Accession Number : ADA305123

Title :   The Nonlinear Viscoelastic Response of Resin Matrix Composite Laminates.

Descriptive Note : Contractor rept.,

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

Personal Author(s) : Heil, C. ; Cardon, A. H. ; Brinson, H. F.

PDF Url : ADA305123

Report Date : JUL 1984

Pagination or Media Count : 150

Abstract : A review of possible treatments of nonlinear viscoelastic behavior of materials is presented. A thermodynamic based approach, developed by Schapery is discussed in detail and is used as the means to interpret the nonlinear viscoelastic response of a graphite epoxy laminate, T300/934. Test data to verify the analysis for Fiberite 934 neat resin as well as transverse and shear properties of the unidirectional T300/934 composited are presented. Long time creep characteristics as a function of stress level and temperature are generated. Favorable comparisons between the traditional, graphical and the current analytical approaches are shown. A free energy based rupture criterion is proposed as a way to estimate the life that remains in a structure at any time. (AN)

Descriptors :   *STRESS ANALYSIS, *VISCOELASTICITY, *EPOXY LAMINATES, STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, TIME DEPENDENCE, STRUCTURAL ANALYSIS, DEFORMATION, SHEAR MODULUS, STIFFNESS, MATRIX MATERIALS, MOISTURE CONTENT, RUPTURE, TRANSITION TEMPERATURE, NONLINEAR SYSTEMS, TEMPERATURE GRADIENTS, MATHEMATICAL PREDICTION, RESPONSE, SHEAR STRESSES, CREEP, MOLECULAR STRUCTURE, RELAXATION, FAILURE(MECHANICS), EPOXY RESINS, FREE ENERGY, ACCELERATED TESTING, HUMIDITY, GRAPHITE EPOXY COMPOSITES, SHEAR STRENGTH.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE