FORMULA FOR ESTIMATION OF EFFECTIVE APPLIED LOAD AT CRACKED SECTION CONSIDERING COMPLIANCE CHANGE AND ITS APPLICATION UNDER DYNAMIC LOADING CONDITIONS

摘要

The refinement of the piping integrity assessment methods has emerged as a priority issue, in response to heightened concerns about the beyond design basis accident following several events. The compliance change in structures may have a significant influence on the fracture estimation. For instance, the deformation of a crack in the piping system may result in a decrease of the applied moment at the cracked section. To consider these effects, the authors have developed the general formula for prediction of the effective applied moment at circumferential cracked section based on the elastic beam theory. Using the developed formula, one can evaluate the extent of the load reduction at a crack position due to the change in compliance. This paper aims to expand the applicability of the formula for dynamic loading conditions. By conducting the time history analysis using FE model accompanying the comparisons with the piping system experiment results, it was confirmed that the formula is also available for dynamic loading conditions. It is expected that the proposed formula can be implemented in sthe piping integrity assessment to consider the restraint effect.