Isogeometric FE-BE free vibration analysis of plates resting on a Pasternak foundation and in contact with fluid

In this study, an isogeometric analysis (IGA)-based numerical framework is presented to investigate the dynamic characteristics of plates resting on a Pasternak foundation and in contact with fluid. The overall framework consists of a hybrid isogeometric finite element-boundary element (FE-BE) method, performing dry and wet analysis based on the linear hydroelasticity theory. In dry analysis, the dynamic characteristics are determined under in vacuo condition using an isogeometric finite element method (FEM) based on the Mindlin plate theory. Subsequently, in wet analysis, utilizing the predicted dry dynamic characteristics (dry natural frequencies and mode shapes) and assuming the surrounding fluid is ideal, the effect of fluid presence is determined in terms of generalized added mass coefficients using an isogeometric boundary element method to predict the wet dynamic characteristics (wet natural frequencies and mode shapes). To show the versatility of the presented framework, two select problems available in the literature, involving a vertical rectangular plate and a circular plate, are investigated. The predicted hydroelastic vibration characteristics are compared with those obtained from other numerical frameworks in the literature. The effects of fluid depth, geometric parameters, and foundation parameters are examined adapting in-depth parameter studies.