Avaliação estrutural de painéis enrijecidos fabricados em aço inoxidável

Abstract

Stiffened plate panels present several applications in Engineering, for instance, in naval/offshore structures, where they are employed as structural elements of ships and vessels. Other utilizations include bridge structures, storage tanks and so on. Essential aspects of the failure mechanisms of stiffened plated panels are the initial geometrical imperfections and residual stresses embedded in such structures due to the fabrication processes. Some technical design guides present rules to be applied to the design of carbon steel stiffened plated panels. However, with the technological evolution of the materials and their stricter demands on corrosion and mechanical resistance, it is necessary to utilise special steel whose design is not covered in the codes, as mentioned earlier. Hence, this work aims to assess the ultimate resistance of austenitic stainless steel stiffened plated panels and verify the influence of different initial imperfections on their structural capacity. In order to achieve this objective, experimental tests of stainless steel stiffened panels were carried out at the laboratory, with an aspect ratio between the panel length and the stiffener spacing of 2.70 and 4.35 to cover the practical values used in the naval/offshore structures. Afterwards, a FE model was developed and calibrated against experimental results. A parametric analysis was performed to enlarge the database to check if the current rules applied to carbon steel structures can be applied to stainless steel stiffened plated panels. The results showed that some design rules could provide conservative and non-conservative designs for values of low and high slenderness, respectively. Finally, a new equation based on the calibration of the Cx parameter (ratio of the ultimate strength concerning uniaxial normal stress to the specified minimum yielding point of the plate in the longitudinal direction) was proposed providing improved results.