基于CEL模型的搅拌摩擦焊温度场及材料流动数值模拟

Numerical Simulation of Temperature Field and Material Flow of Friction Stir Welding Based on CEL Model

基于欧拉-拉格朗日耦合(Euler-Lagrangian coupling,CEL)模型,采用ABAQUS有限元分析软件建立了钛钢复合板金属材料搅拌摩擦焊(friction stirwelding,FSW)热力耦合数值模型。研究焊接工艺参数对温度场的影响,并采用示踪粒子法监测焊缝区材料的塑性流动行为,分析焊接材料流动与缺陷形成的关系。通过开展搅拌摩擦焊试验,对焊缝截面塑性应变及焊接缺陷的模拟结果进行验证。结果表明,随着旋转速度的提高,焊缝最高温度逐渐升高。最佳焊接工艺参数为旋转速度300r/min,焊接速度40mm/min。温度场研究结果表明,焊接过程中后退侧温度比前进侧温度高大约25℃;在等效塑性应变场中,由于前进侧塑性变形大,当焊接工艺不当时,后退侧金属无法补充到前进侧,容易在前进侧产生焊接缺陷;焊缝材料主要先从底部上升到表面随后通过轴肩的作用在后方堆积。

Based on the Euler-Lagrangian Coupling(CEL)model in ABAQUS software,a thermal-mechanical coupling numerical model of Friction Stir Welding(FSW)of titanium-steel clad plate was established.The influence of process parameters on the temperature field and the plasticity of the weld zone were discussed.The tracer particles were inserted in the model to investigate the plastic flow and defect formation during FSW process.The experimental results and simulation results were compared to illustrate the formation of welding defects during FSW process.The results show that with the increase of rotation speed,the maximum temperature of the weld increased gradually.The optimal welding process was 300r/min for rotation speed and 40mm/min for traveling speed.The temperature simulation results indicate that the temperature on the retreating side is about 25℃higher than the temperature on the advancing side.In the equivalent plastic strain field,the advancing side presentes high plastic deformation which is similar to the experimental result.The tracer particles simulation results indicate that the weld material mainly rises from the bottom to surface and then accumulates in the back of the shoulder.