高阶单元在焊接热弹塑性有限元分析中的应用

为研究高阶单元对热弹塑性有限元分析中变形的影响,建立了不同网格尺寸、单元阶次的三维有限元模型,利用通用有限元软件ABAQUS对CO₂气体保护堆焊过程进行热弹塑性有限元分析,比较线性单元和二阶单元在温度和变形的计算精度及时间.结果表明,二阶单元能够更好地反映焊接区域的变形特点,焊接变形的计算结果与试验结果更加接近;单元阶次仅对应力应变场分析有较大影响,对于温度场计算结果影响不大.

Application of high order elements in welding thermal elastic-plastic finite element analysis

Three dimensional finite element model with different mesh sizes and element orders was established to investigate the effect of high order elements on the deformation in thermal elastic-plastic finite element analysis. The process of CO₂ gas shielded arc welding was simulated by general finite element software ABAQUS. Several conclusions were drawn after comparing the calculation accuracy and time of temperature field and welding deformation between linear element and quadratic element. The results show that quadratic element could better reflect the deformation characteristics in the welded area,and the calculated results were close to the measured ones. The element order had great influence on the stress strain field,but had little effect on the calculated temperature field.