Mass damping

Ratio of transverse and longitudinal effective masses, damping constant... 

A single-degree-of-freedom (SDOF) system is subjected to zero-mean stationary white noise excitation with spectral intensity Spo = 0.0048 s. The mass, damping coefficient and stiffness are taken to be Af = 1.0 kg, C = 0.4ar N s/m, and K = (4 r) N/m so that the natural frequency and damping ratio of the system are 2.0 Hz and 5.0%, respectively. Its velocity is sampled at a rate of 100 Hz for 10 s. To generate the time history of the velocity measurement, 10% of the rms noise is superimposed onto the velocity time history, i.e., the root-mean-square (rms) of the measurement noise is equal to 10% of the rms value of the noise-free velocity of... 

By means of various methods (Ewins 1984), the respective frequency response Xij a)) can be approximated by the superposition of several (n) adapted harmonic oscillators (so-called modal harmonic oscillators). Their parameters, the modal eigenfrequency co , the associated eigenvector as well as the modal damping 6 , correspond to the modal matrices Mm, Dm, and Cm (Gawronski 2004), but they are not comparable with a real mass, damping, or stiffness. Those modal harmonic oscillators only describe an... 

Here, M, C, and K are the structural mass, damping and stiffness matrices, respectively, and x is the structural displacement with respect to the ground. Xg is the ground acceleration, r,q is the ground acceleration application matrix, F is the... 

The frequency response function Hj m) depends on the mass, damping and stiffness matrices it is a function of the natural frequencies >/, the modal damping ratios /, and the normalized mode shapes given by ... 

From the resulting system of equations (equation 33) the mass, damping and stiffness matrices for the finite element can be obtained. 

Here m is the floor mass, mb, Cb, kb the base mass, damping and stiffness constants and iig the horizontal ground acceleration. The damping coefficients and frequencies for base and structural subsystems are given by... 

Tuned Mass Damper (TMD) A passive vibration control device which is a single-degree-of-ffeedom system consisting of mass, damping, and stif iess components. 

Considering a force and base excited SDOF host structure with mass, damping and natural frequency denoted and, respectively,... 

Kelly, J. M., Hasegawa, K. (1992). Application of a mass damping system to bridge structures. Report No. UCB/EERC 92/12. Berkeley, CA Earthquake Engineering Research Center. 

The ASME STS-1 Steel Stacks [2] governing standard used in the design of steel stacks is important, and everyone should be familiar with it. In Example E.7 in the standard, the mass damping parameter is used as a... 

Now look at the sixth criterion the mass damping parameter. According to Table 3.2 (from Table 5.2.1 of ASME STS-1 [2]), an unlined stack has a structural damping value, x, of 0.004, which Findlay [3] states is commonly used. According to Note 3 of this table, a structural damping value of 0.006 can be used only when the stack has a lining of a minimum of 2 inches thick... 

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