Abstract
In previous report the author has derived an equation for calculating the principal stresses in a glass seal between two metal tubes, which is avairable for the design of glass-to-metal seals.
In this paper the theory is extended to the case of the glass sealing between three concentric metal tubes, which covers the wide range of the expansion coefficient of glass and metal.
The experimental background of the theory has been furnished by photoelastic study.
The results have proved that it is desirable to use an external metal cylinder of large thermal expansion in order to give a large compression in glass, although a large difference in the expansion of glass and internal metal cylinder should be avoided because of the shearing stress.
The stress calculated from the thermal expansion of sealing members are large compmared with the observed values measured by photoelasticity. This difference may be attributed to the “end dffect” of short cylinders, although the theory is practically useful for the design of the seals of this type.
