Testing glass fiber reinforced polymer beams for their dynamic properties

Glass Fiber Reinforced Polymer (GFRP) is a modern construction material characterized by high strength, corrosion resistance, and significantly lower self-weight compared to steel. These properties make it an attractive alternative to traditional structural solutions, particularly in applications where reducing the weight of the structure is advantageous. At the same time, lightweight elements may exhibit increased susceptibility to vibration, which makes the analysis of their dynamic behavior essential for evaluating the practical applicability of such materials. The aim of this study was to determine the dynamic properties of GFRP beams and to verify the parameters adopted in the numerical model by comparing the results of modal analysis with experimental data. Numerical simulations were performed in ABAQUS, while experimental studies were carried out using a non-destructive impulse excitation test with a modal hammer. The obtained results enabled the identification of natural frequencies, mode shapes, and the assessment of the level of agreement between the numerical model and the actual behavior of the tested beams. The presented findings form the first stage of a broader research project. The next step will involve casting a concrete slab using high-performance lightweight concrete (HPLWC), connecting it with the GFRP beam, and re-evaluating the dynamic properties of the composite system.