Currently the finite-element method (FEM) is considered as the most promising analysis tool among the existing methods of analysis which are usually based on the continuum mechanics approach, but accuracy of the FEM solutions for nonlinear problems of solid mechanics can be hardly guaranteed and the computing cost is still prohibitive. To overcome such a drawback of the nonlinear FEM including their application to reinforced concrete folded plate structures, this paper presents the application of the harmonic coupled finite-strip method (HCFSM) to structure stability analysis. The theoretical stress-strain relations of various concrete strength classes and reinforcement, knowing only the minimum number of mechanical material parameters that come from standard test procedures, are determined from the rheological-dynamical analogy (RDA). As an illustrative example, a feasible reinforced concrete folded plate structure is analysed in detail. The ultimate resistance of two characteristic cross sections of a folded plate structure is calculated using working diagrams of concrete and steel according to Eurocode 2 and according to the RDA. Diagrams of interaction N u-M u are drawn for several combinations of material working diagrams and are mutually compared.