A Dislocation based Constitutive Model for Warm Forming of Aluminum Sheet

摘要

The formability of aluminum sheet can be improved considerably by increasing the temperature.udAt elevated temperatures, the mechanical response of the material becomes strain rate dependent.udTo accurately simulate warm forming of aluminum sheet, a material model is required thatudincorporates the temperature and strain rate dependency. In this paper, the dislocation basedudAlflow hardening model is used. The model incorporates the influence of the temperature andudstrain rate effect on the flow stress by means of the storage and dynamic recovery of dislocations.udIt also includes the effects of solute level, particle fraction and grain size. Cylindrical cup deepuddrawing simulations are presented using shell elements. The anisotropic behavior of the sheet isuddescribed by using the Vegter yield locus. Experimental drawing test data is used to validate theudmodeling approach, where the model parameters follow from tensile tests.