【摘要】 在ASME Ⅷ-2图5.1和JB 4732(2005年确认)表5-1当量应力的类别和极限中,对只涉及一次应力时都用实线标出应采用设计载荷,涉及二次应力和峰值应力时都用虚线标出应采用操作载荷。但二者都未说明设计和操作载荷的具体涵义和区别。联系起ASME Ⅷ-1和ASME Ⅷ-2在固定管板式换热器以及要考虑和管板固定相连的壳体和管箱径向热膨胀差的浮头式换热器时也都提及设计工况载荷和操作工况载荷。根据二次应力和峰值应力对元件构成失效的原理以及载荷性质对此进行原理分析。更多还原

【Abstract】 For stress classification and limits, both in Figure 5.1 in ASME VIII-2 and Table 5-1 in JB 4732(confirmed in 2005), solid lines are used for indicating design loads should be applied when primary stress is involved, and dotted lines are used for indicating operating loads should be applied when secondary or peak stresses are involved. But no explanations for exact meanings of design and operating loads and their differences are demonstrated in these two standards. In ASME VIII-1 and ASME VIII-2, for fixed tubesheet heat exchanger and floating tubesheet heat exchanger, in which fixed tubesheet is welded to shell side cylinder and radial thermal expansions in channel and shell should be taken into account, loads under design condition and operating condition are mentioned. In this paper, these loads and their use were analyzed from theory and engineering application.更多还原