EXPERIMENTAL AND NUMERICAL STUDY OF DAMAGED TUBULAR MEMBERS UNDER LATERAL LOADS

摘要

Structural behavior of dent damaged tubular members by local indentation remains a key issue for the safety and failure assessment of critical structures, including marine and nuclear facilities, oil and gas pipelines. This failure mode most often arises from very large localized plastic deformations caused mainly by excessive or accidental loads such as, for example, during the collision of adjacent risers in deepwater floating production systems (FPS). The complex interaction between the local deformation in the dented region and global bending of the tubular member may severely reduce the plastic collapse load while, at the same time, strongly affecting its load-deflection behavior. This study presents an experimental and numerical investigation of the structural behavior of a dented tubular member under lateral load which is applicable to marine risers. Experimental load-deflection curves measured using a 41/2″ O.D. (114 mm) API N80 pipe (580 MPa yield stress) with varying length characterize the plastic response during local indentation and global bending. 3D finite element models are employed to generate numerical solutions describing the large deformation, non-linear behavior for the tested pipes. The experimental results agree well with the numerical results. The analyses provide further insight into the structural response of tubular members and risers which dent damage effects.