Computational modelling of concrete structures subjected to pre-static loading and subsequent impact dynamics

In the dynamic analysis of concrete structures, the mechanical behavior of concrete materials under initial static stress and dynamic loads requires careful consideration. To this end, we propose a novel static–dynamic integrated numerical method that amalgamates the static–dynamic multiaxial strength criterion with an enhanced iteration of the concrete damage plastic model. This enhancement involves the incorporation of a novel multiaxial damage variable, effective hardening function, and refined rate-dependent criterion, thereby enabling more accurate representation of the actual dynamic strength of concrete. A comparison with the conventional model underscores the superior fidelity of the refined model in characterizing the multiaxial damage evolution throughout the loading trajectory, delineating intricate three-dimensional hardening phenomena, and predicting the ultimate dynamic strength of concrete materials with increased precision. The proposed numerical method was validated through dynamic loading tests on a single element and an impact test on a concrete slab. Subsequently, numerical experiments were conducted on concrete walls subjected to varying initial static pressures and impact velocities using a customized numerical framework. The simulation outcomes demonstrate a nuanced relationship where the dynamic bearing capacity of concrete walls increases proportionally with the loading velocity under constant initial static loads, while exhibiting a declining trend in response to increasing initial vertical static pressures under fixed impact velocity conditions.