in this paper, homotopy perturbation method (hpm) has been applied to investigate the effect of magnetic field on cu-water nanofluid flow in non-parallel walls. the validity of hpm solutions were verified by comparing with numerical results obtained using a fourth order runge–kutta method. effects of active parameters on flow have been presented graphically. the results show that velocity in bo...

the problem of observer design for nonlinear systems has got great attention in the recent literature. the nonlinear observer has been a topic of interest in control theory. in this research, a modified robust sliding-mode observer (smo) is designed to accurately estimate the state variables of nonlinear systems in the presence of disturbances and model uncertainties. the observer has a simple ...

in this paper, pile behavior embedded in layered soil deposits subjected to seismic loadings is analyzed using a nonlinear fiber element for simulation of soil – pile interactions. in the created model, both pile and surrounding soil are modeled using fiber elements in a practical beam on nonlinear winkler foundation (bnwf) concept. herein, the features of drain–3dx finite element software are ...

Displacement-based methods are recognized as appropriate approaches to reach the goals of performance-based seismic design method. In the direct displacement-based seismic design method, the seismic yield displacement is applied as one of the important design parameters. In this paper, a new relation is suggested to determine the lateral displacement pattern at first yielding of eccentrically b...

The development of control systems for a two degreeof-freedom vibration suppression system using a magnetorheological (MR) fluid damper is the subject of this paper. It is assumed that system encounters impulsive disturbance forces. The objective is to use the (MR) fluid damper for the position control and vibration suppression of the payload. The control force is generated by regulating the el...

Nonlinear control allocation is an important part of modern nonlinear dynamic inversion based flight systems which require a highly accurate model aircraft aerodynamics. Generally, accurately implemented onboard determines how well the system nonlinearities can be canceled. Thus, more results in better cancellation, leading to higher performance controller. In this paper, presented that combine...