基于非线性理论的船舶结构稳定性研究

摘要

Based on the nonlinear analysis of structures,the analysis method of the structural stabili ty has been improved. The critical load on structure is determined through analysis of linear stability based on the eigenvalue analysis.With this load,the upper limit of the critical load on real structure can be forecasted and the impact of structure's linearity on its stability can be well reflected.Therefore, the instable displacement of structure can be derived.In the analysis of nonlinear stability,NEWTON-ROPHSON method and cylindrical are-length method are used to calculate the nonlinear structural critical load. Meanwhile,the impact of structural defect on its stabil ity is discussedin detail and the method of calculating the defective structural stability is proposed. Through analysis and comparison of various samples,the relationship among the structural boundary,geometrical defective change and structural stability is established and the effectiveness of the analysis method of stability and its applicability to service bulk carrier is verified.%本文以结构的线性分析为基础,对船舶结构的线性稳定性分析方法进行了改进.同时,采用基于特征值分析的线性稳定性分析方法得到了船舶结构的临界载荷,从该载荷值可以预测出实际结构临界载荷的上限并能较好地反映船舶结构线性性能对其稳定性的影响,据此得出船舶结构的失稳位形.在非线性稳定性分析中,采用NEWTON-ROPHSON方法及弧长法求解考虑非线性时船舶结构的临界载荷,并详细讨论了结构缺陷对稳定性的影响,提出考虑结构缺陷时船舶结构稳定性计算方法.通过不同类型的算例进行分析比较,总结出船舶结构边界条件、几何缺陷变化与船舶结构稳定性之间关系,验证了本文稳定性分析方法的正确性、有效性及对现役散货船船体结构的适用性.