ABSTRACT
The theory of elastoplastic structures includes two fundamental assertions known as the static and kinematic theorems. While proving static and kinematic theorems, the virtual work equation is set up for a collapse mechanism. In the frame of conception of stepwise connections’ loss and recovery, generalized upon the multistep loading process, the limit state of an elastoplastic system means emergence of a collapse mechanism at some load. In analysis methods based on hypothesizing about the look of the collapse mechanism and testing the hypothesis by one means or another, the concept of assumed collapse mechanism is in use. The kinematic method is to construct a collection of assumed collapse mechanisms with one degree of freedom and select among them a mechanism that keeps equilibrium under the lowest load. To ensure the validity of solutions obtained by the kinematic method, it is supplemented by methodical instructions on construction of collapse mechanisms for structures of various types.
