The stepped preload stress was generated in the process of wrapping and clamping. The distri-bution of the preload stress was compressed in the inner wall, and tensed at the outer wall while the con-tact of the middle layers was slack. The purpose of the super hydrostatic test was not only to detect the whole strength and the capacity of seal, but also to enhance the contact and to redistribute the stress of the middle layers, which the stress of inner wall was yielded by the super hydrostatic test. On the basis of the theoretical analysis, the lower limit pressure of super hydrostatic test was the initial yield pressure, and the upper limit pressure was the fully yield pressure. The scope of the hydrostatic test pressure, which is about 1.5 to 1.8 times of the design pressure, was verified by the test when the diameter ratio was 1.2 to 1.4.%整体多层夹紧式高压容器在包扎夹紧过程中产生了台阶状预应力,其基本规律是内壁压缩强化,外壁拉伸强化,中间接触松弛.超水压试验不仅能检验宏观强度和致密性,同时还使内壁发生变形以达到消除中间层板的接触松弛和调整容器应力分布的目的.从理论上看,超水压试验压力的下限是内壁发生初始屈服,上限是容器不出现全屈服,当容器径比在1.2～1.4之间时,试验水压范围为1.5～1.8倍设计压力.
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