ACTIVE CONTROL OF VIBRATION TRANSMISSION IN A CYLINDRICAL SHELL

Abstract The theoretical analysis of active control of harmonic power transmission in a semi-infinite cylinder using a circumferential array of control forces and a circumferential array of error sensors is considered, and the extent of control which is achievable for a realistic control force configuration is examined. The model considered is a semi-infinite cylinder, simply supported at one end, anechoically terminated at the other end and excited harmonically by an array of in-phase primary forces arranged in a line around its circumference. Control is achieved by an array of independent control forces applied downstream from the primary forces. For three or more control forces it is possible to achieve a power transmission reduction of 30 dB for both acceleration and power transmission cost functions, provided that the error sensors are in the far field of the primary and control forces.