The invention provides a large-amplitude vertical-torsional coupled free vibration device, which belongs to the technical field of vertical-torsional coupled free vibration device for wind tunnel test. The gear blocks are consolidated at both ends of the beam. The screws, beam, and the gear blocks are fixed on the model, and they can fulfil the vertical-torsional coupled free vibration. The toothed plate is attached to the sliding block that iteratively moving along the vertical guide rail which is fixed to the ground. The vertical springs attached to the sliding blocks provide both vertical and torsional linear stiffness for the suspension vibration system. The springs only have vertical linear tensile deformations without any lateral tilt, which ensures the linear vertical and torsional stiffness of the model, and the lateral freedom is effectively restrained. This device can achieve the large-amplitude vertical-torsional coupled free vibration of the model, and the deficiency of the traditional device where springs are apparently tilted and the inefficacy of linear stiffness can be avoided. The lateral vibration is restrained, and it is applicable to large-amplitude vertical-torsional coupled free vibrations.

According to one embodiment, a structure evaluation system includes an impact imparting unit, a sensor, and a structure evaluation device. The impact imparting unit applies impacts to a structure. The impact imparting unit applies the impacts at a frequency equal to or less than a frequency determined in accordance with an intensity at which the impacts are imparted. The sensor detects elastic waves. The structure evaluation device evaluates a deterioration state of the structure on the basis of the detected elastic waves.

Systems and methods for monitoring the condition of structural systems such as bridges and roadbeds. The systems include a magnetometer mounted on a structural element of the structural system; and a magnet mounted on a surface adjacent the structural element so that the magnetometer is positioned within a magnetic field of the magnet. The magnetometer measures characteristics of the magnetic field of the magnet. Position of the structural element is determined from measured characteristics of the magnetic field and a predetermined relationship between the characteristics of the magnetic field and the position of the structural element within the magnetic field. The position information determines other parameters, such as the deflection of the structural element in three-dimensional space, and the response of the structural element to dynamic loading.

A measurement device includes: an obtainer that obtains a plurality of images of a support member that movably supports a structure, the plurality of images being captured at mutually different times while the structure is subjected to varying loads; and a measurer that measures displacement of the support member based on the plurality of images obtained by the obtainer.

A sensing system (10) for monitoring the integrity of a structure has first and second channels (12 and 14) arranged for sealing onto a surface (16) of the structure (18) to form respective spaced apart first and second galleries (20 and 22). A fluid (F1) is in the first gallery (20) and a fluid (F2) is in the second gallery (22). A measurement system (24) measures for a change in a pressure independent physical characteristic: a) in the first gallery (20); b) in the second gallery (22); c) between the first gallery (20) and the second gallery (22); or d) a combination of two or more of a), b) and c) where the change is dependent on a mass flow of fluid from one of, or between, the sealed galleries due to a crack in the structure. The pressure independent physical characteristic of the fluid can be the conductivity of the fluid or the optical properties of the fluid.

Fatigue fuse mounting systems and methods are discussed in this application. It is advantageous in the field of structural monitoring for fatigue fuses that are engineered to break in sequence to both be mounted near each other and also to work toward ensuring the fatigue fuses all undergo similar load cycling. Simply sticking a set of fatigue fuses to a structure can result in each fatigue fuse from an engineered set undergoing different load cycling, which can reduce their effectiveness. Thus, fatigue fuse mounting systemsand methods of implementing the systemsare contemplated in this application. The system includes a structural frame and a fatigue fuse mounting cartridge. These components work together to ensure that each fatigue fuse in a set undergoes more uniform load cycling, thereby improving structural monitoring performance.

A damage diagnosing device includes: a generating unit which generates second vibration characteristic information including a characteristic value of an increase characteristic opposite to an amplitude of oscillation exhibited by first vibration characteristic information, relating to a structure including a supporting portion and a supported portion supported at a support point by the supporting portion; a calculating unit which calculates a degree that values indicated by the first vibration characteristic information and the second vibration characteristic information have changed from reference values relating to the first vibration characteristic information and the second vibration characteristic information as a result of damage that has occurred in the structure; and a diagnosing unit which diagnoses the damage on the basis of the degree of change, to more accurately diagnose damage that has occurred in a structure having a supporting portion and a supported portion supported at a support point by the supporting portion.

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.

A stress measurement device includes a first obtaining unit obtaining thermal data including information indicating a temperature of a measuring region, a second obtaining unit obtaining data related to stress occurring in one part of the measuring region, and a controller finding stress occurring in the measuring region from the thermal data and the data related to the stress. The controller finds, first waveform data respectively on the one part and a part other than the one part based on a change with time of the thermal data, and second waveform data based on a change with time of the data related to the stress. The controller finds, disturbance data through a deduction of the second waveform data from the first waveform data on the one part, and stress data indicating stress occurring in the part through a deduction the disturbance data from the first waveform data on the part.

A vibration measurement apparatus 10 is an apparatus for measuring vibrations of an object 30. The vibration measurement apparatus 10 includes: a surface-direction displacement calculation unit 11 configured to calculate, based on time-series images of a measurement target area that are output from an imaging apparatus 20, a displacement in a surface direction of the measurement target area; a normal-direction displacement calculation unit 12 configured to calculate a displacement in a normal direction of the measurement target area, based on the time-series images and the displacement in the surface direction of the measurement target area; and a vibration calculation unit 13 configured to calculate vibrations of the object 30, based on the calculated displacement in the surface direction of the measurement target area and the calculated displacement in the normal direction of the measurement target area.