ESTIMATION OF THE STRENGTH OF VERTICAL CYLINDRICAL LIQUID STORAGE TANKS WITH DENTS IN THE WALL

l a n b a t o r S u l e i m e n o v Doctor of Technical Sciences, Professor Department of Architecture*** N u r l a n Z h a n g a b a y Corresponding Author PhD, Associate Professor* E-mail: Nurlan.zhanabay777@mail.ru A k m a r a l U t e l b a y e v a Doctor of Chemical Sciences, Associate Professor Department of Chemistry*** M a s r a h A z r i f a n A z m i M u r a d PhD Doctor, Professor, Deputy Dean (Research and Graduate Studies) Universiti Putra Malaysia UPM Serdang, Selangor Darul Ehsan, Malaysia, 43400 A i b a r s h a D o s m a k a n b e t o v a PhD, Associate Professor Department of Mechanics and Mechanical Engineering Mukhtar Auezov South Kazakhstan University Tauke Khan ave., 5, Shyment, Republic of Kazakhstan, 160012 K h a s s e n A b s h e n o v PhD, Associate Professor** S v e t l a n a B u g a n o v a PhD, Associate Professor Department of Building Technologies, Infrastructure and Management International Education Corporation Ryskulbekova str., 28, Almaty, Republic of Kazakhstan, 050043 A r m a n M o l d a g a l i y e v PhD, Associate Professor** K u a n y s h I m a n a l i y e v PhD, Associate Professor Department of Architecture*** B o l a t D u i s s e n b e k o v PhD* *Department of Construction and Construction Materials*** **Department of Mechanics and Mechanical Engineering*** ***Mukhtar Auezov South Kazakhstan University Tauke Khan ave., 5, Shyment, Republic of Kazakhstan, 160012 A multi-level mathematical model was used to estimate the stressed-strained state of a cylindrical reservoir with a defect in the wall shape in the form of a dent; the concentration of stresses in the defect zone was studied. The proper choice of the mathematical model was verified; it has been shown that the engineering assessment of the stressed-strained state of the wall of a cylindrical tank with the variable thickness could employ ratios for a cylindrical shell with a constant wall thickness. The spread of values is 2‒10 %. This indicates the proper choice of the mathematical model, as well as the fact that it is possible, for an engineering assessment of the stressed-strained state of the wall of a cylindrical tank with variable thickness, to use the ratios for a cylindrical shell with a constant wall thickness. The stressed-strained state of the dent zone in the tank wall was numerically estimated, which proved the assumption of significant stress concentrations in the dent zone and indicated the determining effect on the concentration of stresses in the dent zone exerted by its geometric dimensions and its depth in particular. The concentration of stresses in the zone of dents in the tank wall was investigated in the ANSYS programming environment at different sizes of dents on the tank wall, for which two dimensionless parameters were introduced: the dimensionless radius of the dent and the dimensionless depth of the dent. Based on the results of a numerical study into the stressed-strained state of the dent zone in the tank wall, graphic dependences were derived of the stress concentration coefficient on the dimensionless depth of the dent for various values of the dimensionless radius of dents, which does not exceed 2 % of the indicator. Based on fitting the stress concentration curves on the dimensions of the dent and tank, a formula was derived for calculating the stress concentration coefficient as a function of the dimensionless radius ξ and the dimensionless depth ς of the dent. The resulting formula makes it possible, with known dimensionless parameters of the depth and radius of the dent, to determine the coefficients of stress concentration in the dented zone of the tank wall


Anna Kharchenko
National Transport University, Kyiv, Ukraine ORCID: https://orcid.org/0000-0001-8166-6389 This paper reports a study of the cement-concrete coating on bridges using FRP reinforcement. That has made it possible to design optimal structures by selecting the height for reinforcement arrangement in the layers of a roadbed in order to ensure strength characteristics.
An engineering method for calculating a hard roadbed with composite reinforcement has been devised, which makes it possible to take into consideration its work both in a joint package of the structure with a slab and separately -when it exfoliates from the slab of the bridge's span structure. Underlying this research are effort-determining methods, estimation dependences from the theory of bending layered structures, as well as dependences from elasticity theory to assess the strength of materials for a roadbed. The consideration of shear strains when designing slabs has helped establish that the deflections according to the devises method were 1.4 times larger than those in the classical approach.
The method was tested by a numerical experiment, which confirmed the need to use composite reinforcement in the upper layers of a road surface on bridges, which improves its durability by 1.2 times. The results of the numerical experiment indicate that the equivalent stresses in the lower layers of a free-moving roadbed were 2.91 MPa, and, when operating in a joint assembly with a slab, they took a negative value (-0.2 MPa).
Practical application of the devised calculation method makes it possible to determine the refined normal stresses in the layers of a roadbed, taking into consideration the characteristics of structure operation. Owing to this, additional opportunities open up for calculating the roadbeds of bridges whose design utilizes the most common types of span structures in the bridge industry.
Keywords: cement-concrete coating, roadbed, layered structures, composite materials, stressed-strained state. This paper reports the improved load-bearing structure of a hopper car for transporting pellets and hot sinter. In order to increase the strength of the load-bearing structure of a hopper car under the influence of high temperatures from the transported cargo, the use of cladding made of composite material has been proposed. This solution also contributes to a 5 % reduction in the wagon's tare compared to the prototype car.
The dynamic load on the load-bearing structure of a hopper car was determined. This study was carried out for the case where an empty wagon was moving over an irregularity between the rail joints. The calculations showed that the studied dynamics indicators did not exceed the permissible values. At the same time, the ride of a hopper car is rated as «excellent».
The main indicators of the strength of the carrying structure of a hopper car were determined taking into consideration the proposed improvement. That took into account the temperature effect exerted on the load-bearing structure of a hopper car by hot sinter. It was established that the maximum equivalent stresses occur in the zone of interaction of the girder beam with the pivot beam and are about 290 MPa. At the same time, stresses in the cladding of a hopper car are about 200 MPa, which is 12 % lower than those in a regular structure.
Modal analysis was carried out to determine the frequencies and shapes of the natural oscillations of the bearing structure of a hopper car with a composite cladding. The calculation results demonstrated that the first natural frequency exceeds 8 Hz. Therefore, the safety of the wagon is provided.
The coefficient of fatigue resistance of the load-bearing structure of a hopper car was calculated. It was established that its value is almost twice as high as the permissible one. That is, the resistance to fatigue of the supporting structure is provided.
The research reported here could contribute to ensuring the strength of the load-bearing structures of hopper cars, reducing the cost of maintenance, and increasing the efficiency of their operation.
Keywords: transportation mechanics, hopper car, load-bearing structure, composite material, dynamic load, strength, fatigue resistance. 13. Ibrahim, I. D., Jamiru, T., Sadiku, E. R., Kupolati  In this research, a numerical investigation has been conducted to analyze the dynamic load of the composite structure. The composite structure was solved and analyzed using the static structure tool. There is a physical model that has been imported and meshes have been done accordingly. Shear stress, von-mises stress, and total deformation are all considered as part of the analysis. Using finite elements to simulate the composite structure and response to the applied loads. Because dynamic loads were regularly applied, frequency response was examined. In this study after verification of this computer simulation with experimental results and the results showed it was confidence 95 %. This percentage confidence allows proceeding numerical analysis. Deformation of the entire structure has been computed and found to be 10 mm, which is the maximum amount of overall deformation that can be caused by the applied load, In the Y-axis, a dynamic load was applied. The imposed dynamic load has been studied numerically and interpreted in terms of shear stresses.
As a result of the maximum applied load, the maximum shear stress is 10 MPa. The complete composite construction was subjected to Von-Mises stress measurements. The structure's ability to withstand these stresses was determined by conducting a series of tests. The greatest von mises stress that can be applied in this study was 40 MPa. An investigation of how to react to vibration has already been carried out. In the numerical results, it was found that the reaction to the vibration was inconsistent. In terms of amplitude, the highest values may be found at 200 Hz, while the lowest values can be found at 20 Hz.
Keywords: ANSYS, FEM, Fractional corrosion, L-shape sandwich, USV, Vibration, Von-mises stresses, shear stresses, total deformation, vibration response. The industrial development of cities is the main cause of the destruction and degradation of natural resources around the world. Urbanization negatively affects the species composition of plants, the atmosphere and soil cover of areas of populated areas of large cities of the World. Tree plantations are the main mechanism for stabilizing the ecological situation in large cities and arid territories of the countries of the World.
In this regard, in order to obtain a large number of genetically identical plants using their micropropagation, it is necessary to automate the main stages of this technological process.
The result of the study is the creation of an adaptive phalanx gripper of a robotic complex for automating the technological process of handling operations. That will have a positive effect on solving the urgent problem of planting greenery in large cities and areas of arid territories not only in the Republic of Kazakhstan, but also in other countries of the World and represents a fundamentally new approach to solving the environmental problems of the Earth.
The article substantiates various options for structural-kinematic schemes of the robot gripper, taking into account the stochastic conditions of its interaction with the overloaded object. Mathematical methods have been created for the selection and justification of the geometric, structural-kinematic and dynamic parameters of grippers for overloading plant microshoots and their computer 3D models. Software has been developed for modeling the functioning of a remotely controlled physical prototype of a mobile robot with an adaptive gripper for reloading microshoots from a transport tank to a cargo tank.
Keywords: robot, adaptive gripper, Kalman coefficient, microshoot overload, plant micropropagation. It is known that the air suspension of vehicles, in which diaphragm-type air springs are used as an elastic element, do not provide the necessary vibration damping. The reason for this is that such air springs have a relatively large passive part. As a result, a relatively small mass of compressed air crosses through the throttle installed between the air spring and the additional reservoir. This mass of air contains thermal energy, into which the energy of vibrations, which enters through the walls of the additional reservoir into the environment, has turned. This is interpreted as vibration damping, which is insufficient due to the low air mass.
Therefore, hydraulic vibration dampers are installed parallel to the diaphragm air springs, which complicates and increases the cost of the vehicle. Increasing the damping properties of such air suspensions could eliminate these hydraulic vibration dampers, which would reduce costs and simplify operation.
An air suspension with an improved air spring has been proposed, which has an increased effective area and a reduced «passive» capacity, an empirical formula has been built to determine its damping coefficient, as well as an expression for the stiffness coefficient. Mathematical modeling of oscillations of vehicles with different designs of pneumatic springs was carried out in order to improve their damping. The mathematical model takes into account the change in the parameters of the air spring during vibrations. The study was carried out for the diesel train DL-02. Using mathematical modeling, the effectiveness of the air suspension with an improved air spring has been proven: its damping index reaches 0. На основі використання багаторівневої математичної моделі оцінено напружено-деформований стан циліндричного резервуару з дефектом форми стінки у вигляді вм'ятини та вивчено концентрацію напружень у зоні дефекту.