A frequency-wavenumber-domain formulation is presented in this paper for calculation of the Green's functions and wave propagation modes in a stratified fluid body underlain by a layered viscoelastic soil medium. The Green's functions define the solid and fluid displacements and fluid pressures due to uniform disk loads acting in either the soil or fluid media. The solution is in the frequency ...

Invention of carbon nanotube (CNT) in the 1990s introduced a new class of materials whose extraordinary mechanical, thermal, and electrical properties seemed appealing enough to the research community to devote their time and effort for the purpose of analyzing composite materials reinforced by CNTs. Particularly, the marvelous stiffness of CNTs has made it possible to reach a high-modulus comp...

In this paper, a novel approach proposed for structural damage detection from limited number of sensors using extreme learning machine (ELM). As the number of sensors used to measure modal data is normally limited and usually are less than the number of DOFs in the finite element model, the model reduction approach should be used to match with incomplete measured mode shapes. The second-order a...

In this paper, the extended finite element method (XFEM) is employed to investigate the statics and vibration problems of cracked isotropic bars and beams. Three kinds of elements namely the standard, the blended and the enriched elements are utilized to discretize the structure and model cracks. Two techniques referred as the increase of the number of Gauss integration points and the rectangle...

The present study investigates buckling characteristics of both nonlinear symmetric power and sigmoid functionally graded (FG) beams. The volume fractions of metal and ceramic are assumed to be distributed through a beam thickness by the sigmoid-law distribution (S-FGM), and the symmetric power function (SP-FGM). These functions have smooth variation of properties across the boundary rather tha...

In this study, mass, stiffness and damping matrices of the Nosrat jacket; located in Persian Gulf; equipped with Semi Active Tuned Mass Damper (SATMD) system have been derived after modeling the structure in SACS software. Owing to huge number of the degrees of freedom in the model, computation of on-line control of SATMD was time consuming. For this purpose, the size of the model was reduced i...

in the present paper, an algorithm is presented for reliability analysis of beams with random material properties under static spatially random loads. the randomness may be due to the employed manufacturing process that leads to components with slightly different microstructures. since the material properties are random, the stiffness matrices and subsequently, the response will be of random na...

FINGER iS a Lisp-based system to derive formulas needed in finite element analysis, and to generate FORTRAN code from these formulas. The generated programs can be used with existing, FORTRAN-based finite element analysis packages. This approach aims to replace tedious hand computations that are time consuming and error prone. The design and implementation of FINGER are presented. Techniques fo...

where n is the forcing function. In our problems, the mass and stiffness matrices are symmetric with the former semidefinite and the latter being positive definite. (We have ignored the damping term for now but it will be relevant in future.) The forcing function n is a product of a vector f that specifies the spatial distribution of the force and a scalar function g(t) that governs the tempora...