Approximate analytical solution in slow-fast system based on modified multi-scale method  

作　　者：Xianghong LI Jianhua TANG Yanli WANG Yongjun SHEN 

机构地区：[1]Department of Mathematics and Physics,Shijiazhuang Tiedao University,Shijiazhuang 050043,China [2]Department of Mechanical Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China

出　　处：《Applied Mathematics and Mechanics(English Edition)》2020年第4期605-622,共18页应用数学和力学（英文版）

基　　金：the National Natural Science Foundation of China(Nos.11672191,11772206,and U1934201);the Hundred Excellent Innovative Talents Support Program in Hebei University(No.SLRC2017053)。

摘　　要：A simple,yet accurate modi?ed multi-scale method(MMSM)for an approximately analytical solution in nonlinear oscillators with two time scales under forced harmonic excitation is proposed.This method depends on the classical multi-scale method(MSM)and the method of variation of parameters.Assuming that the forced excitation is a constant,one could easily obtain the approximate analytical solution of the simpli?ed system based on the traditional MSM.Then,this solution for the oscillator under forced harmonic excitation could be established after replacing the harmonic excitation by the constant excitation.To certify the correctness and precision of the proposed analytical method,the van der Pol system with two scales subject to slowly periodic excitation is investigated;this system presents rich dynamical phenomena such as spiking(SP),spiking-quiescence(SP-QS),and quiescence(QS)responses.The approximate analytical expressions of the three types of responses are given by the MMSM,and it can be found that the precision of the new analytical method is higher than that of the classical MSM and better than that of the harmonic balance method(HBM).The results obtained by the present method are considerably better than those obtained by traditional methods,quantitatively and qualitatively,particularly when the excitation frequency is far less than the natural frequency of the system.

关 键 词：modified multi-scale method(MMSM) slow-fast system multi-scale method(MSM) van der Pol system 

分 类 号：O241.8[理学—计算数学]