Sub-scale bellows internal pressure buckling test (II) report

Tsukimori, Kazuyuki*; Iwata, Koji; Imazu, Akira; not registered; not registered; Shimakawa, T.*

There is an idea of the application of piping expansion joints to main piping systems of Large-scale FBRs as one of the cost reduction measures. The internal pressure buckling test of bellows is one of the important items of the FBR piping expansion joints feasibility study. In PNC the internal pressure buckling test is going on in order to establish the analytical method and rules for the internal pressure buckling of bellows. In this report the buckling test results of the series of the sub-scale bellows (12B, 730 convolutions) subjected to internal pressure are described, which were obtained during 1986 FY. The followings are the main results. (1)The root bulge occurred in the region between 7 and 10 convolutions and the column squirm occurred in the region between 15 and 30 convolutions. The simple plastic hinge mechanism predicts the critical pressure well in the former region and the simple column squirm analysis in the latter. (2)The initial bending angle of bellows affected the critical pressure badly only in the case of the column squirm. The buckling pressure of bellows must be estimated taking the bending deformation into consideration.