Selecting Criterion of Long-Term Strength in Assessing Durability of Constructions Operating Under Non-isothermal Loading Processes

Abstract

The paper summarizes one the approach to the describing the Pisarenko-Lebedev generalized long-term strength criterion, which is used in determining the equivalent stress in the Yu. Rabotnov’s kinetic equation of damageability. Finding the equivalent stress is one of the important yet difficult-to-solve problems. There are multiple long-term strength criteria, but no precise recommendations on their use, which is what makes this problem so difficult to solve. The most reasonable and universal criterion is generalized Pisarenko-Lebedev generalized long-term strength criterion. The authors proposed a simple and easy-to-use method to find the equivalent stress when using the Pisarenko-Lebedev generalized strength criterion. This method for concretizing the Pisarenko-Lebedev generalized long-term strength criterion, in the first approximation accounts for alterations in the plastic properties of the material as a function of the loading time, temperature, and stresses, enabling the research to account for the prevalence of viscous or brittle fracture, which in its turn enables more accurate damage and time-to-rupture predictions. More detailed experimentation to test this criterion and its concretization method requires further research based on in-site experiment data.