长期荷载作用后钢-竹组合工字形梁受力性能研究  

RESEARTH ON MECHANICAL PROPERTIES OF STEEL-BAMBOO COMPOSITE I-BEAMS AFTER BEING SUBJECTED TO LONG-TERM LOADING

作　　者：王嘉琳 李玉顺[1] 周佳如 闫智民 WANG Jialin;LI Yushun;ZHOU Jiaru;YAN Zhimin(School of Civil and Environmental Engineering,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学土木与环境工程学院,浙江宁波315211

出　　处：《工业建筑》2020年第8期160-165,181,共7页Industrial Construction

基　　金：国家自然科学基金项目(51678310,51978345);国家重点研发计划资助(2019YFD1101002);宁波市科技计划项目(202002N3090)。

摘　　要：为了探究长期荷载作用后钢-竹组合工字形梁的力学性能,以竹板厚度、钢板厚度和宽度、截面高度为参数,设计制作了8根钢-竹组合工字形梁试件,其中4根为长期加载试件,施加长期荷载后进行二次加载破坏试验,其余4根为短期试件,直接进行加载破坏试验,来作为对比。对长期加载试件和短期试件进行分析,对比破坏特征、破坏形态、破坏荷载,研究钢-竹组合工字形梁的荷载-应变关系、荷载-挠度关系、承载力衰减等力学性能的变化,探讨钢-竹组合工字形梁在长期荷载作用后承载力与挠度的计算方法。试验结果表明:钢-竹组合工字形梁在长期荷载作用后,仍具有良好的受力特性。长期荷载作用对钢-竹组合工字形梁的最终破坏形态无影响,组合梁二次加载破坏与直接加载破坏受力过程均呈弹性、屈服、开裂、极限四个阶段;长期试件的挠曲变形与短期试件的挠曲变形相差不大,增加竹板厚度、钢板厚度和宽度、截面高度,可提高长期加载试件的极限荷载,长期试件承载力的衰减程度约为10%;采用所提出的算式计算钢-竹组合工字形梁长期荷载作用后的承载力与挠度,理论值与试验值吻合较好。In order to explore the mechanical properties of steel-bamboo composite I-beam after being subjected to long-term loading,eight steel-bamboo composite I-beam specimens were designed and fabricated with the parameters of bamboo plate thickness,steel plate thickness and width,and section height.Four of them were long-term loaded specimens.After being subjected to long-term loading,secondary loading failure tests were carried out.The other four were short-term loaded specimens,and loading failure tests were carried out directly for comparison.The longterm and short-term loaded specimens were analyzed,and the failure characteristics,failure modes and failure loads were compared.The load-strain relationship,load-deflection relationship and bearing capacity attenuation of steelbamboo composite I-beams were studied.The calculation method of bearing capacity and deflection of steel-bamboo composite I-beams after being subjected to long-term loading was discussed.The test results showed that the steelbamboo composite I-beams still had good mechanical properties after being subjected to long-term loading.Long-term load had no effect on the ultimate failure mode of steel-bamboo composite I-beams.The secondary loading failure and direct loading failure of composite beams had four stages of elasticity,yield,cracking and ultimate strength.The flexural deformation of long-term loaded specimens was little different from that of short-term loaded specimens.Increasing the thickness,width and section height of bamboo plate could improve the ultimate bearing capacity of long-term loaded specimens.The bearing capacity of long-term loaded specimens decreased by about 10%.This paper calculated the bearing capacity and deflection of steel-bamboo composite I-beams after being subjected to long-term loading by using the proposed formula,and the theoretical value was in good agreement with the experimental value.

关 键 词：钢-竹组合梁 长期荷载 破坏试验 承载力衰减 挠曲变形 

分 类 号：TU398.9[建筑科学—结构工程]