工字形截面受弯钢梁负载下焊接加固试验研究

发布时间：2018-04-16 02:03

本文选题：负载 + 工字形截面　；参考：《土木工程学报》2015年01期

【摘要】：负载下焊接钢加固受弯钢梁的加固方法已在各类建筑结构的加固工程中得到广泛应用。为研究初始负载对焊接加固后钢梁的受力特性的影响,进行加固钢梁的受弯静力试验研究,试验包括3个不同初始负载下焊接加固的钢梁和1个作对比的未加固钢梁,材料类型均为普通碳素钢Q345B级钢。被加固钢梁为工字形双轴对称截面,加固方式为上下翼缘外侧对称贴焊钢板全长加固。钢梁端部约束采用夹支。基于试验结果,研究负载下加固前后钢梁的截面应变应力分布变化,失稳破坏形式和稳定承载力,并对试验结果和规范计算结果进行对比。结果表明:试件焊接加固冷却后,腹板受拉区拉应变和受压区压应变都增大,钢梁跨中挠度增大。加固后钢梁的稳定承载力是受初始负载大小和最终破坏模式影响的,加固后发生整体失稳的试件,初始负载对其稳定承载能力会产生不利的影响。研究为后续的数值参数分析提供重要基础数据,为优化现有设计方法提供参考依据。
[Abstract]:The method of strengthening bending steel beams with welded steel under load has been widely used in various building structures.In order to study the effect of initial load on the mechanical characteristics of welded strengthened steel beam, the bending static test of strengthened steel beam is carried out. The experiment includes three welded strengthened steel beams under different initial loads and one unstrengthened steel beam compared with each other.The material types are ordinary carbon steel Q 345B grade steel.The strengthened steel beam is I-shaped double axisymmetric section, and the reinforcement mode is full length reinforcement of the upper and lower flange lateral symmetrical bonding welded steel plate.The end of the steel beam is restrained by clamps.Based on the test results, the variation of strain stress distribution, failure mode and stability bearing capacity of steel beams before and after strengthening under load are studied, and the results of test and code calculation are compared.The results show that the tensile strain and compressive strain in the tension zone and compression zone of the web are increased and the mid-span deflection of the steel beam increases after welding and cooling.The stability bearing capacity of the strengthened steel beam is affected by the initial load and the ultimate failure mode.The study provides important basic data for subsequent numerical parameter analysis and provides a reference for optimizing existing design methods.
【作者单位】：清华大学土木工程安全与耐久教育部重点实验室;中国联合工程公司;重庆大学;
【基金】：《钢结构加固设计规范》国家标准管理组科研专项课题(2013-01)
【分类号】：TU391

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