Zur Analyse hydroakustisch erregter Strukturschwingungen auf FE-BE-Basis

The prediction of excitation, reflection and radiation behaviour of complex structures immersed in incompressible/compressible, non-viscous fluid represents a theoretical and numerical demanding task due to fluid-structure interaction. The paper presented is addressed to a method based on the mathematical model of a boundary value problem of the Laplace/Helmholtz Equation and the added  matrix concept. A combined FE-BE-procedure utilizing a direct boundary integral formulation of the potential fluid problem in interior/exterior domains is employed. The discretization in fluid domain is realized by boundary element collocation method using conventional as well as semi-infinite boundary element formulations. The solution of this partial problem is represented by frequency depended added mass and damping matrix being added to the equations of motion of the structure. Multi-body systems are considered explicitly. The convergence and the influence of frequency and structural impedance in hydro-acoustic range are demonstrated by numerical examples dealing with practical relevant excitation problems