考虑残余应力影响下轴压蜂窝构件稳定承载力研究

发布时间：2018-11-17 21:20

【摘要】：蜂窝构件是将实腹型钢构件进行腹板切割后错位焊接而成,相比原型实腹钢构件,可以在不增加用钢量的前提下,增大截面抵抗矩,提高抗弯承载力。跨度较大的框架结构采用蜂窝梁柱,除减轻结构自重、节省钢材,更有利于穿行管道、线路,增加结构净高,同时结构外露时增加美感。焊接残余应力是钢结构构件在焊接加工过程中经历不均匀高温加热和不均匀冷却后产生的,是存在于构件内部且能白相平衡的一种初始应力。对于蜂窝构件,焊接残余应力的数值大小及分布范围是影响构件整体稳定承载力的一个重要因素,其存在会导致截面刚度降低,屈服提前。蜂窝构件的加工形式有所不同,为在腹板处直接切割开孔或对实腹构件腹板切割后错位焊接,故其残余应力分布较实腹构件也有所不同。现有实腹钢构件残余应力应力分布模型无法满足蜂窝构件分析计算要求。在以往对蜂窝构件的研究过程中,因缺少其残余应力分布的相关资料,往往忽略这一重要因素,这也造成了对残余应力影响下蜂窝受压构件稳定性研究的缺失。基于对此问题的考虑,本文采用盲孔法对7根蜂窝式钢构件开孔处截面焊接残余应力进行检测,对比六边形和圆形两种典型孔型下,不同开孔率、开孔方式蜂窝构件开孔处截面纵向焊接残余应力数值大小和分布范围。分析研究不同开孔形状、开孔率、加工方式下蜂窝构件焊接残余应力分布特点,提出蜂窝式钢构件纵向焊接残余应力分布模型。在试验检测蜂窝构件残余应力分布的数据基础上,根据轴心压杆压溃理论,采用数值分析方法,对考虑残余应力影响下的轴压蜂窝柱稳定承载力进行研究。建立六边形孔口和圆形孔口两种典型孔型下的轴压蜂窝柱有限元模型,将残余应力以初应力的形式计入到有限元模型中,同时考虑轴压柱初弯曲等初始缺陷及材料的非线性,对比分析残余应力对轴压蜂窝柱稳定承载力的影响。给出圆形孔口和六边形孔口轴压蜂窝柱考虑残余应力影响下的换算长细比计算方法。同时,给出了轴压蜂窝柱的λo—(?)k柱子曲线和轴压蜂窝柱稳定系数(?)k计算方法,为轴压蜂窝柱实际工程设计使用提供参考。
[Abstract]:Honeycomb members are fabricated by dislocated welding after web cutting. Compared with prototype solid steel members, honeycomb members can increase the cross section resistance moment and improve the bending capacity without increasing the amount of steel used. The beehive Liang Zhu is used in the frame structure with large span, which not only reduces the weight of the structure and saves steel, but also facilitates the passage of pipelines and lines, increases the net height of the structure, and increases the aesthetic feeling when the structure is exposed. Welding residual stress is a kind of initial stress which exists inside the steel structure and can be balanced in white phase after it is heated and cooled inhomogeneously at high temperature during the welding process. For honeycomb members, the numerical value and distribution range of welding residual stress is an important factor affecting the overall stability bearing capacity of the members, and its existence will lead to the reduction of section stiffness and early yield. The processing forms of honeycomb members are different. The residual stress distribution of honeycomb members is different than that of solid web members because they are dislocated and welded directly at the web or after cutting the web plates of the solid web members. The existing models of residual stress distribution of solid steel members can not meet the requirements of honeycomb members analysis and calculation. In the past research on honeycomb members, due to the lack of relevant data on the distribution of residual stress, this important factor is often ignored, which also leads to the lack of stability study of honeycomb members under the influence of residual stress. Based on the consideration of this problem, this paper uses blind hole method to detect the welding residual stress at the opening section of 7 honeycomb steel members, and compares the different open hole ratios between hexagonal and circular typical holes. The numerical value and distribution range of the longitudinal welding residual stress at the opening section of honeycomb members with open holes. The distribution characteristics of welding residual stress of honeycomb members under different hole shapes, open hole rates and machining methods are analyzed. A longitudinal welding residual stress distribution model for honeycomb steel members is proposed. Based on the experimental data of residual stress distribution of honeycomb members, the stability bearing capacity of honeycomb columns under the influence of residual stress is studied by means of numerical analysis according to the collapse theory of axial compression bar. The finite element model of honeycomb column with axial compression under two typical holes of hexagonal and circular orifice is established. The residual stress is included in the finite element model in the form of initial stress, and the initial defects such as initial bending of axial compression column and the nonlinearity of material are taken into account at the same time. The influence of residual stress on the stability bearing capacity of honeycomb columns under axial compression is analyzed. A method for calculating the conversion ratio of length to slenderness of honeycomb columns with circular and hexagonal orifices under axial compression considering the influence of residual stress is presented. At the same time, the 位 _ o- (?) k column curve and the calculation method of the stability coefficient (?) k of the axial compression honeycomb column are given, which provides a reference for the practical engineering design of the axial compression honeycomb column.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU391

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