بررسی اثرات کمانش گیرها در جلوگیری از انتشار دینامیکی کمانش در خطوط لوله دریائی

It is undeniable that instability plays a significant role in the design of pipelines. Local buckles induced by excessive force on specific part of pipeline can locally reduce the collapse pressure of a pipeline and cause local failure. Periodic placement of buckle arrestors along the pipeline can ensure that collapse only effect the length of pipe between two arrestors on either side of the initiation site. Arrestor spacing is usually derived by specific practical considerations on the particular line (e.g. installation and repair procedure) but typically spacing of 90-240m has been used. In the present study, the propagation and arresting of dynamic buckle are modeled using the finite element method. For the post buckling analysis, the material and geometrical nonlinearity are considered. The effects of arrestor spacing on cross over pressure have been evaluated for different diameter to thickness ratio of pipeline (D/t), arrestor’s thickness to pipe’s thickness ratio (h/t), and arrestor’s length to pipe’s diameter ratio (La/D).