ABSTRACT
This phenomenon, called strain-softenina, represents a violation of Drucker's (1988) stability postulate: σ έ > 0 and therefore makes the classical theory of plasticity inap plicable .
The consequences of this violation were investigated by Maier et al. (1966, 1971, 1973) who showed that, even in the absence of geometric instability effects, the following phe nomena may occur:
- loss of stability, in controlled load conditions, - loss of stability, in controlled displacement
conditions (snap-back), - bifurcation of the equilibrium path, - loss of uniqueness in the incremental elasto-plastic
response, - pathological dependence of the results on the type of mesh used in the numerical analysis.
