偏心距对胶合木空心柱受压性能的影响  

Influences of eccentricity on the compressive performance of glulam hollow columns

作　　者：陈领 刘佳桐 刘瑞越 王解军[1] CHEN Ling;LIU Jiatong;LIU Ruiyue;WANG Jiejun(College of Civil Engineering,Central South University of Forestry&Technology,Changsha 410004,Hunan,China)

机构地区：[1]中南林业科技大学土木工程学院,湖南长沙410004

出　　处：《中南林业科技大学学报》2023年第2期166-179,共14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学研究项目(9010263203077)。

摘　　要：【目的】为探讨落叶松胶合木空心柱的偏心受压性能,【方法】对7组不同偏心距的试件进行单向偏心受压承载力试验,研究胶合木空心柱的破坏模式、破坏机理、承载力、荷载-应变关系、荷载-挠度关系,并将偏心受压柱与轴心受压柱进行对比。通过考虑柱中侧向挠度来增大偏心压力产生的弯矩,提出了胶合木空心柱偏压承载力计算公式。【结果】小偏心受压柱破坏模式为弯曲凹侧木材被压屈,产生纵向裂缝,弯曲凸侧木材没有明显的破坏;大偏心受压柱破坏模式为弯曲凹侧木材压屈,纵向开裂,弯曲凸侧木材被拉断破坏。偏心距为30~100 mm的试件,其极限承载力分别下降至轴心受压试件承载力的61.51%~31.16%。偏心受压柱承载力改进公式计算结果与试验值相差在10%以内,比目前我国木结构设计标准及胶合木结构技术规范公式的计算更准确。【结论】空心柱大小偏心的界限偏心率约为0.6。大偏心受压破坏与小偏心受压破坏不同的是:弯曲凸侧有明显的破坏现象,且破坏比较突然;试件承载力迅速降低,挠曲变形较大。随着偏心距增加,木柱的承载力逐渐降低,但下降幅度减小。从荷载-应变关系、荷载-挠度关系曲线中可以看出,空心胶合木柱具有一定的塑性变形能力,满足工程用材的要求。研究成果可为工程设计提供理论参考。【Objective】This article aimed to explore the eccentric compressive performance of larch glulam hollow columns.【Method】Oneway eccentric compressive bearing tests were conducted on seven groups of the specimen with different eccentric distances to study the failure mode,failure mechanism,bearing capacity,load-strain relationship,and load-deflection relationship of glulam hollow columns,and to compare the eccentric compressive columns with the axial compressive columns.By considering the lateral deflection in the column to increase the bending moment generated by the eccentric pressure,the calculation formula of the eccentric compressive bearing capacity of glulam hollow columns was proposed.【Result】The failure mode of the small eccentric compressive columns was that the timber on the curved concave side was compressed,resulting in longitudinal cracks,and the timber on the curved convex side had no obvious failure.The failure mode of large eccentric compressive columns was that the timber on the curved concave side was compressed and cracked longitudinally,and tensile failure was observed on the timber on the curved convex side.The ultimate bearing capacity of the specimens with an eccentric distance of 30-100 mm decreased from 61.51%to 31.16%of the bearing capacity of the axially compressed specimens.The difference between the calculation results of the improved formula of bearing capacity of the eccentric compressive column and the test value was within 10%,which was more accurate than the calculation of the current Standard for design of timber structures and the formula of the Technical code of glued laminated timber structures in China.【Conclusion】The eccentricity of the hollow column is about 0.6 for the limit of dimension eccentric.Differences between the large eccentric compressive failure and small eccentric compressive failure:the obvious failure observed on the curved convex side,the sudden failure of the curved convex side,the rapid decrease of the specimen bearing capacity,and the large

关 键 词：胶合木空心柱 偏心受压 极限承载力 模型试验 理论分析 

分 类 号：S718.2[农业科学—林学]