Peridynamic anisotropic behavior analysis of 3D-printed concrete structures

As a layer-wise construction method, 3D-printed concrete (3DPC) introduces weak interfaces between layers, resulting in different mechanical behavior in different directions. Most studies investigate this anisotropic behavior based on experimental specimen-scale samples and do not apply it in practical engineering. To address this need, the present paper develops a peridynamic (PD) method for the anisotropic behavior analysis of 3DPC structures. As a bond-based method, the interfaces of 3DPC are easily identified by bond division and modeled by reducing bond properties in PD, establishing a simple numerical scheme for structural analysis. Through bond-based correspondence, the bi-scalar plasticity-damage model is incorporated to describe the hardened properties of 3DPC after printing. On this basis, the dynamic effect is included to consider the threat of extreme loads, under which structures show more pronounced anisotropic behavior. The developed method is rigorously verified against two experiments and is finally applied to a systematic numerical study of an arch bridge, including both static and dynamic cases. The results provide a deep understanding of the anisotropic behavior of 3DPC structures. Furthermore, the proposed method shows good performance in guiding 3D printing design and determining the optimal printing direction, demonstrating its capability for practical engineering applications.