Estimation of fusion front in 2D axisymmetric welding using inverse method

This paper deals with heat transfer analysis in a static welding process. A method is developed to estimate the evolution of a 2D axisymmetric shape of a fusion front. The estimation is performed from theoretical temperature measurements taken in the solid part from a multiphysics problem which is validated with an experiment. The estimation procedure is based on the conjugate gradient method coupled with the iterative regularization algorithm. The gradient is computed using adjoint equations. The goal of this work is to apply an ALE (Arbitrary Lagrangian Eulerian) moving mesh method suitable for solving two-dimensional and axisymmetric moving-boundary problems. Owing to the calculation of the fluid flow inside the melt pool, the definition and the resolution of the multiphysics problem are very difficult (unknown phenomena and computation time). Thus a simplified problem, without the liquid zone, is developed. This means that at each time increment, the domain is modeled considering the fusion of the material and the shape is estimated by an inverse method. (C) 2011 Elsevier Masson SAS. All rights reserved.