钢夹板-螺栓连接胶合木梁抗剪性能试验  

Experiment on shear behavior of glulam beams connected with steel splints and bolts

作　　者：陈爱军[1] 王虎瑞 贺国京[1] 王皓磊[1] 王解军[1] CHEN Aijun;WANG Hurui;HE Guojing;WANG Haolei;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12期187-196,共10页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金面上项目(52378211);湖南省自然科学基金面上项目(2021JJ31160);中南林业科技大学高层次人才引进项目(2019YJ036);湖南省科技创新计划资助项目(2020RC4049)。

摘　　要：【目的】为探究钢夹板-螺栓连接胶合木梁的抗剪性能。【方法】考虑螺栓顺纹间距(80、100、120 mm)、螺栓并列和错列布置方式等参数的影响,设计制作了7组共21根钢夹板-螺栓连接胶合木试验梁,并采用五点弯曲法进行了试验梁的抗剪性能试验。【结果】1)钢夹板-螺栓连接胶合木梁整体工作性能优良且组合效应显著,其受力过程经历弹性和弹塑性两个阶段。相较于普通胶合木梁,其刚度和抗剪承载力均有较大的提升。2)胶合木梁剪切破坏源于综合应力较大的跨中中性轴附近,其破坏形态为顺纹错动剪切破坏,破坏前无明显征兆,为脆性破坏。螺栓均有轻微的弯曲变形,表明胶合木梁采用钢夹板-螺栓连接形式具有较高的可行性与稳定性。3)与普通胶合木梁相比,随着螺栓顺纹间距的增加,螺栓并(错)列布置的试验梁极限承载力提高了24.5%、35.7%、48.8%(20.0%、30.1%、38.2%),极限竖向位移降低了7.2%、11.8%、16.1%(11.9%、19.1%、26.4%)。并列组试验梁木材主应变增长趋势相较错列组试验梁木材主应变更大,错列组试验梁的开裂荷载比并列组试验梁提高较多。4)由钢夹板-螺栓连接胶合木梁抗剪承载力简化计算式得到的抗剪承载力计算值与试验值能较好吻合,平均误差均在9%以内,且计算值偏于保守。【结论】通过钢夹板-螺栓连接胶合木梁的抗剪性能试验,分析了其破坏过程,总结了其在极限状态下的受力变形规律,揭示了破坏机理,并基于试验数据拟合,提出了抗剪承载力简化计算公式。【Objective】The shear behavior of the glulam beams connected with steel splints and bolts was explored.【Method】Considering the bolts spacing along the grain of glulam beams(80 mm,100 mm,120 mm),the parallel or staggered arrangement of bolts and other parameters,7 groups of 21 test beams were designed and manufactured.The shear behavior of the test beams was tested by the five-point bending method.【Result】1)The glulam beams connected with steel splints and bolts had excellent overall working performance and remarkable combined effect.Its stress process went through two stages:elasticity and elasticoplasticity.Compared with the pure glued wood beam,its stiffness and shear capacity were greatly improved.2)The shear failure of glulam beams originated near the mid-span neutral axis where the comprehensive stress was large,and the failure mode was the shear failure along the grain.There was no obvious sign before the failure,which was the brittle failure.All the bolts had slight bending deformation,which indicated that the steel splint-bolt connection was feasible and stable for glulam beams.3)Compared with pure glulam beams,the ultimate bearing capacity of test beams arranged in parallel(staggered)with bolts increases by 24.5%,35.7%,48.8%(20.0%,30.1%,38.2%)and the ultimate vertical displacement decreases by 7.2%,11.8%,16.1%(11.9%,19.1%,26.4%)as the distance between bolts increases along the grain.The growth trend of wood principal strain of test beams in parallel group was larger than that of test beams in staggered group,and the cracking load of test beams in staggered group was higher than that of test beams in parallel group.4)The calculated values of shear capacity of glulam beams connected with steel splints and bolts were in good agreement with the experimental values.The average errors were within 9%,and the calculated values tend to be conservative.【Conclusion】This paper summarizes the stress and deformation law of glulam beam connected with steel splints and bolts in the limit state,reveals its

关 键 词：钢夹板-螺栓连接胶合木梁 抗剪性能试验 并、错列布置 螺栓顺纹间距 

分 类 号：S791.22[农业科学—林木遗传育种]