh and a frequency response for f<fh substantially equal to that of a double shunt; an analogue compensation device connected in series to the geophone and having a frequency response equal to that of a double integrator in the frequency band [fl, fh]; an analogue integrator device connected in series to the analogue compensation device; and an analogue/digital converter device connected in series to the analogue integrator device, the analogue/digital converter device being adapted to convert the output signal from the analogue integrator device into a digital signal.

A diagnosis apparatus 1 includes: a generation unit 2 configured to acquire vibration information indicating vibration produced in a structure 20 from a plurality of sensors 21 provided to the structure 20, and to generate, using the vibration information, natural vibration mode information indicating a natural vibration mode shape; an occurrence rate calculation unit 3 configured to calculate a rate of occurrence of a normal natural vibration mode shape based on the number of times vibration was applied to the structure 20 and the number of times the normal natural vibration mode shape was generated when the vibration was applied; and a diagnosis unit 4 configured to diagnose whether or not repair and reinforcement performed on the structure were effective based on the rate of occurrence and a reference value.

The invention discloses a real-time online monitoring, perception, and early warning method for vortex-induced vibration of suspension bridges. Based on the fast Fourier transform FFT of the bridge acceleration monitoring signal, The first-order nature frequency of the bridge can be obtained by reading the horizontal coordinate corresponding to the first-order energy peak of the spectrum and determine the high-pass filter cut-off frequency. The low-frequency noise is eliminated by the filter in order to calculate the displacement of the bridge by the recursive acceleration integration method; Taking the integrated displacement data as the real part and its Hilbert transform as the imaginary part, the analytic signal is plotted and evaluated in the complex plane to achieve the perception and early warning of VIVs. The advantages of the invention are real-time, high precision, accuracy and intuition, online real-time VIV perception and measurement of bridge vibration parameters during VIV can be realized.

According to one embodiment, a structure evaluation system according to an embodiment includes a plurality of sensors, a position locator, and an evaluator. The plurality of sensors detect elastic waves. The position locator locates positions of elastic wave sources by using the elastic waves among the plurality of elastic waves respectively detected by the plurality of sensors having an amplitude exceeding a threshold value determined according to positions of the sources of the plurality of elastic waves and the positions of the plurality of disposed sensors. The evaluator evaluates a deteriorated state of the structure on the basis of results of the position locating of the elastic wave sources which is performed by the position locator.

A stress distribution image processing device including: a processing unit configured to: designate a normalization region which includes a portion of stress equal to or larger than a predetermined threshold value in a screen of a stress distribution image of a target object; and normalize pixels in the normalization region based on stress values in the normalization region to obtain a normalized image.