Abstract: In order to further clarify the ultimate load-bearing capacity of the hull structure, it is necessary to comprehensively consider the effects of initial welding defects, the Bauschinger effect of the material and the properties of the cyclic loading on the ultimate strength of hull stiffened plates. The thermal elastic-plastic finite element method was used to simulate the welding process of the flat-bar stiffened plate, and then the ultimate strength of the stiffened plate reaching the elastic shakedown state under cyclic compression-tension loading was analyzed. The research results show that the welding residual stress of the hull stiffened plate is most significantly released after the first cyclic unloading and is increased with the increase of the cyclic load amplitude. Under cyclic loading, the ultimate strength of the hull stiffened plate is increased after reaching the elastic shakedown state, but the cyclic load amplitude does not have a significant effect on the improvement of ultimate strength. Under the same cyclic load amplitude, the ultimate strength calculated by Chaboche model is slightly higher than that by the ideal elastoplastic model. The thermal elastic-plastic finite element method can be used to directly obtain the initial welding defects of hull stiffened plate, which has a certain reference value for the further study of the ultimate load-bearing capacity of the hull structure under cyclic loading.

Key words: ship engineering; cyclic loading; hull stiffened plates; thermal elastic-plastic finite element method; ultimate strength

摘要： 为进一步明晰船体结构极限承载性能，有必要综合考虑焊接初始缺陷、材料鲍辛格效应以及载荷循环属性对船体加筋板极限强度的影响。采用热弹塑性有限元法对扁钢加筋板进行焊接数值模拟，并开展了循环压缩-拉伸载荷下达到弹性安定状态的加筋板极限强度分析。研究结果表明：船体加筋板焊接残余应力在首次循环卸载后释放程度最显著，并随循环载荷幅值增大而增加；在循环载荷作用下，船体加筋板达到弹性安定状态后的极限强度有所提升，但循环载荷幅值对其极限强度提升效果不明显；在相同循环载荷幅值下，采用Chaboche模型计算得到的极限强度比理想弹塑性模型要高；采用热弹塑性有限元法能直接获取船体加筋板焊接的初始缺陷，对进一步研究船体结构在循环载荷下的极限承载性能具有一定参考价值。

关键词: 船舶工程；循环载荷；船体加筋板；热弹塑性有限元法；极限强度