顶板与竖向加劲肋围焊端部局部应力优化分析

Investigate on local stress optimization of deck-vertical stiffener welding end

针对顶板与竖向加劲肋围焊端部疲劳细节,提出角钢支撑和加劲肋开孔2种应力优化方法。通过数值模拟结合疲劳试验,研究优化方法对围焊端部应力水平和疲劳性能的影响,分析角钢厚度、开孔竖向距离和横向深度3类尺寸参数对优化效果的影响。结果表明:角钢支撑约束顶板面外变形,可降低围焊端部应力水平。加劲肋开孔削弱围焊端部刚度,可降低围焊端部分配的次应力。增加角钢厚度、减小开孔竖向距离、增加开孔横向深度可提升应力优化效果。降低围焊端部疲劳应力可延迟或避免疲劳裂纹的产生,加劲肋开孔不影响裂纹扩展寿命和扩展路径。

With respect to the fatigue details of the deck-vertical stiffener welding end,two stress optimization methods were proposed,including setting angle steel support and perforation of vertical stiffener.Through numerical simulation and fatigue test,the influence of the optimization method on the stress level and fatigue performance of the welding end was investigated,and the influence of three types of dimensional parameters of angle steel thickness,vertical distance and transverse depth of perforation on the optimization effect was analyzed.The results showed that the stress level at the welding end can be optimized by reducing the rigidity of the welding end with angle steel support.The perforation of vertical stiffener reduced the rigidity of the welding end,and the secondary stress distribution of the welding end can be reduced.Increasing the angle steel thickness,decreasing the vertical distance and increasing the transverse depth of the perforation can improve the stress optimizationeffect.The fatigue crack can breaded or avoided by reducing the fatigue local stress at the welding end.The perforation of vertical stiffener does not affect the crack propagation life and path.