THERMOMECHANICAL ANALYSIS OF THE DC CASTING PROCESS FOR AA5182 BILLETS -COMPARISON OF SOLID STATE CONSTITUTIVE LAWS ON MODEL PREDICTIONS OF STRAIN AND BUTT CURL

摘要

Recently, thermomechanical finite element (FE) models based on fundamental principles have emerged as powerful tools to predict the temperature distribution and stress-strain fields in the solidifying ingot during the Direct Chill (DC) casting process. A critical aspect of these process models is the way the constitutive behavior of the material is modeled in the solid state, as this can influence the stress, strain, and butt curl predictions during the casting process. This paper compares four different methods of modeling constitutive behavior, in the solid state, available in the commercial FE package ABAQUS~(TM), namely: elastic-plastic, elastic-rate dependent plastic, elastic-creep, and combined elastic-creep-plastic using data measured on as-cast AA5182 at strain rates and temperatures consistent with those typically seen during DC casting. The comparison of the different methods was done using a 2-D uncoupled axi symmetric thermal and stress model of an aluminum billet during the start-up phase of the DC casting process.