Hydrodynamic Response of a Bottom Mounted Flexible Membrane Structure In Gravity Waves Available to Purchase

The present paper describes a numerical model for the interaction between a bottom-mounted fluid-filled membrane and surface gravity waves. The longitudinal dimension of the membrane is much larger than its sectional dimensions thus effectively yielding a two-dimensional problem. The membrane is elastic and is assumed to be very thin, massless and without any flexural rigidity. The static shape of the membrane is first computed by considering the equilibrium of the external loads with the membrane hoop stress. The linear differential equation governing membrane deformations due to dynamic loads is obtained from the classical membrane theory of shells and solved using the finite element method. Both the kinematic and dynamic boundary conditions are satisfied at the fluid-membrane interface. The motions of both the internal and external fluids are computed respectively by two boundary element models based on potential theory, which in turn are coupled with the finite element model. Through a numerical example, the proposed model is shown to be effective in simulating the dynamic behavior of the membrane in gravity waves. Introduction Membrane and tension structures have been used extensively in structural and architectural design of buildings. Many analytical and numerical techniques are available to analyze these structures for a variety of engineering applications (Leonard [7]). These membrane structures change their geometry to accommodate external loads rather than increase stress levels, and therefore are efficient engineering structures in the severe environment. The dynamic behavior of a fluid filled membrane can be easily tuned by adjusting the interior pressure. A number of feasibility studies have been carried out to investigate the applications of membrane structures in the ocean environment. One of the earliest studies was carried out by Green [3] to investigate the dynamic behavior of pneumatic breakwaters.