摘要
开展了定向凝固镍基合金DZ125高温循环变形特性的试验研究;试验包括纵向[001]、横向[010]和45o[011]三个晶向;温度包括室温、650℃、760℃、850℃和980℃。试验观察到材料变形的率相关、循环硬化/软化、平均应力松弛等力学现象。试验还得到了这些力学行为与温度、晶向、应变率、应变范围的关系。基于以上的材料变形特征,采用各向异性扩展的Chaboche统一型粘塑性本构模型对DZ125合金的力学特性进行了本构建模研究。开发了基于遗传算法的材料参数提取和优化方法。并通过ABAQUS用户子程序(UMAT)结合有限元方法,进行了数值模拟验证和变形预测。
High-temperature cyclic deformation experiments carried out for directionally solidified Ni-base DZ125. Tests include three different directions： vertical [001], transverse [010] and 45° [011]. The experiments were done at room temperature, and the temperature of 760℃, 850 ℃, 980℃. The rate-dependent, cyclic hardening /softening, and cyclic relaxation of mean stress phenomena have been observed in experiment. These tests also obtained relationship between these mechanical behavior and temperature, crystal, strain rate, and strain amplitude. Based on the above deformation characteristics, the modified anisotropic Chaboche unified visco-plastic constitutive modeling is used to model the mechanical characteristics of DZ125. Genetic algorithm optimization methods are used to obtain material parameters. Numerical simulation and deformation forecast were done by coding the user＇s material subroutine （UMAT） in ABAQUS platform.
出处
《强度与环境》
2013年第1期17-22,共6页
Structure & Environment Engineering
