Thermal Ratcheting of Uranium Simulated with a Thermo-Elasto-Visco-Plastic Polycrystal Model

Uranium aggregates accumulate large plastic deformation during thermal cycling (ratcheting). This process is the result of highly anisotropic single crystal properties, texture, and a complex coupling between thermal, elastic and plastic mechanisms of deformation. Here we present a thermo-elastic-viscous crystal plasticity model and apply it to the prediction of thermal ratcheting in clock-rolled uranium. The model captures the plastic relaxation of intergranular stress induced by thermal cycling and leads to an understanding of the coupling of the deformation mechanisms in uranium. Results are compared with ratcheting measurements.