重组竹-钢夹板螺栓连接节点承载特性和破坏形态  

The Bearing Properties and Failure Mode of Bolted Steel-Bamboo Scrimber-Steel Connections

作　　者：李霞镇 任海青[2] 李贤军[1] 钟永[2] 徐康[1] 郝晓峰[1] Li Xiazhen;Ren Haiqing;Li Xianjun;Zhong Yong;Xu Kang;Hao Xiaofeng(School of Material Science and Engineering,Central South University of Forestry and Technology,Changsha 410004;Research Institute of Wood Industry,CAF,Beijing 100091)

机构地区：[1]中南林业科技大学材料科学与工程学院,长沙410004 [2]中国林业科学研究院木材工业研究所,北京100091

出　　处：《林业科学》2021年第8期157-166,共10页Scientia Silvae Sinicae

基　　金：湖南省重点研发计划项目(2020NK2021);湖南省林业科技创新项目(XLK201903);湖南省自然科学基金项目(2020JJ5971);湖南省教育厅优秀青年基金项目(19B609)。

摘　　要：【目的】研究重组竹-钢夹板单螺栓连接节点承载特性和破坏形态,为竹结构螺栓连接设计与应用提供参考和借鉴。【方法】采用正交设计方案,对重组竹-钢夹板单螺栓连接节点试样进行单轴压缩加载试验,利用方差分析和多重比较法分析螺栓直径、主构件厚度和端距对初始和屈服后刚度(K_(1)、K_(2))、屈服和极限载荷(F_(y)、F_(u))及延性率的影响规律。【结果】螺栓直径对初始和屈服后刚度(K_(1)、K_(2))、屈服和极限载荷(F_(y)、F_(u))及延性率具有显著影响,随螺栓直径增大,螺栓连接节点的初始和屈服后刚度(K_(1)、K_(2))、屈服和极限载荷(F_(y)、F_(u))显著增加,但延性率明显减小;主构件厚度对初始和屈服后刚度(K_(1)、K_(2))、极限载荷(F_(u))及延性率影响显著,但对屈服载荷(F_(y))无显著影响;端距对屈服后刚度(K_(2))、极限载荷(F_(u))及延性率影响显著,但对初始刚度(K_(1))和屈服载荷(F_(y))无显著影响。钢夹板单螺栓连接重组竹的有效破坏主要以Ⅱ型和Ⅲ型2种破坏模式呈现,且当厚径比(L/D)处于3.75~6.00之间时,螺栓呈现“单铰”屈服模式;当厚径比(L/D)处于6.00~13.50之间时,螺栓呈现“双铰”屈服模式。【结论】重组竹-钢夹板螺栓连接节点承载性能和破坏形态受螺栓直径、主构件厚度和端距的共同影响,重组竹-钢夹板单螺栓连接节点的最小主构件厚度和最小端距可分别设置为90 mm和4d(d为螺栓直径),此时节点各承载性能趋于稳定且延性率达到最佳状态。当节点试样满足最小端距和主构件厚度要求时,螺栓屈服模式随厚径比(L/D)增大逐渐由“单铰”屈服转变为“双铰”屈服,节点最终破坏表现为主构件销槽承压和螺栓弯曲同时发生,此时主构件和螺栓均能充分发挥材料的力学性能,是较为合理的破坏模式。【Objective】The bearing properties and failure modes of single bolted steel-bamboo scrimber(BS)-steel connections were studied,to provide some references for the design and application of bolted connection for bamboo structure.【Method】Influence factors such as bolt diameter,main member thickness and end distance were designed by orthogonal scheme,to systematically analyze the influence laws of the initial stiffness(K_(1)),post-yield stiffness(K_(2)),yield load(F_(y)),ultimate load(F_(u))and ductility rate of the connections which were tested under the uniaxial compression,by means of variance analysis and multiple comparisons,in order to reveal the bearing properties and failure modes of the single-bolted connections of steel-BS-steel.【Result】The bolt diameter had significant effects on initial stiffness(K_(1)),post-yield stiffness(K_(2)),yield load(F_(y)),ultimate load(F_(u))and ductility rate,of which the former four parameters were all increased with bolt diameter,while the latter ductility rate was decreased.Except for the yield load(Fy),the effects of the main member thickness on the initial stiffness(K_(1)),post-yield stiffness(K_(2)),ultimate load(F_(u))and ductility rate were all prominent.Besides,the post-yield stiffness(K_(2)),ultimate load(Fu)and ductility rate were remarkably affected by the end distance,while its effects on the initial stiffness(K_(1))and yield load(F_(y))were reversely.Moreover,the effective failure modes of the single-bolted steel-BS-steel connections were presented as type-Ⅱor type-Ⅲ.The yield mode of bolt was presented as“single-hinge”failure when the L/D value was from 3.75 to 6.00,while it was presented as“double-hinge”failure mode when the L/D values was from 6.00 to 13.50.【Conclusion】The bearing capacity and failure mode of the single-bolted steel-BS-steel connection were affected by the bolt diameter,end distance and main member thickness simultaneously.It was suggested that the minimum dimensional requirement of the main member thickness and end d

关 键 词：重组竹-钢夹板 螺栓连接 承载性能 影响因素 破坏形态 

分 类 号：TU366.3[建筑科学—结构工程]