Investigation of the Elastic-Plastic Design Method in Section VIII Div. 2

Abstract

Section VIII Div. 2 contains an elastic-plastic stress analysis option that is based on the ultimate instability load. The performance of the method is evaluated by using the PVRC burst disk tests. The prediction of the failure load is attempted using both a “best estimate” and the Section VIII Div. 2 material model. The strain limit against local failure is assessed as well. Starting from the notion that Design Codes try to establish safety margins against ultimate failure (burst) and against excessive deformation from the as-designed shape, this paper also examines the proposed method of using a factor of safety against instability (burst) in conjunction with a strain limit (protection against local failure). Implications for the application of the method to design are discussed.