Accession Number : ADA305258

Title :   Notched Strength Prediction of Composite Materials Using Weibull-Type Integrals for Uniaxial and Biaxial Loading,

Corporate Author : DELAWARE UNIV NEWARK CENTER FOR COMPOSITE MATERIALS

Personal Author(s) : Wetherhold, Robert C.

PDF Url : ADA305258

Report Date : DEC 1979

Pagination or Media Count : 50

Abstract : The Weibull distribution model for brittle fracture is applied to a hole size study in uniaxial tension and to a study in biaxial tension. This application of the Weibull model uses a numerical integration of stress functions across a high-failure-risk volume. The results for uniaxial tension indicate a hole size effect which agrees in form with the "point-stress" or characteristic dimension theory. The uniaxial strength predictions based on Weibull theory are uniformly conservative. The predictions also show increasing notch sensitivity as the material becomes more "perfect", that is, has fewer and smaller inherent flaws. The biaxial Weibull study accurately predicts the failure mode and the strengthening effect of biaxial tension. The biaxial strength predictions are also generally conservative. The Weibull distribution model for brittle fracture is applied to a hole size study in uniaxial tension and to a study in biaxial tension. This application of the Weibull model uses a numerical integration of stress functions across a high-failure-risk volume. The results for uniaxial tension indicate a hole size effect which agrees in form with the "point-stress" or characteristic dimension theory. The uniaxial strength predictions based on Weibull theory are uniformly conservative. The predictions also show increasing notch sensitivity as the material becomes more "perfect", that is, has fewer and smaller inherent flaws. The biaxial Weibull study accurately predicts the failure mode and the strengthening effect of biaxial tension. The biaxial strength predictions are also generally conservative. (MM)

Descriptors :   *COMPOSITE MATERIALS, *BIAXIAL STRESSES, *AXIAL LOADS, *NOTCH TOUGHNESS, LOAD DISTRIBUTION, WEIBULL DENSITY FUNCTIONS, MAXIMUM LIKELIHOOD ESTIMATION, STRENGTH(MECHANICS), FRACTURE(MECHANICS), BRITTLENESS, HOLES(OPENINGS), FAILURE(MECHANICS), NOTCH SENSITIVITY.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE