焊缝模型对圆钢管节点极限承载力影响有限元分析

Finite element analysis of effects of weld seam model on ultimate capacity of CHS joints

以圆钢管节点试件的试验数据为基础,通过非线性有限元计算可知两腹杆的极限承载力具有焊缝有限元计算值略微大于无焊缝有限元计算值,且具有焊缝模型有限元极限变形计算值小于相应无焊缝模型有限元极限变形有限元计算值.以节点处增加一圈壳体单元,并取此壳体单元厚度为弦杆壁厚的一半的方法,建立壳体焊缝有限元模型.实体和壳体有限元参数分析结果均表明:焊缝模型的建立均使得圆钢管节点刚度增加,导致节点极限承载力提高.具有焊缝的壳体有限元模型计算结果与试验相比仍然有较大误差,而实体有限元与试验结果比较接近.

Based on experimental results of circular hollow section （CHS） joints, the non-linear FEA suggests that the ultimate capacity of joints with weld seam is larger than that of joints without weld seam; ultimate deformation of joints with weld seam is smaller than that of joints without weld seam. The practical methods build shell weld seam by adding a ring of shell element whose thickness is half that of chord. The results of shell and solid FEA indicate that weld seam model increases stiffness and ultimate capacity of CHS joints. Shell FEA results still have some errors compared with experimental results, while solid FEA results are closer to experimental results.