Maximum permissible vibration

The maximum permissible vibration, in mils (0.001 in.), during shop test at rated speed shall be equal to the square root of 20,000 divided by the sum of rated speed plus meeh-anieal and eleetrieal runout for the overhung rotor design. Only the aetual total measured runout may be subtraeted from the unfiltered peak-to-peak amplitude measured during testing to attain the shaft vibration. The meehanieal-plus-eleetrieal runout subtraeted from the unfiltered peak-to-peak amplitude shall not exeeed 0.5 mils regardless of total runout. 

In a hot gas expander, the major problems associated with catalyst fines are centered on erosion of components and particulate plugging. Either problem can cause machine vibration and sometimes power train emergency shutdown. Because many failures have resulted from these factors, machinery manufacturers recommend that the maximum permissible solids concentration upstream of an expander not exceed 200 ppm. It is further stipulated that 97% of the particles be smaller than 10 p. Allowing concentrations of 160 ppm with 95% of the particle less than 10 p is considered reasonable. 

Figure 3.1 Energy levels and wave functions of harmonic oscillator. Heavy line bounding potential (3.2). Light solid lines quantum-mechanic probability density distributions for various quantum vibrational numbers see section 1.16.1). Dashed lines classical probability distribution maximum classical probability is observed in the zone of inversion of motion where velocity is zero. From McMillan (1985). Reprinted with permission of The Mineralogical Society of America.

Figure 4. Relative rotational state distributions of OH products from overtone-vibration-induced unimolecular decomposition of HOOH. The solid bars are populations for excitation of the main local mode transition (6v0H) and hatched bars are populations for excitation of the combination transition (6v0H + v ). The quantum number N denotes the rotational OH angular momentum. Figures 4a and 4b show results obtained probing the Q, and R, branches, respectively, of OH. The error bars in Fig. 4(a) show the maximum range of values obtained and are typical of the uncertainties for all states. (Reproduced with permission from Ref. 39.)...

Engineers and designers should select equipment for installation which has low vibration and noise characteristics. They can require permissible maximum noise levels in specifications for new equipment. They can determine whether an operation, process, or piece of equipment that is noisy can be avoided or eliminated by use of a quieter one. Equipment that might vibrate should be mounted on firm, solid foundations. If equipment vibrates, they can determine whether or not its characteristics can be changed by use of devices such as dynamic dampers, rubber or plastic bumpers, flexible mountings and couplings, or resilient flooring. Where vibrations of fixed equipment cannot be eliminated, mount the equipment on vibration isolators to prevent transmission of motion. 

Fig. 7.7 Approximate nonadiabatic coupling vector Xgi (see the text for the definition) at t = 18.625 fs, at which the nonadiabatic coupling term reaches its maximum value in the collision of a water dimer anion and a water monomer. Although the vectors are time-dependent, their spatial orientations change only minimally during the periods of the vibration motions. (Reprinted with permission from T. Yonehara et al, Chem. Rev. 112, 499 (2012)).

Figure 7.7 First experimental detection of a MRFM experiment, made by Rugar, Yannoni and Sidles in 1992. Electron spin resonance was detected in a saintle of DPPH. Notice the maximum amplitude of vibration of the cantilever, less than 3 A Adapted with permission from [10].

Figure 1.3 The resonant gate field effect transistor, one of the first MEMS devices. A released metal cantilever beam forms the gate electrode over the diffused source-drain channel. The input signal is applied to the input force plate, which causes the cantilever beam to vibrate, modulating the current through the transistor. Maximum vibration occurs at the resonant frequency of the cantilever beam, enabling the device to act as a high-Q electromechanical filter. (Reprinted with permission from IEEE Trans. Electron Devices, The resonant gate transistor, H.C. Nathanson, W.E. Newell, R.A. Wickstrom and J.R. Davis Jr., 1967 IEEE.)...

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