Models for Predicting the Long-Term Strength of Rheonomic Materials

Reliable modeling and prediction of the long-term strength of materials are relevant, as they allow for accurate determination of the service life of structures and components made from these materials. The aim of this work is to develop models of the long-term strength of rheonomic materials under constant stress and step loading using the principle of damage accumulation, as well as a model for predicting their long-term strength under constant stress based on short-term test data. Using the developed models, the long-term strength of optical fiber with a moisture of 30% and 85% under constant stress from 1600 to 2100 MPa and aluminum alloy under a step change of stress at a temperature of 180 °C were predicted with high accuracy; the long-term strength of pearlitic steel was predicted based on short-term tests under constant stress at temperatures from 98 °C to 293 °C. The developed models have important practical significance, as they can be used for modeling and predicting the long-term strength of rheonomic materials in practice, particularly in cases where the conditions of their operation and loading history are known.