CHAPTER 1
INTRODUCTION
1.0 Background of the study
The use of the Finite Element Method (FEM) in product development is now well
establishedhowever, its use in manufacturing processes is not very common and is part of the field of new applications in computational mechanics. The most important reason for this development is the industrial need to improve productivity and quality of products and to have better understanding of the influence of different process parameters. The modelled phenomena play an important role at various stages of the production of steel parts, for example, welding, heat treatment and casting, among others.
The importance of these applications lies in determining the evolution of stresses and deformations to predict, for example, susceptibility to cracking and thus prevent failures during manufacturing or even service. Furthermore, this simulation tool can be used to optimize some aspects of the manufacturing process.Welding is defined by the American Welding Society (AWS) as a localized coalescence ofmetals or non-metals produced by either heating of the materials to a suitable temperature with or without the application of pressure, or by the application of pressure alone, with or without the use of filler metal (Mackerle, 2004). Welding techniques are one of the most important and most often used methods for joining pieces in industry. Any information about the shape, size and residual stress of a welded piece is of particular interest to improve quality.
The analysis of welding processes involves several branches of Physics, and requires thecoupling of different models addressed to describe the behaviour of a phenomenological system.