Quantification of plastic buckling behavior of steam generator tubes with wear defect under external pressure

초록

In this paper, systematic FE analysis of tubes with flat wear defects is performed to investigate plastic buckling and subsequent post-buckling behaviors of steam generator tubes with flat, rectangular wear defects under external pressure. The FE model and analysis are validated by comparing with published experimental and numerical data. It is found that the second (2nd) buckling mode may occur after the first (1st) buckling mode, depending on the tube geometry. From systematic FE analysis results, the 1st and 2nd buckling pressures were quantified using quadratic function in terms of defect depth, tube geometry (radius-to-thickness ratio) and material (yield strength). The condition for the occurrence of the 2nd buckling mode is also provided. It is also found that the occurrence of the 2nd buckling mode changes the stress state in the tube.

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