Experimental study on the influence of lamination parameters on the vibration characteristics of variable stiffness composite laminates

In this study, the vibration characteristics of composite laminated plates with variable stiffness were studied using a modal analysis experiment based on the hammering method and a free vibration attenuation experiment. Twenty-five variable stiffness laminates fabricated from carbon fiber-reinforced resin matrix composite prepregs were manufactured via an automated fiber placement process. By varying the parameters, such as the fiber angle (< 0 degrees|15 degrees >, < 15 degrees|30 degrees >, < 30 degrees|45 degrees >, < 45 degrees|60 degrees >, < 60 degrees|75 degrees >, < 74 degrees|89 degrees >), curve ply ratio (0, 0.5, 1), and the number of layers (8, 12, 16), these laminates were tested in a dynamic signal analyzer to obtain their modal frequency and modal damping. These parameters were observed to significantly affect the modal parameters. As experimental investigations on the vibration characteristics of variable stiffness composite laminates are very rare, this study can be considered a reference for future work.