On the Collapse of Long, Thick-Walled Tubes Under External Pressure and Axial Tension

Abstract

The paper presents the results from a combined experimental and analytic study on the collapse of long, thick-walled tubes subjected to external pressure and axial tension. The experiments involved tubes of diameter-to-thickness ratio (Dm /t ) 10 to 40. Collapse envelopes were obtained for two different pressure-tension loading paths. Collapse tests involving initially ovalized tubes were also carried out. The collapse strength predicted with a two-dimensional elasto-plastic model applying J2 flow rule was in good agreement with the experiments. The results show that the collapse strength under combined loading is strongly influenced by initial ovality and that the shape of the stress-strain curve has a significant influence on the tension-pressure collapse envelope.