Dilatational Relaxation in Cylindrical Seals

This paper presents a viscoelastic thermal stress analysis which illustrates the importance of dilatational stress relaxation in cylindrical seals. When the core is elastic and the cladding is glass, dilatational stress relaxation has no significant influence on the stresses in the seal. However, when the core is glass and the cladding is elastic, this relaxation has a profound effect. For the latter seal, the setting temperature is weakly dependent on seal dimensions. In fact, stress development during cooling can be accurately predicted from the “fluid core” analysis by Scherer and Cooper, using the fictive temperature of the glass as the setting temperature.