联合弯矩作用下含裂纹船体结构剩余极限强度评估方法研究

Residual Ultimate Strength Evaluation Method of Cracked Hull Structure under Combined Bending Moment

裂纹损伤对于船体结构来说难以避免,将削弱结构的极限强度,所以研究含裂纹损伤船体结构的剩余极限强度意义重大。对于含裂纹舱段结构,现有的研究主要针对垂向弯矩作用下的剩余极限强度,对于联合弯矩作用下的研究还很欠缺。本文采用非线性有限元分析方法,研究了垂向弯矩和水平弯矩联合作用下含裂纹舱段的剩余极限强度。提出了计算含裂纹船舯舱段在联合弯矩作用下剩余极限强度的计算公式,通过对含裂纹箱型梁的有限元计算结果进行拟合,得到公式中待定系数的表达式。研究结果表明,本文提出的方法可以快速预测船体结构在联合弯矩作用下的剩余极限强度。

Crack damage is inevitable for ship structures and can weaken the ultimate strength of the structures.Therefore,it is of great significance to study the residual ultimate strength of ship structures with crack damage.Existing research mainly focuses on the residual ultimate strength of cracked hulls under vertical bending moment,and there is still a lack of research under combined bending moment.In this paper,the residual ultimate strength of a cracked midship section under combined action of vertical moment and horizontal moment is studied by using nonlinear finite element(FE)analysis.An evaluation formula is proposed to calculate the residual ultimate strength of the cracked midship section under the combined bending moment.Undetermined coefficients in the formula are obtained by fitting FE calculation results of cracked box girders.The results indicate that the proposed method can be used for rapid prediction of the residual ultimate strength of cracked hull structures under combined bending moment.