Compression Performance of Steel Pipelines with Welded Slip Joints

The results of full-scale compression tests are presented for the welded slip joints (WSJs) of steel pipelines of nominal 300, 810, and 910 mm (12, 32, and 36 in.) diameter (D), representing diameter-to-thickness (t) ratios (D/t) ranging from 48 to 255. Also, the results of numerical simulations with a 2D axisymmetric solid finite-element model using the program ABAQUS are presented and shown to compare favorably with the experimental measurements. On the basis of finite-element simulations, dimensionless charts are developed that show the ratio of the maximum axial compressive load to yield load of the pipe versus D/t for various wall thicknesses. The charts also apply for internal, external, and for combined internal and external fillet welds. Conclusions are drawn with respect to WSJ ductility, pipeline performance, axial compressive capacity of the joints, fatigue cyclic response, and capacity of WSJ due to earthquake loading. In general, the WSJ capacity is shown to decline from approximately 85% of theoretical maximum load of a straight pipe with comparable wall thickness for D/t=48, to as low as 40% for D/t=255.