Powierzchnie graniczne dla modelu sprężysto-plastycznego pręta przy uwzględnieniu zmian geometrii

The paper is concerned with the influence of geometric effects on limit surfaces. An appropriate perfectly elastic-plastic structural model is chosen for discussion of the problem, and some features of this influence on the behaviour of the structure are demonstrated. Stabilizing geometric effects (with Maier-Drucker's stability condition satisfied) cause an increase of the convexity of limit surfaces, locally passive processes occur in the course of simple loadings, an increase of the maximal load carrying capacity is observed. If destabilizing geometric effects are present, the concave limit surfaces are formed; this, as a rule, leads to unstable behaviour and decreas of the maximal load carrying capacity of the structure.