№2 2020
№2 2020

№2 2020

DOI: 10.37153/2618-9283-2020-2

№2 2020

Content

Research of Stability and Seismic Resistance of Non-Uniform Two-Layer Rods in Elastic Medium

Authors:    Hasanova T.J.    Tagiyeva Saida Abdulali   
Rubric:     Theoretical and experimental studies   

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Simulation considered after the main seismic impacts are removed from the structure, the two-layer rod, which is in an elastic environment, is subjected to periodic longitudinal forces. In the investigated work the Bubnov”s-Galerkin method was used, numerical calculations were made. The main area of dynamic instability is built and shown in the figure, where the dotted line marks the solution of a homogeneous problem.


Nanotehnologija the use of Aluminium-containing Raw Materials in the Petrochemical Industry to Produce High -performance Brick

Authors:    Abdrakhimov V    Аbdraкhimova Elena S.   
Rubric:     Theoretical and experimental studies   

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The reduction in the reserves of traditional natural raw materials makes us look for new ways to replace it with different types of waste. At the same time, the costs of exploration, construction and operation of quarries are excluded, and significant land plots are exempt from the impact of negative anthropogenic factors. The experience of advanced foreign countries has shown the technical feasibility of this direction and its application as a tool for protecting the natural environment from pollution. On the basis of inter-shale clay and high-alumina nanotehnologija raw materials petrochemical spent catalyst IM-2201 NovoKuibyshev petrochemical plant derived ceramic brick with high physicalmechanical properties without the use of traditional natural materials. Using nanotechnogenic petrochemicals – spent catalyst IM-2201, containing more than 70% A12O3, a ceramic brick was obtained that corresponds to the M200 brand. It is possible to build load-bearing walls of the lower floors of high-rise buildings (15 floors or more) from M200 ceramic bricks. Innovative proposals for the use of industrial waste: interslant clay and spent catalyst in the production of high-strength ceramic earthquake-resistant bricks with high strength and frost resistance have been developed. The absolute advantage of using multi-tonnage waste of the spent IM-2201 catalyst and inter-shale clay for the waste of oil shale is 
the unloading of the environmental situation.


Development of base oscillation models and regulatory approaches to the calculation of critical structures for seismic impacts

Authors:    Vedyakov Ivan I.    Vladimir K. Vostrov   
Rubric:     Theoretical and experimental studies   

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Two principal approaches to generating calculated seismic impacts, proposed in the practice of earthquake - resistant construction, were used and  refined: for the construction site and for the structure. There are special, emergency and extreme seismic loads that create an emergency situation - the occurrence of a mode of beats or resonant vibrations, as well as self-oscillations (acute resonance), leading to a violation of either the operational properties or the load-bearing capacity of the structure. Proposals are formulated for the revision of the Russian standards of earthquake-resistant construction, based on three-level impact for responsible and unique structures using the proposed refined approaches to generating calculated seismic impacts.


Free Vibrations of Rigid Kinematic Support of Yu.D. Cherepinsky

Authors:    Tyapin A.G.   
Rubric:     Theoretical and experimental studies   

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The author derives the equation of free vibrations for kinematical rolling support of Yu.D.Cherepinsky. Both support and the surface below are assumed rigid. It is shown that Lagrange equation is similar to the equation of motion for rotational oscillator where the rotation centre, rotational inertia and stiffness are changing every moment, depending on displacements. This equation can be further simplified to the linear form with the error proportional to the second degree of displacements. This equation looks somewhat like the equation for classical pendulum, but effective length in our case is controlled by curvature radii of support and of the rolling surface, as well as by the position of vertical load relative to the centre of the support. Non-linear characteristic is soft. The main nonlinearity is in the inertial term, and not in the stiffness term.


Calculation of Wave Velocities in Segmented Pipelines with Flexible Joints

Authors:    Israilov M.    Smirnova L.N.   
Rubric:     Theoretical and experimental studies   

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Engineering methods for finding the average (averaged) velocity of propagation of longitudinal waves in pipelines with flexible joints are presented. By accurate analysis of the problem of oscillations of a one dimensional periodically inhomogeneous structure it is shown that the results of engineering approaches for rod velocity are the first or long-wave asymptotic approximation which valid when the period of external influence (the length of the seismic wave) significantly exceeds the size of the periodicity cell of the pipeline (the length of the pipe with a joint). Thus, it is established that when this condition is met, the problem of pipeline dynamics with joints is reduced to a much simpler problem of vibrations of a homogeneous pipeline, the velocity of wave propagation in which is equal to the found average value.
Numerical examples are given that demonstrate a significant (sometimes by an order of magnitude) decreasing of the rod velocity in the presence of flexible joints.