Dynamic stability of structural systems subjected to base excitation

The design of civil structures to assure stability is generally carried out within the framework of static stability analysis, even when the expected excitation scenario involves dynamic response. We explore the issues of dynamic stability of inelastic systems subject to base motion by examining a single degree-of-freedom model problem. This paper gives a general overview of the dynamic stability problem. The particular phenomena addressed include the connection between static and dynamic stability, parametric resonance, inelastic stability of systems subjected to impulse energy, and inelastic stability of systems that experience damage associated with cumulative energy dissipation and extreme distortion. We conclude that dynamic stability of structures is as much an issue of serviceability as it is strength. The simple systems explored in this paper should shed some light on the general problem of dynamic stability of structures subjected to earthquake ground motions.