HIGH RESOLUTION SPECTRAL ANALYSIS NDE TECHNIQUES FOR FLAW CHARACTERIZATION PREDICTION AND DISCRIMINATION

THE METHOD OF ULTRASONIC SPECTROSCOPY HAS BEEN PROVEN TO BE EFFECTIVE IN NONDESTRUCTIVE EVALUATION OF STRUCTURAL MATERIALS OF INTEREST TO US ARMY. MUCH IMPROVEMENT OF THE METHOD CAN BE DERIVED FROM THE CURRENT ADVANCES IN DIGITAL SIGNAL PROCESSING, MODERN SPECTRAL ANALYSIS, AND DIGITAL PATTERN RECOGNITION. THE PHASE I STUDY MAKES EXTENSIVE USE OF THE MAXIMUM ENTROPY SPECTRAL ANALYSIS TO IMPROVE THE CAPABILITY IN FLAW CHARACTERIZATION, PREDICTION AND DISCRIMINATION. INDEED ALMOST ALL DESIRED INFORMATION ABOUT THE FLAWS CAN BE EXTRACTED EFFECTIVELY FROM THE MAXIMUM ENTROPY SPECTRAL ANALYSIS. THE PHASE I STUDY PROVIDES THEORETICAL AND EXPERIMENTAL FOUNDATIONS FOR EXTENSIVE TESTING OF ALGORITHMS IN PHASE II IN AN EFFORT TO DEVELOP AND IMPLEMENT A HIGHLY RELIABLE NONDESTRUCTIVE EVALUATION SYSTEM.