A Novel System for Ship Structure Crack Arrest and Repair

The new high-speed aluminum vessels in use by the Navy are designed to preclude crack initiation; however, experience with aluminum structures has demonstrated that plate cracking will occur and grow at an accelerated pace compared to other metals. Permanent repairs are expensive, time consuming, and hence, not feasible for the shipboard environment. The processes that represent the state-of-the-art are expensive, difficult and potentially hazardous to install, and are not able to simultaneously arrest crack growth and provide a watertight seal. Our novel solution to provide a robust repair of cracked aluminum alloy (5000 series) structures on Navy ships is our handheld Compact Repair System (CRS). We have adapted a conventional solid-state welding process currently used for large-scale manufacturing (conventional friction stir welding) and miniaturized the technology to facilitate the repair of cracks. Our CRS is ideally suited to portable systems for shipboard structural repair applications. During the Phase I project, we will assemble the CRS, complete repair testing on relevant materials, and design the prototype for shipboard repair. During Phase II, we will complete the system design, fabrication, and testing and transition the technology to the Navy fleet.