A phase-field damage-plasticity approach for analyzing bonded anchors with supplementing reinforcements

Bonded anchors are widely used fastening elements in civil and structural engineering applications, particularly where high-strength connections are required for structural safety and performance. These anchors are essential in various construction scenarios, such as the retrofitting of existing structures or the installation of structural components. To further enhance the load-bearing capacity of these systems, post installed supplementary reinforcement (PISR) bars can be introduced. This reinforcement strategy is particularly effective in improving performance under tensile and shear loading conditions. In order to accurately assess and predict the load-bearing capacity of such reinforced bonded anchor systems, we investigate a novel numerical modeling approach based on a phase-field damage-plasticity framework. The method builds upon the Concrete Damage Plasticity (CDP) model originally developed by Grassl and Jirásek (2006), incorporating a recent phase-field extension. This extension is crucial in addressing the issue of mesh sensitivity commonly encountered in conventional damage models. The phase-field approach allows for a smooth and continuous representation of crack initiation and propagation, thereby enabling the simulation of complex failure patterns. The proposed model is implemented within an explicit finite element (FE) framework, using the commercial software package Abaqus/Explicit. This platform allows for efficient simulation of nonlinear material behaviors under various loading scenarios. Our numerical implementation ensures stable and accurate results even for complex three-dimensional geometries and highly nonlinear problems involving contact and bonded interfaces. To evaluate the robustness and accuracy of the proposed modeling strategy, we conduct a comprehensive numerical study that includes a wide range of test cases and reinforcing conditions. The simulation results are benchmarked against experimental data. The findings demonstrate that the proposed phase-field damage-plasticity approach exhibits excellent predictive capabilities. It accurately captures both the global structural response and the localized damage evolution of the bonded anchor systems with and without supplementary reinforcement. Overall, the study highlights the effectiveness and versatility of the proposed computational framework. The combination of the CDP model with the phase-field method offers a powerful tool for analyzing and designing reinforced fastening systems in complex and demanding engineering applications. Accordingly, this approach is well-suited for investigating structural elements subjected to various loading conditions.