Hydrodynamic Forces on Composite Structures

Using a tow tank environment an experiment was set up to measure for response of composite samples of varying stiffness to a geometrically comparable more rigid aluminum sample which was tested at increasing speeds. Also, a square composite shape was tested in a frame providing clamped boundary conditions. Testing of this sample over varying speeds was also performed at varying position angles and was analyzed for force, strain and flow visualization. Results show complex behaviors in fluid flow and structural deformation because of the effects of the free surface and fluid-structure interaction. The comparable mass density between composite plates and water results in pronounced fluid structure interaction. Proximity to the free surface highly influences the test data along with the position angle. Negative position angles in combination with high speeds result in an air pocket open to the atmosphere which translates to a sharp decrease in strain on the sample. Positive position angles yields different free surface effects including vortices and the onset of cavitation.