摘要
The motion stability problem of continuous systems is usually treated by two methods; the normal mode approach and the global approach, including the Lyapunov direct method and the energy method. The former is equivalent to the latter only under the condition that the sets of normal modes are complete (individual case of completeness can be proved). During the past three decades, eonsidereble progress was made on the application of the Lyapunov direct method to continuous systems.
