Efficient simulation of single and poly-crystal plasticity based on the pencil glide mechanism

The present work demonstrates that the pencil glide mechanism is a physically reliable and a computationally efficient model to simulate the nonlinear behaviour of b.c.c. single and polycrystals. For that purpose, the pencil glide extension of Schmid’s criterion used by Gilormini [1] is incorporated in a single crystal model and in a homogenized polycrystal model accounting for large elastoviscoplastic deformations. The response of the pencil glide model in terms of stress-strain curves and lattice rotation is compared to the prediction based on the consideration of all ({110}〈111〉+ {112}〈111〉) slip systems. In the case of α-iron single crystals both approaches are shown to accurately reproduce recent experimental results [2, 3]. The comparison is extended to α-iron polycrystals behaviour under tension, compression, rolling and simple shear loading conditions. The evolution of crystallographic textures obtained either based on pencil glide or using the 24 slip systems is analyzed and compared to classical experimental results from the literature. Limitations of the approach, especially in the case of simple shear textures, are also pointed out. The pencil glide approach can be viewed as a reduced order model enhancing computational efficiency of crystal plasticity simulations involving many slip mechanisms.