胶合木预应力套管螺栓连接梁柱节点受力性能

Mechanical performance of glulam beam-column joints with prestressed tube bolts

胶合木结构中的梁柱大多采用钢填板螺栓进行连接,即通过内嵌的钢板、采用螺栓连接梁柱构件。然而,这种连接方式存在螺孔与螺杆间空隙大、初始刚度低、木材易劈裂等问题。为提高节点的初始刚度、改善既有破坏模式中木材劈裂问题,提出一种将T形钢连接件的翼缘通过对拉螺栓连接于柱侧、T形钢连接件的腹板插入梁端并通过预应力套管螺栓与梁端紧密连接的节点构造。为了研究套管形状对节点受力性能的影响,分别制作使用方形套管和圆形套管的胶合木预应力套管螺栓节点试件,开展单调和往复加载试验。基于试验,得到了节点刚度、承载力以及延性等性能,并分析不同形状预应力套管螺栓节点的受力性能。结果表明:与传统钢填板螺栓节点相比,所提出的预应力套管螺栓连接梁柱节点初始刚度是其3倍以上;使用方形套管可延缓木材劈裂、减缓节点的刚度退化,但承载力比圆形套管节点降低9%。

The connection of beams and columns in glulam structures often adopts the bolt connection with steel plates,which connects beam and column components through embedded steel plates and bolts.However,this connection method has problems such as large gaps between bolt holes and bolt rods,low initial stiffness and wood splitting.In order to increase the initial stiffness of the joint and improve the problem of wood splitting in the existing failure mode,a joint construction was proposed,in which the flange of the T-shaped steel connector is connected to the column sides with split bolts,and the web of the T-shaped steel connector is inserted into the beam end and tightly connected to the beam end with the prestressed tube bolts.To study the influence of tube shape on the mechanical performance of joints,the prestressed tube bolted glulam joint specimens with square tubes and circular tubes were made respectively,and monotonic and cyclic loading tests were carried out.Based on the experiments,the stiffness,bearing capacity,and ductility of the joints were studied,and the mechanical performance of bolted joints with prestressed tubes of different shapes was analyzed.The results indicate that compared with the traditional steel plate bolted joints,the initial stiffness of the proposed beam-column joints with prestressed tube bolts is increased by more than two times.Using square tubes can delay wood splitting and slow down the stiffness degradation of the joint,but the ultimate bearing capacity is 9%lower than those of circular tubes.