Publicações

Teixeira, A.P. e Guedes Soares, C. (2001), “Assessment of Partial Safety Factors for Tankers”, Proceedings of the JCSS Workshop, Zurick (in electronic form)

The way in which designers deal with ensuring safety at the design stage is to introduce so-called safety factors. Intuitively, it is easy to feel that the greater the uncertainty about possible outcomes, the larger the risk of unwanted situations and the larger the required safety factor in order to make sure that these situations are not encountered. During the last decades there have been considerable developments of methods and tools for probabilistic computation purposes that are capable of representing in a rational manner the uncertainties in the design of structures. One advantage of these methods is that they allow the use of partial safety factors that reflect the uncertainties in each of the variables instead of the former approach of using only one global safety factor. However, there exists currently a gap between existing design practice based on partial safety factor format design codes and the potential usage of probabilistic methods. In fact, the results of reliability analyses have shown that the semi-empirical design rules have not been calibrated against a uniform reliability level. This paper presents the calculation of the partial safety factors to be used for a probability based design rule of tankers in order to achieve pre-defined target safety levels. The results are obtained for four tankers ranging from 133 to 313 m length on the basis of reliability analysis using a first order reliability method. The evaluation of the wave induced load effects that occur during long-term operation of the ship in the seaway is carried out and the still water loads are defined on the basis of a statistical analysis. The ultimate collapse bending moment of the midship cross sections of the tankers is used as the basis for the reliability formulation.

Se nao conseguiu obter uma copia desta publicação: Peça uma cópia desta publicação



Para informação sobre todas as publicações do CENTEC pode descarregar: Lista Completa de Publicações do CENTEC