(2) The detuning of the intrinsic frequency of tubes, the number of tubes in the calculation, axial-flow and the curvature of U-tubes, which influence on the critical velocity of tube arrays, are studied carefully.
The purpose of this article is to clarify the various characteristic frequencies of a linear single degree of freedom mass spring system with viaoous damping. The frequencies are: undamped frequency ω0 ( resonant frequency, phase resonant frequency, velocity amplitude resonant frequency ) , natural frequency ωn, ( displacement ) amplitude resonant frequency Ωad and acceleration amplitude resonant frequency Ωaa.
This study investigated the dynamic modulus of elasticity (DMOE) of wood panels of Fraxinus mandshurica, Pinus koraiensis, and Juglans mandshurica using the natural frequency measurement system of fast Fourier transform (FFT).
The natural frequency reached 1.201-kHz using finite element analysis, and the practice measurement result was 1-kHz.
Using the differentials of a stiffness matrix to design parameters, a method for calculating the sensitivity of natural frequency is presented.
Through the mode analysis of the liquid-solid coupled system, the first-order natural frequency, diaphragm vibration shape and amplitude-frequency relationship are obtained.
The natural frequency of the system was less than that of the structure on rigid foundation if the SSI is not taken into account, while its damping ratio was larger than that of the structure.
The forward problem is to solve the natural frequencies through a cracked structural model and the inverse problem is to quantitatively determine the crack parameters using the experimental testing frequencies.
Contour plots of normalized crack location versus normalized crack size were plotted by using the first three natural frequencies as the inputs.
The estimations of natural frequencies and damping coefficients of the platform found as a result of data processing of microacceleration measurements made during its free oscillations are obtained.
Determining the natural frequencies of fluid oscillations in complex pipelines
Below we formulate the problem of the natural frequencies of small oscillations of a liquid for the general case of an equilibrium liquid surface in a weak potential mass force field.
On this assumption, deviations of the Zeitgeber-frequency from the intrinsic frequency of the dependent systems cause phase-angle differences between the two systems.
Also, with short and relatively weak intersegmental connections, the network remains robust against perturbations as well as intrinsic frequency differences along the chain.
The temporal variation of the tidal component of the wind changes the observed frequency, sometimes substantially, while leaving the intrinsic frequency unaltered.
The intrinsic frequency and vertical and horizontal wavelengths of gravity waves in the stratosphere are 2f-3f, where f is the Coriolis parameter, and 2-3?km and 300-500?km, respectively.
Numerical evidence is given here that the family of such orbits is a continuous function of the rotation frequency Ω which varies between Ω?=?0, for the planar figure eight orbit with intrinsic frequency ω, and Ω =?ω for the circular Lagrange orbit.
The local-ether wave equation incorporating a nature frequency and the electric scalar potential is presented, from which the electrostatic force in conjunction with the inertial mass is derived.
It is found that, with the flow velocity increased, the nature frequency of the pipes reduced, increased, reduced again and so on.
Meanwhile the third-order approximate analytic expression is given for describing the nonlinear relation between nature frequency and peripheral moment, transverse loads, amplitude, base angle under the small deformation.
Changing from case 1 to case 2, the overall bridge system becomes softer which makes the nature frequency smaller.
For example, if a structure is damaged locally, its stiffness will decrease which lead to nature frequency decrease and damping increase.