Accession Number : AD0745176

Title :   An Investigation of Initial Yield Surfaces for Unidirectional Reinforced Composites,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s) : Ericson,Walter Alfred

Report Date : MAR 1972

Pagination or Media Count : 203

Abstract : Initial yield surfaces of unidirectional fiber reinforced composites subjected to combined longitudinal, transverse normal, and longitudinal shear loads are calculated. The composite is composed of filaments arranged in a periodic square array embedded in a matrix material. The constituent materials are assumed to be homogeneous and isotropic, while the composite is assumed to be macroscopically homogeneous and transversely isotropic. The finite element method, using linear strain triangles, is employed to calculate the stresses throughout the composite. Von Mises yield criterion is used to calculate the elastic limit of the local microscopic combined stresses in the composite. A parametric evaluation is carried out by changing individual constitutent properties and evaluating the effect of this variation on the composite properties. Yield surfaces for several functional composites are included, as well as a computer program, in FORTRAN IV LANGUAGE, FOR THE CALCULATION OF A YIELD SURFACE. (Author-PL)

Descriptors :   (*COMPOSITE MATERIALS, LOADS(FORCES)), THESES, FIBERS, REINFORCING MATERIALS, MECHANICAL PROPERTIES, EPOXY RESINS, ALUMINUM ALLOYS, NUMERICAL ANALYSIS, BORON, GLASS TEXTILES, LAMINATES, CARBON FIBERS, COMPUTER PROGRAMS

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE