Abstract Modal analysis is very important for structural dynamics research. However, the simulation results have certain limitations and cannot be fully applied to engineering applications.Using LMS (LMS Test.lab) data equipment, modal experiments were carried out on pressure shell in air water respectively. The natural frequency damping ratio of each order mode are calculated using polyMAX(pol...

In this paper, the modal properties of the Alamosa Canyon Bridge obtained using ambient data are compared to those obtained from impact hammer vibration tests. Using ambient sources of excitation to determine the modal characteristics of large civil engineering structures is desirable for several reasons. The forced vibration testing of such structures generally requires a large amount of speci...

in this paper, optimum location of power system stabilizers in order to damp inter-area oscillations has been investigated by using modal series method. nonlinear effects grow in dynamical behaviors of heavily loaded stressed power systems significantly. hence linear based methods and techniques no longer present clear and exact response of the systems. in this article by defining new nonlinear...

The nonlinear system becomes an area with numerous investigations over the past decades. The conventional modal analysis could not be  applied on nonlinear continuous system which makes it impossible to construct the reduced order models and obtain system response based on limited number of measurement points. Nonlinear normal modes provide a useful tool for extending modal analysis to nonlinea...

Reduced-order mass weighted proper orthogonal decomposition (RMPOD), smooth orthogonal decomposition (SOD), and state variable modal decomposition (SVMD) are used to extract modal parameters from a nonuniform experimental beam. The beam was sensed by accelerometers. Accelerometer signals were integrated and passed through a high-pass filter to obtain velocities and displacements, all of which w...

This paper discusses static and dynamic response of nanoplate resting on an orthotropic visco-Pasternak foundation based on Eringen’s nonlocal theory. Graphene sheet modeled as nanoplate which is assumed to be orthotropic and viscoelastic. By considering the Mindlin plate theory and viscoelastic Kelvin-Voigt model, equations of motion are derived using Hamilton’s principle which are then solved...

In order to build efficient reduced-order models (ROMs) for geometrically nonlinear vibrations of thin structures, a normal form procedure is computed for a general class of nonlinear oscillators with quadratic and cubic nonlinearities. The linear perturbation brought by considering a modal viscous damping term is especially addressed in the formulation. A special attention is focused on how al...

As the 2nd report, we present a practical calculation method for torsional vibration of highly damped system with rubber couplings. This calculation system, constructed by a modal analysis technique, outputs frequency response characteristics, forced vibration responses, and mode animations. In respect of a damping model and calculation accuracy, it was verified that the assumption of general v...