θ参数法在涡轮盘蠕变变形分析中的应用

针对某直接时效ZSGH4169涡轮盘的蠕变变形展开研究,建立了16参数的θ参数法模型，对ZSGH4169高温合金在不同温度、不同载荷下的蠕变曲线进行了模拟；将该模型同有限元程序结合，开发了相应的用户子程序，并验证了子程序的计算能力及计算精度；将模型应用于涡轮盘的蠕变分析。结果表明:该模型能够准确模拟ZSGH4169在650℃及700℃下3个阶段的蠕变行为，与Norton率等传统模型相比，建模能力更强且精度更高，特别是能够开展变载、变温等复杂条件下蠕变的数值模拟。进而获得了涡轮盘盘心孔、盘缘螺栓孔两个危险位置处蠕变应变随时间的变化规律以及应力松弛曲线，其具有工程指导意义。 

Application of θ projection method in analysis of creep deformation of turbine disc

The creep deformation of direct aging ZSGH4169 turbine disc was studied. Firstly, a θ projection model with 16 parameters was established to characterize the creep behavior of the ZSGH4169 superalloy at different temperatures and loads. Secondly, the corresponding user subroutine combined with the general finite element program was developed, and the calculation precision was also validated. Thirdly, the model was used to simulate the creep deformation of the turbine disc. The calculated results show that the model can describe three stages of creep behaviors of ZSGH4169 under 650℃ and 700℃. Compared with the conventional models such as Norton rate model, the model had greater modeling capability and higher accuracy, so it could be used particularly in case of the change of the loading and temperature. Furthermore, the long time creep deformation and stress relaxation of the turbine disc at the center hole and bolt hole were obtained, providing a guidance for the engineering design.