This is the first in a two-paper series that investigates the influence of intramolecular vibrational modes on nonlinear, time-domain, electronically resonant signals. Both Transient Grating ͑TG͒ and Three Pulse Photon Echo Peak Shift ͑3PEPS͒ signals were collected from several probe molecules: Nile Blue,

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...

and in which a and 6 are constants, arises in applied mathematics in two main groups of problems. The first group, of which Mathieu's problem of the transverse vibrations of a taut elliptic membrane is typical, consists of boundary problems relative to some partial differential equation, such as the wave equation, where the boundary is an ellipse—or possibly a hyperbola. Here a fundamental requ...

An asymptotic analysis is carried out for the equations of free vibrations of a beam having varying curvature and cross-section. The effect of splitting the asymptotic limit for eigenvalues into two families is revealed and its connection with boundary conditions is discussed. The analysis of the properties of the asymptotic solution explains the phenomenon of transformation of mode shape with ...

where t is the time, fi is the frequency of the mode, di is the damping coefficient, ai is the excited amplitude, and θi is the initial phase. In general, θi is ignored and then, i-th mode parameter is represented as φi = ( fi,di,ai). As the result, a collection of mode parameters (φ1, ...,φr) determines the vibration specification of the structure, and modal sound synthesis uses it as the soun...

The fundamental frequencies and mode shapes of steel and carbon fiber–reinforced plastic (CFRP) cylindrical shells with steel inserts were investigated using finite element analysis and modal testing. The free-free boundary condition was tested with modal testing using the roving hammer method and verified by finite element analysis using ABAQUS. The results show good agreement between the test...

A spatially dense wireless sensor network was designed, developed and installed on a long-span suspension bridge for a 3-month deployment to record ambient acceleration. A total 174 sets of data 1.3 GB were collected from 64 sensor nodes on the main span and south tower of the Golden Gate Bridge. Analysis of the vibration data using power spectral densities and peak picking provide approximate ...

There is a worldwide interest in the proper design of embankment dams to resist earthquake loadings. For the first time in Iran, a complete ambient vibration survey due to low-level loads such as wind, machinery activities, low level tectonic activities, and water exit from bottom outlet was performed on Marun embankment dam. These kinds of ambient vibration tests are suitable for manifesting t...

There is a worldwide interest in the proper design of embankment dams to resist earthquake loadings. For the first time in Iran, a complete ambient vibration survey due to low-level loads such as wind, machinery activities, low level tectonic activities, and water exit from bottom outlet was performed on Marun embankment dam. These kinds of ambient vibration tests are suitable for manifesting t...

This study deals with the vibration and stability analysis of double-graphene nanoribbon-system (DGNRS) based on different nonlocal elasticity theories such as Eringen's nonlocal, strain gradient, and modified couple stress within the framework of Rayleigh beam theory. In this system, two graphene nanoribbons (GNRs) are bonded by Pasternak medium which characterized by Winkler modulus and shear...