Characterization of the dynamic mechanical properties of low-iron float glass through Split-Hopkinson-Pressure-Bar tests

Abstract

Low-iron ultra-clear float glass (LIFG) has been widely used in landmark and large-scale buildings in recent years due to its aesthetic characteristics. A better understanding of the dynamic mechanical properties of LIFG is essential for the blast resistance analysis and design of glass facades. This paper presents a series of quasi-static tests and dynamic tests (using Split-Hopkinson-Pressure-Bar) to study the dynamic compressive and tensile behavior of LIFG. Strain rate effect has been investigated on compressive strength in the range of 10-5 s−1 to 103 s−1 and splitting tensile strength in the range of 10-5 s−1 to 40 s−1. During the tests, an ultra-high-speed camera was employed to capture the crack initiation and propagation. The test results show that both the dynamic compressive and tensile strengths of LIFG are strain-rate dependent, nevertheless the dynamic tensile strength is more sensitive to strain rate than the compressive strength. The strain rate effect is insignificant on the Young’s modulus of LIFG. In addition, the upper limits of strain rate are identified for dynamic compression and splitting tension of glass through SHPB facilities based on a conceptual analysis. For LIFG specimens with the length of 8 mm (for compression) or the diameter of 20 mm (for splitting tension), the upper limit of strain rate is about 2500 s−1 for compression and about 40 s−1 for splitting tension. Increasing or reducing the specimen dimension will correspondingly decrease or increase the upper strain rate limits.