Experimental Studies on Impact Resistance of 3D Printed Concrete Spherical Structure with Carbon Fiber Reinforced PLA Honeycomb Energy Absorber (2026-03)¶

The impact resistance of 3D-printed concrete spherical structures is inherently low due to their brittle nature and limited energy dissipation capacity. This study introduces carbon fiber reinforced PLA honeycomb energy absorber and investigates their influence on the impact performance of 3D-printed concrete spherical shells. A series of gravity drop-hammer tests were conducted on four structural configurations, including standard and geometrically optimized shells, with and without embedded absorbers. Both traditional strain gauges and 3D Digital Image Correlation (DIC) techniques were employed to capture the dynamic responses. The experimental results indicate that: (1) The inclusion of honeycomb absorbers markedly enhances energy dissipation and reduces strain concentration, while structural optimization further improves stress redistribution and deformation control. (2) Tensile failure remains the dominant failure mode, initiated by localized overstress and material inhomogeneity. (3) The DIC method demonstrated reliable feasibility in visualizing transient full-field strain evolution in three-dimensional space, effectively complementing conventional contact-based measurements. Overall, the combined energy-absorbing and optimization strategies substantially improve the impact resistance of 3D-printed concrete shells, providing experimental evidence and methodological support for the design of resilient additive-manufactured concrete structures.