The problem of lateral buckling of a free-supported wooden strip with a constant narrow cross-section loaded with concentrated force in the middle of the span is considered. In the study of lateral buckling of the beam was used energy method. For the case of load application in the center of gravity, the problem is reduced to a generalized secular equation. The dependence between the value of the critical force and the position of the point of application of the load is obtained. A linear approximating function is chosen for this dependence. The results obtained by the authors are compared with the analytical solution using Bessel functions and the numerical iterative method.

Keywords: thermal conductivity, finite element method, the steady-state temperature field, radiation-heat shield, thick-walled cylinders

The concept of “partial failure” used in practice is analyzed as a state in which the possibility of continuing the operation of a technical device remains. It is argued that partial failures are widespread in the operation of technology, but unlike full failures, under which the continuation of work becomes impossible in any mode, not fully understood. A number of reliability indicators are proposed that take into account the specifics of partial failures and the possibility of continuing work when they occur. Attention is drawn to the fact that the decision to continue the operation of the device in the presence of a partial failure is associated with risks. The essence of the risks lies in the possibility of receiving damage in the form of further deterioration of the technical condition of the partially failed device. However, in many cases such a risk may be justified. The task of deciding on the continuation of the operation, in the conditions of a partial failure is a complex task of system analysis. Its solution will require the use of complex models compiled using modern methods of mathematical descriptions and research.

Keywords: partial failure, reliability theory, reliability indicators with partial failure, risks of continued operation, making decisions on continuation of operation

This paper proposes a method for detecting damage truss rod cantilever structure on the basis of new information sign "Express - distinguishing between" damage. It is based on the analysis of the phase diagrams for modeling its transient oscillations. Produced comparison of various parameters damped oscillations truss rod design for the structure without damage and corruption. Processed and analyzed the frequency response based on them phase diagrams. To analyze the response considered in the frequency range from 0 to 100 Hz. An analysis of the phase diagrams in different frequency regions design is presented as an information sign "Express - distinction" of having damage to the truss.

Keywords: Truss rod design, damage, finite element modeling, information sign, transient fluctuations of the amplitude-frequency analysis, phase diagrams

The problem of temperature stresses in revetments of concrete plates taking in the account various conditions of temperature impact is considered. Contact conditions for various friction coefficient are considered. The simulation is made using finite element method in Ansys © software. The examples of exact simulations for stress fields are given for different parameters of problem

Keywords: temperature stresses, concrete plate, finite element method