Strength and damage content of sectional glass shells with different types of dismantable joints

Abstract

1. A study was made of the structural strength of inorganic glass in sectional spherical and cylindrical shells with new types of dismantable mechanical joints under conditions of external hydrostatic pressure. It was found that the choice of joint design and processing parameters on the basis of study of the effect of these parameters on the stress-strain state of the shell makes it possible to create a favorable stress state in the glass element so as to significantly increase and stabilize the maximum load-carrying capacity, endurance, and durability of the structure. 2. Sectional shells with dismantable joints realized by joining glass elements end to end showed satisfactory resistance to fracture under brief one-time and long-time applications of hydrostatic pressure but low resistance under pulsating loads, thus limiting the use of such a joint. 3. Designs in which glass bears directly against metal in the joint should be used only for brief one-time loading with external pressure: such a joint does not have reliable resistance to fracture of the glass element under long-time or repeated static loading. 4. Dismantable joints with a hinge guarantee resistance to fracture under one-time loading to relatively high external pressures but do not perform well in an absolute sense and are therefore not recommended for introduction. 5. An efficient dismantable joint of glass elements was designed with ends in the area of the butt joint that have roughly the same stiffness, thus ensuring reliable resistance to fracture up to 1600 kgf/cm2 for spherical shells and up to 1400 kgf/cm2 for cylindrical shells and providing more than 100 cycles of service at 1000 kgf/cm2 for both. 6. A new dismantable joint combining a glass element with a high-stiffness metal flange was also developed. This joint withstands brief applications of pressure up to 1100 kgf/cm2 and ensures reliable shell operation under a cyclic load of 600 kgf/cm2 for 100 cycles. 7. The results of the findings from the above studies have been put to use by interested organizations to make new and more modern equipment.