Papers by Keyword: Calculation

Abstract: The article presents a simulation model for determining the required area of easily removable structures to protect against progressive collapse. The simulation model allows you to calculate the area of easily removable structures depending on the input parameters, to obtain the dynamics of the change in the parameters of the combustible medium depending on the change in the properties of the combustible gases that are in the room.

Abstract: The presence of melting temperatures oscillatory and stepwise changes for hydrocarbons four homologous series is demonstrated and analyzed. The oscillating dependence is manifesteds on the principle of «even-odd» molecules with different deviations from linearity. According to the working hypothesis, this is due to the presence of the matter smallest structural unit in the cluster form of with a certain coordination number. The oscillation of melting temperatures in hydrocarbons series is explained by the fact that clustering can occur both at the site of the final carbon in the molecule and at other carbons in the molecule chain, and this fact depends on the «even-odd» effect. Based on the known values of melting temperatures in homologous series, the clusters probable structure is assumed. It is shown that graphs for the calculated values of equivalent lengths of these clusters correlate with corresponding graphs for hydrocarbons melting temperatures. An approximation formula has been developed to predict melting temperatures of hydrocarbons based on the values of the equivalent length and the cluster molecular weight, which operates with an approximation coefficient of 0.997 and a mean deviation of 4.2 K.

Abstract: The water temperature distribution and spatio-temporal variation law of the reservoir have a great influence on the water quality and ecological environment of the reservoir, and it is also an important temperature boundary condition for the design of concrete dam of hydropower station project, which is of great significance for the optimal design and operation of the reservoir. There are many factors affecting the water temperature of the reservoir, and it is difficult to predict the water temperature distribution accurately because of the lack of data and experience. In this paper, a numerical analysis model is established for the reservoir of a hydropower station on the Nam Ngum in Laos, and the water temperature of the reservoir is calculated and predicted, and the water temperature distribution in the reservoir and the water temperature distribution in front of the dam are analyzed and discussed. The results show that the solar shortwave radiation is the main factor affecting the temperature stratification of the reservoir. The stable low temperature layer of the reservoir is not obvious, but there is a tendency to form stratification. The research results can provide water temperature value for the design of concrete dam of the hydropower station and provide reference for the prediction of the water temperature of other similar reservoirs.

Abstract: The features of the structures of complex monolithic reinforced concrete structures are given, the necessity of their organizational and technological design to ensure quality, reduce the duration and safety of construction and installation works is substantiated. A fragment of the formwork for complex curvilinear beams is presented, where the permanent and temporary loads, the permitted steps of the main and secondary beams and remote scaffolds for the PERI and CRAMOS modular formwork systems, which are more common in RA, are calculated in detail.

Abstract: The resonant frequency and Q factor of the SiC microcantilever were theoretically analyzed and calculated based on the stereotyped basic theories of the cantilever beam, and the relationship between the vibration mode and structure geometries was also simulated. Modal analysis by means of finite element method was performed on millimeter-, micron-and nanoscale microcantilevers, and the results showed that the smaller the microstructure was, the higher the resonant frequency can be obtained. The Q factor can be extracted from hamonic spectra after modal analysis, and the amplitude of Q factor was about 10⁵. This paper shows that SiC epitaxial layers have great potential in microcantilevers.

Abstract: Computer simulation of vacancy clusters distribution by depth in molybdenum irradiated by alpha particles within Cascade probability method has been carried out. Cascade probability functions have been calculated taking into account energy losses for alpha particles in molybdenum and depending on number of interactions and depth of particles penetration. Microhardness comparison of calculations and modified experimental data show their satisfactory fit.

Abstract: In this work, the calculation algorithms of cascade and probability functions and vacancy nanoclusters concentration were developed and their calculations for various incident particles in silicon and iron were made.

Abstract: The design and calculation of prefabricated assembled reinforced concrete wall protection of cable well plays an important role in ensuring the smooth construction works of railway cable wells. In this paper, taking Ningqi railway route cable well as an example, the design and inspection of prefabricated reinforced concrete wall protection of railway cable wells are analyzed. The calculation includes strength checking and stability checking. Through those checking’s the prefabricated assembled reinforced concrete wall protection of cable well is ensured to meet the requirements of engineering and mechanical performance. The research results also provide some reference and guidance to similar railway cable wells engineering.

Abstract: The paper is devoted to the study of the nonlinearity of the output signal of the pressure sensor on the silicon on sapphire structure (SOS). The authors constructed a mathematical model of the strain-gauge and carried out numerical simulation by using the ANSYS 12.1 software. For comparative analysis, the problem was solved both in a geometrically nonlinear and in a geometrically linear formulation. To account for the elastic-plastic properties of the silver solder PSR72, the Prandtl diagram was used. As a result, the maximum stresses and deformations in the sapphire crystal, solder, and titanium membrane under which the design successfully works were determined, and also the nonlinearity of the output signal was estimated in depending of the applied pressure. According to calculations, the nonlinearity of the output signal is 11.3%. The received value is unacceptable for this type of sensor, and requires further tuning, which negatively affects the accuracy of the product and its cost.

Abstract: This paper was focused on analysis of deformation process in the chip root after milling of material C45. The aim of research was to evaluate the degree of deformation by using the method of oriented test lines. Experimental value of degree of deformation was compared to achieve in computer simulation of milling process in Deform software. The results from the chip root indicates of little differences between simulations and experimental obtained value of degree of deformation.