A suspension system for an exciter device. The exciter device includes a piston extending through an opening of a moveable housing and generates a vibrational force by causing a linear reciprocating movement of the housing relative to the piston. The suspension system includes an axial suspension magnet fixedly coupled to the housing and positioned proximate the opening. The axial suspension magnet is configured to oppose a magnetic field of a permanent magnet that is fixedly coupled to the piston and the opposing magnetic fields dampen movement of the housing relative to the piston as the first axial suspension magnet approaches the permanent magnet. A radial guide bushing is positioned within the opening surrounding a circumference of the piston. The radial guide bushing is formed of a compressible and flexible material and is configured to restrict radial movement of the housing relative to the piston.

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.

A pseudo-static test device and method for seismic behavior of connection joints of a wallboard. The device includes ground anchor holes, a support frame including a steel beam and two steel columns, and a test wallboard. A bottom plate of the steel beam is provided with at least two first connecting holes. A top plate each steel column is provided with a second connecting hole. A bottom plate of each steel column is provided with a third connecting hole. The bottom plate of the steel beam is provided with a connection joint assembly configured to hingedly or rigidly connect a top of the test wallboard to the steel beam. Each first connecting hole is connected to the second connecting hole through a flange assembly.

A pseudo-static test device and method for seismic behavior of connection joints of a wallboard. The device includes ground anchor holes, a support frame including a steel beam and two steel columns, and a test wallboard. A bottom plate of the steel beam is provided with at least two first connecting holes. A top plate each steel column is provided with a second connecting hole. A bottom plate of each steel column is provided with a third connecting hole. The bottom plate of the steel beam is provided with a connection joint assembly configured to hingedly or rigidly connect a top of the test wallboard to the steel beam. Each first connecting hole is connected to the second connecting hole through a flange assembly.

Object analysis comprising measuring a frequency-dependent natural oscillation behavior of the object by dynamically-mechanically exciting the object in a defined frequency range (f) by means of generating a body oscillation by applying a test signal, and detecting a body oscillation generated in the object on account of the exciting. Moreover, the method involves simulating a frequency-dependent natural oscillation behavior for the object by generating a virtual digital representation of the object, and carrying out a finite element analysis on the basis of the virtual representation comprising dynamically exciting, in a simulated manner, the virtual representation into a virtual frequency range for generating a virtual body oscillation, calculating the virtual body oscillation generated in the object on account of the exciting in a simulated manner, and deriving an object state on the basis of a comparison of the measured natural oscillation behavior and the simulated frequency-dependent natural oscillation behavior.

In one embodiment, a system and method for determining a natural frequency of a structure involve modeling the structure, creating a synthesized excitation comprising a plurality of waves having various frequencies within a defined range of frequencies, applying the synthesized excitation to a base of the modeled structure, and generating response data indicative of a natural frequency of the modeled structure that is based upon the application of the synthesized excitation.

In one embodiment, a system and method for determining a natural frequency of a structure involve modeling the structure, creating a synthesized excitation comprising a plurality of waves having various frequencies within a defined range of frequencies, applying the synthesized excitation to a base of the modeled structure, and generating response data indicative of a natural frequency of the modeled structure that is based upon the application of the synthesized excitation.

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 vibrator-mounted holder is attached to a casing of a vibration generator which moves a vibrator to generate a vibration when used. The vibrator-mounted holder includes a vibrator, a vibrator retention unit retaining the vibrator, a fixing unit fixed to a casing, and an arm. The vibrator includes a magnet having a plate shape parallel to a horizontal surface and a yoke arranged on the magnet. The arm connects the fixing unit to the vibrator retention unit, and supports the vibrator retention unit in a manner that the vibrator retention unit is displaceable with respect to the fixing unit. The yoke has a projecting portion which is projected downward and fixed to the vibrator retention unit. The arm is connected to a portion, at which the projecting portion is arranged, within the vibrator retention units.

A pseudo-static test device and method for seismic behavior of connection joints of a wallboard. The device includes ground anchor holes, a support frame including a steel beam and two steel columns, and a test wallboard. A bottom plate of the steel beam is provided with at least two first connecting holes. A top plate each steel column is provided with a second connecting hole. A bottom plate of each steel column is provided with a third connecting hole. The bottom plate of the steel beam is provided with a connection joint assembly configured to hingedly or rigidly connect a top of the test wallboard to the steel beam. Each first connecting hole is connected to the second connecting hole through a flange assembly.