LINE ADMITTANCE AT THE JUNCTION OF 2 PLATES WITH AND WITHOUT FLUID LOADING

A time harmonic line force or moment is applied at the junction of two plates in welded contact, with or without unilateral fluid loading. T he objective is the 2 x 2 matrix of admittances relating the applied f orce and moment to the deflection and rotation at the load. The struct ural asymmetry leads to coupling between force and rotation, and betwe en moment and deflection, even in the absence of fluid loading. The im pedance matrix is derived for sources with linear phase variation of t he form e(iky gamma) for real k(y). The dry plate problem is addressed first, and displays the possibility of a resonance when the drive is in phase with a flexural Stoneley wave, which is defined here. The flu id-loaded problem is attacked by expressing the vibration of either pl ate and the acoustic response in the fluid as transforms, the integran ds of which are derived using the Wiener-Hopf technique. It is found t hat the wet response shows the same general behaviour as for the dry p lates, but without the possibility of a structural resonance. Numerica l examples are presented showing the frequency dependence of the admit tance matrix for joined steel plates in water. The general theory for distinct plates under fluid loading also provides a new formula for th e line admittance of a uniform plate in a fluid. (C) 1996 Academic Pre ss Limited