钢一混凝土组合空腹板架结构负弯矩区力学性能研究

Mechanical behaviors of composite open-web plate structure under negative moment

为研究钢—混凝土组合空腹板架结构负弯矩区力学性能,基于有限元分析软件Abaqus建立两跨半连续空腹板有限元模型,考虑了材料和几何非线性,对模型进行了竖向均布荷载作用下的力学性能研究,重点分析了中间支座负弯矩区钢筋、混凝土板、剪力键以及钢肋的受力特点。研究结果表明:负弯矩区混凝土板受拉开裂,板内分布钢筋主要承受拉力作用,且受力均匀;负弯矩区段的剪力键使混凝土板受到较大的冲切作用,且该范围随着负弯矩的降低而逐渐减弱,因此,在对结构负弯矩区进行设计、分析时应合理考虑混凝土板的有效宽度,并采取有效措施降低剪力键对混凝土板的冲切作用。

In order to study the mechanical behaviors of composite open-web plate structures under negative moment,a finite element model was established using the finite element program ABAQUS.A uniformly distributed load was applied to the structure. The numerical model considered both the material and geometric nonlinearities and fully reflected the complex behaviors of the open-web plate structure under negative moment during loading. The mechanical behaviors of the steel bar ,the concrete slab,the shear key and the steel ribs were analyzed. The results show that the concrete slab which located in the negative moment area will crack under minimal ten s io n, so the steel bar bears most of the tension uniformly. The concrete slab which located in the negative moment areasustained a lot of punching from the shear keys, and this phenomenon will be gradually weakened with the decrease of the negative moment. Therefore, in the design of the negative moment a r ea, the effective width of the concrete slab should be considered reasonably, and effective action should be taken to reduce the punching on concrete slabs.