According to one embodiment, a structure evaluation system of the embodiments includes a plurality of sensors, an arrival time determiner, a reliability calculator, and a map generator. The plurality of sensors detect elastic waves. The arrival time determiner determines arrival times of the elastic waves using elastic waves detected by the plurality of respective sensors. The reliability calculator calculates reliabilities related to measurement waveforms of the elastic waves on the basis of the arrival times. The map generator generates a first map on the basis of the calculated reliabilities or the reliabilities and a distance.

A structural vibration monitoring method based on computer vision and motion compensation provided in the present disclosure adopts a dual-camera system for self-motion compensation. The dual-camera system consists of a primary camera and a secondary camera rigidly connected to each other. The primary camera directly measures a structure displacement. This method inevitably includes an error generated due to motion of the primary camera. Meanwhile, the secondary camera measures displacements of translation and rotation, so as to estimate a measurement error caused by the motion of the primary camera. Then, with the displacement directly measured by the main camera minus the measurement error, a corrected structure displacement is obtained, thereby truthfully and accurately monitoring vibrations of a bridge structure.

An abnormality estimation apparatus 10 includes: a detection unit 11 configured to detect a vibration response when a vehicle passes over an expansion and contraction apparatus 23, using vibration information indicating vibration that occurs in a bridge; a first index calculation unit 12 configured to calculate a first index for determining the presence or absence of an abnormality in the expansion and contraction apparatus 23, using the vibration response; and an estimation unit 13 configured to estimate the presence or absence of an abnormality in accordance with a change in the first index.

A bridge displacement calculating apparatus comprises a DC component removing part, a high-pass filter part, a first integration part, and a second integration part. The DC component removing part outputs DC-removed acceleration data. The high-pass filter part uses, as a cutoff frequency, the reciprocal of a time in which a vehicle has passed between the frame bodies of the bridge. The first integration part integrates input data thereto. The second integration part integrates input data thereto and outputs displacement data. The high-pass filter part receives DC-removed acceleration data, the first integration part receives the output of the high-pass filter part, the second integration part receives the output of the first integration part, or the first integration part receives the DC-removed acceleration data, the high-pass filter part receives the output of the first integration part, and the second integration part receives the output of the high-pass filter part.

A displacement component detection apparatus 10 is provided with: a displacement distribution calculation unit 11 configured to calculate, from time-series images of a measurement target region of an object 30 output from an image capturing device 20 configured to capture the images of the measurement target region, a displacement distribution in a region that corresponds to the measurement target region in the images; a movement amount calculation unit 12 configured to calculate, based on the displacement distribution and image capturing information, a movement amount in the surface direction of the measurement target region and a movement amount in the normal direction of the measurement target region; and a surface displacement calculation unit 13 configured to calculate, from the displacement distribution, a surface displacement component in the measurement target region, using the movement amount in the surface direction of the measurement target region and the movement amount in the normal direction of the measurement target region.

The present disclosure provides an automatic test system for actual stress of a bridge based on DIC technology, where the system includes a camera, a phosphor spraying device, a computer, and a sliding rail; the sliding rail is arranged on both sides of an upper wing of a box-shaped concrete beam; the phosphor spraying device is used to spray phosphor on a web of the box-shaped concrete beam to form speckles of varying light and shade; the camera is slidably connected to the sliding rail through a bracket, and is used to photograph the speckles and transmit a speckle image to the computer; and the computer is used to analyze and process the speckle image taken by the camera and generate a time history diagram of stress.

The invention relates to a bridge exciter for inducing vibrations in railway or roadway bridges, which comprises a servo-hydraulic actuator connected to a wagon designed to transport the same over tracks or a road. The actuator generates a force by moving a variable-weight reaction mass guided by linear bearings. It comprises hydraulic equipment that enables direct transmission of the vibrations to the infrastructure, independent of the rolling gear of the wagon or the rubber-tired vehicle, via false wheels. The movement of the actuator piston is controlled by a computer allowing the actuator to apply general forces on a bridge or roadway that do not exceed the maximum acceptable displacement of the piston: harmonic, impulsive, and transient forces. The equipment is provided with the necessary load control elements.

Embodiments herein provide a system (100) to estimate the amplitude of oscillations in a turbulent flow system (102) that exhibits oscillatory instabilities. The system (100) comprises of a sensor (102A) mounted on the turbulent flow system (102) to detect an oscillatory variable in the system obtaining a signal, a signal conditioner (104) that conditions the signal from the sensor, an amplitude estimator (110) that estimates the amplitude of the limit cycle oscillations, and also predict the proximity of the system to the oscillatory instability, a processor (108) connected to the amplitude estimator (110) to compare the predicted oscillation amplitude with a threshold value. The amplitude is estimated by estimating the spectral measure of the time series signal obtained from the system.

The invention discloses a method and a system for predicting the corrosion fatigue life of prestressed concrete bridges. A corrosion level of the strand is predicted to obtain the residual tension force of a structure. A stress concentration factor is integrated to consider the stress concentration effect caused by pitting corrosion, and a growth model of the elastic stress of the strand under the coupled effect of corrosion and fatigue is proposed. A growth model of the plastic stress of the strand is established using a cross-section loss of the strand as a fatigue damage parameter based on a degenerated elastic modulus of the concrete after fatigue. Failure criteria for the concrete, the strand, and a longitudinal tension bar are defined, so that a set of methods for analyzing the life of a prestressed concrete bridge subjected to corrosive environment and fatigue load are formed.

A system for monitoring survey reflectors arranged at a plurality of locations on an object, having: a camera, including: one or more light sources arranged to illuminate a field in space corresponding to at least 10% of a field of view of the camera, preferably the whole field of view; an image sensor receiving light beams from reflections of the beam by the survey reflectors and providing data; a body with an optical entry system, the image sensor located on a first side and the light source on a second side of the body; and a processing unit processing the data.

The processing unit is configured to determine locations of the survey reflectors from the image sensor data and detect movement of the survey reflectors based on a comparison of the determined locations with previously determined locations.