Q235钢墙板-Q460高强钢立柱结构体系残余应力分布试验研究

在箱式钢结构中起主要承载作用的侧面墙板-立柱结构体系中,受墙板蒙皮支撑作用的高强钢立柱,其残余应力分布受与墙板焊接连接过程影响,与独立工作焊接H形截面构件有较大差异。为研究Q235钢墙板—Q460高强钢立柱结构体系的残余应力分布规律,采用盲孔法对6个结构体系试件和2个独立Q460高强钢焊接H形截面试件进行了试验研究。基于测量数据,得到了所有试件的全截面残余应力分布,分析了墙板与立柱焊接连接、截面尺寸等因素对残余应力分布的影响,并研究了截面各板件间残余应力的相互影响及自平衡性。结果表明：立柱与墙板的焊接在一定程度上降低了立柱后翼缘中部的最大残余拉应力,减小了后翼缘残余压应力的分布范围,对前翼缘和腹板无明显影响;残余拉应力幅值与截面尺寸无直接关系,残余压应力随着板件宽厚比的增大而减小;各板件间残余应力存在相互影响作用,前翼缘、腹板以及后翼缘与墙板组合板件这3部分分别满足自平衡。提出了适用于Q235钢墙板—Q460高强钢立柱结构体系的较为准确和安全的残余应力分布数学模型,为后续研究受墙板蒙皮支撑的高强钢立柱稳定性奠定基础。

EXPERIMENTAL STUDY ON RESIDUAL STRESS OF Q235 STEEL WALLBOARD-Q460 HIGH STRENGTH STEEL COLUMN STRUCTURAL SYSTEM

The wallboard-column structural system on the side of box-type steel structures plays a main bearing role. The residual stress distribution of the high strength steel column supported by stressed skin wallboards is affected by the welding with wallboards, as a result, it is quite different from the welded H-section of an individually working member. In order to investigate the residual stress distribution of Q235 steel wallboard-Q460 high strength steel column structural systems, an experimental study was conducted using hole-drilling method, including six structural system specimens and two independent Q460 high strength steel welded H-section specimens. Based on the experiment results, the magnitude and shape of residual stress distribution over the entire section were obtained. The effects of the welding connection between wallboards and column, sectional dimensions and the interaction among component plates on residual stress distribution were analyzed. The self-equilibrium of residual stress occurring in each plate was examined. The welding between wallboards and column reduces the maximum tensile residual stress in the middle of the column rear flange to a certain extent, and reduces the distribution range of the compressive residual stress in rear flange, but has no obvious influence on the front flange and web. The tensile residual stress amplitude is not directly related to the sectional dimensions. The compressive residual stress amplitude decreases with the increase of the plate width-thickness ratio. There is an interaction between the residual stresses of the component plates. The residual stresses of front flange, web and rear flange-wallboards composite plate can be considered to satisfy self-equilibrium respectively. An accurate and reliable residual stress distribution mathematical model for Q235 steel wallboard-Q460 high strength steel column structural system was proposed, which lays a foundation for subsequent research on the stability of high strength steel columns supported by stressed wallboard skin.