Thermal Stress Analysis by Mesh Superposition Method (2nd Report, Handling of Thermal and Viscoelastic Behavior)

Abstract

In order to reduce the periods of development and investment of materials, it is a very important point to reveal the effect of the local heterogeneity on the mechanical characteristics. However, it is not easy to analyze the effect of the local heterogeneity on microscopic stress using a conventional finite element method. A multi-scale analysis is suggested to estimate the mechanical characteristics for a material with a local heterogeneity. The formulation and the application of the mesh superposition method handling thermal stress by the product process have been reported in this paper. It has been cleared that the proposed procedure has advantage to the thermal stress analysis considering the local heterogeneities. The glass-rich region in a fusion cast refractory has the property of viscoelasticity at high temperature. To estimate the residual stress due to casting process, it is necessary to treat not only thermal but also viscoelastic behaviors. The viscoelastic behavior of the local heterogeneities has been considered with the mesh superposition method and the numerical analysis system has been established. By the system, it is able to estimate the residual stress of the small glass-rich region in a fusion cast refractory and the effect of stress relaxation by thermal cure has been also demonstrated.