A mixed time integration scheme for virtual fabrication of steel plate girders

In this paper the use of mixed time integration is proposed to increase the efficiency of welding simulation. A technique similar to the one commonly used in sheet metal forming is applied to the welding of steel plates. The welding procedure can be divided into two very distinguishable parts with significantly different characteristics. The first part, the phase of the actual welding, is a fast paced, rapidly changing process that involves highly nonlinear material behavior. The second part, the phase of cooling down, is a slow paced, slowly changing process that does not result in dramatic changes in the material behavior. In this project, explicit time integration was used for the thermo-mechanical analysis of welding and implicit time integration was proposed for the subsequent cooling phase. This paper presents examples based on the conventional fully implicit solution and the proposed explicit integration solution using the finite element codes ABAQUS/Standard and ABAQUS/Explicit, respectively.