Detecting Crack Nucleation/Damage Mechanisms In Sea-Based Aviation Environments Navy SBIR FY2012.1 Sol No.: Navy SBIR FY2012.1 Topic No.: N121-099 Topic Title: Detecting Crack Nucleation/Damage Mechanisms In Sea-Based Aviation Environments Proposal No.: N121-099-0509 Firm: Technical Data Analysis, Inc. 3190 Fairview Park Drive Suite 650 Falls Church, Virginia 22042 Contact: Nagaraja Iyyer Phone: (703) 226-4070 Web Site: www.tda-i.com Abstract: TDA recognizes the need for analytical formulations for crack nucleation predictions and sensors to detect crack nucleation in environment assisted cracking of Naval aircraft structures. TDA proposes to investigate the role of microstructural damage evolution during pre-crack nucleation and stress field imposition; and methodologies, both electrochemical and electromagnetic, for measuring early response on the development of stress field and initiation of corrosion sensitive zones. This SBIR effort dovetails seamlessly with TDA's current work with ONR's UNIGROW-UNICORR program, in addition to the development of sensors for laboratory use as well as for leave-on placements on aircraft. TDA will develop analytical formulations for Navy material-environment systems. The analytical formulations will be incorporated into UNIGROW-UNICORR program to work as a design tool to predict nucleation of cracks in user-selected environment and loading situations. TDA also proposes to develop novel techniques using a combination of DCPD and ECN to detect small cracks. A prototype sensor capable of measuring small micro cracks of 10microns or less in corrosive mediums as well as providing continuous corrosion activity will also be developed. TDA will conduct critical tests using the proposed novel techniques and outline the steps needed for future sensor development. Benefits: The UNIGROW-UNICORR tool will provide designers as well as maintainers to predict corrosion damage during design and operation stage, but also allow them to evaluate its impact on overall structural strength and integrity considering local corrosion and interplay of other mechanisms. Because of tool's versatility, it has the potential to cater to the needs of a variety of industries encompassing big and small companies in off-shore oil drilling, civil engineering construction, aerospace boat/ship building and automotive. Early detection of cracks, specifically at the nucleating stage, will result in immense benefits for operational aircraft since proper remedial course of action can be planned and executed. A smart sensor that can continuously detect corrosion activity and minute cracks while they are forming is needed by many industries. The development of a suitable crack detection technique will enable development of a methodology to study crack initiation but may also be used to map out the range of stress states that may lead to active crack propagation. The data gathered using this approach can be integrated with a FEA model of the stress states of the structure of interest to map out the regions of highest susceptibility. The sensors can be developed further for real time assessment of performance of aircraft. Return