INVESTIGADORES
OLLER  Sergio Horacio Cristobal
artículos
Título:
A finite element model for thermomechanical analysis in casting processes
Autor/es:
D. CELENTANO; S. OLLER; E. OÑATE
Revista:
JOURNAL DE PHYSIQUE IV
Editorial:
EDP-Sciences
Referencias:
Año: 1993 vol. 03 p. 1171 - 1180
ISSN:
1155-4339
Resumen:
This paper summarizes the recent work of the authors in the numerical simulation of casting processes. In particular, a coupled thermomechanical model to simulate the solidification problem in casting has been developed [7,8,9]. The model, based on a general isotropic thermoelasto-plasticity theory and formulated in a macroscopical point of view, includes generalized phase-change effects and considers the different thermomechanical behaviour of the solidifying material during its evolution from liquid to solid. For this purpose, a phase-change variable, plastic evolution equations and a temperature-dependent materialconstitutive law have been defined. Some relevant aspects of this model arc presented here.Full thermomechanicd coupling terms have been considered as well as variable thermal and mechanical baundary conditions: the first are due to air gap formation, while the second involve a contact formulation. Particular details concerning the nurncrical implementation of this model are also mentioned. An enhanced staggered scheme, used to solve the highly non-linear fully coupled finite element equations, is proposed. Furthermore, a proper convergence criterion to stop the iteration process is adopted and, although the quadratic convergence of Newton-Rapshon´s method is not achieved, several numerical experiments demonstrate reasonable convergence rates. Finally, an experimental cylindrical casting test problem, including phase-change phenomena, temperaturedependent constitutive and contact effects, is analyzed. Numerical results are compared with some laboratory measurements.