基于J-C模型的GH907高温合金动态本构关系及失效关系

Dynamic Constitutive Relationship and Failure Relationship of GH907 Superalloy Based on J-C Model

使用万能材料试验机、霍普金森拉杆和霍普金森压杆装置研究了航空发动机机匣材料GH907高温合金在常温下的准静态力学性能及20~400℃下的动态力学性能;基于试验结果,拟合得到Johnson-Cook(J-C)本构模型和失效模型参数,并对试验合金动态压缩过程进行模拟以验证本构模型参数的有效性。结果表明:常温下在0~3000 s^(-1)应变速率范围内拉伸时,试验合金具有明显的应变速率效应,但是压缩时对应变速率不敏感;在20~400℃温度范围内,试验合金的软化效应明显;建立的J-C模型能够较为准确地预测该合金在不同温度和应变速率下的力学行为,试样几何尺寸和最大应力的仿真结果与试验结果的相对误差在2%以内。

The quasi-static mechanical properties at room temperature and dynamic mechanical properties at 20-400℃ of the aircraft engine casing material GH907 superalloy were investigated on the universal test machine,Hopkinson tension bar and Hopkinson pressure bar equipments.Based on the test results,the parameters in the Johnson-Cook(J-C)constitutive model and failure model were obtained by fitting,and the dynamic compression process of the test alloy was simulated.The effectiveness of the constitutive model parameters were evaluated.The results show that during tension at room temperature and the strain rates of 0-3000 s^(-1),the test alloy was sensitive to strain rates,but during compression was not.At temperatures of 20-400℃,the softening behaviour of the test alloy was obvious.The established J-C models could accurately predict the mechanical behavior of the alloy at different temperatures and strain rates;the relative errors between the simulation and the test results of the sample geometrical size and maximum stress were within 2%.