Ideal Failure Models of Structures for Analysis by FEM and AFEM

This paper substantiated the need for the notion of ideal failure model of structure to be introduced when the Finite Element Method (FEM) and Additional Finite Element Method (AFEM) are used for nonlinear analysis at limit states. The criterion of collapse of the system ought to be determined for such analysis. An ideal failure model is suggested for description of structure at limit state; it is a design diagram of this structure at the state of ultimate equilibrium (ultimate limit state), i.e. at the moment previous to collapse. The point is that the initial design diagram ought to change step-by-step loading in accordance with nonlinear properties manifesting as the ultimate limit state is reached. As a result the initial design diagram transforms into an ideal failure model of the considered structure.