Механика машин, механизмов и материалов (Jun 2011)
Estimated Parameters for the Transient Oscillations of a Mechanical System with One Degree of Freedom in the Vibration Test
Abstract
When testing by sweep method the items are operated by the vibrations at all the frequencies within the range. Choosing the conditions of the accelerated tests on the action of sinusoidal vibrations with variable exciting frequency requires determining of dynamic amplitude-frequency characteristics (AFC) of items. The solution of differential equation of the load kinematic excited motion and the results of theoretical and experimental study of AFC of mechanical systems under transient vibrations are given. The parameters of the dynamic AFC depending on the speed of frequency scanning are worked out. Data processing are resulted in receiving empirical dependences for evaluating the maximum value of acceleration-relative transfer ratio, the ratio of the maximum of dynamic AFC frequency shift relative to the frequency of natural oscillations, coefficient of expansion of the dynamic resonance frequency band, the ratio of average AFC frequency shift relative to the frequency of natural oscillations for the exponential and linear laws of frequency scanning. The experimental data correlated with a high degree of compliance with theoretical results.