ABSTRACT
The stability criteria for conservative elastic systems are not appropriate for non-conservative ones. For conservative systems, the Euler – and Energy stability and the Lyapunov stability criteria are available. For non-conservative systems two new criteria may be applied: The Extra Energy Stability and Three Domain Stability criteria. The conventional static and dynamic stability criteria for conservative systems are set in contrast to the new stability criteria for both – conservative and non-conservative systems. The stability of massless conservative and non-conservative stability systems can be analyzed by means of linear methods. Conservative systems have non-trivial states of equilibrium, and static stability limits can be calculated by applying equilibrium conditions. The two criteria proposed by "Lyapunov" are crucial for investigating the stability of dynamically conservative stability systems. The fundamental system is described in the Introduction, can be calculated in most cases very easyly and the knowledge of the static stability is essential.
