Sub-scale bellows internal pressure buckling test (I) 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 FBR piping expansion joints feasibility study is going in PNC, and the pressure buckling test of bellows is one of the important items of the study. In PNC the internal pressure buckling test is going on with full-scale bellows test specimens (42) at oarai Engineering Center, and on the other hand with sub-scale bellows (20, 12) in other place in order to establish the analytical method and rules for the internal pressure buckling of bellows. In this report the result of the series of the sub-scale bellows internal buckling tests is discribed, which was carried out during 1984FY and 1985FY. The following is the main result. (1)In the relation among the thickness, the number of convolutions and the buckling pressure, the test data characteristic was similar to the estimated limit - EJMA standard for the squirm and the equations by RI Ltd. for the root bulge. This result made it certain that the pressure limit for bellows buckling could be constructed on the basis of existing evaluation methods. (2)Initial bending angle of bellows badly effected on the limit of bellows buckling pressure only in the case of the squirm. The pressure limit for the bellows buckling must be estimated taking the bellows displacements into consideration.