塑性垮塌二元评定准则在压力容器分析设计中的应用  

APPLICATION OF DUAL EVALUATION CRITERION FOR PLASTIC COLLAPSE IN PRESSURE VESSEL ANALYTICAL DESIGN

作　　者：左安达 罗从仁 姜凤银 Zuo Anda;Luo Congren;Jiang Fengyin(Wison Engineering Ltd.,Shanghai,201210;CNPC Eastchina Design Institute Co.,Ltd.,Qingdao,Shandong,266000)

机构地区：[1]惠生工程(中国)有限公司,上海201210 [2]中石油华东设计院有限公司,山东青岛266000

出　　处：《石油化工设备技术》2024年第6期18-23,35,I0002,共8页Petrochemical Equipment Technology

摘　　要：一次加载情况下的塑性垮塌失效是压力容器需重点防范的失效模式之一。文章介绍了一种塑性垮塌二元评定准则。该准则综合吸收了ASME规范强度准则和EN标准变形准则的设计理念,并借鉴了确定许用应力的思想,可同时防止塑性垮塌和过度塑性变形。该准则的评定可基于载荷-抗力系数法并通过弹塑性分析一次性实现。弹塑性分析需采用材料的真实应力-应变曲线,并考虑几何非线性效应。文中以圆柱壳上大开孔接管结构为例,详细介绍了该准则在有限元软件中的实现方法并给出了详细的评定步骤。将该二元准则与应力分类法的评定结果进行对比发现,应力分类法关于塑性垮塌失效的评定准则对某些结构承载进行评定时,可能会出现过于保守的情况,二元准则相较于应力分类法更为先进和精确,能给出较为合理的适中方案。Plastic collapse failure is one of the key failure modes for pressure vessels under the condition that load is applied once.A dual evaluation criterion for plastic collapse is introduced in this paper.The criterion integrates the design concept of strength criteria based on ASME code and deformation criteria based on EN standard,and also borrowing the ideas of determining allowable stress.It can prevent both plastic collapse and excessive plastic deformation.The evaluation of the criterion can be carried out by the load-resistance coefficient method based on elastic-plastic analysis.Elastic-plastic analysis shall use the real stress-strain curve of the material and consider the geometric nonlinear effects.Taking the large opening nozzle on cylindrical shell as example,this paper introduces the realization method of this criterion in finite element software and evaluation steps in detail.Compared with the result of stress classification,it is found that the evaluation criteria by stress classification method for plastic collapse failure may be too conservative for some structures.The dual criterion is more advanced and accurate,and can provide a more reasonable solution.

关 键 词：塑性垮塌 压力容器 二元评定准则 弹塑性分析 应力分类法 

分 类 号：TH49[机械工程—机械制造及自动化]