Abstract：A single degree-of-freedom (SDOF) semi-active on-off control suspension system with time-delay is studied in this paper. After the dimensionless form is deduced, the first-order approximately analytical solution is obtained by the averaging method. The comparison of the amplitude-frequency curves obtained by the analytical solution and the numerical one shows the correctness of the method and results in this paper. At last, the system stability is analyzed, and the instability condition and the critical time-delay are presented. The periodical change of stability with the time-delay is also illustrated.
2012, Vol. 31 
