压力容器2025，Vol.42Issue(8)：46-53,8.DOI:10.3969/j.issn.1001-4837.2025.08.006
U形膨胀节壁厚不均匀减薄与承压能力的研究
Study of the wall thickness uneven thinning and pressure-bearing capability of the U-shaped expansion joints
摘要
Abstract
In order to investigate the influence of uneven wall-thinning on the load-bearing capacity of expansion joints,this paper conducts a finite element simulation of the hydroforming process for single-layer,single-wave U-shaped bellows expansion joints.It analyzes the effects of non-uniform wall thinning,the tube blank wall thickness(t),the relative size of the inner wall curvature radius at the expansion joint peak/trough(r/Db),and the relative wave height(h/Db)on the wall thinning rate at the peak of the hydroformed expansion joint.The results indicate that the influences of t and r/Db on the wall thinning rate are negligible,whereas the wall thinning rate increases with h/Db,showing an approximately linear relationship.Based on the numerical simulations,a correlation between the wall thinning rate and h/Db is further fitted.The relative error of the calculated results from this correlation is around 10%,which meets engineering design requirements.Three expansion joint models are established based on the nominal thickness,equivalent wall thickness,and post-hydroforming thickness,and their pressure-bearing capacities are analyzed using the limit load method.A strength weakening coefficient is defined to quantify the change in pressure-bearing capacity.It is found that the pressure-bearing capacity of the hydroformed expansion joint decreases,with the strength weakening coefficient primarily influenced by the wall thinning rate at the peak.Finally,a correlation between the strength weakening coefficient and the wall thinning rate at the peak is fitted.The research findings provide an important reference for the design and strength safety assessment of U-shaped expansion joints.关键词
U形膨胀节/液压成形/数值分析Key words
U-shaped expansion joint/hydroforming/numerical analysis分类
机械制造引用本文复制引用
ZOU Kexin,QIAN Caifu,XIE Yue,SONG Yu,WU Zhiwei..U形膨胀节壁厚不均匀减薄与承压能力的研究[J].压力容器,2025,42(8):46-53,8.基金项目
国家重点研发计划项目(2023YFC3010500) （2023YFC3010500）
