考虑滑移的竹-原木组合梁力学性能试验分析  

Experimental analysis of mechanical properties of bamboo log composite beams with slip effect

作　　者：孟阳君 陈强[3] MENG Yangjun;CHEN Qiang(School of Intelligent Architecture,Changde College,Changde 415000,Hunan,China;School of Civil Engineering and Architecture,Hunan University of Arts and Science,Changde 415000,Hunan,China;College of Civil Engineering,Hunan City University,Yiyang 413000,Hunan,China)

机构地区：[1]常德学院智能建筑学院,湖南常德415000 [2]湖南文理学院土木建筑工程学院,湖南常德415000 [3]湖南城市学院土木工程学院,湖南益阳413000

出　　处：《中南林业科技大学学报》2025年第4期139-150,共12页Journal of Central South University of Forestry & Technology

基　　金：湖南省自然科学基金项目(2021JJ50136)。

摘　　要：【目的】为了更好评定竹-原木组合梁的抗弯刚度、挠度、应变高度关系等力学性能,提出考虑滑移的竹木组合梁理论。【方法】开展原木梁与竹-原木组合梁的对比试验,结合理论分析,提出考虑滑移的竹-原木组合梁力学性能评价指标。【结果】结合弹性力学的基本原理,推导考虑滑移的竹木组合梁滑移理论,得出几种常见荷载作用下的滑移量、附加挠度等表达式,展示滑移沿梁长的分布图示。相较于原木梁,竹-原木组合梁的极限荷载为其1.61倍,抗弯刚度提升最大幅度达到55.5%。考虑折减之后的构件的组合抗弯刚度,与实测的组合抗弯刚度误差最大为4.22%。不考虑滑移影响,竹-原木组合梁跨中挠度普遍小于试验结果值。根据附加挠度,采用试算法可得竹-原木组合梁界面滑移刚度。研究结果表明,挠度计算时务必考虑层间滑移。以平均滑移刚度为标准,竹-原木组合梁3个试件极限荷载作用下端部的滑移量分别为0.57、0.72、0.68 mm。竹-原木组合梁试件的跨中截面应变高度曲线符合平截面假定,形心偏移量很小。【结论】竹-原木组合梁相较于原木梁,增大刚度的同时也提升构件的延性。考虑滑移的影响,构件产生附加挠度,计算整体挠度时,必须考虑抗弯刚度的折减。梁底粘贴薄片竹皮形成的竹木组合梁,可以不考虑形心轴的偏移,由此得出考虑滑移的附加挠度公式是准确可靠的。推导得到的考虑滑移的竹-木组合梁理论及相关公式可供同类项目参考。【Objective】In order to evaluate the mechanical properties of bamboo log composite beams better,such as bending stiffness,deflection,and strain height relationship,a theory of bamboo log composite beams considering slip is proposed.【Method】The comparative tests between log beams and bamboo log composite beams were conducted,combined theoretical analysis,mechanical performance evaluation indicators for bamboo log composite beams considering slip were proposed.【Result】Using the basic principles of elasticity,the slip theory of bamboo wood composite beams considering slip was derived,and expressions for the slip value and additional deflection under several common loads were obtained,meanwhile,the distribution diagram of slip along the axis of components is displayed.Compared to log beams,the ultimate load of bamboo log composite beams is 1.61 times that of them,and the maximum increase in bending stiffness reaches 55.5%.The maximum error between the combined bending stiffness considering discounts and the measured combined bending stiffness is 4.22%.Without considering the influence of slip,the mid span deflection of bamboo log composite beams is generally smaller than the test results.Based on the additional deflection,the sliding stiffness of interface between the bamboo and wood can be obtained using the trial calculation method.Analysis and calculation indicate that interlayer slip must be considered when calculating deflection.Based on the average slip stiffness,the slip values at the end of the three bamboo log composite beams under ultimate load are 0.57 mm,0.72 mm,and 0.68 mm,respectively.The strain height curve of the mid span section of the bamboo log composite beam specimen conforms to assumption of plane section,and the centroid offset is very small.【Conclusion】Compared to log beams,bamboo log composite beams not only increase stiffness but also improve the ductility of the components.Considering the influence of slip,additional deflection is generated in the component.When calculating th

关 键 词：竹木组合梁 试验 滑移 附加挠度 刚度折减系数 

分 类 号：S795[农业科学—林木遗传育种] TU366[农业科学—林学]