Prediction of dynamic response of high-Strength concrete − based on the modified constitutive model

Concrete with new features such as high strength and a high tension–compression ratio has been developed to enhance building safety and the defense structure capability, which also poses a challenge to classical constitutive models such as the Holmquist-Johnson-Cook (HJC) model. This study proposes a flexible constitutive model that is suitable for concrete-like materials with varying strength and tension–compression ratios. Known as the three-invariant model, it features the explicit introduction of two mechanical characteristic parameters: the tension–compression ratio and the Lode angle. By strictly passing through (or closely approximating) six benchmark stress state points, the model effectively captures tension–compression anisotropy and yield behaviors across the entire range of hydrostatic pressure. To further extend the static model to dynamic conditions, a unified S-type strain rate equation is developed. This equation accounts for dynamic tension–compression anisotropy arising from the material's intrinsic properties by considering the influence of hydrostatic pressure on strain rate effects. Experimental data from various rock and concrete specimens subjected to true triaxial stress states are compared with calculated data. The results confirm that the proposed model accurately reflects the yield strength and improves the predicted accuracy of structural responses under complex stress states.