Clutch with the torsional-dumper spring:

POG model of the torsional dumper spring:

Transformed POG model:

where:

See the paper:  R. Zanasi, A. Visconti, G. Sandoni, R. Morselli, "Dynamic Modeling and Control of a Car Transmission System'', 2001 IEEE/ASME International Conference on Advanced Intelligent Mechatronics - AIM'01, Como, vol. 1, pp. 416-421, 9-11 July 2001, ISBN: 0-7803-6737-5.