Sooho Pyo, Junghyun Nam, Yoonsang Kim and Sunwoong Choi
Papers # 2010 Vancouver
The Notched Ring Test (NRT) has been recently developed to measure slow crack growth (SCG) in plastics pipes and fittings. The NRT specimen in the form of a notched full ring is directly obtained from the extruded pipe or injection molded fitting and has demonstrated its effectiveness in generating slow crack growth in a time frame of order of magnitude shorter than the currently available test methods. Recently, the NRT test has been utilized to include larger pipes up to 400mm diameters and the results are presented. Also, a solution to the difficulty associated with the detection of on-set slow cracking will be demonstrated with the development of the modified displacement method. In addition, a generalized solution for the stress intensity factor calculation for NRT specimens will be described and examples presented.