Surrogate model based mechanical characterization of lead-free soldered joint material exhibiting ratcheting behavior: An advanced methodology

This study is focused on the methodology dedicated to the identification of parameters of a general Chaboche model [1] for a nanosilver sintered material. This material is used, in particular, for die-attachment in power electronics applications under harsh temperature conditions. This material model is an elastic-viscous-plastic constitutive model accounting for creep and kinematic hardening mechanisms which underlie ratcheting behavior. The proposed methodology relies on an evolutionary algorithm which is coupled with state-of-the-art surrogate modeling. The implemented procedure enables an efficient and robust identification of the parameters of the constitutive model. The methodology is applied to the characterization of a sintered nanosilver joint. Experimental data are extracted from literature in the case of a classical lap-shear test [2]. The Chaboche model is identified for three temperatures from 25°C to 325°C. A monotonic variation of the parameters in function of the temperature is imposed in order to ease the interpolation of parameters inside the temperature range. The parameters identified for the Chaboche model present a better correlation with experiments for each temperature than the Ohno-Wang and Anand constitutive models identified in [2].