Journal Article

Investigating Stress Limitations in Dynamic Response of Coral Limestone Concrete: Integrated FDM-DEM Simulations and Experimental Validation

Zhang, Yuzhu, Zhang, Jinrui, Gong, Yi, Hu, Haoran, Luo, Yi

2025

Overview

This study established a dynamic impact simulation system for a coral limestone cement composite subjected to bidirectional stress confinement conditions by using a coupled method of continuous medium FDM (a coupled continuum-discontinuum approach integrating finite difference continuum modeling (FDM) and the discrete element method (DEM) granular analysis), and verified its accuracy through indoor experiments. The study first conducted dynamic mechanical performance tests on reef limestone concrete using an SHPB experimental device, exploring the effects of the strain-rate governed high-rate response, energy evolution, and failure modes. Subsequently, an FDM-DEM coupled model was used to simulate the impact-induced behavior of concrete at multiaxial stress conditions and constraint conditions, analyzing the strain-rate dependent performance of concrete exposed to biaxial monotonic loading. Test outcomes indicate that the increase in strain rate significantly enhanced the dynamic peak stress, and the collapse behavior shifted from type I to type II. As static loading in the σ2 direction increased, the dynamic peak stress in the σ1 direction decreased, while the dynamic peak stress in the σ2 direction increased, indicating that the constraint stress in the σ2 direction had an inhibitory effect on the sample’s failure. Through the time-history monitoring and analysis of cracks, it was found that the internal crack growth rate accelerated as the stress increased, while the crack growth tended to stabilize when the stress decreased. Additionally, this study explored the effect of stress constraints on the fragmentation patterns, revealing changes in the failure modes and crack distributions of the sample under different stress states, providing a theoretical basis and technical support for island and reef construction and engineering protection.

• Publisher: MDPI AG,MDPI
• Subject: Aggregates / Analysis / Axial stress / Cement / Concrete / Constraints / Continuum modeling / Coral reefs / Coupled modes / Crack propagation / Discrete element method / Dynamic response / Engineering / Experiments / Failure modes / Fuzzy logic / Limestone / Mechanical properties / Performance tests / Propagation / Shear tests / Simulation methods / Strain analysis / Strain gauges / Strain rate