Author Description

Flame straightening is a manufacturing process for achieving geometry of elements and members made up of structural steel. The technical background on flame straightening in the workshops of steel constructors is often based only on empirical knowledge, if it exists at all. As a consequence, the straightening of steel construction elements to achieve the required geometrical shape absorbs a large part of the manufacturing costs. This is due to uncertainty about the correct flame straightening process and the lack of background knowledge on its effects. Even though in scientific circles there is some knowledge on the mechanisms of flame straightening for different temperatures, holding times and steel grades, the knowledge is scattered, not well documented and has not been transferred to complex steel structures, sections, stiffness and real (extended) geometries. Also, application techniques, flame straightening procedures and an insight parameter clarification in particular for high strength steels do not exist at all. This report presents the results of the European research project Optistraight. Through experimental, numerical and analytical investigations, the mechanisms of different flame straightening processes have been clarified. Together with the available, but scattered, knowledge on this fabrication process the results give an in-depth view of the flame straightening process. Based upon this knowledge, prediction means have been developed to estimate the straightening result beforehand and to avoid expensive 'trial-and-error' tests, detrimental impacts on the material or excessive energy inputs.