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──模型分析之一

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

为了描述韧性材料的率相关力学行为，提出了一个具有“过应力”特征的统一型粘塑性本构模型。通过模型分析的方法，将该模型与典型的Ｂｏｄｎｅｒ－ｐａｒｔｏｍ统一型粘塑性本构模型进行了对比分析。重点考察了该模型对工程材料三种基本变形过程的描述能力：（１）瞬时塑性。（２）循环塑性。（３）蠕变变形（包括应力松驰、蠕变恢复）。

In order to rnodify the description to the rate dependent mechanical behaviour of ductile materials,in this paper, a new unified viscoplastic constitutive model posspssing overstress characteristics was suggested.Comparing this model with the Bodner-partom's model,it has been found that the new model is more reasonable indescribing the experimental phenomena of instantaneous plasticity, cyclic plasticity and creep deformation(in-cluding stress relaxation and creep recovery)of engineering materials.