一种用于热端部件高温蠕变分析的统一型粘塑性本构模型──模型分析之二

A NEW UNIFIED VISCOPLASTIC CONSTITUTIVE MODEL FOR CREEP ANALYSIS──PART Ⅱ

提出一种具有“过应力”特征的“统一型”粘塑性本构模型［５］。为了考察该模型在复杂应力状态下对材料变形行为的描述能力，文中将该模型应用于拉扭组合变形，重点在以下三个方面对该模型的描述能力进行分析研究，①材料在变形过程中屈服面（后继屈服面）的变化情况。②在非比例加载情形下某些材料呈现的循环附加强化／软化现象。③高温情形下热恢复效应对承受非比例循环加载的材料变形行为的影响。

To examine the describing ability of the unified viscoplastic constitutive model proposed by theauthors of this paper, which is of the overstress characteristics, the investigations for the new modelled materialunder combined tension/torsion loading have been carried out. The analyses are mainly concentrated on the threeaspects: the chang of the yield surface (subsequent yield surface). the additional cyclic hardening/softening ofthe material under nonproportional cyclic loading. the influence of thermal recovery on the nonproPOrtionaldeformation. The results show that the descriptions given by the new model are in reasonable agreement withexperimental observations.