@_ctnbeh_: Double Pendulum The sketched multibody system consists of a bar (1) (length $\ell$, mass $m_1$, body-fixed frame $\mathrm{K}$) and a circular disk (2) (radius $R$, mass $m_2$, body-fixed frame $\mathrm{W}$). Both bodies are connected by a joint, as sketched, and perform free oscillations around the equilibrium position. The system is initially deflected and then released. In addition to the deflection, an initial angular velocity is applied to the circular disk (2). The resulting oscillation is highly chaotic and analogous to the oscillation of a typical double pendulum with two rigid bars. #engineering #animation #simulation #university #chaos