Numerical analysis of rolled beam deformations subjected to heat straightening

Abstract

Restoration of the steel structures by heat straightening process has a long history, but national studies in this field have not been reported yet. The physical nature of this process is thermo mechanical, and the most of conducted studies have included the empirical investigation of angular distortions and mechanical deformations of structures and the restoration with the help of accelerators such as hydraulic jacks. In the present study, the numerical heat transfer and structural analysis of the process were carried out on an I-shaped cross section steel beam without application of external load. Oxy acetylene torch was considered as the heat source, and the Gaussian normal distribution model was used to model the input heat flux from flame to the beam surface. Three dimensional transient heat transfer and thermo elastic plastic deformations were analysed by finite element method in ANSYSTM software, and the results of thermo elastic plastic deformations were evaluated based on the amount of plastic rotation in the beam. Also role of the effective parameters such as supporting conditions, torch speed in different heating zones, heating dimensions and the path of torch movement on upper wing of the beam were studied. The results of numerical simulations carried out were in reasonable agreement with existing empirical data and showed the contribution of thermal deformation in the final deformations of the beam due to the non-application of external force.

Keywords

• heat straightening process
• thermal-structural analysis
• plastic rotation
• vee and strip heating
• flame heating