内压标准椭圆封头弹塑性屈曲分析及失效载荷研究  

Investigation on Elastic-plastic Buckling and Failure Load of Standard Elliptical Head under Internal Pressure

作　　者：鲁雨 贺小华[1] 

机构地区：[1]南京工业大学机械与动力工程学院

出　　处：《压力容器》2019年第11期25-33,共9页Pressure Vessel Technology

基　　金：国家自然科学基金项目“基于HILL屈服准则的正交各向异性金属承压结构分析设计方法”(51675260)

摘　　要：采用有限元弹塑性屈曲分析,考虑椭圆封头的最大形状偏差并在过渡区施加局部厚度减薄缺陷,针对不同材料和厚径比δe/Di,较为系统地讨论了内压标准椭圆封头结构屈曲载荷Pcr与极限载荷P的变化规律。研究结果表明,厚径L比小于某临界值时,屈曲载荷低于极限载荷,分析模型发生屈曲破坏;厚径比大于某临界值时,屈曲载荷高于极限载荷,分析模型发生强度破坏。不同材料分析模型厚径比临界值存在一定差异,对高强钢13MnNiMoR材料而言,GB1502011标准防止标准椭圆封头内压弹性屈曲失效的厚径比规定偏于冒进。本文结果可为内压薄壁标准椭圆封头设计准则提供指导。Using finite element elastic-plastic buckling analysis and considering the maximum shape deviation of the elliptical head and by applying a local thickness thinning defects in the transition zone,the variation law of buckling load P cr with limit load P L of the standard elliptical head under internal pressure was systematically discussed for different materials and thickness diameter ratioδe/D i.The results show that when the thickness-diameter ratio is less than a critical value,the buckling load is lower than the limit load,and the buckling failure occurs for the elliptical head analysis model,whereas the thickness-diameter ratio is greater than a critical value,the buckling load is higher than the limit load,and the strength failure may occur for the elliptical head analysis model.There are some differences in the critical values of thickness-diameter ratio for analysis models of different materials.For high strength steel material 13MnNiMoR,the thickness-diameter ratio stipulated in GB 150—2011 code to prevent the failure of elastic buckling of standard elliptical heads under internal pressure may lead to insufficient safety margin.The results of this study provide guidance for the design criteria of standard thin wall elliptical heads under internal pressure.

关 键 词：椭圆形封头 弹塑性屈曲 屈曲载荷 极限载荷 

分 类 号：TH49[机械工程—机械制造及自动化] O344.3[理学—固体力学]