COSATI CODES f lELD C«OUP SUB. GR. 1& SUBJECT TERMS tCoHtinua on ravana if naeanary and idanttfy by bioc* numbtr) Acoustics Acoustic Radiation Variational Principle 19. ABSTRACT tContin I lavana if nactuary and idantify by btoek numbar) ABSTRACT A variational principle governing the acoustic pressure on the exterior of an arbitrary body is derived from the Kirchhoff-Helmholtz integral relation....

In this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equations of orthotropic plates, Generalized Differential Quadrature method (GDQM) was applied on buckling equations and thus a set ...

In this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equations of orthotropic plates, Generalized Differential Quadrature method (GDQM) was applied on buckling equations and thus a set ...

In recent years, impedance measurement method by piezoelectric (PZT) wafer activesensor (PWAS) has been widely adopted for non-destructive evaluation (NDE). In this method, theelectrical impedance of a bonded PWAS is used to detect a structural defect. The electro-mechanicalcoupling of PZT materials constructs the original principle of this method. Accordingly, the electricalimpedance of PWAS c...

For the purpose of improving the working reliability of the blisk (integrally-bladed disk) under severe environment, a passive vibration reduction method by depositing a hard coating on both sides of blades is developed and then investigated systematically. Firstly, an analytical model of the blisk-deposited hard coating is taken into account. Secondly, by using the Oberst beam theory and axial...

Abstract. In this article we study the estimation of bifurcation coefficients in nonlinear branching problems by means of Rayleigh-Ritz approximation to the eigenvectors of the corresponding linearized problem. It is essential that the approximations converge in a norm of sufficient strength to render the nonlinearities continuous. Quadratic interpolation between Hilbert spaces is used to seek ...

Least-squares principles use artificial " energy " functionals to provide a Rayleigh-Ritz-like setting for the finite element method. These function-als are defined in terms of PDE's residuals and are not unique. We show that viable methods result from reconciliation of a mathematical setting dictated by the norm-equivalence of least-squares functionals with practicality constraints dictated by...

Sound transmission between rooms is often encountered for the acoustic design and noise control engineers. A clear understanding on the acoustical behavior of rectangular cavities connected by flexible panel structure can be of the fundamental significance. In this paper, sound transmission between rooms through the flexible partition with its edges elastically restrained is investigated. Both ...

A comparison of the buckling analysis of the nanoplate and nanocomposite plate with a central square hole embedded in the Winkler foundation is presented in this article. In order to enhance the mechanical properties of the nanoplate with a central cutout, the uniformly distributed carbon nanotubes (CNTs) are applied through the thickness direction. In order to define the shape function of the ...