Analysis of vibration characteristics based on variable‐angle hybrid laminates

Abstract Composite laminates are widely used in the aerospace field. Aircraft wings are subject to strong aerodynamic interference, which produces resonance, instability and other phenomena. To avoid this resonance and reduce the vibration of laminates it is essential to adopt a variable‐stiffness laminate. Methods for changing the stiffness include designing the fiber path and inserting a damping layer. The former can increase the natural frequency but does not improve the damping performance. Here we demonstrate how, depending on the resin's agglomeration, variable‐angle hybrid laminates made of carbon fiber and Kevlar fiber increase the damping performance. By using a short beam shear test we found that sandwich hybrid samples with a hybrid ratio of 50% performed better than inter‐laminar hybrid samples, which increased by 19.5%. Based on the results of interlayer properties, 8 layers of pure carbon fiber (CF) laminates and carbon fiber‐kevlar fiber (CF‐KF) hybrid laminates with variable angles were manufactured. Modal tests demonstrated that the change in fiber angle had a greater impact on the natural frequency, the maximum result of which was seen at an angle of <60|75>. By inserting, the KF layer the damping ratio of the <15|30> hybrid laminate increased by 5.45% more than pure CF laminates. These results can be referenced to improve the damping parameters of variable‐angle laminates.