含裂纹薄壁圆柱壳结构在断裂-屈曲复合破坏下的极限荷载研究

Research on Ultimate Load of Cracked Thin-walled Cylindrical Shell Structure under Fracture-Buckling Combined Failure

含裂纹薄壁结构的极限荷载分析对于开展钢结构的安全和耐久性研究有重要的意义。针对含裂纹薄壁圆柱壳结构在断裂-屈曲复合破坏下的力学行为,基于J积分理论,采用有限元方法研究了含裂纹薄壁圆柱壳结构在轴心及偏心受压下的临界极限荷载,分析裂纹存在对临界极限荷载的影响,同时考察了相对裂纹长度、偏心度、等效长细比因素对其的影响。结果表明这些因素对临界极限荷载影响很大且相互影响。最后拟合得到了轴压含裂纹薄壁圆柱壳的极限荷载近似计算公式。所得研究结论对研究含裂纹结构的失效模式确定具有理论和工程参考价值。

The ultimate load analysis of cracked thin-walled structures is of great significance for the research on the safety and durability of steel structures.Aiming at the mechanical behavior of cracked thin-walled cylindrical shell structure under fracture-buckling combined failure,based on J integral theory,the critical limit load of cracked thin-walled cylindrical shell structure under axial and eccentric compression was studied using finite element method.The influence of the existence of cracks on the critical ultimate load was analyzed,and the effects of relative crack length,eccentricity,and equivalent slenderness factors were also examined.The results show that these factors have a great influence on the critical ultimate load and influence each other.Finally,an approximate formula for the ultimate load of a thin-walled cylindrical shell with cracks under axial compression was fitted.The research conclusions are of theoretical and engineering reference value for the study of the failure mode determination of structures with cracks.