An acoustic impedance measuring system configured to measure an acoustic impedance of an acoustic component includes a first chamber, a second chamber, a first sound pressure sensing device, a second sound pressure sensing device and a sound source. The first sound pressure sensing device is configured to sense a sound pressure in the first chamber. The second sound pressure sensing device is configured to sense a sound pressure in the second chamber. The sound source is connected to the first chamber, wherein the sound source generates a sound propagating towards a first cavity inside the first chamber. The acoustic component is disposed between the first chamber and the second chamber for being measured the acoustic impedance of the acoustic component, and the acoustic impedance of the acoustic component is measured by the first sound pressure sensing device and the second sound pressure sensing device.

A method determines a wrapping configuration of a film wrapped around products to form a palletized load to be moved along a path. The method includes using a defined wrapping configuration, measuring physical quantities acting on the load as a result of movements and/or stresses when the load is moved along different test paths, obtaining a path as a suitable composition of base elementary path stretches, obtaining physical quantities acting on the load along the path as physical quantities associated to the base elementary path stretches, positioning the load on a motion platform, operating the motion platform based on the physical quantities to simulate movements and/or stresses acting on the load moved along the path, checking if the load has remained stable and/or compact, modifying the wrapping configuration if the load did not remain stable and/or compact, and repeating the steps.

A vehicle-body carrying apparatus is configured to house and carry a vehicle body of an unmanned vehicle. The apparatus includes a housing, a data collecting device, a diagnostic device, and an informing device. The housing is capable of housing the vehicle body. The data collecting device is configured to collect data relating to structural soundness of the vehicle body housed in the housing. The diagnostic device is configured to diagnose the structural soundness of the vehicle body based on the collected data. The informing device is configured to inform a user of a diagnostic result obtained by the diagnostic device.

An elastic material vibration test apparatus includes a lower support plate having an upper surface on which an elastic material to be tested is placed, an upper support plate disposed above the lower support plate to be spaced apart from the lower support plate, a pillar connecting the lower support plate and the upper support plate, a pressing rod configured to pass through the upper support plate and ascend and descend in a vertical direction, an air bearing installed on the upper support plate and supporting an outer surface of the pressing rod in a non-contact state, a pressing plate coupled to a lower end of the pressing rod to press an upper surface of the elastic material, and one or more weights coupled to the pressing rod above the air bearing.

A vibration data collection device monitors vibration of a machine, generates original machine vibration waveform data based on the monitored vibration, and removes portions of the original machine vibration waveform data that do not indicate an occurrence of a vibration event related to a potential fault in the machine. The vibration data collection device then stores thinned waveform data that includes blocks of the original machine vibration waveform data and excludes the portions that have been removed. A data analysis computer generates a thinned waveform plot based on the thinned waveform data. In some embodiments, the thinned waveform plot includes the blocks of original machine vibration waveform data separated in time by gaps representing the portions that have been removed. In some embodiments, the thinned waveform plot that includes the blocks of the original machine vibration waveform data and representative blocks of data that each represent the portions of the original machine vibration waveform data that have been removed. A display device displays the thinned waveform plot for viewing by an analyst.

An acoustic or mechanical vibration testing system includes a MIMO control system coupled to at least two separately controllable groups of vibration transducers and at least two control sensor transducers wherein the number of control sensor transducers need not be equal to the number of controller output drives or number of separately controllable groups of vibration transducers. The MIMO control system utilizes both a predetermined initial reference specification and a modified reference specification, wherein data acquired during system operation under conventional MIMO control is used to create the modified reference specification based on actual system performance and limitations thereof so as to maintain closer correspondence to the predetermined initial reference specification with less required system drive power, as a function of the predetermined initial reference, and less risk of damage to the test system and the test article during the performance of a test.

A deterioration discrimination system according to the present disclosure includes: an optical fiber cable (20) configured to be laid in a utility pole (10); a communication unit (31) configured to receive an optical signal from optical fibers (21) included in the optical fiber cable (20); a detection unit (32) configured to detect, based on the optical signal received by the communication unit (31), vibrations that are generated in the utility pole (10); and a discrimination unit (41) configured to discriminate, based on a vibration frequency of the vibrations that are generated during a specified period among the vibrations that are detected by the detection unit (32), deterioration of the utility pole (10).

The present invention provides a test device for a quasi zero stiffness isolator, and belongs to the technical field of vibration response tests of isolators. The device comprises a negative stiffness adjusting mechanism, a positive stiffness adjusting mechanism, and a beam-damping block mechanism. The negative stiffness adjusting mechanism and the positive stiffness adjusting mechanism are connected successively and installed on a beam-mass block system. The test device for the quasi zero stiffness isolator can realize smooth longitudinal vibration of a tested system, and can also flexibly adjust the positive stiffness value and the negative stiffness value of an overall mechanism. The present invention is suitable for a vibration model test of the quasi zero stiffness isolator, and solves the problems of complicated use method, impossibility of flexible adjustment of mechanism stiffness and complicated replacement process of stiffness elements in the device for the existing quasi zero stiffness isolator.

A method of evaluating a natural frequency of a piezoelectric vibrator including a vibrating membrane and a piezoelectric element, includes: acquiring power-generating wave information of the piezoelectric vibrator from vibration of the vibrating membrane, which is caused by generating an electric field in a piezoelectric film of the piezoelectric element to displace the vibrating membrane and then extinguishing the electric field in a state where the vibrating membrane is displaced; and measuring a period of a power-generating wave based on the power-generating wave information and determining a reciprocal of the period as the natural frequency of the piezoelectric vibrator.

A vibration detection apparatus applied to a nuclear magnetic resonance while drilling instrument, including a vibration table. The vibration table is configured to horizontally clamp the nuclear magnetic resonance while drilling instrument and further includes a graduated barrel that contains a detection liquid; the graduated barrel is configured to be suspended at the upper side of the vibration table and be spaced apart from the nuclear magnetic resonance while drilling instrument; when the vibration table performs vibration, the graduated barrel keeps stationary, and the nuclear magnetic resonance while drilling instrument preforms high-pressure emission and measurement by means of the graduated barrel. Therefore, the nuclear magnetic resonance while drilling instrument can obtain the echo signal of the graduated barrel during vibration, thereby more accurately detecting the performance thereof and shortening a detection time length.