A vibration control system calculates a Kurtosis Response Spectrum (KRS) of a response waveform which characterizes non-Gaussianity in a random vibration test and is utilized for vibration control. The system compares a target KRS and the response KRS, and controls a characteristic of a phase used to generate a waveform for control such that the response KRS becomes equal to the target KRS. The waveform for control is generated by applying a random phase to each frequency component of an amplitude corresponding to Power Spectral Density (PSD). The system controls a characteristic of this phase (e.g., standard deviation) per frequency, controls the KRS, deforms the waveform for control on the basis of an equalization characteristic, and calculates a drive waveform. The system sequentially updates the equalization characteristic on the basis of the response waveform and the drive waveform. The calculated drive waveform is provided to a vibration generator.

Disclosed is a system and method for testing a structure mode of vibration based on digital image recognition, which comprises a camera, targets, a bridge, a vertical acceleration sensor and a lateral acceleration sensor; the camera is arranged near the bridge head of the bridge; the bridge is equipped with a plurality of targets equidistantly inside guardrails on both sides; and the vertical acceleration sensor and the lateral acceleration sensor are fixedly arranged on the camera. The present application avoids the arrangement of a large number of sensors and complicated wiring in the bridge vibration detection, saves time and reduces economic cost, is convenient to operate, has relatively high precision, and has broad application prospects.

A new vibration test-cell that allows a static load to be applied simultaneously with lateral vibration coupled with in-situ microscopy that allows for the ability to open a fatigue crack up to a desired gap, as well as generate acoustic emission (AE) from vibration excitation, micro-fracture events are captured by the AE measurement while the physical observation of the crack faying surfaces is performed in-situ with an optical microscope embedded in the test cell.

A sensitivity analyzing device and method are disclosed. The device includes a vibration exciter to configure a vibration exciting pattern and apply a physical force to one face of a test object based on the pattern; a first sensor in contact with the one face of the test object to measure a physical force applied to the test object; a second sensor in contact with an opposite face of the test object to collect a vibration of the test object caused by the physical force; and a sensitivity analyzer configured to: control the vibration exciter to configure the vibration exciting pattern; convert the physical force signal measured by the first sensor and the vibration signal collected by the second sensor in responses to the vibration exciting pattern into frequency domain signals to calculate a frequency response function of the test object; and calculate a sensitivity index of the test object.

A displacement spring and a rotational spring are arranged on both ends of the multi-segment continuous beam to simulate arbitrary boundary conditions, and a lateral displacement function of the multi-segment continuous beam over a whole segment is constructed. A strain energy, an elastic potential energy of simulated springs at a boundary, a maximum value of a kinetic energy, and a Lagrangian function of the multi-segment continuous beam are calculated. The improved Fourier series of the displacement function is substituted into the Lagrange function. An extreme value of each undetermined coefficient in the improved Fourier series in the Lagrangian function is taken to obtain a system of homogeneous linear equations which is further converted into a matrix. An eigenvalue problem of the standard matrix is solved for to obtain the natural frequency.

A vibration test apparatus for vibrating a payload. The vibration test apparatus includes an inductive position sensor assembly which has a first member attached to a displaceable armature and a second member attached to a shaker frame. The inductive position sensor assembly is configured to generate at least one control signal indicative of an axial position of the armature based on a displacement dependent electromagnetic coupling between the first member and the second member.

An adaptive loading method for real-time hybrid simulation testing based on a space frame model. The system initial delay is controlled to be close to 0 before the loading of seismic wave by a dual compensation strategy for the initial delay based on the initial delay compensation and the adaptive loading segment, thereby solving the problem of insufficient estimation and compensation of the initial delay in the real-time hybrid simulation. In addition, the test substructure of the space frame model is equated as a test element, and the overall displacement response corresponding to the test substructure in the overall model is converted to the actual loading relative displacement of the test substructure by using the signal conversion module, thereby realizing the real-time loading of the large-scale spatial frame model with great rigidity.

An analysis method of optimizing vibration performance of a part of an automotive body, including: acquiring a maximum displacement of vibration of the part of the automotive body; acquiring a load required for applying a same displacement as the acquired maximum displacement, to the part of the automotive body; setting a design space by setting a part or member that supports the part of the automotive body as an optimization target; generating an optimization block model formed of three-dimensional elements in the set design space; generating an optimization analysis model by combining the generated optimization block model to the automotive body; and acquiring an optimal shape of the optimization block model by: applying the acquired load as a load condition; and performing optimization analysis for the optimization block model taking an inertial force that occurs in the part of the automotive body due to vibration into consideration.

The present invention relates to a system for identification and active control of vibrations (101) in a structure (103), 11 comprising at least one inertial device (102) associable with the structure (103), comprising at least one movable mass (104) and configured for a first controlled movement of the at least one movable mass (104) in order to excite the structure (103); one or more movement sensors (201) configured for detecting vibrations of the structure (103); at least one processing device (202, 302) operatively connected to the one or more movement sensors (201) and to the least one inertial device (102), the at least one processing device (202, 302) being configured for: identifying a set of first parameters determinable by the one or more movement sensors (201) in response to environment-induced vibrations of the structure (103); identifying a set of second parameters determinable by the one or more movement sensors (201) in response to the first controlled movement of the at last one movable mass (104); calculating a dynamic model, wherein the set of first and second parameters are made consistent taking into account the at least one movable mass (104); detecting threshold-exceeding vibrations of the structure (103) by the one or more movement sensors; controlling the at least one inertial device (102), wherein the at least one inertial device (102) is further configured for a second controlled movement of the at least one movable mass (104), based on the dynamic model. The present invention further relates to a respective method for identification and active control of vibrations in a structure.

A vibration signal-based smartwatch authentication method includes generating incremental vibration signals using a vibration motor in a smartwatch; performing frequency band-based hierarchical endpoint segmentation to obtain vibration signals at a plurality of frequency bands; extracting frequency-domain features for the vibration signals at the plurality of frequency bands; training a dynamic time warping model by taking the vibration signals at the plurality of frequency bands as a training data set, training a nearest neighbor model by taking the extracted frequency-domain features as training data; collecting to-be-authenticated vibration signals which are processed to serve as test data signals; discriminating similarities between the test data signals and corresponding training data signals through the dynamic time warping model, giving a classification result through the nearest neighbor model, performing weighted calculation on a discrimination result of the dynamic time warping model and a discrimination result of the nearest neighbor model to obtain an authentication result.