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Date: 28 Mar 2014

Spatial double physical pendulum with axial excitation: computer simulation and experimental set-up


Physical and mathematical model of a three-dimensional double physical pendulum being coupled by two universal joints is studied. Upper joint of this pendulum is periodically rotated in its axial direction. Damping forces and torques inside joints as well as an influence of the gravitational field and damping forces and torques inside joints are taken into account during derivation of the ODEs of this mechanical system. The work consists of mathematical modelling, computer simulation and parts of the experimental analysis to confirm the numerical simulations. The experimental setup realizes kinetic excitation by an non-constant periodic torque of servomotor, controlled by the computer. Four incremental encoders are mounted on pendulum joints, so the angles of rotation of the pendulum are measured in real-time and analysed by an originally developed acquisition software. Future plans of the mathematical and experimental model are also discussed. Presented exemplary results showed a number of non-linear effects, including chaos, quasi-periodic and periodic dynamics.