奥氏体不锈钢滞回本构模型研究

准确的材料滞回本构模型是保证弹塑性地震反应预测准确性的基本前提,如果本构模型选取不当,会对计算结果产生较大影响。为此该文提出了奥氏体不锈钢考虑循环强化作用的单轴滞回本构模型,包括骨架准则及滞回准则。建立数学模型描述奥氏体不锈钢在循环荷载作用下的受力性能。根据提出的理论模型并利用ABAQUS用户材料子程序UMAT,采用Fortran语言二次开发了能够进行循环荷载下奥氏体不锈钢计算分析的程序。通过与试验结果进行对比,表明提出的模型能够准确描述奥氏体不锈钢材料的滞回行为,兼顾计算精度和效率,为奥氏体不锈钢结构体系强震分析提供有力工具。

STUDY ON HYSTERETIC CONSTITUTIVE MODEL OF AUSTENITIC STAINLESS STEEL

An accurate constitutive model is the primary condition for ensuring the precision of elastic-plastic seismic analysis. If the material constitutive model is not appropriate, it would induce great effect on calculation results. Therefore, the uniaxial hysteretic constitutive model of austenitic stainless steel considering cyclic hardening is proposed, including skeleton criteria and hysteresis criteria. The mathematical models are established to describe the behavior of austenitic stainless steel under cyclic loading. Based on the proposed model and user subroutine interface UMAT in ABAQUS, the calculation program is developed for the structural analysis of austenitic stainless steel structures under cyclic loading. By comparing with test curves, the results show that: the hysteretic behavior of austenitic stainless steel can be well described by the proposed model. Both computational accuracy and efficiency can be ensured. It provides a powerful tool for seismic analysis of austenitic stainless steel structures.