One of the major problems in experimental vibration analysis is to determine location of transducers. It is important to place the transducers on locations with largest vibration amplitude and to avoid locations with zero-movement (nodal lines). These locations are best seen from vibration mode shapes. Finite element analysis (FEA) provides numerical values for natural frequencies, which are so...

This article presents the use of the synchrosqueezing transform (SST) for the timefrequency analysis of shock and vibration measurements. The time-frequency resolution properties of SST is demonstrated by analyzing acceleration measurements from pallets dropped from heights and vibration of pallets acquired in controlled laboratory settings. The article presents results that indicate that SST, ...

There is a worldwide interest in the proper design of embankment dams to resist earthquake loadings. For the first time in Iran, a complete ambient vibration survey due to low-level loads such as wind, machinery activities, low level tectonic activities, and water exit from bottom outlet was performed on Marun embankment dam. These kinds of ambient vibration tests are suitable for manifesting t...

There is a worldwide interest in the proper design of embankment dams to resist earthquake loadings. For the first time in Iran, a complete ambient vibration survey due to low-level loads such as wind, machinery activities, low level tectonic activities, and water exit from bottom outlet was performed on Marun embankment dam. These kinds of ambient vibration tests are suitable for manifesting t...

In recent years, as the weight of IT equipment has been reduced, the demand for motor fans for cooling the interior of electronic equipment is on the rise. Sensory test technique by inspectors is the mainstream for quality inspection of motor fans in the field. This sensory test requires a lot of experience to accurately diagnose differences in subtle sounds (sound pressures) of the fans, and t...

The measurement of frequency response functions (FRFs) on nominally identical items reveals usually a considerable scatter induced by some inherent variabilities. In this paper a stochastic parametric approach is suggested in order to analyze the variability of the FRFs, where random as well as uncertain structural properties are modeled as a function of independent random variables with prescr...

Natural vibration analysis of plates represents an important issue in engineering applications. In this paper, a new and simplify method for vibration analysis of circular and rectangular plates is presented. The design of an effective robust controller, which consistently attenuates transverse vibration of the plate caused by an external disturbance force, is given. The dynamics of the plate i...

In this study, both theoretical linear model and numerical model are used to predict and optimize the frequencies of shimmy related modes and the level of the vibration for a vehicle. A theoretical multi-body linear model of 32-DOF were used for quasi-static analysis and modal analysis. The theoretical model was verified by comparing the results of modal analysis with those of modal test for fr...

Application of a neural network approach to data exploration and the generation of a model of system normality is described for use in novelty detection of vibration characteristics of a modern jet engine. The analysis of the shape of engine vibration signatures is shown to improve upon existing methods of engine vibration testing, in which engine vibrations are conventionally compared with a f...

In this study, the effect of posture, vibration magnitude and frequency on seat-to-head (STH) and back support-tohead (BTH) transfer functions has been studied under vertical sinusoidal vibration. Twelve healthy male subjects were participated in experimental work to measure vertical vibration transmitted to the occupants head in three representative postures (erect, vertical back on and forwar...