Collapse Pressure of Reeled Rigid Pipes

Abstract

This work deals with a numerical and experimental investigation on the effect of plastic strains inferred to steel pipes during reeling installation process and its subsequent effect on the collapse pressure of these pipes. Experimental tests on full-scale models were carried out in order to calibrate a numerical tool to simulate the whole process. Pipe samples are bent and straightened over the rigid surfaces of circular dies. Subsequently, the samples are tested quasi-statically under external pressure until collapse in a pressure vessel. A threedimensional nonlinear finite element model was developed to simulate the bending and straightening process as it occurs during installation. The model was implemented with the dimensions and initial imperfection measured on test samples and takes into account finite displacements and elastic-plastic behavior under the Mises potential flow law with isotropic or kinematic hardening. The model is then used to determine the collapse pressures of plastically strained pipes and evaluate the combined effect of the parameters that most affect its values.