Effective buckle arrestors for offshore pipelines

Offshore pipelines are subjected to various forces, depending on the subsea conditions such as temperature, axial forces, pressure (internal and external), bending, and earthquake forces. The response of offshore pipelines in with-standing these forces involves elastic response as well as inelastic response. Buckle arrestors are installed at regular intervals along the length of the pipeline to prevent buckling occurring due to a combination of forces. Present research work focuses on the improvement in buckling strength of offshore pipelines which are stiffened with 3 different types of buckle arrestors. Buckling experiments were conducted on pipeline models fabricated from seamless stainless steel pipes of grade SS304. The pipeline models stiffened with three different buckle arrestors configurations; longitudinal continuous stiffener, sinusoidal stiffener, and angular stiffener. The purpose of our research is to study the effectiveness of buckle arrestor configuration in improving resistance to buckling and to identify optimum buckle arrestor configurations and their applicability to offshore pipelines. The study was conducted by finite element simulation of buckle arrestors using ANSYS. The stainless steel pipe models of 1 m length, 16 mm outer diameter, 11.8 mm inner diameter, 2.1 mm thickness are considered for finite element analysis and for conducting experiments. The results obtained from finite element analysis and experiment results show that the efficiency of buckle arrestor found to be more in case of pipeline stiffened with longitudinal continuous buckle arrestors.