ZHOU Yu,WANG Li,LIU Zuoqiu.Analysis of algorithm stability and period elongation of time finite element[J].Acta Scientiarum Naturalium Universitatis Sunyatseni,2022,61(03):110-115.
ZHOU Yu,WANG Li,LIU Zuoqiu.Analysis of algorithm stability and period elongation of time finite element[J].Acta Scientiarum Naturalium Universitatis Sunyatseni,2022,61(03):110-115. DOI: 10.13471/j.cnki.acta.snus.2020B096.
Analysis of algorithm stability and period elongation of time finite element
The time finite element method is used to solve structural dynamics because of its strict prior error bounds and the characteristics of calculation error do not spreading over time. This paper mainly analyzes the algorithm stability and period elongation of the time finite element method. The stability of the algorithm is controlled by the spectral radius of the time finite element transfer matrix. When the spectral radius is less than 1, the time finite element has long-term stability. The period elongation is the relative error between the calculation period and the theoretical period. The larger the value, the higher the unpredictability of the long-term response. The analysis results show that for a damped system(damping ratio is greater than 0.05%), when the time step is less than the period, the spectral radius of the algorithm is less than 1. For undamped systems(or damping ratio is less than 0.05%), when the time step is less than 0.3 times of the period, the algorithm is conditionally stable. On the other hand, the period elongation of the algorithm is almost 0, which means that the calculation of time finite element will not cause period drift. Finally, the application of the time finite element to the dynamic analysis of the beam verifies the advantages of the algorithm in accuracy.
关键词
时间有限元稳定性分析周期延长率
Keywords
time finite elementanalysis of stabilityperiod elongation
references
杨昌棋,刘成群. 求解动力响应的时间有限元法[J]. 振动与冲击, 1987(4):73-79.
于开平,邹经湘. 时间域有限元法[J]. 力学进展, 1998,28(4):461-468.
HULBERT G M. Time finite element methods for structural dynamics [J]. Int J Numer Methods Eng, 1992,33:307-331.
LIX D, WIBERGN E. Structural dynamic analysis by a time-discontinuous Galerkin finite element method [J]. Int J Numer Methods Eng, 1996,39:2131-2152.
FRENCHD A, SCHAEFFER J W. Continuous finite element methods which preserve energy properties for nonlinear problems [J]. Appl Math Comput, 1991,39:271-295.
FRENCHD A, PETERSONT E. A continuous space-time finite element method for the wave equation [J]. Math Comput, 1996,65:491-506.