Design and performance analysis of a nonlinear energy sink attached to a beam with different support conditions

In this work, design and performance analysis of a nonlinear energy sink, attached to a beam (the primary system) with different support conditions, will be investigated. Here, the effects of both beam properties and external shock excitation are studied. For this purpose, equations of motion are derived by the Lagrange method. Then, parameters of the nonlinear energy sink are optimized by both sensitivity analysis and particle swarm optimization method. The results show that, increasing the first natural frequency of the primary system, on which an external impulse is imposed, will postpone the nonlinear energy sink activation. Also, increasing the amplitude of the shock excitation will tend to decrease the optimum value of the nonlinear energy sink stiffness. Using the particle swarm optimization method to obtain the optimized parameters of the nonlinear energy sink and its interaction with the primary system, which is a continuous one, is a new research area presented in this work.