Improving performance of a nonlinear absorber applied to a variable length pendulum using surrogate optimization

The paper investigates a nonlinear vibration mitigation strategy of variable length pendulum subjected to harmonic external excitation. A absorber in form tri-pendulum system is used reduce the response primary pendulum. Thus, non-stationary problem using another passive absorber. Due genuine interest capturing dynamic interaction, numerically studies performance mass and absorber, first, by constructing 2D maps unrestrained parametric space, which demonstrate qualitative behavior system. Then, surrogate optimization technique tune absorber’s parameters within given bounded set parameters’ values. conducted based on priori known reeling speed or acceleration/deceleration pendulum, thereby completely removing need for acquiring current states essential active feedback control. obtained numerical results validate proposed high when it properly tuned.