This study is concentrated on the natural frequencies and mode shapes of a simple three-member space frame coupled with a dynamic vibration absorber. The dynamic vibration absorber is modeled as a six-degree-of-freedom mass-spring system. For the first time, the free vibration of an elastic structure with a six-degree-of-freedom mass-spring system is found. Each member of the space frame has un...

it has been proved that natural frequencies are stationary at the natural modes. also it has been shown that at the first mode it is a minimum and for systems with finite number of degrees of freedom the highest frequency is maximum (reference 1 and 2). beyond these statements nothing more can be said about the behavior of the natural frequencies without defining precisely the manner in which t...

A novel approach to fault detection and diagnosis of gearbox based on Ensemble Empirical Mode Decomposition (EEMD) and Teager Kaiser Energy Operator (TKEO) technique is presented. The time-domain vibration signal of the gearbox with gear crack fault is measured. EEMD can adaptively decompose the vibration signal into a series of zero mean Amplitude Modulation-Frequency Modulation (AM-FM) Intrin...

Abstract: This paper is concerned with the construction of an improved sliding mode control for the active suspension system of a one-wheel car model subject to the excitation from a road profile. The active control is composed of the equivalent and the switching controls where an improved sliding surface is proposed. The active control force is generated by operating a pneumatic actuator due t...

This paper provides a state-of-the-art review of eigenstructure assignment methods for vibration cancellation. Eigenstructure assignment techniques have been widely used during the past three decades for vibration suppression in structures, especially in large space structures. These methods work similar to mode localization in which global vibrations are managed such that they remain localized...

The study of the applications of piezoelectric materials in the active vibration control of flexible structures has been ongoing for more than a decade. Based on the Linear Quadratic Gauss (LQG) optimal control method, the paper introduces an effective procedure to suppress the vibration of flexible structures with the sensors/actuators are symmetrically collocated on both sides of the same pos...

In the paper problem of feedback control vibrational fields in a vibration unit double synchronization mode is studied. The algorithms for by means phase shift between rotors are proposed. performance closed loop mechatronic systems examined simulation model two-rotor SV-2M.

background: topical anesthesia has been widely advocated as an important component of atraumatic administration of intraoral local anesthesia. the aim of this study was to use direct observation of children’s behavioral pain reactions during local anesthetic injection using cotton-roll vibration method compared with routine topical anesthesia. materials and methods: forty-eight children partici...