木-钢组合工字梁抗弯性能试验分析  

Timber-steel composite I-beam flexural performance test

作　　者：刘瑞越 卢迎 陈领 杨钦南 吴珍珍 陆冬冬 王解军 LIU Ruiyue;LU Ying;CHEN Ling;YANG Qinnan;WU Zhenzhen;LU Dongdong;WANG Jiejun(College of Civil Engineering,Central South University of Forestry&Technology,Changsha 410000,Hunan,China;Hunan Institute of Transportation Engineering,Hengyang 421200,Hunan,China;Guangzhou First Municipal Engineering Co.,Guangzhou 510000,Guangdong,China;Xiangtan University,Xiangtan 411100,Hunan,China;Huashe Design Group Co.,Nanjing 210000,Jiangsu,China;CCCC Second Navigation Engineering Bureau Co.,Wuhan 430000,Hubei,China)

机构地区：[1]中南林业科技大学土木工程学院,湖南长沙410000 [2]湖南交通工程学院,湖南衡阳421200 [3]广州市第一市政工程有限公司,广东广州510000 [4]湘潭大学,湖南湘潭411100 [5]华设设计集团股份有限公司,江苏南京210000 [6]中交第二航务工程局有限公司,湖北武汉430000

出　　处：《中南林业科技大学学报》2023年第10期166-177,共12页Journal of Central South University of Forestry & Technology

基　　金：国家国际科技合作专项(2014DFA53120);中南林业科技大学科研项目(9010263203077)。

摘　　要：【目的】为了解决胶合木工字梁弯曲加载时,因为腹板的胶合木抗剪强度较低,在没有充分发挥木材的抗拉和抗压能力时就发生胶合木工字梁腹板顺纹剪切破坏的问题。【方法】本研究设计了一个腹板是工字钢梁,上下木板采用螺栓连接的新型钢木组合工字梁,并与胶合木工字梁一起进行三分点弯曲加载对比试验,分别观察木-钢组合梁和胶合木梁的破坏模式、跨中挠度变化、截面高度和翼板的应变发展情况,研究2种结构梁的截面承载力。【结果】胶合木工字梁的破坏模式为脆性的顺纹剪切破坏;木-钢组合工字梁的破坏模式为钢腹板屈服且木材翼缘发生了顺纹剪切破坏;木-钢组合工字梁的极限荷载、初始刚度、强度储备分别比胶合木工字梁高出79.7%、3.2%、140.1%;达到极限荷载时木-钢组合工字梁顶板木材翼缘的最大纵向压应变约是胶合木工字梁的2.08倍,底板木材翼缘的纵向拉应变约是胶合木工字梁的2.75倍。【结论】木-钢组合工字梁是一种科学合理的组合形式,不仅有效地解决了胶合木工字梁在弯曲加载下因纵向抗剪强度较低而发生剪切破坏的问题,而且可为木-钢组合工字梁在大跨径的梁单元结构研究提供参考。采用Rammer公式计算得到的胶合木工字梁的抗剪强度与试验误差为4.49%。该研究成果也使得木-钢组合工字梁的木材拉压强度能很好地发挥。【Objective】In order to solve the problem that the glued laminated wood beam web shear damage occurs when the glued laminated wood beam is loaded in bending because of the low shear strength of the web,without giving full play to the tensile and compressive capacity of the wood.【Method】In this paper,a new steel-wood combination I-beam with the web being an I-beam and the upper and lower wood plates bolted together was designed and subjected to three-equal point bending loading comparison tests together with glued laminated wood beams to observe the damage modes,mid-span deflection changes,section height and strain development of the wing plates of the steel-wood combination beam and glued laminated wood beam,respectively,to study the cross-sectional load capacity of the two structural beams.【Result】The test results showed that the damage mode of the glued woodworking beam was brittle with plain shear damage;the damage of the timber-steel combination I-beam was yielding of the steel web and plain shear damage of the wood flange;the ultimate load,initial stiffness and strength reserve of the timber-steel combination I-beam were 79.7%,3.2%and 140.1%higher than those of the glued woodworking beam;the maximum longitudinal compressive strain of the wood flange of the top plate of the wood-steel combination I-beam was 2.08 times higher than that of the glued woodworking beam when the ultimate load was reached,and the longitudinal tensile strain of the timber flange of the bottom plate was 2.75 times that of the glued laminated timber beam.【Conclusion】The wood-steel composite I-beam is a scientific and reasonable combination form,which not only effectively solves the problem of shear damage of glued laminated wood beams under bending loading due to low longitudinal shear strength,but also provides a reference for the structural study of wood-steel composite I-beams in beam units with large spans.The shear strength of the glued laminated timber I-beam obtained by using Rammer’s formula has an error of 4.4

关 键 词：胶合木工字梁 工字钢梁 顺纹剪切破坏 对比试验 极限荷载 

分 类 号：S781.21[农业科学—木材科学与技术] TU398.6[农业科学—林学]