Q550GJ高强钢焊接H型截面残余应力试验研究

Experimental Study of Residual Stresses in Q550GJ High-strength Steel Welded H-type Sections

为了推动高强结构钢Q550GJ在我国钢结构工程中的应用,研究了Q550GJ高强钢焊接H型截面试件的残余应力分布规律.首先试验研究了Q550GJ钢材的力学性能,其屈服强度、抗拉强度和伸长率符合国家现行规范,屈强比小于0.85.然后设计和加工了7个Q550GJ高强结构钢焊接H型截面构件,采用分割法对其进行残余应力试验.研究了Q550GJ高强结构钢焊接H型截面构件的残余应力分布规律,分析了不同参数的影响.研究结果表明:翼缘中部和腹板两端近焊缝区域出现较大的残余拉应力,但没有达到钢材的屈服强度,且随着宽厚比的变化呈不规律变化;翼缘外伸部分中部和腹板中部都呈现基本恒定的残余压应力;残余压应力随着板件宽厚比的提高而相应减小;其余部位是从残余拉应力到残余压应力转变的过渡区域.

For promoting the application of high strength steel in steel structure, the distribution of Q550GJ high-strength steel welded H-type sections was studied. The mechanical properties of Q550GJ steel were researched firstly. The result shows that the yield strength, tensile strength and elongation of the steel are consistent with the present specification. And its yield ratio is lower than 0. 85. Secondly 7 columns of 550GJ high-strength steel with welding H-type sections were designed and manufactured. The distributions of the residual stresses in these columns were researched experimentally by the partition method, and the effects of the different parameters were analyzed. The analysis results show that there are bigger residual tensile stresses in the middle of the flanges and near the welded regions of the web, the biggest stress is lower than the yield stress of the steel, and the changes of the residual tensile stresses are irregular. There are constant residual compression stress in the middle of the overhanging regions of the flanges and the web, the residual compression stress become smaller as the increasing of the width-thickness ratio. And the residual stresses of other regions of the column are transferred from the tensile＆amp;nbsp;stresses to the compression stresses.