Analytical Predictions of Plastic Deformations of Heated Steel

Abstract

Thermal stresses are frequently used to camber steel beams or remove unwanted plastic deformation. A local concentration of heat is applied. The heated steel expands, but the expansion is restricted by the surrounding unheated metal. Compressive stress develops and yielding occurs. The method is complex and is practiced as an intuitive art which is not well understood by structural engineers. This paper describes a study of the theoretical models for predicting the effects of the process. The models are temperature‐dependent, inelastic models. The computation of heat flow is described, and methods of analysis and their convergence are noted. The advantages and disadvantages of the different models are noted, and the computed results are correlated to recent experiments. The results are generally in good agreement with trends noted in experiments. They show that increased temperature, heat angle and depth of heat increases the plastic deformation. Bending moments that cause compressive stress in the heated area also increase the plastic rotation, while an increase in the yield stress reduces the deformation. The analysis shows that large plastic strains must be expected with the V‐heat pattern. The results of this study provide a step in understanding this complex process.