Modal parameter extraction of high speed shafts is of critical importance in mechanical design of turbo-pumps. Due to the complex geometry and peripheral components of turbo-pumps, difficulties can arise in determination of modal parameters. In this study, modal properties of a turbo-pump shaft, was studied by experimental modal analysis, and using different excitation techniques. An innovative...

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...

The acoustic response to propagation through oceanographic uncertainty has been derived using polynomial chaos expansions to the coupled mode equations for propagation in range dependent environments. In this approach the sound speed variability is decomposed into vertical EOF mode shapes for uncorrelated components of the sound speed defect. Horizontally each of these EOFs is assumed to be cha...

M MDO OML A novel method has been developed for calculating q gradients of aerodynamic force and moment coefi% TSV cients for an aeroelastic aircraft model. This method t/c uses the Global Sensitivity Equations (GSE) to acX count for the aero-structural coupling, and a reduceda order modal analysis approach to condense the cou6 piing bandwidth between the aerodynamic and strucA rural models. Pa...

This paper describes dynamic analysis using proposed fast finite element method for a shock absorbing structure including a sponge. The structure is supported by nonlinear concentrated springs. The restoring force of the spring has cubic nonlinearity and linear hysteresis damping. To calculate damping properties for the structures including elastic body and porous body, displacement vectors as ...

This paper presents an efficient approach for the modal analysis of coupled soil-structure systems, which dynamic response is strongly influenced by embedment in soil. The methodology based on a finite element-perfectly matched layer model that allows derivation frequency-independent system matrices and computation properties system. achieved solving nonlinear eigenproblem using Compact Rationa...

Abstract Task-based language teaching is considered an effective way to achieve a harmony between grammar and communication. The present study investigates two different ways of teaching modal verbs: task-based versus traditional approaches. To this purpose, an Oxford Placement Test was administered to select 40 homogeneous participants out of a larger population who took this test. The selecte...

Abstract We present a modal analysis of coupled two-core integrated waveguides fabricated by femtosecond laser writing as function the core-to-core distance, illuminating position and input light wavelength. In order to do that we use correlation filter method, implementing computer generated holograms in phase-only spatial modulator. Due waveguide symmetry, prove it is not necessary encode com...