Temperature Distribution During Plate Bending by Torch Flame Heating

Abstract

The flame bending of metal hull plates involves a complex thermoplastic process. In order to investigate the thermoplastic behavior it is first necessary to determine the time-varying temperature field in the plate. In this paper the temperature distribution during flame bending of a plate is studied using a distributed heat source moving along the plate surface at a constant speed. The temperature distribution is determined by the numerical solution of the partial differential equation describing the heat conduction in the plate as the distributed heat source passes. The equation is solved using the finite-element program ADINAT in the transient analysis mode. A number of results are presented to illustrate the transient behavior of the temperature near the plate edge as well as the quasi-steady-state temperature distribution. The results are shown to be in qualitative agreement with published experimental data. Additional studies are presented to clarify the influence on the temperature distribution from different material parameters, torch parameters and plate thicknesses. The point heat source expression was modified following Iwasaki's approach [4]. The temperature distribution calculated from this modified expression is shown to be in agreement with the numerical results.