Modeling & Testing of Inflatable Structures for Rapidly Deployable Port Infrastructures

摘要

An experimental investigation of the fluid-structure interaction of a water filled inflatable membrane structure in the near shore environment was performed in the Coastal Marine Engineering Laboratory at the United States Naval Academy. The structure of interest was a 10' x 2' x 0.75' tubular bag developed at the Center for Innovation in Ship Design (CISD) at the Naval Surface Warfare Center (NSWC), Carderock Division as a proof of concept for the design of a rapidly deployable inflatable structure causeway to be used either as a ship to shore connector or a breakwater. The experiments were performed over a range of test conditions including three incident wave angles, three water depths, and a number of wave heights corresponding to various sea states. Results confirmed the previous conclusions that the bag is stable and well grounded for most operational sea conditions. Large amplitude and low frequency waves can induce significant motions of the structure, but the static and dynamic frictional coefficients between the structure and the surface in contact play a critical role in these motions. For conditions where the structure was at an angle of 45 deg to the incident waves, highly nonlinear wave conditions are produced which created wave over-topping and oscillatory motions of the structure.