A finite element model was developed to simulate the vibratory stress relief after welding. Both resonant and nonresonant vibrations can relieve residual stresses in welded structures by creating plastic deformation around the weld area. For the non-resonant vibration, the stress reduction strongly depends on the vibration amplitude. For the resonant vibration, the vibration frequency is the ke...

Vibration based monitoring techniques are widely adopted for monitoring the condition of rotating machinery. However, in the case of wind turbines the measured vibration is complex due to the high number of vibration sources and modulation phenomenon. Signals are generated by tooth meshing, shaft rotation, gearbox resonance vibration signatures and a substantial amount of noise. Therefore, extr...

Based on the existing dual-stage control scheme for hard disk drives, this paper focuses on the design and analysis of adaptive feedforward control of airflow induced suspension vibration, which utilizes the vibration signal obtained from instrumented suspension. In this scheme, a strain signal on the surface of the instrumented suspension is obtained which is indicative of the suspension’s vib...

In this paper, we present vibration suppression and balance control algorithm for biped humanoid robots in the motion embedded CoM Jacobian. The vibration control is employed during a single supporting phase, which can suppress vibration induced by structure flexibility. Because the previously proposed walking control method in the whole body coordination (WBC) framework is based on the rigid b...

We propose and experimentally demonstrate a novel ultra-long range and sensitive distributed fiber vibration sensor. Only one unidirectional Mach-Zehnder interferometer (MZI) is employed in this scheme as the sensing element. In this sensor structure, we utilize chromatic dispersion-induced walk-off effect between the vibration signals sensed by two distributed feedback (DFB) lasers at differen...

In this paper, a new micromachined tuning fork gyroscope (TFG) with an anchored diamond coupling mechanism is proposed while the mode ordering and the vibration sensitivity are also investigated. The sense-mode of the proposed TFG was optimized through use of an anchored diamond coupling spring, which enables the in-phase mode frequency to be 108.3% higher than the anti-phase one. The frequenci...

In this work, a 3-D simulation is performed to study for the solid-fluid coupling effect driven by piezoelectric materials and utilizes asymmetric obstacles to control the flow direction. The result of simulation is also verified. For a micropump, it is crucial to find the optimal working frequency which produce maximum net flow rate. The PZT plate vibrates under the first mode, which is symmet...

The aim of this paper is to conduct experimental modal analysis and numerical simulation to verify the structural characteristics of a deployable-retractable wing for aircraft and spacecraft. A modal impact test was conducted in order to determine the free vibration characteristics. Natural frequencies and vibration mode shapes were obtained via measurement in LMS Test. Lab. The frequency respo...

During the advent of active structural acoustic control, attempts were made to target and control structural vibration mode shapes to reduce radiated sound power. In the late eighties and early nineties work on acoustic radiation mode shapes developed an alternative way to target structural acoustic radiation. By attempting to control the radiation mode shapes, contributing structural modes cou...