Tension Effects on Pressure Capacity of Tubular Members

Abstract

An investigation of the effects of axial tension on the pressure capacity of tubular members is presented. Unstiffened and ring-stiffened tubes are analyzed using a rigorous finite-element technique that accounts for changes in the geometry of the tube, elastoplastic material behavior, longitudinal and cross-sectional imperfections, and residual stresses from the tube manufacturing process. A study is conducted to assess the significance of several factors influencing pressure-tension interaction, such as the loading path, the presence of residual stresses, and the stiffener spacing. The calculations indicate that closely spaced stiffeners amplify pressure-tension interaction, since they restrain the tube cross section against ovalization and allow material response well beyond initial yielding. Computational results are obtained and compared with available experimental data as well as widely used design equations. Good agreement is found between test data and predictions based on the technique developed in the present study. However, the design equations substantially underestimate the pressure capacity of stiffened tubes.