Plastic Collapse Behavior of Pipe with Local Wall Thinning Subjected to Bending Moment

摘要

Monotonic bending tests are conducted on 102 mm diameter carbon steel pipe specimens with local wall thinning in order to investigate the collapse behavior and strength. The local wall thinned area of the pipe is subjected to tensile or compressive stress by applied bending moment. Observed fracture modes were cracking, elephant foot type local bucking, ovalization and buckling + ovalization. The maximum moments obtained from the tests were compared with the plastic collapse moments (M_(po)) based on net - stress criterion. For the most specimens, measured maximum moments are larger than that of calculated one, nevertheless failure mode. Special attention was paid to plastic deformation ability of the pipe. Because this is a very important factor for the structural integrity of statically indeterminate pipe system [7,8].