In this work we study the invariant sets which emerge from zero-Hopf bifurcations that general Van der Pol-Duffing equations can exhibit. We provide sufficient conditions for simultaneous bifurcation of three periodic solutions and two torus origin system. use recent results related to averaging method in order analytically obtain our results. also numerical examples all analytical provide.

Based on a non classical plate theory, an analytical model is proposed for the first time to analyze free vibration problem of partially cracked thin isotropic submerged plate in the presence of thermal environment. The governing equation for the cracked plate is derived using the Kirchhoff’s thin plate theory and the modified couple stress theory. The crack terms are formulated using simplifie...

the current study presents a new analytical method for buckling analysis of rectangular and annular beams made up of functionally graded materials with constant thickness and poisson’s ratio. the boundary conditions of the beam are assumed to be simply supported and clamped. the stability equations were obtained by using conservation of energy. the critical buckling load and first mode shape we...

the current paper focuses on some analytical techniques to solve the non-linear duffing oscillator with large nonlinearity. four different methods have been applied for solution of the equation of motion; the variational iteration method, he’s parameter expanding method, parameterized perturbation method, and the homotopy perturbation method. the results reveal that approximation obtained by th...

We study the stability and exact multiplicity of periodic solutions of the Duffing equation with cubic nonlinearities, x + cx + ax − x = h(t), (∗) where a and c > 0 are positive constants and h(t) is a positive T -periodic function. We obtain sharp bounds for h such that (∗) has exactly three ordered T -periodic solutions. Moreover, when h is within these bounds, one of the three solutions is n...

A rational elliptic balance method is introduced to obtain exact and approximate solutions of nonlinear oscillators by using Jacobi elliptic functions. To illustrate the applicability of the proposed rational elliptic forms in the solution of nonlinear oscillators, we first investigate the exact solution of the non-homogenous, undamped Duffing equation. Then, we introduce first and second order...

The delayed Duffing equation $${\ddot{x}}(t)+x(t-T)+x^3(t)=0$$ is shown to possess an infinite and unbounded sequence of rapidly oscillating, asymptotically stable periodic solutions, for fixed delays such that $$T^2<\tfrac{3}{2}\pi ^2$$ . In contrast several previous works which involved approximate the treatment here exact.

An attempt is made in this study to estimate the noise level present in a chaotic time series. This is achieved by employing a linear least-squares method that is based on the correlation integral form obtained by Diks in 1999. The effectiveness of the method is demonstrated using five artificial chaotic time series, the Henon map, the Lorenz equation, the Duffing equation, the Rossler equation...

A horizontal axis wind turbine blade in steady rotation endures cyclic transverse loading due to wind shear, tower shadowing and gravity, and a cyclic gravitational axial loading at the same fundamental frequency. These direct and parametric excitations motivate the consideration of a forced Mathieu equation with cubic nonlinearity to model its dynamic behavior. This equation is analyzed for re...