the course of consecutive experiments in this report aimed to a research or introductory identification about mechanical and acoustical properties of maple (acer velutinum) wood. studied factors were included quality factor (due to internal friction), acoustic coefficient, acoustical conversion efficiency as well as the modulus of elasticity (young’s modulus) which they were all accomplished us...

An approximate numerical mthod is presented for analysis and determination of modal characteristics in straight, pretwisted non-unifom helicopter blades. The analysis considers the coupled flapwise bending (out of plane), chordwise bending (in plane), and torsion vibration of both rotating and non-rotating blades. The proposed method is based on the integral expansion of Green functions (struct...

Elastic structures of buildings and machines, the dynamic behavior mathematical model which is problem longitudinal vibrations rods, are widespread in modern technology. In this regard, study issues related to rods also an urgent currently. terms solving such problems, we considered formulation (free forced) vibration obtained spectra natural frequencies ω n own forms φ (x) vibration, u(x, t) –...

This paper deals with free vibration analysis of thick Laminated curved panels with finite length, based on the three-dimensional elasticity theory. Because of using two-dimensional generalized differential quadrature method, the present approach makes possible vibration analysis of cylindrical panels with two opposite axial edges simply supported and arbitrary boundary conditions including Fre...

Effects of vibrating structure on the free-field motion are presented through a field experiment at the Euro-Seistest and a corresponding numerical simulation. Ground motion has been recorded by a dense temporary three-component (3C), two-dimensional (2D) seismic network installed at increasing distances from a model building forced into vibration by pull-out tests. The building is a five-story...

In this study, the buckling and free vibration of Timoshenko beams resting on variable elastic foundation analyzed by means of a new finite element formulation. The Winkler model has been applied for elastic foundation. A two-node element with four degrees of freedom is suggested for finite element formulation. Displacement and rotational fields are approximated by cubic and quadratic polynomia...