BENCH-KJ: BENCHMARK ON ANALYTICAL CALCULATION OF FRACTURE MECHANICS PARAMETERS Kl AND J FOR CRACKED PIPING COMPONENTS - PROGRESS OF THE WORK

摘要

For many design and ageing considerations fracture mechanics is needed to evaluate cracked components. The major parameters used are K and J. For that, the different codes (RSE-M appendix 5, RCC-MRx appendix A16, R6 rule, ASME B&PV Code Section XI, API, VERLIFE, Russian Code...) propose compendia of stress intensity factors, and for some of them compendia of limit loads for usual situations, in terms of component geometry, type of defect and loading conditions. The benchmark bench-KJ, proposed in the frame of the OECD/IAGE Group, aims to compare these different estimation schemes by comparison to reference analyses done by Finite Element Method, for representative cases (pipes and elbows, mechanical or/and thermal loadings, different type and size of cracks). The objective is to have a global comparison of the procedures but also of all independent elements as stress intensity factor or reference stress. The benchmark will cover simple cases with basic mechanical loads like pressure and bending up to complex load combinations and complex geometries (cylinders and elbows) including cladding or welds: these cases are classified into 6 tasks. Twenty-nine partners are involved in this benchmark. This paper gives a short overview of the different tasks of the benchmark and presents the analysis of the results for the four first tasks, devoted on the elastic stress intensity factor calculation (task 1) and J calculation in cracked pipes (taks 2 and 3).