Dynamic Mechanical Behavior and Constitutive Model of a Newly Designed Reactive Nanoinorganic Cement-Based Composite

Abstract

Recently, reactive nanoinorganic cement-based composite (RNICC) has attracted considerable attention as a high-strength and high-performance concrete. Understanding the mechanical properties and establishing a constitutive relationship of RNICC are of great significance for improving the numerical simulation of the mechanical behavior of RNICC structures under extreme impact and blast loading. In this study, quasi-static compression–tension and dynamic compression tests were performed on a RNICC to obtain the mechanical properties, strain rate effect, and damage modes. The results revealed that the compressive behavior of RNICC is sensitive to the strain rate effect. The main form of compressive damage of RNICC is cement matrix cracking at low strain rate. The cement matrix cracking and steel fiber fracture simultaneously occur at a high strain rate. The Holmquist–Johnson–Cook (HJC) constitutive model was used to describe the mechanical behavior of RNICC at high strain rates. Based on the experimental results, detailed test procedures and parameter characterization methods were established to determine the HJC model parameters for RNICC. The accuracy of the proposed HJC model parameters was validated by comparing the experimental data of the dynamic compression tests with finite-element simulation results based on LS-DYNA software.