Active vibration control of structures undergoing bending vibrations
First Claim
1. An active vibration control subassembly for a structure having first and second generally opposing sides, said structure undergoing bending vibrations caused by a source independent of said subassembly, and said subassembly comprising a first piezoceramic actuator plate vibratable by a first applied electric AC signal, said first plate connected to said first side of said structure such that vibrations in said first plate induced by said first AC signal cause bending vibrations in said structure and such that said first plate is compressively prestressed along said structure when said structure is free of any bending vibrations, and wherein said first AC signal is controllable such that bending vibrations in said structure caused by vibrations in said first plate induced by said first AC signal are generally opposite in phase to bending vibrations in said structure caused by said source.
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Abstract
An active vibration control subassembly for a structure (such as a jet engine duct or a washing machine panel) undergoing bending vibrations caused by a source (such as the clothes agitator of the washing machine) independent of the subassembly. A piezoceramic actuator plate is vibratable by an applied electric AC signal. The plate is connected to the structure such that vibrations in the plate induced by the AC signal cause canceling bending vibrations in the structure and such that the plate is compressively pre-stressed along the structure when the structure is free of any bending vibrations. The compressive prestressing increases the amplitude of the canceling bending vibrations before the critical tensile stress level of the plate is reached. Preferably, a positive electric DC bias is also applied to the plate in its poling direction.
55 Citations
10 Claims
- 1. An active vibration control subassembly for a structure having first and second generally opposing sides, said structure undergoing bending vibrations caused by a source independent of said subassembly, and said subassembly comprising a first piezoceramic actuator plate vibratable by a first applied electric AC signal, said first plate connected to said first side of said structure such that vibrations in said first plate induced by said first AC signal cause bending vibrations in said structure and such that said first plate is compressively prestressed along said structure when said structure is free of any bending vibrations, and wherein said first AC signal is controllable such that bending vibrations in said structure caused by vibrations in said first plate induced by said first AC signal are generally opposite in phase to bending vibrations in said structure caused by said source.
Specification