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In the transducer arrays which are used in sonar to radiate powerful, directional sound beams, acoustic interactions between the transducers have many important effects. To predict the acoustic radiation power cancellation, 37 acoustic transducers are considered as theoretical model. Total radiation impedances and acoustic radiation power of the transducers are extracted using the equivalent electric circuit scheme. Based on the theoretical results the acoustic radiation power of the transducer has been found dependent of the mutual coupling effects.

The normalized self- and mutual-radiation impedances for a square piston in a rigid infinite baffle are formulated as quadruple surface integrals by using geometric relations and the impedances are evaluated numerically. Self-radiation resistance and reactance coefficients are compared to the tabulated values of Burnett and Soroka. Mutual radiation resistance and reactance coefficients exhibit an expected oscillatory decay as functions ofkaand the frequency of oscillation is dependent on the spacing parameterd/a. The amount of interaction impedance is dependent on the orientation of the pistons with respect to each other. When separation is along the diagonal direction at 45 °C, mutual-radiation impedance is minimized. The quadruple integrals for the radiation impedances are not restricted in their range of applicability.

The objective of this research is to determine how a cutting tool vibrates when chatter occurs and how this motion is related to the acoustic emission signal. Modal analysis impact tests were conducted to obtain the actual natural frequencies and mode shapes of the Cutting Tool Support Structure (CTSS) system. Cutting tests were also conducted to determine the phase relationship between feed and cutting direction accelerations. Acoustic emission tests were performed to determine the relation between AE signals and two accelerations. Bursts of AE signal were observed to occur approximately at the direction turning points of the Lissajous loop.