The modeling and simulation of the welding process has been of main concern for different fields of applications. Most of the modeling of such a problem has been mainly in 2-D forms that may also include many sorts of approximation and assumptions. This is due to limitations in the computational facilities as the analysis of 3-D problems consumes a lot of time. With the evolution of new finite element tools and fast computer systems, the analysis of such problems is becoming in hand. In this research, a simulation of the welding process with and without metal deposition is developed. A new technique for metal deposition using element movement is introduced. It helps in performing full 3-D analysis in a shorter time than other previously developed techniques such as the element birth.

The structure in which the welding process is performed highly affects the residual stresses generated in the welding. This effect is simulated by choosing the appropriate boundary conditions in modeling the welding process. The major parameters of the boundary conditions are the method by which the base metal is being fixed and the amount of heat being applied through the torch. Other parameters may include the coefficients of thermal heat loss from the plate which may simulate the media in which the welding is taking place. In modeling the welding process, two-dimensional forms of approximation were developed in analyzing most of the models of such problem. Three-dimensional models analyzing the welding process were developed in limited applications due to its high computation time and cost. With the development of new finite element tools, namely the element movement technique developed by the authors, full three-dimensional analysis of the welding process is becoming in hand. In the present work, three different boundary conditions shall be modeled comparing their effect on the welding. These boundary conditions shall be applied to two models of the welding process: one using the element birth technique and the other using the element movement technique showing the similarity in their responses verifying the effectiveness of the latter being accomplished in a shorter time.

The modeling and simulation of the welding process has been of main concern for different fields of applications. Most of the modeling of such a problem has been mainly in 2D forms that may also include many sorts of approximation and assumptions. This is due to limitations in the computational facilities as the analysis of 3D problems consumes a lot of time. With the evolution of new finite element tools and fast computer systems, the analysis of such problems is becoming in hand. In this research, a simulation of the welding process with and without metal deposition is developed. Change of phase and variation of properties with temperature are taken into account. A new technique for metal deposition using element movement is introduced. It helps in performing full 3D analysis in a shorter time than other previously developed techniques such as the element birth.

No abstract

keywords:Limit load Reference volume Oblique nozzle Convergence Lower bound a b s t r a c t Limit load analysis is usually performed by the interpretation of stress redistribution using either linear elastic or inelastic methods. Several redistribution iterations are required to achieve an accurate estimate of the limit load. In this paper the reference volume method is illustrated and shown to be effective in finding the limit load using few linear elastic redistribution iterations. The reference volume is based on the concept of using a part of the volume of the component that is undergoing plastic deformation. The method is applied to a two-dimensional indeterminate beam and a full three dimensional model of an oblique nozzle. This illustrates different cases of reference volumes to verify the analysis procedure.