Application of the Explicit Euler Method for Numerical Analysis of a Nonlinear Fractional Oscillation Equation

In this paper, a numerical analysis of the oscillation equation with a derivative of a fractional variable Riemann-Liouville order in the dissipative term, which is responsible for viscous friction, is carried out. Using the theory of finite-difference schemes, an explicit finite-difference scheme (Euler's method) was constructed on a uniform computational grid. For the first time, the issues of approximation, stability and convergence of the proposed explicit finite-difference scheme are considered. To compare the results, the Adams-Bashford-Moulton scheme was constructed as an experimental method. The theoretical results were confirmed using test examples, the computational accuracy of the method was evaluated, which is consistent with the theoretical one, and the simulation results were visualized. Using the example of a fractional Duffing oscillator, waveforms and phase trajectories, as well as its amplitude-frequency characteristics, were constructed using a finite-difference scheme. To identify chaotic regimes, the spectra of maximum Lyapunov exponents and Poincare points were constructed. It is shown that an explicit finite-difference scheme can be acceptable under the condition of a step of the computational grid.