SHORT CIRCUMFERENTIAL THROUGH-WALL CRACKED PIPES SUBJECTED TO STRETCH-BENDING LOAD

The methods for assessment of elastic-plastic fracture behaviour of cr acked components include the net section plastic collapse concept, the J-integral approach, and the two-parameter R-6 failure assessment dia gram, Revision 3. These failure assessment methods are usually used to obtain fracture behaviour prediction with a reasonable degree of accu racy without carrying out complicated full-length numerical fracture a nalysis. Ln the current work, fracture experiments on stainless steel pipes with short circumferential through-wall cracks under stretch-ben ding load were conducted. Stretch-bending load refers to the loading s ituation where axial load is generated that is proportional or related to the applied bending load. The J-integral values derived from the e xperimental load-point load-displacement data under stretch-bending an d pure bending conditions are compared to investigate the effect of ax ial load on the J-resistance curves. The results show clear dependence of crack resistance force on axial load for short circumferential cra cks. Crack resistance force decreased noticeably for increased stretch -bending loading compared to pure bending loading. (C) 1998 Elsevier S cience S.A. All rights reserved.