Dynamic modeling of sail mounted hydroplanes system- Part I: Modal characteristics from a transfer matrix method

Hydroelastic stability and vibration analysis of full-scale fairwater planes system/or bow planes system mounted on the sail (bridge)/or main body can be quite complex. With the aim of addressing these problems, the present paper, Part I of a two part work, focuses on two aspects: (i) modeling and computation of the natural vibration characteristics of the entire assembly system utilizing and comparing two approaches, based on a finite element commercial software ANSYS and a recently developed Transfer Matrix Method of Multibody systems (MSTMM). Results show the latter technique is computationally accurate and efficient. It is also shown that an equivalent model consisting of one hydroplane with a torsional spring under specified boundary conditions may capture the dynamics behavior of the whole system; and (ii) implementing an equivalent model and MSTMM to obtain in-vacuum uncoupled pure bending and torsional frequencies. Such a treatment of the problem enables one to get a better understanding of the various parameters involved in the linear/nonlinear hydroelastic problem from a two degrees-of-freedom (2-DOF) reduced order model.