5. Study of configuration stability

This section describes the approaches used to study instability phenomena. The approaches differ according to the type of model used (continuous or discrete). As the continuous approach is rather complex, only its broad outlines will be discussed. The study of stability will focus more on the discrete case.

In all cases, a stable equilibrium of the CPP is necessarily a minimum of the potential energy (figure 13 a), while an unstable equilibrium is either a maximum (figure 13 b) or a saddle point (figure 13 c), which may locally, at the...