Accession Number : AD0717952

Title :   Failure of Glass Under Biaxial Loading.

Descriptive Note : Technical rept. no. 2, Jan-Dec 70,

Corporate Author : NATIONAL BUREAU OF STANDARDS WASHINGTON D C INST FOR MATERIALS RESEARCH

Personal Author(s) : Wiederhorn,S. M. ; Johnson,H.

Report Date : DEC 1970

Pagination or Media Count : 25

Abstract : The report presents the results of two studies on the fracture behavior of glass at elevated pressures. One was conducted in an inert environment at pressures up to 20 kbar. The other was conducted in water at pressures up to 7 kbar. Fracture mechanics techniques were used in both studies. In inert environment the fracture surface energy of three glass compositions was found to be independent of pressure suggesting that no change in the fracture mechanism occurs as a result of pressure. The brittle behavior of glass thus differs from plastics and metals which are observed to become stronger and more ductile with increasing pressure. The fracture behavior of glass in water was also observed to be insensitive to pressure. It is suggested that the reason for this null effect results from compensating mechanisms, in which the increase in fracture resistance arising from a positive activation volume for stress corrosion cracking process is balanced by a decrease in fracture resistance due to increased hydroxyl ion concentration at the crack tip. (Author)

Descriptors :   (*GLASS, FRACTURE(MECHANICS)), (*UNDERWATER VEHICLES, GLASS), HIGH PRESSURE, STRESS CORROSION, HYDROSTATIC PRESSURE, CONTROLLED ATMOSPHERES

Subject Categories : Ceramics, Refractories and Glass
      Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE