分片式型钢-螺栓胶合木梁柱节点转动性能试验研究

Experimental study of rotational behavior of bolted glulam beam-to-column connections with two-part steel section

胶合木框架结构中常采用钢填板-螺栓连接节点,但其易在梁上出现木材横纹劈裂和顺纹剪切脆性破坏,为解决此问题,提出分片式型钢-螺栓胶合木梁柱节点形式,通过在钢填板上下增设翼缘来限制木材横纹裂缝发展。为量化其转动性能,对柱中、柱端2组共6个足尺节点开展了低周反复加载试验。试验结果表明:相比于普通钢填板-螺栓连接节点,分片式型钢-螺栓胶合木梁柱节点的受弯承载力、相对受弯承载力系数、初始刚度、延性系数分别提高了98%、57%、71%、62%。基于节点受力机理和欧洲规范相关计算方法,提出了分片式型钢-螺栓节点的受弯承载力和初始刚度的计算方法,计算结果与试验结果误差最大为13.2%。

Bolted beam-to-column connections are widely used in framed glulam timber buildings.However,such connections are prone to perpendicular-to-grain tensile splitting and parallel-to-grain shear failure of wood due to the relatively low strength of wood.An innovative connection design was proposed in this paper,in which the slotted-in steel plate is replaced by a steel section.The upper and bottom flanges of the steel section can provide transverse constraint to the timber in the jointing area and alleviate the perpendicular-to-grain tensile and parallel-to-grain shear cracking.Low-cycle repeated loading tests were conducted on six full-scale nodes in two groups,including nodes inside the column and nodes at the end of the column.The test results show that the bending moment resistance and its ratio to the bending moment resistance of the glulam beam,the initial rotational stiffness and the ductility ratio of the proposed connections can be increased by 98%,57%,71%and 62%,respectively,compared with conventional bolted glulam beam-to-column joints.Based on the load carrying mechanism of the joints and relevant European code specifications,a calculation formula of the bending moment resistance and the initial rotational stiffness of the proposed connections was proposed.The error between the calculation results and the experimental results is less than 15%.