Failure behavior analysis of steel strip-reinforced flexible pipe under combined tension and internal pressure

The mechanical behaviors of steel strip-reinforced flexible pipe (steel strip PSP) under combined axial extension -> internal pressure (T -> P) load path were investigated. Typical failure characteristics of pipe samples under pure internal pressure and T -> P load path were identified in the full-scale experiments. A theoretical model for pipe under tension load was proposed to capture the relationship between axial extension of the pipe body and stress state of the steel strip. Numerical study based on finite element (FE) method was conducted to simulate the experiment process, and good agreement between FE data and experiment results were observed. Sensitivity study was conducted to study the effect of some key parameters on the pipe antiburst capacities in T -> P load path; the effect of preloaded internal pressure on the pipe tensile capacity in P -> T load path was also studied. Useful conclusions were drawn for the design and application of the steel strip PSP.