高温下H型钢焊接空心球节点抗弯力学性能研究

Study on the bending mechanical properties of H-beam welded hollow spherical joints at high temperature

采用有限元分析对H型钢焊接空心球节点高温下的抗弯性能进行研究,温度范围为20〜800℃,模拟得到常温和高温下节点的弯矩一转角曲线。通过对球径、壁厚、H型钢高度、宽度、腹板和翼缘厚度的参数化分析,得到节点高温下塑性抗弯承栽力、极限抗弯承栽力和初始刚度的退化规律,提出承栽力和初始刚度的计算公式。节点受纯弯荷载作用下,H型钢和球节点交界处应力迅速增长,塑性区域从交界处向周围扩展破坏时,球节点发生屈曲破坏,翼缘和腹板较多区域均未达到极限强度。

The bending resistance of H-shaped steel welded hollow ball joints at high temperature was studied by finite element analysis and the temperature range was 20~800℃.The bending moment-angle curves of joints at room temperature and high temperature were obtained by simulation.Through the parametric analysis of ball diameter,wall thickness,height and width of H-shaped steel,and thickness of web and flange,we obtained the degradation law of plastic bending capacity of joints at high temperature,ultimate flexural capacity and initial stiffness under high temperature.The formulas for calculating the bearing capacity and initial stiffness were presented.Under the action of pure bending load,the stress at the junction of H-section steel and ball joint increased rapidly,and the plastic zone expanded from the junction to the surrounding area.When the failure occurred,the ball joint would buckle and the ultimate strength of the flange and web would not be reached.