高强度超大截面热轧与镀锌等边角钢构件残余应力和稳定性研究

发布时间：2018-07-22 19:25

【摘要】：高强度钢材钢结构在国内外的实际工程中有越来越多的应用,建筑行业已经应用到690MPa及以上强度钢材,我国输电铁塔行业近年也开始用到420MPa及以上强度钢材。已有研究表明输电铁塔工程中高强度大截面单角钢完全可以替代组合普通角钢和圆钢管,且高强度大截面单角钢塔具有传力路径明确、受力均匀等优点,同时降低了人工误差和工程造价,但目前尚缺乏对该种类角钢性能的系统研究,对于该角钢轴心受压构件的设计方法尚缺乏足够的研究依据。为了能得到该新型角钢较为系统的性能研究,本文的研究对象选为Q420高强度钢L300 X 30超大截面热轧与镀锌等边角钢。本文首先系统的介绍了残余应力的研究进展,之后采用切条应变法试验测量6个角钢(包括2种试件长度和2种表面处理方式)的截面残余应力,试验得到该试件截面的纵向残余应力分布,同时统计国内外角钢分布曲线,提出了残余应力分布模型和计算公式。其次,采用盲孔法试验测量2件角钢焊接端板构件(包含2种表面处理方式),试验得到该试件的焊接残余应力分布,得到了该试件沿角钢肢中位置的焊接残余应力分布模型,并提出了计算公式。再次,本文采用通用有限元分析软件ABAQUS建立考虑几何初始缺陷和截面残余应力分布的角钢轴心受压模型,与国内外试验数据对比验证了模型的准确性和可靠性,进行了参数分析,最后计算得到热轧与镀锌角钢轴压构件的ψ-λη柱子曲线,与我国和欧美规范现有设计曲线进行对比,建议了规范现有曲线的选取,提出了该热轧与镀锌角钢轴压构件合适的柱子曲线、计算公式和设计方法。
[Abstract]:High strength steel structures have more and more applications in practical projects at home and abroad. The construction industry has been applied to 690 MPA and above strength steel, and the transmission tower industry in China has started to use 420 MPA and above strength steel in recent years. It has been shown that the single angle steel with high strength and large section can completely replace the combination of common angle steel and circular steel pipe in the transmission tower project, and the high strength and large section single angle steel tower has the advantages of clear transmission path and uniform force. At the same time, the artificial error and the engineering cost are reduced, but at present there is no systematic research on the performance of this kind of angle steel, and the design method of the axial compression member of the angle steel is still lack of sufficient research basis. In order to obtain a systematic performance study of this new type of angle steel, Q420 high strength steel L300X30 hot rolled and galvanized equilateral angle steel is selected as the object of study in this paper. In this paper, the research progress of residual stress is introduced systematically, and then the cross-section residual stress of 6 angle steels (including two specimens length and two surface treatment methods) is measured by the shear strain method. The longitudinal residual stress distribution of the specimen section is obtained by experiments, and the distribution curves of angle steel at home and abroad are analyzed, and the model and calculation formula of residual stress distribution are put forward. Secondly, two welded end-plate members of angle steel (including two surface treatments) were measured by blind hole method. The welding residual stress distribution of the specimen was obtained, and the model of welding residual stress distribution along the position of angle steel limb was obtained. The calculation formula is also put forward. Thirdly, the axial compression model of angle steel considering geometric initial defects and residual stress distribution of section is established by using Abaqus, a universal finite element analysis software. The accuracy and reliability of the model are verified by comparing with the experimental data at home and abroad. The parameter analysis is carried out, and finally, the 蠄-位畏 column curves of hot-rolled and galvanized angle steel axial compression members are calculated and compared with the existing design curves of our country and European and American codes, and the selection of the existing curves of the codes is suggested. An appropriate column curve, calculation formula and design method for the hot-rolled and galvanized angle steel members are presented.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391

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