An Approach for Analyzing the Dynamic Strength Increment of Concrete Material

• Published in: IOP conference series. Earth and environmental science 2019-12, Vol.371 (4), p.42037
• Main Authors: Xu, Peibao, Ge, Dali, Zhao, Jun, Yu, Yong, Li, Kai
• Format: Article
• Language: English
• Subjects: Calibration; Compressive strength; Concrete; Design analysis; Empirical analysis; High strain rate; Laboratory tests; Material properties; Mathematical models; Split Hopkinson pressure bars; Strain rate sensitivity
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/371/4/042037

The Split Hopkinson Pressure Bar (SHPB) is usually used to get the dynamic compressive strength of concrete materials at strain-rate between 101 and 103s−1. It is widely accepted that the main influencing factors of dynamic strength include strain-rate effect and inertial effect in SHPB tests, which result in obvious scattered phenomenon existing in the test data. However, many empirical formulae of dynamic increase factor were directly obtained from the scattered test data to describe the material properties, which has been overestimated strain-rate effect for design analysis. In present paper, numerical simulations with a rate-independent material model are used to study this pseudo-strain-rate sensitive phenomenon because it is very difficult to quantify these influences by conducting laboratory tests. Then a unified approach for processing the scattered test data of normal concrete is available especially for mid-high strain rate. Moreover, the quantitative relations among the strain-rate effect, inertial effect and calibration test data have been obtained with the help of the corresponding numerical simulations, and semi-empirical formulae are also proposed to describe the inertial effect and strain-rate effect.