GH4169合金高温力学行为本构建模及参数识别

Constitutive Modeling and Parameter Identification of Mechanical Behavior for GH4169 Alloy at High Temperature

针对涡轮盘用GH4169合金开展了高温下单调拉伸、对称循环及非对称循环的实验工作,结果表明,该材料具有比较明显的循环软化和平均应力松弛特性。采用带Ohno/Wang修正的Chaboche粘塑性理论本构方程,对其表现出的复杂力学现象进行本构建模,介绍了Levenberg-Marquadt非线性优化算法,结合材料实验数据并通过该算法识别了本构方程参数,将本构方程通过用户子程序嵌入到有限元软件ABAQUS中,对GH4169合金的上述实验现象进行了数值模拟,计算曲线与实验曲线取得了较好的一致性。

Tests concerning monotonic loading, symmetric and unsymmetric cycling were carried out at high temperatures in GH4169 used for turbine disk. The results showed that the material had a distinct characteristic of cyclic softening and mean stress relaxation. The Chaboche type viscoplastic constitutive model modified by Ohno/Wang was adopted to model the mechanical behaviors. The Levenberg-Marquadt nonlinear optimization strategy was introduced briefly. Combing the material test data and utilizing the strategy, parameters of the constitutive model were identified. The model was implemented into ABAQUS and the material tests were numerically simulated. Some good agreement between test data and calculated curves was achieved.