Colin H. Hansen
Dept. of Mech. Eng., Univ. of Adelaide, Adelaide, South Australia 5005
Active control of vibratory power transmission in a semi-infinite cylinder, using a circumferential array of control forces and a circumferential array of error sensors, is investigated experimentally and theoretically. The model considered is a semi-infinite cylinder, free at one end, anechoically terminated at the other end, and excited 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 levels of power transmission reduction in excess 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. The study also demonstrates how it is possible to simplify power transmission measurement methods for a realistic control force configuration.