Modeling of ductile crack propagation in expanded thin-walled 6063-T5 aluminum tubes

• Procedure for determining the ductile failure locus for tubes is proposed.
• Modeling framework for predicting ductile failure during expansion of tubes.
• Model and experimental results from tubular expansion show very good agreement.
• Relevant to the solid expandable tubular (SET) technology for oil-well completion.
• Modeling framework is a very suitable tool for optimization of the SET process.

In this paper the ductile failure behavior of mechanically expanded 6063-T5 aluminum tubes was studied experimentally and numerically. The expansion of the tubes was performed mechanically by using a conical mandrel with the objective to study the failure mode that governs the expansion process of this material. To localize the failure the tubes were drilled with circular holes. The fractured surfaces of failed expanded tubes were examined and revealed a flat ductile dimple rupture characteristic. A finite element model, which is based on continuum damage mechanics, is developed to mimic the experiments. The model also predicts ductile crack propagation and failure in the expanded tubes with embedded holes very well making it a suitable tool for studying the tubular expansion process and for optimizing the expansion tools.