Compression Strength of Borosilicate and Soda-Lime Silicate Glasses Using a Dumbbell-Shaped Specimen
Abstract
The compression strength of a borosilicate and a soda-lime silicate glass is measured under quasi-static and dynamic strain rates with a dumbbell-shaped specimen. Two different specimen orientations were machined, parallel (vertical) and perpendicular (horizontal) to the plate thickness, and some specimens of each glass were etched prior to testing. A dumbbell specimen was used since the typical cuboid or cylindrical specimen develops a large stress concentration at the ends of the specimen, leading to premature failure and correspondingly low strength values. The dumbbell-shaped specimen allows one to differentiate between valid and invalid failure for each experiment by observing, with a high-speed camera, where fracture initiateswithin the specimen gage section (valid) or from the specimen ends (invalid). However, damage can initiate in both the ends and the gage section (nearly) simultaneously, clouding the determination. Time correlating the force/stress measurement to the observed images has some uncertainty that can add additional ambiguity. The success rates for each glass were completely opposite: relatively high for borosilicate and very low for the soda-lime silicate. However, there is no obvious explanation. Despite these issues, it is believed that the dumbbell-shaped specimen is the best geometry for measuring the compression strength of brittle materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2020
- Accession Number
- AD1117665
Entities
People
- Christopher S. Meredith
- Jeffrey J. Swab
Organizations
- United States Army Research Laboratory