The coupled thermo-mechanical analysis in the upsetting process by the dynamic FEM

The effect of temperature is significant on both the die and the workpiece in metal forming processes. But, the applications of coupling mechanical work and thermal effect are somewhat complicated. In this study we apply the dynamic finite element method coupled with thermal effect to analyze the upsetting process with different models. The proposed models, either being drawn for industry necessity or designing for research study, are simulated and compared. At first, the numerical models for the upset forming of steel billet are setup. The models consider the different types of material constitutive equations, different thermal conditions, and Coulomb friction effect. The predicted relationship between the punch load and stroke, the temperature distribution of billet, and the full history of temperature variation are discussed. The influence and usage of the material constitutive equation for the thermal analysis is also assessed. Besides, the developed models of upsetting process are validated by comparison with the published paper. Finally, the proper techniques are implemented to solve the upsetting process with aluminum material. And the temperature distribution on the surface of the billet in experiment is measured by an infrared camera. A good agreement between the numerical result and experiment data shows the availability of the proposed model.