侧扭屈曲的波形钢腹板钢筋混凝土连续组合梁的转动刚度

在负弯矩区,连续组合梁将达到由腹板刚度以及混凝土板和剪力连接刚度所产生的侧扭屈曲的极限状态。这3种刚度构成了组合梁的转动刚度。EC4在平面钢腹板组合梁中定义了这种刚度,但对于波形钢腹板组合梁结构中的刚度尚未有结论性研究。文中提出了一个公式,并基于以下几点来对波形腹板型材组合梁的转动刚度进行评估:1)倒U框架模型的4种代表性的试验结果;2)使用ANSYS有限元软件对数值模型进行构建和标定;3)68个数值模型的计算过程。在这些模型中,研究人员试图改变影响转动刚度的所有参数,例如腹板高度和厚度、平板的大小与类型(混凝土板或组合板)、横截面的剪力连接件的数量以及连接件的纵向间距。

Rotational Stiffness of Continuous Composite Beams with Sinusoidal-Web Profiles for Lateral-Torsional Buckling

In the hogging bending moment region, continuous composite beams are subjected to the ultimate limit state of lateral-torsional buckling, which depends on web stiffness as well as concrete slab and shear connection stiffnesses. These three stiffnesses compose the rotational stiffness of composite beams. Eurocode 4 defines this stiffness in composite beams with plane webs, but there are no conclusive studies on the stiffness of composite beams with sinusoidal-web profiles. This paper presents a formulation to evaluate the rotational stiffness of composite beams with sinusoidal-web steel profiles presented based on (a) test results for four representative prototypes of the inverted U-frame model, (b) the development and calibration of a numerical model using the ANSYS commercial finite element software, and (c) the computational processing of sixty-eight numerical models. In these models, the researchers attempted to vary all the parameters that could influence the rotational stiffness, such as web height and thickness, slab size and type (concrete or composite), number of shear connectors in the cross-section and longitudinal spacing of connectors.