面心立方和体心立方金属的各向同性屈服行为

ISOTROPIC YIELD BEHAVIOURS OF FCC AND BCC METALS

应用TBH理论揭示了在Lequeu等提出的五维应力空间中,各向同性fcc和bcc金属的任意两个切应力构成的屈服轨迹近似地为由主应力构成的π平面的屈服轨迹的内切圆,在此基础上,提出了以HHH屈服函数为基础的。

Isotropic yield surfaces of both fcc and bcc metals have been simulated with the TBH model. Using the five--dimensional stress space proposed recently by Lequeu et al., the yield subsurface on any two of the three shear stresses can be considered approximately as in- scribed circles of their corresponding subsurface on π plane. Based on this concept, the HHH yield function has been transformed into the form where the parameters are uniquely deter- mined by two crystallographic factors: the mean Taylor factor in plane strain (M_p) and the critical shear stress (τ_c) on slip systems.