Statistical-kinematic analysis and limit equilibrium of systems with unilateral constraints

Abstract A general mechanical system involving unilateral constraints is studied and contrasted to a system with bilateral constraints. Some far-reaching consequences of their fundamental dissimilarity are revealed and explained. In particular, it is demonstrated that in the course of loading, a system with unilateral constraints can convert into a stationary (non-working) plastic mechanism. In this case the conventional version of the limit equilibrium method will miss the corresponding value of the load parameter. Therefore, certain precautions must be taken when applying the method, especially, in computer-assisted analysis.