THE USE OF VIBRATION DAMPING INSERTS FOR INSTRUMENT HOUSINGS, PROTECTIVE COVERS AND FENCES IN ORDER TO REDUCE THEIR VIBRATION EXCITABILITY

In instrument-making and mechanical engineering, thin-walled metal structures (TMK) are widely used, which are used for the manufacture of instrument cases and cabinets for the placement of equipment. In addition, TMK is used for the manufacture of vehicle bodies, protective covers and fences

Remote leakage method in heat supply systems out flow

Abstract This paper describes the method of remote sensing of the existence or absence of leaks in functioning heat supply systems developed on the basis of the application of a two-alternative hypothesis. To achieve this goal, we proposed to apply a method for determining the location and volume of leaks, based on the use of energy equivalents. We proposed to check for leakage between static assessments of the state of heat supply systems according to data from a remote manometric survey, with the help of which a simultaneous poll of pressure sensors in the end nodes of the system in question is performed. In the event of sudden changes in the estimated system parameters, it is concluded that there is a leak. If the results of two neighboring evaluations are relatively stable, then a conclusion is made about the absence of leakage. The considered problems are based on mathematical models of flow distribution for a heat supply system. The results of a computational experiment are compared with the results of calculating the parameters in the system based on the results of gauge surveying.</jats:p

Numerical modeling methods for safety assessment at public facilities

Abstract The assessment of the protected evacuation of the population from the fire zone at social facilities in the service sector on the basis of numerical modeling methods has been carried out. The time of safe evacuation of people from the object on the basis of a basic mathematical model for monitoring fire hazards for a specific social object has been regulated. Correlations between the degree of heat and the fire duration have been recorded. Partial concentration of O2, CO2, CO, HCl, measures of smoke aerosol opacity from the fire duration using “Fogard” software package configured for simplified analytical model of human flow have been captured. On the basis of the developed mathematical model of fire development design solutions that provide a secure evacuation of the population from the object have been proposed. The calculation of the blockade duration of routes and passageways for sending people out of the fire zone was made using deterministic fire indicators has been performed.</jats:p

Numerical calculation of a statically indeterminate frame by the finite element method

AbstractA numerical calculation of a statically indeterminate frame with high rigidity elements with the computer program STAB12. EXE using the finite element method is performed. An example of generating the source data for the program STAB12. EXE with subsequent processing of the results of the calculations is given. The features of checking the balance of nodes, rods and the frame as a whole based on the use of values taking into account the signs on the diagrams of torques, longitudinal and transverse forces are described. According to the results of calculations, the computer shows the frame in a deformed state.</jats:p

Flexural strength of fiber reinforced concrete structures

Abstract The paper presents an analysis of dispersed reinforcement methods. Metal fibres have been used when conducting the experiment. It has been shown that the reinforcement of concrete with metal fibers can significantly increase crack resistance for structures made of fiber-reinforced concrete in comparison with similar reinforced concrete structures.It should be noted that blocking crack development and blocking the possibility of the main cracks formation is achieved in structures made of fiber-reinforced concrete due to a more uniform distribution of forces arising in concrete. The results of an experiment on the reaction of beams with dispersed reinforcement to a bending load have been presented. The calculation of stretched and bending element with dispersed and combined reinforcement has been performed. The calculation showed that the use of combined reinforcement in structures can increase their overall bearing capacity. The comparison of the calculation and experiment results has shown a showed good convergence.</jats:p