周期荷载作用下几何缺陷对拱动力性能的影响

he effects of dynamic stability of arch with geometrical imperfection on periodic load were analysis in this paper. First, the coordinate deviations of finite element nodes were taken as random variable, through which the conditional covariance matrix was set up, and the distribution shapes and imperfection amplitude variance of geometrical imperfection were obtained by the decomposition of the matrix. When considering the stability behavior of structure on dynamic load, the motion stability equation that reflecting the long-term dynamic behavior from the stability principle of Lyapunov sense was set up, and the Lyapunov exponent is calculated by this equation. The dynamic stability behaviors of geometrical imperfect arch and perfect arch are compared, and the effects of dynamic stability of arch structure on the frequencies of the periodic load and the amplitude of the geometrical imperfection were researched. The results display that the dynamic stability is very sensitive to the geometrical imperfection that the distribution shape is similar to the static buckling mode, and there exist dynamic buckling areas on the frequencies of periodic excitation.