The existence stability and approximate expressions of periodic solutions of strongly nonlinear nonautonomous systems with multi-degree-of-freedom

摘要

Based upon the conservation of average energy a theorem about the periodic solutions of strongly nonlinear nonautomous systems with multi-degree-of freedom is proved. This theorem can not only decide the existence and stability of the periodic solutions, but at the same time can also give their first-order and second-order approximate expressions.