Calibração do modelo de Drucker-Prager/CAP para simulação numérica do processo de prensagem a frio de pós metálicos

Abstract

An experimental procedure for the calibration of Drucker-Prager/Cap model, using the digital image correlation technique, is presented. The elastic properties were characterized by fitting stress vs. strain curves recorded during loading and unloading cycles in a uniaxial compression test. The plastic material parameters, for yield surface, have been obtained by uniaxial and diametral compression tests. The calibration procedure was performed for three green density values. The digital image correlation technique proved to be of great value in the analysis of this results, considerably increasing the amount and quality of data obtained from mechanical tests, allowing a more complete and accurate analysis, as well as a greater understanding of the yielding mechanisms. The calibrated material model was implemented into AbaqusTM v6.14 for a finite element analysis of cold uniaxial compaction. An experimental procedure was used to validate the overall method by comparing the finite elements results to the experimental observations. The numerical results are in good agreement with the experimental observations.