Toward Efficient Simulation of Cracked 3D-Printed Concrete Beams (2026-03)¶

3D concrete printing (3DCP) has emerged as a promising construction technology, offering enhanced design flexibility, reduced formwork requirements, and material efficiency. Although 3D finite element (FE) analysis is effective in evaluating the structural response of cracked 3DCP beams, it often incurs high computational costs due to the need for refined mesh distribution around the cracks and voids. To address this challenge, focusing on cases with strong interlayer bonding that reduces anisotropy at the macro-scale, the present work simplifies the analysis by using a two-dimensional FE model enabled by a homogenization approach. Material heterogeneity is introduced by incorporating voids within the printed layer, with the void fraction carefully chosen to approximate the mechanical response of the defect-free printed material. Furthermore, this work proposes the analytical form of stress distributions along the thickness of the beam, which couples the concepts of strength of materials and fracture mechanics within the crack-affected region. Using the principle of strain energy equivalence and the stresses obtained from the proposed formulations, the corrected moment of inertia is determined in the cracked geometry. This is then employed in a 1D FE beam analysis, where the structural responses are captured by introducing a spatially varying moment of inertia within the crack-affected region, and its effects are thoroughly examined. Finally, both the theoretical and numerical results (1D and 2D FE) are validated against 3D simulations of actual cracked beam with embedded voids, confirming the efficiency and accuracy of the proposed approach in predicting the stress fields and stiffness of cracked 3D-printed concrete beams.