Accession Number : ADA319676

Title :   Experimental and Theoretical Aspects of Corrosion Detection and Prevention.

Descriptive Note : Final rept. 1 Sep 93-31 Aug 96,

Corporate Author : CONNECTICUT UNIV STORRS DEPT OF MATHEMATICS

Personal Author(s) : Madych, W. R. ; Devereux, O. F.

PDF Url : ADA319676

Report Date : 31 OCT 1996

Pagination or Media Count : 83

Abstract : This report summarizes activities and work completed between September 1, 1993 and October 31, 1996. In addition to this summary it contains two parts consisting of various details. The experimental portion of this project is supervised by 0. F. Devereux and conducted by P. C. Su. It is devoted to the investigation of initiation and growth kinetics of corrosion in airframe alloys, including joined and protectively coated specimens. The goal is to understand fundamental mechanisms by which corrosion damage develops in order to assist in design, maintenance, and performance evaluation of airframe systems. The general investigative procedure is based on the principles of electrochemical impedance spectroscopy, EIS. The theoretical portion concerns (1) the study of a mathematical model of corrosion conducted by G. Hernandez and (2) investigation of certain algorithmic aspects of tomography and signal and image processing supervised by W. R. Madych. The objective of (1) was to determine the theoretical consequences of a well known mathematical model of corrosion in alloys and the details of obtained results were summarized in article 1 on the list which was included in the second annual report. The work associated with (2) may be briefly described as follows: In order to approximate a small portion of a cross section conventional reconstruction algorithms require the averages over all lines which pass through the entire cross section. In this work we show how certain high frequency components of a portion of a cross section can be approximated using only averages over lines which pass through or close to the region of interest. The resulting high frequency information is often sufficient for the detection of flaws, abnormalities, etc. Our method relies on the notions associated with the so-called continuous wavelet transform and the observation that Radon's classical

Descriptors :   *MATHEMATICAL MODELS, *IMAGE PROCESSING, *ALUMINUM ALLOYS, *GALVANIC CORROSION, ALGORITHMS, FOURIER TRANSFORMATION, AGING(MATERIALS), AIRCRAFT MAINTENANCE, DAMAGE ASSESSMENT, CORROSION INHIBITION, ELECTROCHEMISTRY, DEFECTS(MATERIALS), PROTECTIVE COATINGS, STRESS CORROSION, ELECTRICAL IMPEDANCE, HIGH PASS FILTERS, LOW PASS FILTERS, STRUCTURAL INTEGRITY.

Subject Categories : Properties of Metals and Alloys
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE