Quasi-periodic responses can appear in a wide variety of nonlinear dynamical systems. To the best of our knowledge, it has been a tough job for years to solve quasi-periodic solutions, even by numerical algorithms. He...Quasi-periodic responses can appear in a wide variety of nonlinear dynamical systems. To the best of our knowledge, it has been a tough job for years to solve quasi-periodic solutions, even by numerical algorithms. Here in this paper, we will present effective and accurate algorithms for quasi-periodic solutions by improving Wilson-θ and Newmark-β methods, respectively. In both the two methods, routinely, the considered equations are rearranged in the form of incremental equilibrium equations with the coefficient matrixes being updated in each time step. In this study, the two methods are improved via a predictor-corrector algorithm without updating the coefficient matrixes, in which the predicted solution at one time point can be corrected to the true one at the next. Numerical examples show that, both the improved Wilson-θ and Newmark-β methods can provide much more accurate quasi-periodic solutions with a smaller amount of computational resources. With a simple way to adjust the convergence of the iterations, the improved methods can even solve some quasi-periodic systems effectively, for which the original methods cease to be valid.展开更多
文章着重研究了含分数阶微分算子的van der Pol方程的数值解法。首先,基于Adams离散提出了一种针对Caputo分数阶导数的离散格式;然后,进一步基于Newmark-β法构造了完整的逐步迭代格式;最后,通过Newton-Raphson迭代求得了非线性系统的...文章着重研究了含分数阶微分算子的van der Pol方程的数值解法。首先,基于Adams离散提出了一种针对Caputo分数阶导数的离散格式;然后,进一步基于Newmark-β法构造了完整的逐步迭代格式;最后,通过Newton-Raphson迭代求得了非线性系统的响应。在算例分析部分,讨论了分数阶次为0<α<1和1<α<2的van der Pol系统的数值响应。当α→1和α→2时,将所提算法和四阶Runge-Kutta法进行了对比。结果表明,所提数值方法对整数阶微分系统也同样适用。展开更多
文摘Quasi-periodic responses can appear in a wide variety of nonlinear dynamical systems. To the best of our knowledge, it has been a tough job for years to solve quasi-periodic solutions, even by numerical algorithms. Here in this paper, we will present effective and accurate algorithms for quasi-periodic solutions by improving Wilson-θ and Newmark-β methods, respectively. In both the two methods, routinely, the considered equations are rearranged in the form of incremental equilibrium equations with the coefficient matrixes being updated in each time step. In this study, the two methods are improved via a predictor-corrector algorithm without updating the coefficient matrixes, in which the predicted solution at one time point can be corrected to the true one at the next. Numerical examples show that, both the improved Wilson-θ and Newmark-β methods can provide much more accurate quasi-periodic solutions with a smaller amount of computational resources. With a simple way to adjust the convergence of the iterations, the improved methods can even solve some quasi-periodic systems effectively, for which the original methods cease to be valid.
文摘文章着重研究了含分数阶微分算子的van der Pol方程的数值解法。首先,基于Adams离散提出了一种针对Caputo分数阶导数的离散格式;然后,进一步基于Newmark-β法构造了完整的逐步迭代格式;最后,通过Newton-Raphson迭代求得了非线性系统的响应。在算例分析部分,讨论了分数阶次为0<α<1和1<α<2的van der Pol系统的数值响应。当α→1和α→2时,将所提算法和四阶Runge-Kutta法进行了对比。结果表明,所提数值方法对整数阶微分系统也同样适用。
