外压圆筒小加强圈设计的改进方法  

Improvement of design rules for small stiffening ring of external pressure cylinder shell

作　　者：陈冰冰[1,2,3] 徐佳伟 徐伦 张艺奇 高增梁[1,2,3] CHEN Bingbing;XU Jiawei;XU Lun;ZHANG Yiqi;GAO Zengliang(Institute of Process Equipment and Control Engineering,Zhejiang University of Technology,Hangzhou 310023,China;College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,China;Engineering Research Center of Process Equipment and Remanufacturing,Ministry of Education(Zhejiang University of Technology),Hangzhou 310023,China)

机构地区：[1]浙江工业大学化工机械设计研究所,杭州310023 [2]浙江工业大学机械工程学院,杭州310023 [3]过程装备及其再制造教育部工程研究中心(浙江工业大学),杭州310023

出　　处：《压力容器》2022年第5期34-45,共12页Pressure Vessel Technology

基　　金：国家自然科学基金项目(52075490)。

摘　　要：单一规格的加强圈按ASME BPVC.Ⅷ.2的设计方法得出的尺寸可能会出现与按常规设计标准设计相差较大的问题;按ASME BPVC.Ⅷ.2的设计方法,还可能会出现设计外压不变时,原设计合格的小加强圈惯性矩会因圆筒额外加厚反而变成不合格的情况。为克服上述不合理性,提出一种基于设计外压的改进方法。基于“简化傅里叶级数法”模型,给出了一种优于“一致模态法”且能较好预测带加强圈圆筒临界屈曲压力的数值模拟方法(IM-F-GMNIA法),该模拟方法的计算结果与实物试验吻合良好。采用IM-F-GMNIA法进行了23组数值模拟试验,模拟了多种加强圈大小和数量、多种径厚比和长径比的带加强圈圆筒屈曲情况;较系统地考察了去除加强圈后的圆筒的屈曲波数n分别为2和5(代表长圆筒和短圆筒)且屈曲临界压力与屈服压力比ξ为0.22~1.09(涵盖弹塑性范围)的情况下,对比因子β(改进方法的设计裕度与ASME BPVC.Ⅷ.2的可接受设计裕度之比)与因子η(表征设计外压变化)的关系。结果表明,所提出的基于设计外压的改进方法,加强圈惯性矩与设计外压直接关联,该改进方法设计裕度将不低于ASME BPVC.Ⅷ.2方法的可接受设计裕度,且较ASME BPVC.Ⅷ.2方法更为合理。If a single size of stiffener ring is used, its size designed according to ASME BPVC.Ⅷ.2 may be quite different from the conventional design standard.The moment of inertia of stiffener ring qualified in the original design may turn to be unqualified due to additional increase of thickness of the cylindrical shell according to ASME BPVC.Ⅷ.2.To overcome these irrationalities, the improved rules based on external design pressure were proposed.An improved geometrically and materially nonlinear analysis with imperfections based on the simplified Fourier series model(IM-F-GMNIA method) was given, which is better than “Eigenmode imperfections” method and can predict the critical buckling pressure of a cylinder with stiffening ring.IM-F-GMNIA method was applied in numerical simulation experiments to simulate the buckling of cylinders with different diameter-thickness ratios and length-diameter ratios with different sizes and numbers of stiffening rings.The relationship between the correlation factor β(the ratio of the design margin of the modified method to the acceptable design margin of ASME BPVC.Ⅷ.2) and the η factor(which characterizes the change in the external design pressure) was systematically investigated when the buckling wave number n of the unstiffened cylinder is 2 and 5(representing the long cylinder and the short cylinder),respectively, and the ratio of the critical buckling pressure ξ to the yield pressure ranges from 0.22 to 1.09(covering the elastic and plastic range).The results show that the moment of inertia of small stiffening ring designed by the improved rules are directly related to design external pressure, and the improved rules has a design margin not less than the acceptable design margin of ASME BPVC.Ⅷ.2.It shows that the improved rules are more reasonable.

关 键 词：小加强圈 傅里叶级数 数值模拟试验 GMNIA 

分 类 号：TH49[机械工程—机械制造及自动化] TQ050.2[化学工程]