длительная прочность

Creep and Long-Term Strength Modeling for Thick-Walled Tubes under Combined Loading with Axial Force, Torsional Moment and Internal Pressure

We have developed a method for solving the boundary-value problem of rheological deformation and creep rupture of thick-walled tube under combined loading with axial force, torsional moment and internal pressure. Energetic variant of the theory of creep and long-term strength is used to describe creep process. Experimental verification of proposed method has been performed using known test data for creep and long-term strength of thick-walled tubes made of D16T alloy and Steel~20. Calculated dependencies for total axial strain and torsion angle on time are obtained.

The Equivalent Stresses at Calculation of Creep Rupture of Metals Under Complex Stress State (Review)

The criteria of creep rupture of metals under complex stress state are based on conception of equivalent stress σe. The basic attention is gived to determination of dependence of equivalent stress from the main stresses σ1, σ2, σ3 and to determination of dependence of rupture time from value σe. The detailed review of dependencies σe(σ1, σ2, σ3) is described, which were proposed by domestic and foreign scientists. The equivalent stresses σe, which are depended only on main stresses, and σe, which are depended also on the additional constants, are considered separately.