焊接π形截面残余应力试验及分布模型

Experimental study on residual stress and distribution model in welded π-shaped sections

为研究焰切边焊接π形截面钢构件残余应力分布形式及大小,采用分割法对5个不同尺寸的Q345Bπ形截面构件进行试验研究.通过测得的截面各板件残余应力,分析了板件宽厚比对残余应力分布的影响及各板件残余应力的自平衡性.研究结果表明:π形截面构件翼缘、腹板残余压应力与板件宽厚比有直接关系;焊缝附近残余拉应力与板件厚度有关,与板件宽厚比相关性不明显;π形截面3块板件的残余应力分别满足自平衡性.提出了适用于不同尺寸的π形截面构件残余应力分布模型及计算公式,可为π形截面构件的进一步研究与应用提供参考依据.

The residual stresses of5specimens were measured by the sectioning method to investigate the residual stress distribution in Q345B steel welded flame-cutπ-shaped sections.The effects of the plate width-thickness ratio and interaction among component plates were clarified by measuring the residual stress values of each plate.The results indicate that the compressive residual stress in flange and web correlates with the plate width-thickness ratio.Moreover,the residual stress near the welding is related to the plate thickness but not obvious with the plate width-thickness ratio.The residual stress self-equilibrating within each component plate is satisfied.Finally,a residual stress distribution model and a calculation formulate for predicting the residual stress within weldedπ-shaped sections with different dimensions are proposed,it provides a valuable reference for further study and application ofπ-shaped section steel structures.