Problems $21\mathrm{.}6\mathrm{.}4.$

Consider a massless beam with two concentrated masses $m_1$ and $m_2$ located $l_1$ and $l_2$ away from the hinge, respectively. This beam is in static equilibrium with some linear springs and a torsional spring as shown in Fig$\mathrm{.}21\mathrm{.}8\mathrm{.}15.$ A small rotation $$ is applied to the beam. Find the equivalent torsional elastic constant

$56$

Introduction and Terminology for Vibrations

and moment of inertia of this system.

Are the linear springs in series or in parallel? Why?

Figure $21\mathrm{.}8\mathrm{.}15$: Rigid beam with concentrated masses connected by springs.