Abstract:

The feedforward active control of harmonic vibratory power transmission along a semi-infinite plate of finite width has been investigated analytically. One end of the plate was terminated anechoically, the other end was free and the remaining two sides were simply supported. Primary and control source configurations consisted of single sources in various locations and multiple sources arranged in a line across the plate. The primary sources were always located close to the free end of the plate, while the secondary sources were located further along towards the anechoic end. These latter sources were driven in such a way as to minimize the power transmission from the primary sources to the anechoically terminated end of plate. Results show that with careful selection of the control actuator location, the power transmission from a simple harmonic primary excitation can be reduced by approximately 15 dB over a wide frequency range using only one control actuator. Using a number of independently controlled forces placed in a line across the plate produced significant power transmission reductions over a wide range of forcing frequencies with a theoretically achievable maximum of 120 dB for an ideal controller.