Composite railway sleepers are increasingly adopted as durable, low-maintenance, and sustainable alternatives to conventional materials, offering enhanced long-term performance and adaptability under demanding service conditions. In parallel, 3D printing has become an innovative and cost-effective research tool for developing scaled railway components. This study investigates, for the first time, the dynamic behavior of scaled, semi-functional P90-type composite railway sleeper prototypes fabricated by additive manufacturing. The 1:13.33-scale ABS specimens were tested using Experimental Modal Analysis (EMA) in vertical, lateral, and longitudinal orientations under free-free boundary conditions. A detailed Finite Element Model (FEM) was developed in ANSYS, incorporating measured unit weight, accelerometer mass, and elastic support stiffness. Iterative back-analysis was performed to align FEM predictions with EMA-measured fundamental resonance frequencies, yielding excellent correlation at E = 2595 MPa and G = 1120 MPa, with a maximum individual mode deviation of 0.959 % and a total three-mode deviation of 1.601 %. The validated FEM demonstrates partial similitude, a principle long applied in aerospace and mechanical engineering to achieve dynamically consistent results using scaled prototypes. Overall, this study establishes a preliminary methodological foundation for future modal topology optimization (MTO) and full-scale correlation studies, serving as a case-study framework for extending similitude-based dynamic characterization of railway sleeper systems. The proposed methodology can also be broadly applied to investigate and enhance the dynamic behavior of structural components in civil, mechanical, and materials engineering.
Composite railway sleepers are increasingly adopted as durable, low-maintenance, and sustainable alternatives to conventional materials, offering enhanced long-term performance and adaptability under demanding service conditions. In parallel, 3D printing has become an innovative and cost-effective research tool for developing scaled railway components. This study investigates, for the first time, the dynamic behavior of scaled, semi-functional P90-type composite railway sleeper prototypes fabricated by additive manufacturing. The 1:13.33-scale ABS specimens were tested using Experimental Modal Analysis (EMA) in vertical, lateral, and longitudinal orientations under free-free boundary conditions. A detailed Finite Element Model (FEM) was developed in ANSYS, incorporating measured unit weight, accelerometer mass, and elastic support stiffness. Iterative back-analysis was performed to align FEM predictions with EMA-measured fundamental resonance frequencies, yielding excellent correlation at E = 2595 MPa and G = 1120 MPa, with a maximum individual mode deviation of 0.959 % and a total three-mode deviation of 1.601 %. The validated FEM demonstrates partial similitude, a principle long applied in aerospace and mechanical engineering to achieve dynamically consistent results using scaled prototypes. Overall, this study establishes a preliminary methodological foundation for future modal topology optimization (MTO) and full-scale correlation studies, serving as a case-study framework for extending similitude-based dynamic characterization of railway sleeper systems. The proposed methodology can also be broadly applied to investigate and enhance the dynamic behavior of structural components in civil, mechanical, and materials engineering.