A Theoretical Validation Of Burzynski Hypothesis For A Stress-Strain Analysis Of Heat-Resistant Steel

The paper proposes a comparison of the Huber-Mises-Hencky and the Burzynski thermal effort hypothesis to determine the state of stresses and strains in a structural element undergoing thermally variable cyclic loading. The proposed Burzynski temperature-dependent hypothesis has been used to define the equivalent stress as well as the yield surface for heat-resistant St12T steel indicating an essential strength differential effect. Since this effect increases with temperatures, the shape changes and surface movement were analyzed. As an example of application, numerical simulations of thermal loading were performed for a steam turbine blade made of St12T steel. The results of the analysis were used to describe a possible consequences between plasticity models based on the Huber-Mises-Hencky hypothesis and the thermally validated Burzynski hypothesis.