Ehsan Bahmyari

Welding processes with neutral shielding gas are the basic method of connecting the structure of military and commercial aluminum ships that have been built since the early 1950s. The first gas-shielded arc welding process that was developed was tungsten welding with a neutral shielding gas, known as TIG welding. The second welding process is electric arc welding with consumable solid wire, which is also known as MIG. For good aluminum welding, joint preparation must be done correctly and also the selection of welding filler metals must be done correctly. During the process of heating and cooling in the welding cycle, thermal strains occur in the weld metal and the base metal. The stresses caused by strains are the cause of internal forces that cause bending, buckling and rotational displacements, which are called welding distortions. In this research, first, the types of aluminum welding processes, types of marine aluminum alloys, and different welding techniques are introduced. Then, the simulation of the welding process, types of welding distortions caused by aluminum welding, and methods to reduce these distortions are discussed. Finally, by using the finite element method and simulating the welding process of T-shaped joints, the best sequence of welding to reduce distortion for these joints, which are widely used in the construction of vessels, is presented.