腹板-翼缘搭接连接结构钉载分配特性研究

以腹板-翼缘搭接连接结构为研究对象，分析了四点弯曲、三点弯曲两种简支形式的钉载分配特性以及不同简支形式对钉传载荷的影响。利用应变电测法测量了平板及上翼缘螺栓连接区的应力分布;采用ABAQUS软件建立了三维有限元实体模型，对螺栓群的钉载分配行为进行了仿真分析。结果表明,四点弯曲试件的钉载分配特性与三点弯曲的钉载分配特性相比存在明显差异:对于四点弯曲试件，平板以及上翼缘处螺栓群的钉载几乎是对称分布的；而对于三点弯曲试件，结构的不对称造成了钉载分布的不对称。此外，无论四点弯曲试件还是三点弯曲试件，对于平板上单侧的螺栓群，钉载分配均呈两边高、中间低的“浴盆状”分布；对于上翼缘连接区的螺栓群，越靠近两工字梁对接面，钉传载荷越小，反之亦然。

Research on Load Distribution Characteristics for Web-flange Splice Structures

The multi-bolted web-flange splices were studied in terms of evaluating the load distribution among bolt rows of two simply supported types, i.e., four-point bending and three-point bending, as well as the effects of different simply supported types on the bolt-transferred loads. Firstly, the stress distribution of bolted regions which were located on the splice plates and the upper flanges, was preliminarily estimated by means of the strain gauge electric testing technique. Then, three-dimensional finite element models were constructed with ABAQUS software to simulate and analyze the behaviors of the load distribution among bolt rows. The results reveal that the load distribution characteristics of four-point bending specimens are obviously different from those of three-point bending specimens. For four-point bending specimens, the load distribution of bolt rows on splice plates or the upper flanges is almost symmetrical. But what is different about three-point bending specimens is that the asymmetrical structures along the length direction of specimens result in an asymmetry of load distribution. Besides, whether the four-point bending specimens or the three-point bending specimens, the load distribution of unilateral bolt rows located on splice plates is “bathtub-shaped” with the edge rows carrying more amount of load than the inner ones. Furthermore, for bolt rows located on upper flanges, the nearer to the butt surface of two I-beams, the smaller the bolt-transferred load will be and vice versa.