This research program will apply analysis, nondestructive and experimental techniques in order to develop an understanding of impact damage in composite pipes under service conditions. The first phase will consist on the development of a finite element model that will include the effects of internal pressure as indicated by the service conditions of the structure. Endurance prediction models, of the composite after impact, will be developed and verified with experimental testing. The second phase will consist of a testing program with different levels of impact energy and internal pressure ratios on fiber reinforced composite pipes. During the experimental phase, nondestructive evaluation techniques such as acoustic emission, modal analysis and acousto-ultrasonics, will be applied to collect information about the mechanisms associated with failure induced by long term loading after impact. The final phase will consist on the analytical reduction of the experimental results for comparison with predictions from phase one and, the necessary adjustments to the models. This program will contribute to the understanding of the mechanical behavior of fiber composite materials, the ability to evaluate the significance of unexpected damage, and to the knowledge necessary for reliable implementation of composite materials in offshore structures.
