Traditional modal analysis methods use either time domain or frequency domain approaches. Because vibration signals are generally non-stationary, time and frequency information is needed simultaneously in many cases. This paper presents an overview of the applications of joint time-frequency methods for modal analysis. Since a joint time-frequency analysis can decouple vibration modes, it has a...

the main objective of this article is evaluation of the simplified models which have been developed for analysis and design of liquid storage tanks. the empirical formulas of these models for predicting maximum sloshing wave height (mswh) are obtained from mass spring models (msm). a finite element modeling (fem) tool is used for investigating the behavior the some selected liquid storage tanks...

Till now, various models have been proposed in literature to simulate the behavior of riveted structures. In order to find the most accurate analytical method in modeling the dynamic behavior of riveted structures, a comparison study is performed on several of these models, in this research. For this purpose, experimental modal analysis tests are conducted on a riveted plate to verify the effic...

abstracttask-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 selected...

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...

Modal analysis is extensively used to study dynamic behavior of continuous and lumped parameter linear systems. More specifically, modal analysis can be used for the analysis and controller design of dynamic systems. In both cases, reduction of model size without degrading the accuracy is often required for the efficient use of the model. The reduction of modal models has been extensively studi...

Application Note 243-3 Η(ω) = Σ n r = 1 φ φ i j /m (n-) + (2 n) ω ω ξωω 2 2 2 2 2 Modal analysis is defined as the study of the dynamic characteristics of a mechanical structure. This application note emphasizes experimental modal techniques, specifically the method known as frequency response function testing. Other areas are treated in a general sense to introduce their elementary concepts an...

We have developed a theory that unifies the analysis of the modal properties of surface-emitting chirped circular grating lasers. This theory is based on solving the resonance conditions which involve two types of reflectivities of chirped circular gratings. This approach is shown to be in agreement with previous derivations which use the characteristic equations. Utilizing this unified analysi...