摘要
为研究钢夹板螺栓连接胶合木桁架中球铰节点的抗拉性能,针对组合结构特点设计制作可以连接螺栓球与胶合木的新型金属−紧固连接件“U型钢夹板”,设置6组共18个钢夹板螺栓连接胶合木球铰试件。采用千斤顶卧推拉伸试件的试验方法,探讨螺栓顺纹间距(80、100、120 mm)及螺栓并列、错列布置方式对钢夹板螺栓连接胶合木球铰节点抗拉承载力、破坏模式以及破坏机理的影响。研究结果表明:整个抗拉试验过程中,螺栓球内螺纹无剪坏失效,M24抗拉螺栓无拉伸断裂现象,钢夹板与胶合木均未发生明显变形与开裂情况,装配体试件均以滑移破坏结束试验。M8抗剪螺栓以“单铰”破坏为主,随着螺栓间距增大,其装配体试件最大滑移承载力提高;螺栓错列布置的最大滑移承载力比并列要大;且错列布置拥有更高的初始刚度,同间距下螺栓变形程度比并列布置差异化更大;受力边与上下边行的M8抗剪螺栓弯曲更为明显。装配体试件中滑移主要以钢夹板M8抗剪螺栓与胶合木之间的相对滑移为主,但装配体各部件之间的空隙所造成的滑移同样也不可忽略。“螺栓球−M24抗拉螺栓−U型钢夹板螺栓连接件”节点具备良好的整体刚度,保证稳定传递杆件拉力的同时能适配钢−木混合桁架结构的节点连接要求。安装间隙所造成的滑移无法避免,可以采取以下措施对装配体试件改进优化:根据实际承载需求,适当缩小螺栓间距,错列布置螺栓;装配过程适度施加预应力,缩小紧固件空隙;选取高强度、大刚度的装配体配套部件材料。
To investigate the tensile properties of mero joint connected with steel splint bolted glulam truss.Based on the characteristics of steel-timber composite structures,a novel metal-fastening connector was designed and fabricated.It was the U-shaped steel splint,which was used to connect the mero joint with the glulam.A total of 18 specimens from 6 groups were tested.Tensile tests were carried out by applying force to the specimens using two jacks,with the aim of studying the effects of bolt spacing(80,100,120 mm)and bolt arrangement(bolts in parallel and in staggered rows)on the tensile properties,deformation capacity and damage morphology of the specimens.During the entire tensile tests,no shear failure occurred in the internal threads of the mero joint,and no tensile fracture was observed in the M24 tensile bolts.Both the steel splints and the glulam exhibited no significant deformation or cracking,with the specimen failures ending in slippage.The M8 shear bolts primarily failed via a single hinge mechanism.As the bolt spacing increases,the maximum slippage-bearing capacity of the specimens increases.Specimens with staggered bolt arrangements show higher maximum slippage-bearing capacity compared to those with parallel arrangements.The staggered arrangement can also exhibit higher initial stiffness.The deformation of bolts under the same spacing is more differentiated than in the parallel arrangement.The M8 shear bolts in the loaded edge and top and bottom rows can bend more prominently.In the specimens,slippages primarily occur between the M8 shear bolts and the glulam,although slippage due to gaps between the components of the assembly is also significant.The“mero-M24 tensile bolts-U type steel splint bolt connectors”joint demonstrates good overall stiffness,ensuring the stable transmission of rod tension while meeting the joint connection requirements of steel-timber hybrid truss structure.Slippage caused by assembly gaps cannot be avoided.The improvements to the specimens can be made in several ways,which are reducing the bolt spacing according to actual load requirements,using staggered bolt arrangements,applying pre-stress during the assembly process to minimize the gap,and selecting materials with high strength and stiffness for the assembly components.
作者
尹伊璐
陈爱军
贺国京
王皓磊
李龙
YIN Yilu;CHEN Aijun;HE Guojing;WANG Haolei;LI Long(School of Civil Engineering,Central South University of Forestry&Technology,Changsha 410004,China)
出处
《铁道科学与工程学报》
北大核心
2025年第9期4108-4119,共12页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(52378211)
湖南省自然科学基金资助项目(2021JJ31160)
中南林业科技大学高层次人才引进资助项目(2019YJ036)
湖南省科技创新计划资助项目(2020RC4049)
中南林业科技大学研究生科技创新基金资助项目(2024CX02096)。
