Underwater Diver-Applied Composite Patch Repair for Crack Arresting

Marine aluminum structures across different Navy platforms are prone to cracking, particularly in aluminum hulls. Repairing these cracks by traditional means is costly and time-consuming, and the Navy needs an adaptable and durable solution that can be applied underwater without dry docking the vessel. To address this need, Texas Research Institute Austin (TRI Austin) proposes an applied research project to develop an underwater composite patch repair (CPR) capability that can be used for short-term emergent repairs or longer-term permanent repairs. TRI Austin will refine the formulation for its epoxy resin with hydrophobic properties developed in Phase I. The study will perform characterization of the composite properties through mechanical testing in different environmental conditions. Cyclic load testing of patched specimens will verify crack arresting performance. Finite element analysis based upon material data and testing will determine CPR parameters for successful patch designs that arrest cracks. The TRI Austin team will refine the vacuum bagging approach that was successfully demonstrated in Phase I for underwater patch installation including the development of a fixture to facilitate application via a diver. During the Phase II, the TRI Austin team will conduct full diver trials of CPR installation on underwater targets, as well as installation on a Navy platform for evaluations.