混合钢U肋加劲板受压整体稳定承载力数值模拟与计算方法

建立受压混合钢U肋加劲板梁单元有限元模型并进行整体稳定分析,通过在梁单元模型中施加等效应力模拟U肋和被加劲板的不同强度,以5种不同强度组合的U肋加劲板试验试件的破坏模式和荷载-位移曲线对数值模拟方法进行验证。采用经试验验证的有限元模型,变化U肋高度、U肋与被加劲板强度与厚度、构件长度,得到混合钢U肋加劲板整体稳定系数,并与各国规范的柱曲线进行比较。结果表明:在压力荷载作用下,由于非等强钢U肋加劲板中钢材强度较低部分较早达到屈服,这将使得构件整体偏心受压,从而导致构件整体稳定系数均小于1; 等强钢M345-U345柱子曲线位于JTG D64—2015中的a,b类柱子曲线之间,并随着相对长细比的增大逐渐向b类柱子曲线靠近; 非等强钢柱子曲线在相对长细比较小时均低于等强钢M345-U345柱子曲线,而在相对长细比较大时的走势基本一致,其中M345-U420和M420-U345两条柱子曲线与JTG D64—2015中的b类柱子曲线接近; M345-U390和M390-U345两种柱子曲线随着相对长细比的增大逐步与等强钢M345-U345柱子曲线重合接近。

Numerical Simulation and Calculation Method of Hybrid Steel U-rib Stiffened Plate's Compression Overall Stability Bearing Capacity

The beam element finite element model of hybrid steel U-rib stiffened plate was established for the overall stability analysis. By applying equivalent stress in beam element model to simulate the different strength of U-rib and stiffened plate, the numerical simulation method was verified by the failure mode and load-displacement curves of five different strength combinations of U-rib stiffened plate test specimens. By using the finite element model verified by experiments, changing U-rib height, strength and thickness of U-rib and stiffened plate, and component length, the overall stability coefficient of the hybrid steel U-rib stiffened plate was obtained, and compared with the column curves of the national codes. The results show that under the action of pressure load, because the lower part of steel strength in the unequal strength steel U-rib stiffened plate reaches yield earlier, it will make the whole component eccentrically compressed, resulting in the overall stability coefficient of the component less than 1. The equal strength steel M345-U345 column curve is located between the class a and class b column curves in JTG D64—2015, and gradually approaches the class b column curve with the increase of the relative slenderness ratio. The curve of unequal strength steel column is lower than that of equal strength steel M345-U345 column when the relative slenderness ratio is small, and the trend is basically the same when the relative slenderness ratio is large, and the M345-U420 and M420-U345 column curves are close to those of class b column curves in JTG D64—2015. The curves of M345-U390 and M390-U345 columns coincide with those of M345-U345 column curve with increasing slenderness ratio.