I am trying to check natural frequency of a torsional balance. Basically the core of this torsional balance is a torsional spring(pivot) with rotational stiffness of 0.048 Nm/degree. And there will be rotatable arms rotating around the central axis of this torsional spring. Some masses will be mounted on the rotatable arms. I have attached a figure to illustrate.

However, if I conduct frequency analysis in Solidworks Simulation, it doesnt give me torsional spring option. If I conduct motion analysis, it gives me torsional spring option but seems that no frequency result is given.

How should I perform this solidworks simulation? Desperately need your help