船舶圆弧过渡肘板节点的屈曲破坏研究

船体构件腹板在连接端部逐渐升高形成圆弧过渡肘板节点,较大的腹板尺寸导致其受弯时易出现屈曲破坏,从而影响船体结构的安全性。以典型圆弧过渡肘板连接的横梁-肋骨节点结构为研究对象,采用极限强度试验与非线性有限元模拟方法,研究肘板节点受弯时的破坏模式、极限载荷以及屈曲过程,讨论肘板臂长、圆弧半径、面板厚度对节点结构屈曲破坏的影响。结果显示:考虑初始缺陷的非线性有限元模拟结果与试验结果一致;根据肘板尺寸的不同,屈曲破坏的位置包括靠近肋骨的横梁腹板区域以及肘板与横梁过渡圆弧处的腹板区域;随着肘板臂长的增加,不同圆弧半径时节点的极限载荷均为先增大后趋于不变;随着圆弧半径的增加,肘板臂长较小的节点极限载荷缓慢上升,肘板臂长较大的节点极限载荷则近似呈线性增长趋势;面板厚度对极限载荷的影响较小,随着面板厚度的增加,极限载荷先缓慢增加后趋于不变。

Bucking Failure of Arc Bracket Joint in Ship

The web of the member is gradually raised at the ends to form an arc bracket in the hull structure. Buckling failure is likely to occur on the bracket with large-sized web to influence the safety of the ship. Under the bending load, the damage mode, ultimate load and failure process of the beam-rib structure joined by arc bracket are researched in the method of ultimate strength experiment and nonlinear numerical analysis. There is a good agreement between nonlinear numerical simulating results considering initial imperfections and experimental results. In addition, the effects of the arm length, arc radius and panel thickness on buckling failure are discussed. The results indicate that failure modes include the beam web connected to the rib and the web in the arc transition of bracket for different dimensions of bracket. With the arm length increasing, the ultimate load rises and then tends to be constant for different arc radius. With the increase of arc radius, the ultimate load rises slowly for shorter arm length of bracket, and the ultimate load rises approximately linearly for longer arm length of bracket. The effect of the panel thickness on the ultimate load is less, and the ultimate load rises slowly and then tends to be unchanged with the growth of the panel thickness.