Robust Model for Behavior of Complex Materials during Spin Testing

The objective of this project is to develop a practical finite element based simulation of spin-pit tests of discs, incorporating localized effects including: residual stresses, dislocations, and chemical-composition gradients. Some of these localized effects are introduced during the shape forming process. Disc failure in spin-pit tests critically depends on localized effects. A multi-scale finite element model is proposed that enables the incorporation of macro- and meso-scale effects in a single analysis. An important feature of the proposed approach is that it enables the simulation of localized effects that are arbitrarily oriented relative to the geometry of the finite element mesh. This feature is critical because it enables the simulation of the propagation of oriented localized effects, such as fatigue cracks, independent of the mesh geometry. A numerical simulation of a spin-pit test of a disc of simple geometry will be used to demonstrate the feasibility of the proposed approach. In this simulation, location-specific effects such as material properties, locked-in stresses, and dislocations present in the disc at the beginning of the mesh will be assumed known, and will be introduced through procedures developed in this project.