Abstract: This paper presents a ready-to-use formula for determining the number and approximate location of periodic orbits in second-order Lienard systems. As a result of the exact closed-form derived in [16], in which an ordinary differential equation (ODE) must be solved to determine the existence and location of periodic orbits for general non-conservative oscillators, a homotopy functional is defined for Lienard-type systems. This provides a closed-form and ready-to-use polynomial formula with roots as an approximation of the periodic orbit's amplitude. In addition, some examples are analyzed, along with conclusions and future plans.
Andrés García, "On the Homotopy-First Integral Method for Non-conservative Oscillators," Equations, vol. 4, pp. 17-23, 2024, DOI:10.37394/232021.2024.4.3
Andrés García. On the Homotopy-First Integral Method for Non-conservative Oscillators.
Equations. 2024;4:17-23. 10.37394/232021.2024.4.3