A power transmissibility approach for evaluating the performance of transient vibration isolation

The traditional performance indicator of vibration isolation is known as force transmissibility. It over-simplifies the vibration problem by neglecting the floor flexibility, which leads to occasional unsatisfactory performances of traditionally designed vibration isolators. Therefore, in view of this limitation, a power transmissibility method is proposed by Mak and Su as an improved indicator. However, their model does not apply in the scenario of transient vibration excitation. Transient vibration excitations, such as the sudden or frequent starting and stopping of vibratory machines, widely exist in building services equipment. Motived by the problem due to the negligence of transient excitations, an indicator - transient power transmissibility - is proposed to assess the performance of transient vibration isolation. A vibration isolation system designed according to the steady-state power transmissibility of Mak and Su is considered in the simulation. Two transient excitations that are typically experienced by building services equipment are exerted on the system, and the performances are evaluated by the transient vibration transmissibility. The results indicate the necessity of applying the transient power transmissibility to the assessment of transient vibration isolation.