Acceptability VIS-A-VIS fatigue damage of tube sheets containing irregular perforations

摘要

One of the acceptability criteria of Nuclear Vessels concerns fatigue behavior under alternating loadings.In the case of a Steam Generator Tube Sheet, the fatigue analysis concerns not only the nominal geometry of the perforated area but also those regions where anomalous perforations sometimes result from manufacturing difficulties.Non-conform perforations can be justified by running a numerical simulation of the actual geometry. The advantage of such a method is that it yields results which are representative of the misplacement ; the inconveniences are:- time lag between the dectection of a non-conformity and the conclusions of the numerical analysis,- the necessity of running a numerical simulation for each case.An other methods consists of running the numerical simulations in advance in order to determine a "Domain of Acceptability", covering all the situations encountered.In this paper, we present how the Domain of Acceptability could be determined (by using the Finite Element Program SYSTUS) and we give 2 examples of non-conformity analysis.