Skip over navigation

 

From atomistic to discrete dislocation dynamics modelling of bcc metals: deformation of tungsten

Daniel Weygand (KIT), Kinshuk Srivastava (KIT), Peter Gumbsch (KIT)

Joint Session: Discrete Dislocation Plasticity and From Atomistics to Reality: Spanning Scales in Simulations and Experiments

Mon 2:40 - 4:00

CIT 227

It is well known, that plastic flow in bcc metals show non-Schmid behaviour. Therefore atomistic information on the motion of screw dislocation has to be transferred within a multi-scale model to discrete dislocation dynamics models in order to simulate the plastic flow of bcc metals at the. The presented framework takes into account the effect of applied loading and incorporates non-glide components of the stress tensor which strongly influence the critical resolved shear stress. The local stress state modifies the Peierls barrier on the three possible glide planes of the screw dislocation and thereby changes the energy barrier for kink-pair nucleation on these planes. The plane with the lowest activation enthalpy then controls the slip of the dislocation. The simulation results show that experimentally observed slip on the MRSSP at higher temperatures, the tension–compression asymmetry and the orientation dependence of slip activity is well captured. This non-Schmid framework, based on atomistic input, naturally provides a physically based description for the activation of low-Schmid factor planes under compressive loading. "Subject Area:DISCRETE DISLOCATION PLASTICITY"