基于非关联Hill48塑性模型的TC1钛合金板本构模型

Constitutive model of TC1 titanium alloy sheet based on non-associated Hill48 plastic model

采用非演化型和演化型非关联Hill48塑性模型对TC1钛合金板建立了本构模型,并采用新的各向异性指数r值确定方式以及特定的r值-塑性应变拟合函数,得到在两种模型下的屈服轨迹。结果表明:采用非演化型非关联Hill48塑性模型对描述TC1钛合金板应变的各向异性行为产生较大影响,其中采用流动势函数得到的屈服轨迹等双拉点应力相比于采用塑性位势函数的屈服轨迹时增加21%。而演化型非关联Hill48塑性模型同样对于描述TC1钛合金板应变的各向异性行为产生较大影响,其中采用演化型非关联Hill48塑性模型的流动势函数得到的屈服轨迹的等双拉点应力相比于采用非演化型非关联Hill48塑性模型的屈服轨迹时降低26.6%。

The consititutive model was construct by non-evolutionary and evolutionary non-associated Hill48 plastic models for TC1 titanium alloy sheet. A new anisotropic index r-value determination method and a specific r value-plastic strain fitting function were used to obtain the yield trajectory under two models. The results show that the non-evolutionary non-associated Hill48 plastic model has great effect on describing the strain anisotropic behavior of TC1 titanium alloy sheet. Compared with the yield trajectory obtained by the plasticity potential function, the stress at the equal double tension point of the yield trajectory obtained by flow potential function increases by 21%. However, the evolutionary non-associated Hill48 plastic model also has great effect on describing the strain anisotropy behavior of TC1 titanium alloy sheet, and the stress at the equal double tension point of the yield trajectory obtained by flow potential function of evolutionary non-associated Hill48 plastic model decreases by 26.6% compared with that of non-evolutionary non-associated Hill48 plastic model.