Bond Graph Model of a Multi-Layer Piezoelectric (PZT) Beam and Its Application in Semi-Active Hydraulic Mounts

Passive fluid mounts have been in use for the purpose of cabin noise and vibration reduction in the automotive and the aerospace industry. Cabin noise and vibration isolation is provided at a frequency coined “notch frequency”. To obtain the greatest cabin noise and vibration reduction at any desired frequency, the notch frequency needs to be close to that desired frequency. But, due to tolerances on all the fluid mount dimensions, and elastomer material properties, the notch frequency never ends up at the right location on the first manufacturing pass. To resolve notch frequency tuning cycle time, a new fluid mount design is proposed which consists of a conventional single-pumper fluid mount and a 3-layer piezoelectric cantilever beam resulting in a tunable notch frequency mount. Since this new design involves multi energy domains, bond graph modeling technique is used. This new design concept, its mathematical model and simulation results are presented.