Accession Number : ADA301207

Title :   Nonlinear Temperature Dependent Failure Analysis of Finite Width Composite Laminates.

Descriptive Note : Final rept.,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ENGINEERING SCIEN CE AND MECHANICS

Personal Author(s) : Nagarkar, Aniruddha P. ; Herakovich, Carl T.

PDF Url : ADA301207

Report Date : DEC 1979

Pagination or Media Count : 130

Abstract : A quasi-three dimensional, nonlinear elastic finite element stress analysis of finite width composite laminates including curing stresses is presented. Cross-ply, angle-py, and two quasi-isotropic graphite/epoxy laminates are studied. Curing stresses are calculated using temperature dependent elastic properties that are input as percent retention curves, and stresses due to mechanical loading in the form of an axial strain are calculated using tangent modulii obtained by Ramberg-Osgood parameters. It is shown that a'ring stresses and stresses due to tensile loading are significant as edge effect in all types of laminate studies. The tensor polynomial failure criterion is used to predict the initiation of failure. The mode of failure is predicted by examining individual stress contributions to the tensor polynomial. Failure is predicted to always initiate at the free edge, but not always at ply interfaces. The location and mode of failure is shown to be laminate dependent. (MM)

Descriptors :   *LAMINATES, *FAILURE(MECHANICS), *GRAPHITE EPOXY COMPOSITES, THERMOMECHANICS, INTERFACES, COMPOSITE MATERIALS, EDGES, FINITE ELEMENT ANALYSIS, LOADS(FORCES), STIFFNESS, TENSILE PROPERTIES, ELASTIC PROPERTIES, TENSORS, CURING, THERMAL STRESSES.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE