This paper studies the nonlinear vibration analysis of a simply supported Euler-Bernoulli beam resting on a nonlinear elastic foundation under compressive axial load using nonlinear normal modes concept in the case of three-to-one (3:1) internal resonance. The beam’s governing nonlinear PDE of motion and also its boundary conditions are derived and then solved using the method of Multiple Time ...

The main purpose of this work is to compare different criteria for the seismic strengthening of r.c. framed buildings in order to find the optimal combinations of these retrofitting techniques. To this end, a numerical investigation is carried out with reference to the town hall of Spilinga (Italy), a r.c. framed structure with an L-shaped plan built at the beginning of the 1960s. Five structur...

In this paper a simple tool for seismic design of steel structures for a selected ductility level is presented. For this purpose, a consistent set of earthquakes is selected and sorted based on the maximum acceleration of ground surface. The selected records are applied as the base motion to a single-degree-of-freedom system with strain hardening and the maximum response acceleration is determi...

This study aims to design novel tailorable and effective mechanisms by controlling buckling behaviour in structural elements of a composite wing for future morphing application. Instead the traditional against buckling, idea is embrace this built-in instability using nonlinear post-buckling response control stiffness changes which redistribute load structure. To enable desired multi-stable conf...

response modification factor (r factor) is one of the seismic design parameters to be considered in evaluating the performance of buildings during strong motions. this paper has tried to evaluate the response modification factor of concrete coupled shear wall structures with various length/depth ratios of spandrel beams. the effect of diagonal reinforcement of spandrel beam was also evaluated o...

In general, joints are assumed without clearance in the dynamic analysis of multi-body echanical systems. When joint clearance is considered, the mechanism obtains two uncontrollable degrees of freedom and hence the dynamic response considerably changes. The joints’ clearances are the main sources of vibrations and noise due to the impact of the coupling parts in the joints. Therefore, the syst...

We study the buckling of a two-dimensional elastica floating on a bath of dense fluid, subjected to axial compression. The sinusoidal pattern predicted by the analysis of linear stability is shown to become localized above the buckling threshold. A nonlinear amplitude equation is derived for the envelope of the pattern. These results provide a simple interpretation to the wrinkle-to-fold transi...

The nonlocal nonlinear buckling of a double layer graphene sheet (DLGS) covered by zinc oxide (ZnO) piezoelectric layers is investigated in this study. The surrounding circumstances of the system are considered as a Pasternak foundation including spring constants and a shear layer. Graphene sheets are subjected to longitudinal magnetic field and biaxial forces. On the other hand, the ZnO piezoe...

the complete 3d nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. for describing the dynamics of the system, the newtonian derivation procedure is followed. the velocity field inside the pipe formulated using hydrostatic and bernoulli equations. the hydrodynamic effects of external fluids are taken into consideration through the nonlinear drag forces in var...