Effectiveness of Doubler Plates as a Permanent Repair Under Cyclic Loads in a Highly Corrosive Environment

Ship construction represents one of the more challenging planning problems in industry today. The purpose of this proposal is to reduce ship construction and operation costs by making optimal use of available automated fabrication facilities and designingfor maintainability. An efficient algorithm for solving this class of problem has been discovered. The feasibility of developing software tools for automatic assembly planning and detailing of ship structure and outfitting and automatic maintenanceremoval planning will be demonstrated, using this algorithm. The tools would automatically plan assemblies, determine joint locations in piping and seam locations in structure, layout piping in banks, and plan maintenance access. A working prototypewill be developed to verify that acceptable levels of fidelity and performance can be achieved. These new innovative tools will use accurate models of shipbuilding fabrication processes and life cycle operations so that they generate optimal designs/plansfor shop production. In addition to the construction cost and life cycle maintenance savings, use of these tools will enable a substantial reduction in planning man-hours. The intent is to develop software components to be integrated into existingcommercial CAD/CAM and planning systems. New design and planning business practices using these tools will be outlined.Anticipated savings are $160 million per year in construction costs and $1 million per year in planning costs for U.S. shipyards and $16million per year in reduced ship maintenance costs for ship owners. This assumes that 10% of piping fabrication work is moved from in-dock and in-module on-site fabrication to mechanized shop fabrication as a result of this project and that 5% ofstructural fabrication operations are moved from on-site fabrication to mechanized process lanes as a result of this project. A 5% reduction in ship maintenance costs is assumed through optimum design for maintenance.