This paper proposes an improved control method based on modified Delta-Sigma Modulator (DSM) to enhance transient response and improve harmonic contents of buck DC-DC converter. The main advantages of the proposed method are improving the output voltage frequency spectrum, correction of the output voltage harmonic contents and sideband harmonics, reduction of switching noise peaks at the output...

In this paper, transverse and longitudinal vibration of nonlinear plate under exciting of orbiting mass is considered based on first-order shear deformation theory. The nonlinear governing equation of motion are discretized by the finite element method in combination with Newmark’s time integration scheme under von Karman strain-displacement assumptions. For validation of method and formulation...

Nonlinear Time History (NTH) analysis is currently the most reliable method for estimating structural behavior. Considerable computational demand and complexity of this method may cause difficulty for its routine practical application. Based on the Methodology of Endurance Time (ET) method, it can estimate the nonlinear response of structures with a much lower computational cost. In this resear...

A weakly nonlinear spectrum and a strongly nonlinear spectrum coexist in a statistically steady state of elastic wave turbulence. The analytical representation of the nonlinear frequency is obtained by evaluating the extended self-nonlinear interactions. The critical wavenumbers at which the nonlinear frequencies are comparable with the linear frequencies agree with the separation wavenumbers b...

in this paper a simple model of a three story building with inclined first-story columns has presented. the stories are supposed to be rigid and are connected to axially rigid mass less columns by elasto-plastic rotational springs and linear rotational dampers. the considered model is subjected to horizontal component of fault normal pulse with different magnitudes and the governed nonlinear di...

This paper deals with the problem of determining the nonlinear response of a plate endowed with fractional derivative elements and exposed to random loads. It shows that an approximate solution of the nonlinear fractional partial differential equation governing the plate vibrations can be obtained via a statistical linearization based approach. The approach is implemented by considering a time-...

in the conditions in which terrorist attacks on facilities and civilian places increase more and more attention to design of structures against impact loads of explosion is more important and needs special considerations. study of nature of blast loads and methods of applying it on the structure is one of the important problems. explosion is a sudden and rapid release of a great amount of energ...

For a class of nonlinear systems, referred to as Volterra systems, some important properties for system output frequencies are studied in this paper. These properties demonstrate several novel frequency characteristics of system output spectrum and reveal clearly the nonlinear effects on system output spectrum from different kind and degree of nonlinearities. These new results have significance...

In this study, the method of multiple scales is used to perform a nonlinear vibration analysis of a mechanical system in two cases; with dry and lubricated clearance joints. In the dry contact case, the Lankarani-Nikravesh model is used to represent the contact force between the joined bodies. The surface elasticity is modeled as a nonlinear spring-damper element. Primary resonance is discussed...