Accession Number:

AD0291502

Title:

ON THE MECHANICAL BEHAVIOR OF VISCOELASTIC-PLASTIC SOLIDS

Descriptive Note:

Corporate Author:

CALIFORNIA UNIV BERKELEY INST OF ENGINEERING RESEARCH

Personal Author(s):

Report Date:

1962-10-01

Pagination or Media Count:

1.0

Abstract:

THIS PAPER IS CONCERNED WITH A THEORY OF VISCOELASTICPLASTIC SOLIDSWHICH REDUCES TO THAT OF THE CLASSICAL LINEAR VISCOELASTICITY AS ONE LIMITING CASE AND TO THE INVISCID THEORY OF ELASTICPLASTIC SOLIDSIN ANOTHER. WHEREAS THE VISCOELASTIC STRAIN RATES ARE ASSUMED TO BE DERIVABLE FROM THE APPROPRIATE CREEP INTEGRAL LAWS OF CLASSICAL VISCOELASTICITY, THE PLASTIC STRAIN RATES IN STRESS SPACE ARE DEPENDENT NOTONLY ON THE PATH HISTORY BUT ALSO THE TIME HISTORY OF STRESS. AFTER POSTULATING THE EXISTENCE OF A REGULAR LOADING SURFACE IN THE VISCOELASTICPLASTIC STATE AND DEDUCING THE APPROPRIATE CRITERION FOR LOADING, A MAJOR PORTION OF THE PAPER IS DEVOTED TO ESTABLISHING 1 THE CONVEXITY OF THE LOADING SURFACE, 2 THE DIRECTION OF THE PLASTIC STRAIN RATE VECTOR IN STRESS SPACE, AND 3 THE STRUCTURE OF THE CONSTITUTIVE EQUATIONS FOR THE PLASTIC STRAIN RATES. THE LOADING SURFACE OF THE PRESENT THEORY IN CONTRAST TO THAT OF THE INVISCID THEORY OF PLASTICITY, BEING DEPENDENT ON CERTAIN MEASURES REPRESENTING TIME HISTORY OF STRESS, IS ALLOWED TO CONTINUALLY CHANGE ITS SHAPE THIS HAS IMPLICATIONS IN THE INTERPRETATION OF EXPERIMENTAL RESULTS DEALING WITH THE DETERMINATION OF THE INITIAL AND SUBSEQUENT YIELD SURFACES WHERE CORNERS ARE OBSERVED

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE