Railway structures are one of the most important structures in transportation. So the lack of precise study of their dynamic behavior leads to irreparable damages. The significant factors contributing to the accurate analysis of the dynamic behavior of railways are the type of load and foundation used in it. In this study, an Euler-Bernoulli beam subjected to a moving load on a finite depth fou...

Because of difficulty in inspection and retrofit of foundation in comparison with other elements, the common design philosophy is to avoid any nonlinear deformation in the foundation. This paper shows that by employing controlled foundation nonlinearity, in predetermined sections with arrangements for inspection and retrofit, it is possible to reduce seismic demand on superstructure. Localizing...

This study develops a framework to perform integrated analysis for the seismic response of offshore wind turbines (OWTs). The ground motions are introduced in as depth-varying excitations that obtained from free-field site involving equivalent linearization approach. calculated accelerations at different elevations used beam on nonlinear Winkler foundation model, which is then simulate pile-soi...

This article presents an analysis of free vibration of elastically supported Timoshenko beams by using the spectral element method. The governing partial differential equation is elaborated to formulate the spectral stiffness matrix. Effectively, the non classical end boundary conditions of the beam are the primordial task to calibrate the phenomenon of the Timoshenko beam-soil foundation inter...

This paper studies dynamic stability of functionally graded beams with piezoelectric layers subjected to periodic axial compressive load that is simply supported at both ends lies on a continuous elastic foundation. The Young’s modulus of beam is assumed to be graded continuously across the beam thickness. Applying the Hamilton’s principle, the governing dynamic equation is established. The eff...

The classical reduced model for film/substrate bilayers is the one in which film governed by Euler–Bernoulli beam equation, and substrate replaced an array of springs (the so-called Winkler foundation assumption). We derive a refined normal shear tractions at bottom are expressed terms corresponding horizontal vertical displacements, response half-space described exact theory. self-consistency ...

in this article, the bending and free vibration analysis of functionally graded (fg) nanocomposites timoshenko beam model reinforced by single-walled boron nitride nanotube (swbnnt) using micro-mechanical approach embedded in an elastic medium is studied. the modified coupled stress (mcst) and nonlocal elasticity theories are developed to take into account the size-dependent effect. the mechani...

The bending and free vibration of porous functionally graded (PFG) beams resting on elastic foundations are analyzed. material features the PFG beam assumed to vary continuously through thickness according volume fraction components. foundation medium is also considered be linear, homogeneous, isotropic, modeled using Winkler-Pasternak law. hyperbolic shear deformation theory applied for kinema...

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...