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

Period of Performance: 04/17/2001 - 10/14/2001


Phase 1 SBIR

Recipient Firm

BMA Engineering, Inc.
11429 Palatine Drive
Potomac, MD 20854
Principal Investigator


The objectives of Phase I are to survey the use of doubler plates, and provide a methodology for developing quantitative technical rationale (criteria) for their design and their use limitations as a repair fix for surface ships. The specific tasks needed to achieve these objectives of the proposed effort can be enumerated as follows: 1. Identify commonly used repair fixes for surfaces ships, and summarizes experiences of shipyards, owners and operators, 2. Develop methods for stress analysis and residual stresses assessment, 3. Develop methods to assess corrosion concerns, 4. Develop methods for fatigue and fracture assessment, 5. Define the needs of design methods, 6. Develop methods to assess fabrication and maintenance issues, 7. Develop method for setting design criteria and limitations, 8. Demonstrate the methods and processes, 9. Develop a plan for Phase II of the SBIR effort in the form of prototype products with a high potential for successful commercialization, and 10. Optional Effort: Develop a database structure of use experiences, and software architecture and plan. The marine industry needs assistance in understanding the limitations of using doubler plates based on experiences by owners and shipyards. Also, there is a need to efficiently perform designs of doubler plates by recognizing any limitations of their use. The anticipated products from this SBIR effort are in the form of a database and software that would help in meeting the needs of the industry.