GH4169合金的循环本构模型研究

Study on Cyclic Constitutive Model for GH4169 Alloy

关键词:  合金  载荷  隐式积分算法  弹性应力  循环应力  应变曲线

Key words:  Alloy  Loading condition  Implicit integration algorithm  Elastic stress  Cyclic stress  Strain curve

摘要:

为研究GH4169合金在高温环境不同载荷条件下的非弹性响应力学行为，对其开展650℃下单轴拉伸和恒温低周疲劳试验，采用Bodner-Partom(B-P)统一本构理论对其力学行为开展数值模拟研究。通过试验，获得GH4169合金高温单轴拉伸曲线及半应变幅为0.65%，0.75%及0.85%下的循环曲线，基于B-P理论并结合有限元方法，引入介于0～1的缩小因子，研究了本构方程隐式积分新算法，通过ABAQUS用户子程序，计算得到GH4169合金不同载荷条件下的数值模拟曲线。计算曲线与试验曲线均具有较好的一致性，说明B-P模型能较合理地建模GH4169合金的高温非弹性响应力学行为，同时验证了本文模型的完整性和计算程序的正确性。

Abstract:

In order to study the inelastic response behaviors of GH4169 alloy under different loading conditions at high temperature， the uniaxial tension and low cycle fatigue tests were carried out at 650℃. The Bodner-Partom (B-P) unified constitutive theory was used to simulate the mechanical behaviors of GH4169 alloy. Through the experiment， the uniaxial tension stress-strain data and the cyclic stress-strain data at the half-strain amplitudes of 0.65%， 0.75%， and 0.85% were obtained. Based on the B-P theory and the finite element method， the new implicit integration algorithm for constitutive equations were studied by introducing a reduction factor that is between 0 and 1. The B-P model was implemented in ABAQUS software through UMAT subroutine. Numerical simulation curves of GH4169 alloy under different loading conditions were calculated. The calculated results agree well with the experimental results， indicating that the B-P model can reasonably describe such kinds of high temperature mechanical behaviors of GH4169 alloy， and verify the integrity of the B-P model and the correctness of the program.