A fixture for testing stiffness of a vehicle wheel by measuring vibration of the wheel includes a base and a retention member. The retention member is integral to the base. The retention member defines a distal end including a distal diameter and a proximal end being proximate to the base and including a proximal diameter. The proximal end includes a plurality of studs extending upwardly therefrom for being received by lug apertures defined by the vehicle wheel thereby securing the vehicle wheel to the retention member. The distal diameter includes a ratio to the proximal diameter of between 0.6 to 0.8 to one.

System and methods for characterizing a response of a structure-under-test to applied excitation forces using a test fixture. The fixture is selectively coupleable to the structure-under-test and is configured to hold the structure-under-test at a known position and in a known orientation relative to the fixture. A plurality of excitation devices and response sensors are coupled to the fixture. Excitation forces applied to the fixture by the excitation devices are conveyed by the fixture to the structure-under-test and each response sensor measures a dynamic response indicative of a response of the structure-under-test and the fixture to the applied excitation force. A controller receives response sensor data and applies a mathematical coordinate transformation to project the forces and moments corresponding to the applied excitation and the measured dynamic responses to a target point of the structure-under-test and to calculate a system response function based at least in part on the projection.

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.

The disclosure provides a vehicle excitation advice. The vehicle excitation device that excites a vehicle having a plurality of wheels includes a plurality of excitation machine bodies on which the wheels are placed, respectively. The excitation machine body includes a front shaft and a rear shaft on which the wheels are placed at intervals in the in the front-rear direction of the vehicle, and an actuator (hydraulic actuator) that excites vibration to the wheels by moving at least one of the front shaft and the rear shaft in the front-rear direction. The front shaft is inclined such that the inner end portion of the front shaft in the left-right direction of the vehicle is located closer to the front of the vehicle than the outer end portion of the front shaft in the left-right direction of the vehicle.

An excitation device exciting a vehicle 12 by applying a vibration to at least one of a plurality of tires 12t of the vehicle includes: a first restricting part 16 arranged in one of a front and rear direction of at least one of the plurality of tires 12t to restrict a movement of the vehicle in the front and rear direction; a second restricting part 20 arranged in another of a front and rear direction of the one of tires 12t to restrict a movement of the vehicle in the front and rear direction; and an actuator 22 configured to be able to drive at least one of the first restricting part and the second restricting part so as to increase or decrease a distance between each other in a front and rear direction of the vehicle.

The present application provides a double-table vibration testing device. The device includes two auxiliary devices and two vibration devices; each auxiliary device includes a lifting apparatus which is provided with a lifting portion; and a sliding member which is assembled on the lifting portion and slides relative to the lifting portion in a longitudinal direction. A drilling tool (an object to be tested) is held by the two auxiliary devices, so that the weight of the drilling tool does not exceed the maximum load-bearing capacity of the vibration devices. Therefore, the vibration devices are not easily damaged, and the drilling tool is not easy to overturn in the vibration testing process.

Described herein is an optical fibre mounting structure (180) for fibre vibration sensing of a distributed system (100) of spaced apart vibration sources (112-131). Mounting structure (180) includes a base portion (200) having a two dimensional surface area defining a vibration surface (202). A mounting apparatus (236) is adapted to mount the base portion (200) to a support structure (e.g. 104) of the distributed system (100) adjacent one of the vibration sources. A fibre engagement structure (e.g. 210-215) is provided for supportively engaging a length (218) of optical fibre in contact with the vibration surface (202).

A shock isolator is arranged between two automated coupler parts in a vibration testing unit. When the coupler parts are engaged and coupled during vibration testing of a component, the shock isolator is disabled, and when the coupler parts are disengaged and decoupled after vibration testing, the shock isolator is activated to absorb excess shock energy and prevent shock transfer between the coupler parts that would damage the test component. The shock isolator includes a bushing that is inserted in a lower part of the two automated coupler parts and a compressive fit rod that is press-fit into the bushing. The bushing has a chamfered volume and the compressive fit rod has a corresponding compressible volume that is displaced into the chamfered volume to disable the shock isolator. After vibration testing, the compressive fit rod is expandable to a regular shape to activate the shock isolator.

A wind turbine rotor blade load emulator arrangement includes a support unit constructed to support a rotor blade during a fatigue test procedure; an exciter configured to deflect the rotor blade during a fatigue test procedure; and a stiffness augmentation assembly for mounting to the rotor blade over a mounting length, which stiffness augmentation assembly is realized to increase the stiffness of the rotor blade in the mounting length. A method of carrying out a fatigue test procedure on a wind turbine rotor blade uses such a load emulator arrangement.

A method for isolating vibrations for centrifuge testing devices is provided. The method comprises coupling a test payload platform to a number of piezoelectric actuators and coupling the piezoelectric actuators to a reaction mass coupled to a centrifuge arm. A layer of vibration-absorbing material is sandwiched between the reaction mass and the centrifuge arm. The centrifuge arm is rotated around an axis, and the test payload platform is vibrated with the piezoelectric actuators as the centrifuge rotates, wherein the layer of vibration-absorbing material prevents vibrations from traveling down the centrifuge arm.