厚板钢梁节点焊接过程监测评估与有限元分析

Monitoring Estimation and Finite Element Analysis of Thick Plate Steel Beam Joints Welding Process

针对厚板钢梁节点焊接温度和残余应力,以天津某场馆为依托,进行监测评估和有限元分析.对不同板厚(35,mm、50,mm、80,mm、100,mm)和不同路径的横向、纵向残余应力以及焊接温度和支座处混凝土的状态等情况进行了全面监测,分析了厚度对焊接温度和焊接残余应力的影响.结果表明:焊接过程是一个传热过程,属于非均匀瞬态温度场,存在热量传输的"热滞后"现象.沿板宽方向的最高温度出现在钢板中心处,呈中间高、两端低的分布特点,与横向残余应力的分布特点完全一致.随着焊接钢板厚度的增加,纵、横向残余应力及其沿厚度的变化率均明显增大;但厚度超过80,mm后,残余应力的增长速率有明显降低,说明多层、多道焊接方法可有效减小残余应力.

The study of welding temperature and residual stress of thick plate steel beam joints was based on a project in Tianjin.A set of monitoring programs for different thickness(35,mm,50,mm,80,mm,100,mm)were carried out,including the comprehensive monitoring of different paths of transverse and longitudinal residual stresses,welding temperature and the concrete condition at supports.Further,the influence of thickness on welding temperature and residual stress was studied.Based on the real-time welding parameters,the numerical models of thick steel beam welding were established,and the change of residual stress at the welding center with time was analyzed.The result shows that the welding is a process of heat transfer with non-uniform transient temperature field,and there exists the hysteresis phenomenon.The highest temperature in the direction of the plate width appears in the center of plate,which is the same as the distribution characteristics of transverse residual stress.With the increase of the thickness of welding steel plate,transverse and longitudinal residual stresses increases.When the thickness is over 80,mm,the growth rate of residual stress decreases,which means that the multi-pass welding is an effective method for reducing residual stress.