Accession Number : AD0276662

Title :   NUMERICAL METHOD FOR DETERMINING THERMAL STRESSES INVOLVING PLASTIC FLOW

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : VIGNESS,I. ; CLEMENTS,E.W.

Report Date : 24 MAY 1962

Pagination or Media Count : 37

Abstract : Simple approximate methods for determining thermal stresses in nozzles are developed. The mathematical derivation assumes that a section of nozzle can be considered as a flat slab, with a condition of no bending distortion imposed. One surface of the slab is assumed to experience a temperature rise in an exponential manner; no heat loss is assumed to take place from any surface. Thermal properties are assumed to be independent of conditions of stress, and thermal diffusivity is assumed independent of temperature. Stresses are calculated for four cases: I. Constant elastic modulus. II. Modulus as a function of temperature but constant at any given temperature. III. Perfect elastic-plastic material with modulus and flow stress as a function of temperature; reversal of stress induced strains not accounted for. IV. A general condition of perfect elastic-plastic material with strain reversals permitted. A numerical example is given for the derivation of the stress distribution by the method of case IV. (Author)

Descriptors :   *ROCKET NOZZLES, CREEP, EQUATIONS, EXHAUST GASES, GAS FLOW, HEAT TRANSFER, MATHEMATICAL PREDICTION, SURFACE TEMPERATURE, TEMPERATURE, THEORY, THERMAL STRESSES, TUNGSTEN

Distribution Statement : APPROVED FOR PUBLIC RELEASE