内压与轴向拉力作用下锥壳与圆筒连接结构的屈曲分析

Buckling analysis of the cylindrical-to-conical transition junctions under internal pressure and axial tension

在我国压力容器标准GB 150—2011《压力容器》和行业标准JB 4732—1995《钢制压力容器——分析设计标准》(2005年确认)中,锥壳大端或小端与圆柱壳相连接结构的设计方法只考虑了塑性垮塌和丧失安定两种失效模式,并认为通常情况下结构不会发生屈曲。但是当结构的壁厚很薄,并且受到很大的轴向拉力时,有必要讨论是否会发生屈曲。为此,基于弹塑性大变形有限元法,分析了内压和轴向拉力按不同比例加载时,锥壳和圆筒连接结构的屈曲承载力,并以此提出了内压和轴向拉力组合作用下锥壳的屈曲判别式。计算结果表明,依据原有设计规范进行设计的锥壳结构有至少2.4倍的安全余量,所提出的屈曲判别式与数值试验结果吻合较好。

In the pressure vessel standards GB 150—2011 Pressure Vessels and JB 4732—1995 Steel Pressure Vessels—Design by Analysis(Confirmed in 2005),only plastic collapse and shakedown limit are considered in the design of the cylindrical-to-conical transition junctions,and.It is considered that the structure will not buckle in general case.However,it is necessary to discuss whether buckling will occur or not when the wall of the structure is extremely thin under a very large axial tension.For this,the buckling capacity of the cylindrical-to-conical transition junctions under internal pressure and axial tension applied in different proportions was analyzed by the elastic-plastic large deformation finite element method.The corresponding buckling criterion for the conical shell was proposed under the combined action of internal pressure and axial tension.The results show that the cylindrical-to-conical transition junctions designed according to the original design specification has a safety margin of at least 2.4 times,and the proposed buckling criterion are in good agreement with the numerical experiment results.