Accession Number : AD0726745

Title :   Effect of Ductile and Viscous Dissipation on Fracture of Solids. Part I. Plastic Stress and Strain Fields near Crack Tip. Part II. Computer Simulation of Fracture Spreading in a Viscoelastic Solid.

Descriptive Note : Annual progress rept.,

Corporate Author : SOUTH DAKOTA STATE UNIV BROOKINGS DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Wnuk,Michael P.

Report Date : AUG 1971

Pagination or Media Count : 40

Abstract : Effect of small scale yielding occuring pior to fracture is discussEAIn terms of stress and strain fields existing in the immEAIate vicinity of crack tip. The deformation theory of plasticity is employed. Although the solution is incomplete since it does not provide the shape of the plastic zone, it generates some useful correlations between fracture toughness and other matallurgical parameters, like yield strength, ductility, strain hardening exponent and the grain size. In the second part a governing equation of motion, which describes early stages of fracture in a rate-sensitive solid, has been integrated through the use of an analog computer type EDI 380. Three regimes of the tensile pulsating loading, for which there are no closed form solutions, are considered: sinusoidal load, trapezoidal load and randomly oscillating load. (Author)

Descriptors :   (*ALLOYS, *FRACTURE(MECHANICS)), (*CRACK PROPAGATION, MATHEMATICAL MODELS), STRESSES, STRAIN(MECHANICS), PLASTIC PROPERTIES, CRACKS, DEFORMATION, STRAIN HARDENING

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE