In this paper a new form of the homptopy perturbation method is used for solving oscillator differential equation, which yields the Maclaurin series of the exact solution. Nonlinear vibration problems and differential equation oscillations have crucial importance in all areas of science and engineering. These equations equip a significant mathematical model for dynamical systems. The accuracy o...

The Dynamics Research Group (DRG) based in the Department of Mechanical Engineering at the University ofSheffield conducts research into vibrations and the dynamics of structures. The main areas of research are:nonlinear dynamics, structural health monitoring, active and passive vibration control, smart materials andstructures and acoustics.In the field of nonlinear dynamics, th...

this paper evaluates a new and simple controller design method based on qft (quantitative feedback theory) for a two-link manipulator whose first link is rigid and the second is flexible. a piezoelectric patch is attached to the surface of the flexible link for vibration suppression of it. this system is modeled as a nonlinear multi-input multi-output (mimo) control systems whose inputs are two...

Structural Health Monitoring System for Deepwater Risers with Vortex-induced Vibration: Nonlinear Modeling, Blind Identification Fatigue/Damage Estimation and Local Monitoring using Magnetic Flux Leakage

Imperfection sensitivity of large amplitude vibration of curved single-walled carbon nanotubes (SWCNTs) is considered in this study. The SWCNT is modeled as a Timoshenko nano-beam and its curved shape is included as an initial geometric imperfection term in the displacement field. Geometric nonlinearities of von Kármán type and nonlocal elasticity theory of Eringen are employed to derive govern...

Nonlinear effects in vibration responses are investigated for the undamaged composite plate and the composite plate with a delamination. The analysis is focused on higher harmonic generation in vibration responses for various excitation amplitude levels. This effect is investigated using the triple correlation technique. The dynamics of composite plate was modelled using two-dimensional finite ...

Estimation of the modal parameters of mechanical systems or structures is usually achieved by applying the well-known Frequency Response Function (FRF) method to experimental data obtained from free vibration after a shock excitation of the system or forced vibration using a variety of excitation signals. This method is however limited only to linear systems. The problem becomes more complex wh...

The proportional and derivative nonlinear potential feedback controls via piezoelectric sensor and actuator layers are used. A simple and consistent model combining the geometrical nonlinear affects and the feedback control of a piezoelectric/elastic/piezoelectric sandwich beams is derived. A mathematical methodology based on the multiple scales method for nonlinear vibration control of seconda...

Based on the continuum mechanics and a multiple-elastic beam model, the nonlinear free vibration of embedded multiwall carbon nanotubes considering intertube radial displacement and the related internal degrees of freedom is investigated. By using the incremental harmonic balanced method, the iterative relationship of nonlinear amplitude and frequency for the single-wall nanotube and double-wal...