Sajad Hajizade

The use of marine aluminum in modern ships has grown a lot today. However, the use of aluminum can cause problems during the operation of the vessels. Among these problems, we can mention the uncertainty in the manufacturing process of aluminum platets. Evaluating the reliability of a marine aluminum stiffened plate by considering the effects of the heat-affected zone, residual stress, and initial imperfection caused by welding, leads to the design of aluminum structures with greater reliability. Therefore, in this study, to evaluate the uncertainty, a piece of the reinforced aluminum stiffened platest has been selected as the cross section under the load of the hull; Uncertainty in ship structure strength depends on uncertainty in material properties and approximation in the adopted model. The main purpose of this research is to compare the reliability of the ship hull in three common welding modes in the shipbuilding industry (FSW, MIG, and TIG). The results of this study were analyzed according to the welding methods and according to the speed and height of the waves, and placement in each of the hogging and sagging conditions. In general, in all considered cases, with the increase in the speed and height of the wave, the probability of structural damage increases. A comparison of the probability of structural failure in each of the three welding methods shows that friction stir welding with the probability of failure is the most optimal method to ensure the strength of the structure, and MIG and TIG methods are the next priorities respectively.