Про коефіцієнт динамічності нелінійного осцилятора

Nonlinear oscillations caused by the initial deviation of the oscillator from the equilibrium position or the initial velocity given to it in this position are considered. It is assumed that the restoring force is proportional to the sine of the displacement of the oscillatory system. There are two variants of the sine: trigonometric and hyperbolic. In the first variant, the power characteristic of the oscillator is soft, and in the second, it is rigid. A theorem on the coefficient of dynamism of a nonlinear oscillatory system with one degree of freedom is formulated and proved by a geometric method, according to which the dynamic coefficient is less than two for a rigid power characteristic of the system and more than two for a soft characteristic. It is shown that, in contrast to linear systems, in general, the dynamic coefficient of a nonlinear system depends on the magnitude of the instantaneously applied constant force, but the above inequalities are satisfied. Examples of calculations are presented, confirm the theorem.