TECHNOLOGY AREAS: Materials/Processes

ACQUISITION PROGRAM: PMS 501, LCS Program, ACAT 1

OBJECTIVE: Develop an innovative and affordable approach to enable non-destructive evaluation and testing below the waterline for aluminum ships to both detect cracks and measure hull thickness. Proposed systems should demonstrate the ability to enable 100% coverage of the designated hull inspection areas, retain results

DESCRIPTION: Currently available hull thickness sensors use ultrasonics and provide coverage of a single point on the hull. The sensor must then be moved over the hull while the thickness readings are monitored to detect thin areas of hull plate. As the sensor is moved from point A to point B the coverage can be described as a "line". Currently available above-water systems are better suitable to the examination of areas in larger swaths as well as having the ability to detect cracks. These systems are generally array type sensors; however, they are not suitable for underwater applications because of the electronics and the precision involved. Other underwater technology exists that can detect cracks in steel using alternating current field measurements, but this would not work with aluminum due to the lack of magnetic properties.

The topic seeks to explore the development of innovative and alternative approaches for non-destructive evaluation and testing for crack detection and hull thickness measurement below the waterline for aluminum ships. It is desired that proposed technology solutions allow for inspection of wider swaths of hull to be able to provide timely, comprehensive assessments of the condition of the hull to the operator. Proposed concepts should be a reasonable size and shape such that they could be used by a diver or attached to a remote operating vehicle. Inspection criteria for proposed technical solutions should include, but not be limited to, hull geometry, hull physical characteristics focusing on weld seams and other likely crack formation locations together with operator defined thresholds for determining differences in sensor data from a prior inspection. Challenges to this will be the ability to distinguish between weld seams, joint areas, scantlings, hull stiffeners and bulkheads which could askew results and give false readings of hull thickness. Additional challenges will be the ability to develop a watertight enclosure that doesn�t impede the performance of the technical solution(s). The proposed system should retain prior inspection results and determine any changes from the prior inspections to include, but not be limited to, discontinuities in the hull (e.g., crack formation or thickness changes indicating internal corrosion), and physical differences from previous inspections. Of a particular interest is the ability of the operator mark objects/areas for future reference as well as the ability to classify the measured differences into classes of severity for future inspections and analysis including the setting of thresholds for defining a new difference. Concepts proposed should minimize ship impact (e.g., size, weight, power, stowage, etc.) and shall minimize the operational and personnel efforts to initiate, execute, and terminate the inspection process.

PHASE I: Demonstrate the feasibility of the development of innovative, alternative and affordable approaches to enable non-destructive evaluation and testing below the waterline for aluminum ships to both detect cracks and measure hull thickness. Establish performance goals and provide a Phase II development approach and schedule that contains discrete milestones for product development.

PHASE II: Develop, demonstrate and fabricate a prototype as identified in Phase I. In a laboratory environment, demonstrate that the prototype product meets the performance goals established during Phase I. Provide a detailed plan for software and/or hardware certification, validation, and method of implementation into a future ship test and/or design environment. Prepare cost estimates, logistics data packages, and interface documents for use in both forward fit and retrofit ship programs.

PHASE III: Utilizing the technology developed during Phase I and II, work with Navy and industry to certify and implement for use on existing and future naval and commercial shipbuilding programs.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Aluminum hull forms are used through the commercial maritime industry. This technology could also be used to inspect pilings/seawalls, hull inspections on commercial ships, surveillance and reconnaissance, or other underwater inspection activities.

REFERENCES:
1. http://www.ndt.net/article/v08n09/wong/wong.htm

KEYWORDS: Hull; Aluminum; NDE; NDT; Inspection; Underwater

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between November 10 and December 12, 2010, you may talk directly with the Topic Authors to ask technical questions about the topics. Their contact information is listed above. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting December 13, 2011, when DoD begins accepting proposals for this solicitation.

However, proposers may still submit written questions about solicitation topics through the DoD's SBIR/STTR Interactive Topic Information System (SITIS), in which the questioner and respondent remain anonymous and all questions and answers are posted electronically for general viewing until the solicitation closes. All proposers are advised to monitor SITIS (11.1 Q&A) during the solicitation period for questions and answers, and other significant information, relevant to the SBIR 11.1 topic under which they are proposing.

If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (866) 724-7457 or email weblink.