A Novel Comparison of Design-by-Analysis Methods

Abstract

There exist some atypical loads on pressure vessels during transportation. This is particularly true when the pressure vessel weighs over 500 tonnes. In this example vessel, the transportation was via rail on a “Schnabel car,” in which the vessel is suspended horizontally between the top nozzle and the skirt, and a significant axial compressive load is applied. During the evaluation of the stresses in the top head, a particularly novel situation was encountered which brought about some interesting issues with regards to the three design-by-analysis methods: elastic, limit load, and elastic-plastic. This paper discusses the comparison between all three of these design-by-analysis methods, and provides recommendations for which is most appropriate for this type of evaluation. Additional recommendations and warnings are provided for the use of the elastic and limit load methods as well.

Application of Inelastic Method and Its Comparison with Elastic Method for the Assessment of In-Box LOCA Event on EU DEMO HCPB Breeding Blanket Cap Region

“…The elastic design-by-analysis codes and standards with the relatively large safety factors are thought of as a conservative criteria. However, it has been reported in [19] that the elastic rules failed to predict the failure due to non-standard loading on a pressure vessel, which could only be successfully predicted by the nonlinear elastoplastic analysis. The ductile material failure mechanism is essentially inelastic and nonlinear, while the elastic design codes are evolved from a linear, single-strength concept that does not account for the plastic deformation or its growth history [20].…”

Metodologia numérica para a análise de tensões elásticas no projeto por análise de vasos de pressão nucleares

“…Os métodos de análise do Projeto por Análise são comparados em [20], para vasos de pressão, porém para a situação de transporte do componente. O componente é simulado com cargas de suportes horizontais e análises elásticas, limites e elasto-plásticas são realizadas.…”