Effects of nanoparticles on the improvement of the dynamic response of nonuniform-thickness laminated composite beams

The dynamic behavior of nonuniform-thickness laminated composite beams, such as helicopter blades, wind turbine blades, and robot arms, is of high importance in the design and fabrication of such elements. Changing the thickness of laminated structures is a significant challenge during fabrication because different tapering configurations may significantly alter the stiffness of the structures and thus the dynamic response of the structures. In this study, the effect of adding nanoparticles to resin on the stiffness and dynamic behavior of nonuniform-thickness laminated composite beam elements was investigated. A set of experiments were conducted to examine the natural frequencies and damping coefficients of nonuniform-thickness laminated composite beams with different tapering configurations. Adding nanoparticles up to 3% increased the natural frequencies for all tapering configurations. Beyond 3% and up to 7% of nanoparticles, the natural frequency of the beam decreased. The addition of 10% of nanoparticles to resin sharply reduced the natural frequency of the beam but significantly improved the damping coefficient for all the investigated taper models.