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Assisted Data Analysis for Portable Nondestructive Inspection

Description:

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Develop algorithms to assist in the analysis of the outputs (e.g. ultrasonic waveforms and eddy current impedance plane data) from portable nondestructive inspection tools to enhance human interpretation and rate of analysis of the data. This includes addressing data from multiple flaw detection applications, such as angle beam shear ultrasound for crack detection, through-transmission ultrasound detection of water and other foreign objects in honeycomb material, and multi-layer eddy current damage detection using low frequency data. 

DESCRIPTION: There is a significant potential for growth of nondestructive inspections that require the use of portable instrumentation to detect defects in various classes of structures, such as multi-layered metallic structure and honeycomb with either metallic or composite skins. The goal of this topic to develop algorithms that can assist the nondestructive inspector in the interpretation of either ultrasonic or eddy current data from these applications to facilitate the accomplishment of the inspection to increase the efficiency and effectiveness of the nondestructive inspection process. The intent for these algorithms is to be compatible with portable systems that export the data acquired during inspection using readily available interfaces and neutral formats. No specific format is being identified as the capability needs to focus on the analysis of the data and it is understood that translators can be developed for any instrument that exports proprietary data. In addition, the outcome of the automated analysis should be exportable via translators if specific formats are required for performing the automated analysis. The specifics for archiving the data once the analysis has been performed is not within scope of this topic. 

PHASE I: Develop and demonstrate feasibility of using assisted defect analysis methods to facilitate effective and efficient interpretation of hand-held ultrasonic inspections. Initial applications should focus on angle beam shear methods to detect fatigue cracks in laboratory-based single layer metallic structure. 

PHASE II: Demonstrate integration of assisted defect analysis into handheld ultrasonic instruments. Demonstrate capability on representative aircraft structure. Provide sensitivity and false call approximations. Desired capability is to detect all fatigue cracks greater than 0.10” emanating from an free edge of a structure or from a fastener hole assuming no compressive residual stresses affecting the fatigue crack, plus a false call rate of less than 5% threshold, 1% objective. In addition, demonstrate capability to for assisted defect analysis to detect delaminations in 1.0” or thinner polymer matrix composites for defects larger than 0.5” threshold, 0.25” objective with the same false call requirements listed for fatigue crack detection. No specific quantitative metric is defined to improving the speed of the inspection, but an assessment of this improvement is desired. 

PHASE III: Fully integrate the assisted defect analysis into portable nondestructive inspection systems and validate capability via a Probability of Detection study following the guidance of MIL HDBK 1823A. The assisted defect analysis capability will be relevant for hand-held inspections for commercial aviation, power, oil/gas, and other transportation industries. 

REFERENCES: 

1: MIL HDBK 1823A, Nondestructive Evaluation System Reliability Assessment

2:  Structures Bulletin En-SB-08-012, Revision C, In-Service Inspection Flaw Assumptions for Metallic Structures

KEYWORDS: Nondestructive Inspection, Automated Defect Analysis, Ultrasound, Angle-beam Shear Waves 

CONTACT(S): 

Eric Lindgren 

(937) 255-6994 

eric.lindgren@us.af.mil 

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