关键词: 振动与波, 双层隔振系统, 柔性基础, 力传递率, 插入损失, 振级落差, 功率流

Abstract:

Considering the flexibility of the foundation, using the evaluation parameters given by mechanical impedance to evaluate the isolation effect of the double-layer isolation system can not directly reflect the influence of the foundation’s stiffness on the isolation effect. This paper establishes the mechanical model of a flexible foundation double-layer isolation system and derives their physical parameter expressions from the definition of force transmissibility, insertion loss, vibration level difference, transfer power flow rate and insert power flow rate. These expressions can intuitively reflect the influence of the foundation’s stiffness on the isolation effect. Based on the example of a double-layer isolation system and from the influence of foundation’s stiffness values on the variation rule of force transmissibility, insertion loss, vibration level difference, transfer power flow rate and insert power flow rate with the excitation frequency, the conclusion is drawn that for the flexible foundation double-layer isolation system, the results of five kinds of evaluation parameters on the isolation effect are different according to the influence of the foundation’s stiffness. The results evaluated by the force transmissibility have a few differences, while the results evaluated by the insert loss and insert power flow rate have some differences, and the results evaluated by the vibration level difference and transfer power flow rate have big differences.