Beat Vibration Research Articles

On the Radial Vibration of Ball Bearings : Computer Simulation

Computer simulation is used to analyze the radial vibration of ball bearings in order to overcome the experimental and theoretical difficulties : the experimental difficulties are due to the complicated interaction of the dominant factors while the theoretical difficulties are due to the nonlinear spring behaviour and time-dependent excitation of ball bearings. The inner ring motion, which involves the Perret-Meldau problem, is considered in the radial plane for an ideal bearing the massive inner ring of which rotates at a constant speed under a constant radial load. The results show that superharmonic, subharmonic, beat and chaos-like vibrations appear, in addition to harmonic vibration which synchronizes with ball passage.

玉軸受のラジアル振動について : 計算機シミュレーション

Computer simulation is used to analyze the radial vibration of ball bearings in order to overcome the experimental and theoretical difficulties : the experimental difficulties are due to the complicated interaction of the dominant factors while the theoretical difficulties are due to the nonlinear spring behaviour and time-dependent excitation of ball bearings. The inner ring motion, which involves the Perret-Meldau problem, is considered in the radial plane for an ideal bearing the massive inner ring of which rotates at a constant speed under a constant radial load. The results show that superharmonic, subharmonic, beat and chaos-like vibrations appear, in addition to harmonic vibration which synchronizes with ball passage.

Parametric Excitation in the Self-excited Vibration System with Dry Friction : 2nd Report, In the Neighborhood of the Region of Parametric Resonance

In parametrically excited self-excitation systems with dry friction, approximate solutions outside the regions of parametric resonance of second order are obtained and it is ascertained that they are reasonable approximate solutions. Approximate solutions in the neighborhood of parametric resonance of firs order are obtained and critical frequencies where beat vibrations occur and disappear can be determined by the points of intersection of these solutions and parametric resonance curves of first order. By numerical results it is ascertained that this determination method of critical frequencies has high accuracy and the interaction between parametric excitation and self-excited vibration is discussed.

Combined analysis and test of earthquake‐resistant circuit breakers

AbstractFollowing the severe earthquake damage at San Fernando in 1971, it became of technical and perhaps psychological importance to demonstrate that properly re‐designed electrical equipment is able to withstand even worse transient vibration phenomena which can be produced in an earthquake simulator laboratory. This has been accomplished for one column of a 500 kV gas circuit breaker and the test results are used to qualify the much larger original 3‐column assembly by means of a computer‐aided structural analysis. Since the equipment exhibited some closely spaced, cross‐coupled modes of vibration, a valuable comparison could be obtained between the effects produced by El Centro 1940 ground acceleration and those for a more purposeful sine beat vibration input. The latter can be adjusted to produce definite stresses and fatigue effects in specific parts of the equipment due to quasi‐resonance response.

Seismic Testing of Metal Clad and Metal Enclosed Switchgear Using Sine Beat Vibrations

Switchgear in nuclear generating stations must continue to perform its essential functions during earthquakes. Sine beat vibration testing has been used to demonstrate such reliability. These tests have shown that switchgear of standard design will withstand the earthquake levels currently prevalent in nuclear generating station specifications without strength failure or the degradation of the safe performance of principal functions.