Mechanics |
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1995, Special Issue
V.I. Astafev, S.A. Shesterikov, L.V. Stepanova
STRESS AND STRAIN RATES ASYMPTOTICS NEAR THE CRACK TIP UNDER CREEP CONDITION
Stress and creep strain rates fields near the tip for crack of type II for case when material is subject to the steady state creep relations are analyzed. The linear - fractional stress - strain rate relations are assumed. The character of the creep strain rates singularity in the vicinity of the crack tip is discussed. The index of singularity ê depends on the polar angle of physical plane: ê = 1 in the half - plane which does not contain the crack; ê = 1/2 in the rest of plane.
O.A. Loginov
MODELLING OF CRACK GROWTH IN CREEP CONDITION
The theoretical model of creep crack growth with local fracture process zone is proposed. It is assumed that damage accumulation near the crack tip is described by Kachanov's damage pa rameters. The stress and damage distributions near a crack tip are found. These distributions are based on the assumption that stress and damage fields in fracture process zone are coupled by the equation σ e = σ *(1-ω). The proposed model of creep crack growth permits to described such phenomena as delayed fracture under creep conditions, crack initiations and subcritical creep crack growth, unstable crack propagation when crack length reaches its critical value.
E.N. Kozhevnikov, N.G. Dolmatova
HAMILTON OPERATOR EIGENFUNCTIONS IN COORDINATE REPRESENTATION
There are investigated in the article igenfunctions of the sguare of angular Hamilton operator 
which is given by derivatives with respect to cartesians components of vector 
determining this operator. Eigenvalues of 
, are determined, it is shown that eigenfunctions of , are traceless tenzors constructed by vector diad produkts. Some properties of egenfunctions are proved.
L.K. Shiryaeva
DAMAGE ACCUMULATION PROCESS IN METALS UNDER THE STRESS CORROSION CRACKING CONDITIONS
The governing equations for elastic-plastic materials describing the damage accumulation under SCC conditions are presented. Damage evolution equation generalized Kachanov's equation in creep is proposed. The change of failure surface mode during SCC conditions is described. The determination of material constants from available experimental data is proposed.