搅拌摩擦焊刀具承载能力数值模拟

Numerical simulation of tool load bearing capacity in friction stir welding process

厚板或高强合金搅拌摩擦焊中刀具容易在高温与高应力作用下发生破裂,因此对刀具进行承载能力分析具有重要意义。采用Fluent流固耦合模拟9.53 mm厚AA6061铝合金搅拌摩擦焊的热-机械过程,并将模拟的搅拌针压力场和温度场导入ANSYS模型中进行结构分析,研究焊接速度对刀具最大剪切力和安全系数的影响规律。结果表明,刀具最易在搅拌针根部发生断裂,而且随着焊接速度的增加,刀具承受的最大剪切力增大,安全系数降低,刀具承载能力下降。所建立模型的仿真结果与实验数据基本一致。

In the friction stir welding（FSW）of thick plate or high-strength alloy,tools easily rupture under the high stress and high temperature. Therefore,it is of great significance to analyze the tool load bearing capacity. In this paper,a Fluent fluid-solid coupling model is established to simulate the thermal mechanical process for the FSW process of 9.53 mm thick AA6061 aluminum alloy. The resultant temperature and pressure fields of tool pin are imported into ANSYS model for the structural analysis. The effect of welding speed on the maximum shear force and the safety factor is investigated. It is shown that the tool is the most likely to rupture at the root of tool pin. With the increase of welding speed,the maximum shear force of tool increases,resulting in the decrease in safety factor and load bearing capacity. The simulation results of the model are basically consistent with the experimental data.