Experimental and analytical study of three point bend specimen and throughwall circumferentially cracked straight pipe

Transferability of the specimen J-R/J-T curve to the component level is an important issue in the field of fracture mechanics. Towards this goal, frac ture experiments have been carried out on three point bend (TPB) specimen a nd throughwall circumferentially cracked straight pipe of 219 and 406 mm ou ter diameter under four point bending load. The pipe material is SA333Gr6 a nd TPB specimens are machined from pipes. The image processing technique ha s been used to measure the crack growth and crack opening displacement in p ipes. Component J-R curves have been generated from the load-deflection and load-crack growth data of pipe fracture experiments. These are compared wi th the TPB specimen J-R curves. Power law and second order polynomial fitti ng are done on the specimen and component J-R curves and J-T curves are gen erated. Specimen and component J-T curves are compared. Maximum moments in the pipe fracture experiments are also compared with the critical moments p redicted by the 'G factor', 'Z factor' and limit approach. (C) 2000 Elsevie r Science Ltd. All rights reserved.