Design of Vibration Excitation Test Rig with Redundant Degree of Freedom

Abstract

In order to provide controlled indoor experiment condition for the anti-vibration performance test of vehicle suspension, the multi-link vibration excitation test rig with redundant degree of freedom, which can simulate the different roughness roads and can produce stable, ergodic, random vibration excitation, was designed in the paper. First, according to the different redundant degrees of freedom, the four and three degrees of freedom vibration excitation test rig structural schemes were designed respectively, and the solid model and motion simulation of vibration excitation test rig were performed based on virtual technology, then the time history curves of displacement, velocity and acceleration at work bench were obtained. Second, vibration properties and characteristics of the two schemes were ascertained by using self-power spectral density, symbol time series histogram and Shannon entropy, thereby three degrees of freedom scheme was considered better on the basis of random vibration level and impact force of mechanism. Finally, acceleration root mean square of work bench was set as evaluation index of vibration excitation test rig’s vibration excitation energy, and support distance, driven-crank rotation speed and spring stiffness under work bench were selected as influencing factors, then three factors and three levels of orthogonal design was conducted to determine three grades of vibration excitation test rig.