Steel fiber-reinforced concrete under impact loading dynamic constitutive equation

Abstract

This study presents the experimentation of dynamic impact tests on steel fiber-reinforced concrete (SFRC) specimens to analyze dynamic constitutive equation. The dynamic compression experimentation of SFRC with a fiber volume ratio of 0%, 0.75%, and 1.5% was conducted using a Φ75 mm-diameter split Hopkinson pressure bar experimental system. Thus, different steel fiber contents and stress–strain curves under different strain rates are obtained. Results showed that the peak strain value and peak stress of SFRC increase with fiber content and strain rate concurrently. On the basis of the definition of Holmquist–Johnson–Cook constitutive strain rate effect and the stress–strain curves of different strain rates, a dynamic damage constitutive model of SFRC composite under compression is proposed. The proposed concrete material dynamic constitutive model depends directly on the strain, strain rate, material strength factor, and steel fiber content factor. Through simulation and experimental curves, the corresponding material parameters are obtained and show that using this constitutive model allows the fitting results to correspond accurately with the experimental data.