Collapse Performance of HTS (Helical Seam Two Step) Welded Line Pipe

Abstract

Line pipe intended for offshore applications has to be designed predominantly with regard to external pressure in order to avoid collapse. High resistance to external pressure is vitally important for the use of pipes in such applications. A test program has been carried out in order to verify the resistance of HTS (helical seam two step) welded line pipe against collapse. It was demonstrated that the two step pipe manufacturing process has a beneficial effect on collapse resistance. HTS pipes therefore shows a good collapse performance compared to the design equations given in relevant offshore standards. One aim of the work carried out was to quantify the influence of relevant parameters on the result of full-scale collapse test by finite element analysis. The actual collapse pressures and those predicted using currently available design equations are compared and verified for various boundary conditions. The paper concludes with a discussion of the major findings and with a brief outlook to future research issues.

Effects of specimen geometry and anisotropic material response on the tensile strain capacity of flawed spiral welded pipes

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Influence of notch orientation on ductile tearing in SENT specimens

“…[2][3][4]. Studies have shown that, in comparison to UOE pipes, spiral pipes can have equivalent or better properties regarding to bending [5], plastic collapse [6], bursting [7], ductile tearing [8] or buckling resistance [4,9]. Also, it has been shown that the fatigue resistance and fracture arrest properties are at least equivalent to those of UOE pipes [10,11].…”