Limit load, shakedown and ratchet analysis of pressurized lateral nozzle

This paper evaluates the limit load, shakedown limit and ratchet limit of the oblique nozzle based on the linear matching method (LMM). In order to study the influencing factors of the limit load, shakedown limit and ratchet limit of the oblique nozzle, oblique nozzle models with different dip angles, diameter-to-thickness ratios of the oblique nozzle and diameter-to-thickness ratios of the main pipe are established, respectively. Firstly, the limit load, shakedown limit and ratchet limit of the oblique nozzle are studied. At the same time, the influence of the loading mode on the shakedown limit and ratchet limit is also studied. Secondly, oblique nozzles with different defect lengths, widths and depths are established, respectively. The influence of loading paths on shakedown limit and ratchet limit of oblique nozzles with defects are also studied. Finally, shakedown limit and ratchet limit diagrams are obtained based on linear matching method. The correctness of shakedown limit and ratchet limit diagrams is validated by ABAQUS incremental elastic-plastic analysis.