膨胀节承受压力下的失稳

阐述了ＥＪＭＡ标准中防止膨胀节内压平面失稳和柱状失稳的公式与其来源，提出防止内、外压平面失稳的公式，并进行了试验验证。试验结果表明，压缩位移会降低失稳临界压力。压力试验时需注意防失稳，且ＥＪＭＡ标准的外压周向失稳算值欠安全

Instability of expansion joints subjected to pressure loadings

EJMA standards for preventing expansion joints from in plane instability and column instability formulae and their origins are expounded, formulae for preventing internal and external pressure in plane instability are suggested, these formulae have been verified by experiment test The experimental results show that compression movement will reduce instability critical pressure It needs take noticed that the instability should be prevented in pressure testing and the calculation value of external pressure circumferential instability given by EJMA standard is not safe enough