Accession Number : ADA299719

Title :   Fatigue of Polymers and Organic Composites.

Descriptive Note : Final rept. for period ending 31 Aug 93,

Corporate Author : BROWN UNIV PROVIDENCE RI

Personal Author(s) : Suresh, S.

PDF Url : ADA299719

Report Date : SEP 1993

Pagination or Media Count : 5

Abstract : This project is concerned with detailed experimental investigations of cyclic damage evolution and of the development of cyclic plastic' zones ahead of fatigue cracks in polymers subjected to cyclic compression and cyclic tension-compression loads. The implications of such cyclic damage will be examined for a variety of fatigue phenomena including crack closure and variable amplitude fatigue. The fundamental studies will include transmission electron microscopy of near-tip deformation and damage, laser interferometry and quantitative photoelasticity on model systems for a wide range of mechanical loading conditions (i.e., frequency, load ratio, and tension and/or compression cycling). The information derived from the experimental program will also be used to develop conceptual and quantitative life prediction models including reliability analyses. Another major extension of the proposed work will be to experimentally document of cyclic near-fields for a fatigue crack perpendicularly approaching a metal-polymer bimaterial interface and to determine the conditions for the continued advance, acceleration or arrest of the crack as a result of crack-tip/interface interactions.

Descriptors :   *POLYMERS, *COMPOSITE MATERIALS, *FATIGUE(MECHANICS), COMPRESSION, METALS, INTERFACES, ACCELERATION, CRACKING(FRACTURING), CRACKS, ELECTRON MICROSCOPY, CERAMIC MATERIALS, DEFECTS(MATERIALS), PLASTIC PROPERTIES, AMPLITUDE, PHOTOELASTICITY, POLYETHYLENE.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE