Modelling of root formation during the welding process with the help of the 3D Fe method

Numerical simulation of the welding process using the finite element method is a valuable tool used to support and expand experimental work while at the same time excluding experimental inaccuracies. After verification, numerical simulation can make an important contribution to optimisation of the welding process. The two-dimensional idealisations used previously, mainly because they were less costly, have proved insufficient for describing the conditions of the actual weldment. Unrealistic assumptions have to be made in some cases in order to apply the numerical results to the component; consequently calling further conclusions based on the results into question. Only 3D simulations are able to yield a definite force and moment equilibrium and permit, indeed require, input of realistic physical and material properties. On-going developments are discussed. and new results pertaining to root formation during the welding process are reported.