Dynamic collapse mode evolution in carbon composite tubes

An experimental study on the hydrostatic implosion of carbon-fiber reinforced epoxy composite tubes is conducted to explore unique failure and damage mechanisms of collapse. Experiments are performed in a pressure vessel designed to provide constant hydrostatic pressure through the collapse. Filament-wound carbon-fiber/epoxy tubes are studied using high-speed photography to explore the effect of complex damage on the modes of failure. 3-D Digital Image Correlation technique, which is first calibrated for the underwater environment, is used to capture the full-field deformation and velocities during the implosion event. Fourier Series deformation models are used to extract buckling modes from displacement data. The results reveal that the presence of damage in the structure can cause the mode shape to change as the structure deforms.