In this research, the dynamic behavior of sandwich structures with 3D-printed polylactic acid (PLA) honeycomb cores and heterogeneous reinforcing skins was evaluated under low-velocity impact loading. The primary novelty of this study lies in the structural interaction analysis and dynamic performance comparison of the polymeric core with two distinct skins: 2024 aluminum alloy (elasto-plastic behavior) and bidirectional glass fiber/epoxy composite (elastic-brittle behavior) at energy levels of 10, 21, and 30 Joules. To assess weight-independent efficiency, the Specific Energy Absorption (SEA) index was introduced, and the dynamic response curves and failure mechanisms of the PLA, PLA/AL, and PLA/Glass specimens were compared. In addition to the experimental process, a 3D finite element model (3D-FEA) was developed using advanced progressive damage criteria. The numerical model successfully predicted and validated the force-displacement curves and energy absorption capacity with an error of less than 10% compared to experimental data. Finally, a parametric study was conducted to evaluate the effect of reinforcement skin thickness on the energy absorption capacity. Furthermore, mathematical trend analysis using regression revealed that the energy absorption rate in specimens with aluminum face sheets follows a non-linear, saturating pattern, whereas the glass-fiber reinforced structures exhibit a strictly linear and stable efficiency within the tested energy range.