Experimental and numerical investigation of vibration and acoustic properties of composite beams

In this study, acoustic and vibration behaviors of fiber reinforced composite materials such as vibration damping, sound absorption and sound transmission loss were investigated experimentally and numerically. The fibers used in the study consist of aramid, carbon and glass fiber fabrics. Composite materials were produced by vacuum infusion method. The beams used in the experiments were cut in a circular geometry with a length of 250 mm and a thickness of 2 mm, while the plates were cut with a diameter of 100 mm and a thickness of 2 mm. With experimental acoustic impedance tube tests, absorption coefficients and sound transmission loss information of each circular composite plate sample were obtained in the laboratory with the help of transfer functions. The data obtained in the modal analysis tests were analyzed and comparisons were made between the samples. According to the modal analysis results, [C3A]S composites have the best mechanical performance and [G]8 composites have the weakest mechanical performance. In the absorption tests, a 25 mm thick retaining sponge was added to the back of the circular composite plates. The obtained data were analyzed and comparisons were made between the samples. According to the analysis results, [C3A]S composites have the best acoustic absorption performance, while [C]8 composites have the weakest acoustic absorption performance.