Abstract:

GB/T4732 Pressure Vessels Design by Analysis has introduced the new methods for buckling analysis and evaluation in ASME Ⅷ-2-2021. The correct understanding of the new methods will be helpful for their rational use in engineering design in the future. Based on the theoretical principles of buckling, this paper takes typical combined structures in pressure vessels as an example, and carries out finite element numerical calculations using two buckling analysis methods based on elastic and elastic-plastic pre-stress. After comparative analysis, some conclusions were obtained for reference and further discussion. It is reasonable to calculate the buckling load with the first-order buckling mode and determine the allowable load accordingly in buckling analysis. For structures in elastic buckling state, the buckling load values calculated by elastic and elastic-plastic pre-stress analysis are almost the same. In practical engineering applications, elastic pre-stress buckling analysis can be directly used to reduce the calculation workload and improve the calculation efficiency, and the final allowable load value has a greater safety margin than that determined by elastic-plastic pre-stress buckling analysis.

Key words: pressure vessel, finite element, elastic pre-stress, elastic-plastic pre-stress, buckling analysis