Static and Cyclic Fatigue Tests of Fusion-Sealed Pyrex Spheres

摘要

The feasibility of developing reliable glass floats for the search vehicle of the Deep Submergence Systems Project was explored by a proof-testing approach. The investigation incorporated static and cyclic fatigue tests of 10-in.-diameter, fusion-sealed, annealed Pyrex glass spheres under hydrostatic pressure. The results of three series of models tested at different loading rates in sea water showed no apparent effect of loading rate on collapse strength. A fourth series of models tested in oil showed no appreciable difference in strength when compared to the models tested in sea water. Four models initially proof tested to a depth of 30,000 ft survived 5000 cycles of pressure to a depth of 22,500 ft. Each model was then tested to destruction at depths in excess of 30,000 ft. The results obtained in these tests were exploratory and should be used with caution. However, with the possible exception of one model which may have suffered cyclic damage, the results are sufficiently encouraging to warrant further investigations. (Author)