基于机理法考虑动态再结晶的黏塑性本构模型先验知识的确定

Determination of Prior Knowledge on Macro-Micro Coupled Viscoplastic Constitutive Model with Dynamic Recrystallization

  • 摘要: 宏微观耦合本构模型的参数识别往往通过反分析方法进行,为使参数识别结果具有高的置信度,需要确定合适的参数取值范围. 基于考虑动态再结晶的黏塑性本构模型的物理机理,提出该模型参数取值范围的确定方法. 根据模型构造机理,提出通过6步确定该模型参数取值范围的方法;并对300 M低合金钢进行不同温度、应变速率下的热变形试验,测试其流动应力-应变曲线、再结晶晶粒尺寸-应变速率-温度曲线,通过提出的方法并根据提取试验数据,确定模型的先验知识,为参数识别提供基础. 结果表明,确定的参数识别范围大部分可以归类为中等准确和较差准确确定.

     

    Abstract: Parameter identification of the macro-micro coupled constitutive model is generally taken through inverse analysis. To make the identified result reach a high confidence degree, the reasonable parameter value domain must be found. Based on its physical mechanism, a procedure related to the macro-micro coupled constitutive model considering dynamic recrystallization and used to determine the value domain of the parameter was proposed. In detail, a six-step method was first given; the experiments with hot compression deformations of 300 M were carried out under different combinations of temperatures and strain rates, and the data of the true stress-strain curve and microstructure were then obtained. Based on the proposed procedure and the corresponding experimental data, the prior knowledge on the macro-micro coupled viscoplastic constitutive model was finally determined. The research is of importance in parameter identification.

     

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