Viscoelastic Analysis of Thermal Stresses in a Composite Sphere

Viscoelastic analyses of thermal stresses are presented for composite spheres in which the viscous phase constitutes either the core or the cladding. These results should offer a better approximation to the stresses caused by spherical inclusions than the isolated sphere solution. The viscoelastic solution provides a means of finding the appropriate setting temperature for the composite, and its dependence on the volume fraction of the elastic material. The setting temperature of an elastic core composite is also shown to be predictable from that for a sandwich seal of the same materials. A “fluid core” analysis is shown to provide a good approximation when the elastic phase constitutes the cladding. This type of seal is sensitive to the dilatational relaxation behavior of the glass.