一种黏弹塑性统一本构模型

A UNIFIED VISCO-ELASTIC-PLASTLC CONSTITUTIVE MODEL

经过对大量有关统一本构模型的文献资料分析，指出了现有统一本构模型存在的问题，并通过对材料实验数据的分析，指出了黏弹性现象在实验中的表现，并据此将黏弹性引入到弹性黏塑性统一本构模型［１］之中，建立了黏弹塑性统一本构模型；通过模型的数值模拟证明：模型计算结果无论在变形趋势上，还是在数值精度上都与实验数据符合得很好，克服了此前统一本构模型存在的问题．黏弹塑性统一本构模型的产生将统一本构理论的内涵扩大到黏弹性范围，进而构造了一个黏弹塑性理论的新框架．

Large amount of elastic-viscoplastic constitutive theories were examined in order to assess their potential capabilities and limitation in representing the thermo- mechanical structural response. By reviewing some experiment reports, some kinds of visco-elastic phenomena in the experiments were pointed out. In this paper, a new unified visco-elastic-plastic constitutive model is founded by introducing the visco-elastic deformation into the unified constitutive model. That means there is time dependent deformation during the elastic deformation stage. This kind of deformation is not included in the existed constitutive models. The new model has the greater capability for creep, monotonic, cyclic hardening, Bauschinger effect, temperature effect, annealing and history interaction of all these with more accuracy, and it extends the unified consitutive model to visco-elastic-plastic area. To make sure of the accuracy of the Visco-elastic-plastic Unified constitutive model, experiment information of 304 stainless steel were used as samples. The results of simulation are in good agreement with those of the experiment results. Visco-elastic-plastic unified constitutive theory becomes an access between macroscopic phenomenon and the inter change of material structures.