栓焊混合连接狗骨式梁柱钢节点残余应力有限元分析

焊接作为结构连接的一种重要形式被广泛应用于钢结构中.焊接过程中由于温度梯度产生的焊接残余应力,给实际工程安全带来很大的威胁,所以研究钢结构在焊接过程中产生的残余应力是十分必要的.利用有限元数值模拟软件ANSYS建立狗骨式梁柱节点顶底角钢、焊缝、螺栓混合连接的三维有限元模型,模拟梁柱节点焊接的温度场,在热弹塑性理论基础上求解焊接残余应力.结果表明：构件在焊接过程中主要受拉,并且在不同位置的应力各不相同.由于狗骨式节点的存在,削弱了节点对梁部分的约束.在梁上翼缘螺栓上出现焊接残余应力的最大值,在腹板角钢与柱连接的中间螺栓处出现最小值.这与规范中的规定基本相符.

THE FE ANALYSIS OF RESIDUAL STRESS IN WELDING AND BOLT DOG-BONE STEEL BEAM-COLUMN CONNECTIONS

As an important form of structural connections weldings are widely used in steel structures. Welding residual stresses due to temperature gradients in the welding have a great threat to the security of actual projects. Therefore, studying the residual stress in the welding process is essential. This study used the finite element numerical simulation software ANSYS to establish the three-dimensional finite element model of dog-bone style beam-column joint top and bottom angle, welds, bolts mixed connection to simulate the temperature field of welding beam-column joints and the welding residual stress was solved based on thermal elastic-plastic theory. The results show that, the components are mainly in tension in the welding process, and the stress is different at different positions. The constraint of joint to beam is weakened due to the presence of the dog-bone joint. The maximal welding residual stress is in the beam flange bolts and the minimal welding residual stress is in the middle bolt to connect web angle with column. It is basically consistent with the regulations of code.