ISSUES IN THERMAL-MECHANICAL MODELING OF CASTING PROCESSES

Mathematical modeling of stress generation in casting processes is a d ifficult, complex subject that is now receiving increased attention. T his paper reviews the basic equations, solution methods and important phenomena associated with casting processes that require special numer ical treatment. Stress modeling begins with a coupled, transient heat transfer analysis, including solidification, shrinkage-dependent inter facial heat transfer, and fluid flow effects. Further complicating phe nomena include phase transformations, temperature, stress and structur e-dependent plastic-creep, interaction between the casting and the mol d, hydrostatic pressure from the liquid, the effects of fluid flow, an d crack formation. Computational issues include numerical methods for handling these phenomena, mesh refinement, and two-dimensional stress state. Example applications are presented for the thermal-mechanical b ehavior of the solidifying steel shell in the mold region of a continu ous slab easter, using a finite-element model, which accounts for many of these phenomena.