A localized Fourier collocation method is proposed for solving certain types of elliptic boundary value problems.The method first discretizes the entire domain into a set of overlapping small subdomains,and then in ea...A localized Fourier collocation method is proposed for solving certain types of elliptic boundary value problems.The method first discretizes the entire domain into a set of overlapping small subdomains,and then in each of the subdomains,the unknown functions and their derivatives are approximated using the pseudo-spectral Fourier collocation method.The key idea of the present method is to combine the merits of the quick convergence of the pseudo-spectral method and the high sparsity of the localized discretization technique to yield a new framework that may be suitable for large-scale simulations.The present method can be viewed as a competitive alternative for solving numerically large-scale boundary value problems with complex-shape geometries.Preliminary numerical experiments involving Poisson,Helmholtz,and modified-Helmholtz equations in both two and three dimensions are presented to demonstrate the accuracy and efficiency of the proposed method.展开更多
采用基于改进傅里叶级数的方法(Improved Fourier Series Method,简称IFSM)对弹性支撑边界条件下多跨距变轴颈推进轴系进行横向自由振动分析。首先推导带集中质量点的均匀梁横向自由振动微分方程;其次应用IFSM导出轴系的质量与刚度矩阵...采用基于改进傅里叶级数的方法(Improved Fourier Series Method,简称IFSM)对弹性支撑边界条件下多跨距变轴颈推进轴系进行横向自由振动分析。首先推导带集中质量点的均匀梁横向自由振动微分方程;其次应用IFSM导出轴系的质量与刚度矩阵,通过标准的特征值分解得到轴系固有频率及振型。在改进傅里叶级数方法中,位移函数被表示为一个傅里叶余弦级数展开与一个辅助的多项式函数的叠加,解决弹性边界的不连续性问题。通过数值仿真分析计算,分析中间连接法兰的刚度影响,验证分析方法的正确性与有效性。展开更多
基金The work described in this paper was supported by the National Natural Science Foundation of China (Nos.11872220,12111530006)the Natural Science Foundation of Shandong Province of China (No.ZR2021JQ02)the Russian Foundation for Basic Research(No.21-51-53014).
文摘A localized Fourier collocation method is proposed for solving certain types of elliptic boundary value problems.The method first discretizes the entire domain into a set of overlapping small subdomains,and then in each of the subdomains,the unknown functions and their derivatives are approximated using the pseudo-spectral Fourier collocation method.The key idea of the present method is to combine the merits of the quick convergence of the pseudo-spectral method and the high sparsity of the localized discretization technique to yield a new framework that may be suitable for large-scale simulations.The present method can be viewed as a competitive alternative for solving numerically large-scale boundary value problems with complex-shape geometries.Preliminary numerical experiments involving Poisson,Helmholtz,and modified-Helmholtz equations in both two and three dimensions are presented to demonstrate the accuracy and efficiency of the proposed method.
文摘采用基于改进傅里叶级数的方法(Improved Fourier Series Method,简称IFSM)对弹性支撑边界条件下多跨距变轴颈推进轴系进行横向自由振动分析。首先推导带集中质量点的均匀梁横向自由振动微分方程;其次应用IFSM导出轴系的质量与刚度矩阵,通过标准的特征值分解得到轴系固有频率及振型。在改进傅里叶级数方法中,位移函数被表示为一个傅里叶余弦级数展开与一个辅助的多项式函数的叠加,解决弹性边界的不连续性问题。通过数值仿真分析计算,分析中间连接法兰的刚度影响,验证分析方法的正确性与有效性。
