| 摘要: |
| 为研究钢-竹组合工字形梁经历长期荷载作用后的力学性能，以竹胶板厚度、钢板厚度、含钢率为参数设计2组共12个试件，其中一组经过1 a的长期荷载作用后进行受弯破坏试验，另一组直接进行短期受弯试验，对比研究长期荷载作用对组合梁极限承载力衰减、挠度变形、构件延性、截面应变等方面的影响；同时基于有效惯性矩法对组合梁破坏时的挠度进行计算分析.结果表明：组合梁破坏试验现象与其含钢率有关，一般表现为下翼缘竹胶板脱胶开裂，随着含钢率的增加，组合梁破坏范围逐渐向上部扩散；长期加载后，组合梁延性发生改变；竹胶板长期受拉或受压对组合梁的影响基本相同，组合梁中性轴位置未发生改变；组合梁极限承载力衰减程度与竹胶板厚度、钢板厚度、含钢率均有关；由挠度计算公式得到的计算值与试验值吻合较好，误差均在10%以内. |
| 关键词: 长期荷载 钢-竹组合梁 有效惯性矩 承载力衰减 |
| DOI：10.3969/j.issn.1007-9629.2021.06.021 |
| 分类号:TU398 |
| 基金项目:国家自然科学基金资助项目（51978345，51678310） ；浙江省自然科学基金资助项目（LQ19E080007）；宁波市科技计划项目（202002N3090） |
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| Effect of Long-Term Load on Mechanical Properties of Steel-Bamboo Combination Beams |
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MAO Ming1,2, TONG Keting2, ZHANG Jialiang2, WANG Jianmin2, LI Yushun1
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1.College of Civil Engineering & Architecture， Qingdao Agricultural University， Qingdao 266109， China;2.School of Civil and Environmental Engineering， Ningbo University， Ningbo 315211， China
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| Abstract: |
| In order to study the mechanical properties of steel-bamboo combination I-beams under long-term load， thickness of bamboo plywood， thickness of steel plate， and steel content were set as the main parameters to design two sets of 12 specimens. One group was subjected to a bending failure test after a one-year long-term load， and the other was directly subjected to a short-term bending test. The long-term effects of load on the ultimate bearing capacity attenuation， deflection， component ductility， and section strain of combination beams were studied. The deflection of combination beams at failure was calculated and analyzed based on the effective moment of inertia method. The results show that the failure test phenomenon of combination beams is related to the steel content， which is generally manifested as debonding and cracking of the lower flange bamboo plywood. The damage range of the combination beams gradually spread upward as the steel content increased. Ductility of combination beams changed after long-term loading. The effect on the combination beams is basically the same after long-term tension and compression of bamboo plywood， and the position of the neutral axis of combination beams remaines unchanged. The degree of bearing capacity attenuation is related to the thickness of bamboo plywood， steel plate thickness， and steel content. The calculated values obtained from the deflection calculation formula agree well with the experimental values， and the errors are all within 10%. |
| Key words: long-term load steel-bamboo combination beam effective inertia bearing capacity attenuation |
