RESEARCH ON THE VIBRATION REDUCTION AND SOUND RADIATION INDEX PROPERTIES OF THE CABIN WITH INTERNAL EQUIPMENT

摘要

Suitable vibration and noise indices which provide technical direction for vibration and noise reduction, play a very important role in structure analysis and validated test. The contribution of foundation impedance is studied by analyzing the vibration reduction index of a single degree of freedom system. The finite element method (FEM) and boundary element method (BEM) are applied to simulate the vibration and noise indices of a cabin along with internal equipment. The vibration reduction and sound radiation indices of the internal isolator have been calculated to analyze the variation trend with frequency. The results indicate that the difference between vibration level difference and insert loss is very small in most frequency band. Interestingly, the power flow difference and radiated sound power are opposite in phase in middle and high frequency band, which have been proved to be appropriate elements to evaluate the vibration and noise indices of the cabin. The analysis method and procedure can be used to objectively evaluate the vibration reduction property of similar vibration isolators.