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...

The base isolation systems are among the passive control devices that have been used over the last three decades to limit the seismic-induced response of structures. In this regard, the Uniform Building Code provisions (UBC) has incorporated a special section for the seismic design of base isolated structures since its 1991 edition. Due to the importance of the behavior of these structures unde...

The base isolation systems are among the passive control devices that have been used over the last three decades to limit the seismic-induced response of structures. In this regard, the Uniform Building Code provisions (UBC) has incorporated a special section for the seismic design of base isolated structures since its 1991 edition. Due to the importance of the behavior of these structures unde...

In this paper, semi-analytical method for asymmetrical eccentrically stiffened FGM cylindrical shells under external pressure and surrounded by a linear and non-linear elastic foundation is presented. The proposed linear model is based on two parameter elastic foundation Winkler and Pasternak. According to the von Karman nonlinear equations and the classical plate theory of shells, strain-displ...

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...

In this paper, natural frequencies and dynamic response of thick beams made of saturated porous materials resting on viscoelastic foundation are investigated for the first time. The beam is modeled using higher-order beam theory. Kelvin-voight model is used to model the viscoelastic foundation. Distribution of porosity along the thickness is considered in two different patterns, which are symme...

However it is possible to use of numerical methods such as beta-Newmark in order to investigate the structural response behavior of the dynamic systems under random sea wave loads but because of necessity to analysis the offshore systems for extensive time to fatigue study it is important to use of simple stable methods for numerical integration. The modified Euler method (MEM) is a simple nume...

maleic anhydride (man) copolymers with methyl methacrylate(mma), ethyl methacrylate(ema), methyl acrylate(ma), ethyl acrylate (ea) and buthyl acrylate (ba) ( in a 1:1 mole ratio) were synthesized by free radical polymerizations method under vacuum -azobis(isobutironitrile)(aibn) as an initiator of reaction at 701c. the copolymer compositions were determined using related 1h nmr spectra techni...

In this paper, Homotopy Analysis Method is used to analyze free non-linear vibrations of a beam simply supported by pinned ends under axial force. Mid-plane stretching is also considered for dynamic equation extracted for the beam. Galerkin decomposition technique is used to transform a partial dimensionless nonlinear differential equation of dynamic motion into an ordinary nonlinear differenti...

the base isolation systems are among the passive control devices that have been used over the last three decades to limit the seismic-induced response of structures. in this regard, the uniform building code provisions (ubc) has incorporated a special section for the seismic design of base isolated structures since its 1991 edition. due to the importance of the behavior of these structures unde...