The vibration control problem of offshore jacket platforms is studied. According to Morison equation, the total wave force acting on the offshore structure is obtained and is generated by an exosystem. Considering the nonlinear interaction of pile-soil, which is described by a fifth order anti-symmetric polynomial, the nonlinear dynamical model of offshore platforms affected by the wave load di...

Article history: Received: 06.02.2015. Received in revised form: 11.05.2015. Accepted: 15.05.2015. Due to the shortcomings of one mass vibration mill such as inefficiency, high energy consumption and big noise, a double mass high energy vibration mill, in which transient high vibration intensity is produced, is investigated by applying the non linear vibration theory. The nonlinear hard feature...

Currently, the interest in monitoring the vibration of dynamical systems has been increasing. For example, large and complex air and space structures include vibration monitoring systems to forecast sudden failures. Such vibration monitoring is used to diagnose structural health by analyzing vibration characteristics (such as frequency and amplitude). Among the vibration characteristics used, t...

Motion-induced vibration can be greatly reduced by properly shaping the reference command. Input shaping is one type of reference shaping method that is based largely on linear superposition. In this paper we document the impact of nonlinear crane dynamics on the effectiveness of input shaping. As typical bridge cranes are driven using Cartesian motions, they behave nearly linearly for lowand m...

Two elastically coupled nanomechanical resonators driven independently near their resonance frequencies show intricate nonlinear dynamics. The dynamics provide a scheme for realizing a nanomechanical system with tunable frequency and nonlinear properties. For large vibration amplitudes, the system develops spontaneous oscillations of amplitude modulation that also show period-doubling transitio...

The vibration signals of rolling bearings are often nonlinear and non-stationary. Multiscale entropy (MSE) has been widely applied to measure the complexity of nonlinear mechanical vibration signals, however, at present only the single channel vibration signals are used for fault diagnosis by many scholars. In this paper multiscale entropy in multivariate framework, i.e., multivariate multiscal...

In this study, nonlocal nonlinear instability and the vibration of a double carbon nanotube (CNT) system have been investigated. The Visco-Pasternak model is used to simulate the elastic medium between nanotubes, on which the effect of the spring, shear and damping of the elastic medium is considered. Both of the CNTs convey a viscose fluid and a uniform longitudinal magnetic field is applied t...

The paper a nonlinear model of bolt joints structure in vibration environment is built, including the friction, contact and so on complex nonlinear factors. Structure Intensity (SI) of it is calculated by Finite Element Method (FEM) as an approach for the state identification of bolts joints structure in vibration environment. The plots of the structure intensity vector under different tighteni...

Emily Stone Department of Mathematical Sciences, The University of Montana, Missoula, MT 59812 U.S.A. Abstract In this paper we present stability analysis of a nonlinear model for chatter vibration in a drilling operation. The results build our previous work [1, 2], where the model was developed and the nonlinear stability of the vibration modes as cutting width is varied was presented. Here we...