轴心受压高强焊接圆钢管局部屈曲性能研究

建立四种屈服强度圆管短柱的有限元模型,和既有的试验数据对比,验证了圆管的细长极限,并评估了局部屈曲对极限承载力的影响.对圆管残余应力的类型进行梳理并研究三种主要残余应力模型对Q550、Q690、Q800、Q960圆管极限承载力的影响.研究径厚比与极限承载力的关系,结果表明:随着径厚比的增大,极限承载力明显降低;圆管的长...

Research into Local Buckling Behavior of High Strength Steel Welded Circular Tubes under Axial Compression

Compared with the existing experiment data, the finite model for 4 different yield strengths built in this study proves the tube wall slender limit and evaluates the effect of the local buckling on the ultimate capacity. The types of residual stress of circular tubes published in recent years were reviewed, and the effects of three main types of residual stress on the ultimate capacity (Q550, Q690, Q800, Q960) were investigated. The relationship between the diameter and thickness ratio (D/t) and ultimate capacity was examined, which shows that the ultimate capacity is significantly reduced because of increase in D/t. In addition, the effect gradually enhances for higher steel grades due to smaller tube wall slenderness limit, indicating larger local buckling effect. New D/t limit 36, 28, 22, 18 was proposed for Q550, Q690, Q800, Q960 circular tubes respectively. In comparison with the FEM result and experiment data, the formula in the related codes provides conservative result. Therefore, a new theoretical formula for ultimate capacity assessment of high strength steel circular tubes based on the direct strength method and effective area method were put forward.