scholarly journals Modeling of Stress-Strain State in Connection Resource Defines of Volumetric Hydraulic Drive

Author(s):  
Pavel A. Ionov ◽  
Petr V. Senin ◽  
Aleksey V. Stolyarov

Introduction. The article explores the stress-strain state of a distribution pair of aggregates of a volumetric hydraulic drive and the search for ways to increase its durability. Materials and Methods. In the process of studying, the generally accepted principles of the theories of friction, reliability, elasticity, mechanisms and machines, and mathematical modeling were used. To simulate the stress-strain state, an engineering analysis system ANSYS was used. Distribution pairs of hydraulic pumps 313.3.112, GST-112 and Sauer Danfoss 90R075 were chosen as objects of study. Results. As a result of the study there were obtained values of the real contact stresses and long-term current stress on the distribution of pairs of units of volumetric hydraulic drive: the 313.3.112 hydraulic pump is 26,93 MPa; for GTS-112 water pump is of 22.21 MPa for the Sauer Danfoss 90R075 hydraulic pump is 27,12 MPa. It is revealed that the area located on the discharge side is a subject to the greatest loads. This is the cause of one-sided wear of spherical surfaces, which is quite common in units decommissioned. The values of contact stresses in the joints hardened by the method of electric spark machining are on average 1.4 and 9.4 % lower than in not unhardened. In the process of electric spark machining there is a redistribution of stresses on the surface that leads to a decrease of the operating load in the connections. Conclusions. The study allowed modelling the stress-strain state in new and hardened distribution pairs of volumetric hydraulic drive units under operating conditions and suggesting ways to increase its durability. It was established that to increase the wear resistance of a resolving compound and the durability of the volumetric hydraulic drive aggregates, it is necessary to ensure that in distribution pairs the maximum bearing capacity is greater than the maximum long-term operating load in these connections. To solve this problem, it is proposed to create coatings with high tribotechnical properties by the method of electricspark machining. Keywords: resource-limiting compound, volumetric hydraulic drive, modeling, finite element method, bearing capacity, operating load, wear resistance, electrospark machining For citation: Ionov P. A., Senin P. V., Stolyarov A. V. Modeling of Stress-Strain State in Connection Resource Defines of Volumetric Hydraulic Drive. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):537–551. DOI: https://doi.org/10.15507/0236-2910.028.201804.537-551 Acknowledgements: The study was conducted with the financial support of the Ministry of Education and Science of the Russian Federation (state task, direction: development of competencies) project № 11.3416.2017/4.6 “Development of technologies and tools to improve the durability of parts, assemblies, machines and equipment by creating nanostructured coatings sources of concentrated energy”.

Vestnik MGSU ◽  
2021 ◽  
pp. 463-472
Author(s):  
Zaven G. Ter-Martirosyan ◽  
Armen Z. Ter-Martirosyan ◽  
Ahmad Othman

Introduction. In case of brief exposure to static loads or dynamic loads, in conditions of absence of drainage, distribution of total stresses between the skeleton of soil and pore gas-containing water should be taken in account. The situation of the stress-strain state of the base is further complicated when we consider the degree of water-saturation of soil of the foundation (0.8 < Sr ≤ 1). The aim of the study is to pose and solve problem of the stress-strain state of a water-saturated soil massif, Including settlement and bearing capacity of a water-saturated base of a foundation of finite width, depending on the degree of water saturation of soils, taking into account the linear and nonlinear properties of the skeleton of soil and the compressibility of pore gas-containing water. Materials and methods. Henckyʼs system of physical equations are used as a calculation model to describe the relationship between deformation and stresses of soil, which takes into account the influence of the average stress on the deformation and strength properties of the soil. This system allows us to represent the linear deformation of the soil as the sum of the volumetric and shear components of the soil of this deformation. In addition allows us too to determine the deformation of the layer of soil, as part of the compressible thickness of the base of foundation with finite width under conditions of free deformations. Results. Depending on the linear and nonlinear deformation parameters, the settlement can be developed with a damped curve (S – p) and stabilize, and can be developed with a non-damped curve (S – p) and moved to the stage of progressive settlement. Conclusions. Solutions have been made for cases when the water-saturation of the base soils changes in the range of 0.8 to 1.0. It is shown that the settlement and bearing capacity of a water-saturated base significantly depends on the degree of water saturation of soils.


2021 ◽  
Vol 2131 (3) ◽  
pp. 032095
Author(s):  
M V Ariskin ◽  
D O Martyshkin ◽  
I V Vanin

Abstract Design models of single-component and three-component samples were developed on glued fiberglass washers in order to investigate the stress-strain state (SF) of the elements of joints of wooden structures. The picture and the nature of the actual stressed-deformed state of the wooden element with glued washers are obtained. Quite high bearing capacity of wooden structures connection is shown.


2020 ◽  
pp. 28-36
Author(s):  
Volodymyr Sedin ◽  
Vladyslav Kovba ◽  
Yurii Volnianskyi ◽  
Kateryna Bikus

A full-scale experiment was conducted to study the operation of a multi-helix screw pile under static pressing and pulling load in dusty clay soil. Based on the full-scale test of a multi-helix screw pile under static loading in dusty clay soil, numerical modeling of the stress-strain state of the base of the multi-helix screw pile was performed. Multi-helix screw piles are actively used all over the world, and have also become widespread in Ukraine. Foundations made of multi-helix screw piles are often used for industrial construction as well as the foundations of low-rise buildings and structures. Despite the growing demand for the use of multi-helix screw piles in modern construction, there is no official document calculating the features of their design and bearing capacity of a multi-helix screw pile. This poses a number of new tasks for engineers and geotechnical: a) development of new modern calculation methods; b) development and use of modern normative documents and recommendations for the calculation of foundations from multi-helix screw piles in various soil conditions; с) use of computer-aided design systems for calculation of complex geotechnical tasks; d) development of calculation models that will take into account nonlinear models of deformation of materials and soil base. Foundations made of multi-helix screw piles are a promising direction in the field of foundation construction due to the reduction of the duration of the foundation and its economic. This requires the development of regulations with recommendations for the calculation and use of multi-helix screw piles in the field of foundation construction, development of modern calculation models for the calculation of bearing capacity and settling of multi-helix screw piles in different geological conditions. Based on the results of the field study of the work of multi-helix screw piles in clay soils, numerical modeling of the stress-strain state of the base of the multi-turn pile was performed, and their results were compared.


Author(s):  
E M Babich ◽  
S S Gomon

Existing norms of design for wooden constructions valid in different countries including Ukraine entirely disregard the effect of low-cycle repeated loadings during the operation of buildings and structures. The article deals with development of the bearing capacity computation of the bending elements manufactured from solid and glue-laminated wood exposed to repeated loadings in accordance with the deformation model.Equilibrium equations for computing the bending element made of wood after being exposed to repeated loadings are presented in the article. The deformation method is proposed for the computation of the rectangular wooden beams manufactured from solid and glued laminated wood with allowance for the occurrence of folds in the compression zone.The results of the research allow designing the solid and glue-laminated wooden constructions taking into consideration the possibilities of the material and peculiar features of the performance of the element, which in turn will allow choosing the cross-section of the elements of building structures more economically.On the basis of the study of the process of layer deformation by section height and the determination of the characteristics of the stress-strain state of these layers under the effect of repeated loading, it is possible to fulfill more accurate computation of the elements manufactured from wood at different stages of the stress-strain state through destruction.


2019 ◽  
Vol 138 ◽  
pp. 01016
Author(s):  
Yurii Tryapitsin ◽  
Viktor Pakhomov ◽  
Sergei Voinov

It is offered an algorithm for analysis and regulation of the stress-strain state of building constructions and soils of the foundations of structures at designing, building and exploitation, at setting of the mode of exploitation for providing of the required level of reliability, when tensions in them differ from calculation values. Possible options for secured or unsecured reliability are considered. The algorithm consists in determining the necessary decrease in the design stresses or increase the bearing capacity of structure. Offered algorithm is an estimation of necessary displacement of density of distribution of current tension or density of distribution of bearing strength for the achievement of the required level of reliability of the constructions and soil of base of the structure. Further research will be devoted to the consideration of case with unsecured reliability, for which it is necessary to assess the necessary displacement of the distribution density of the existing stresses or the distribution density of the bearing capacity to achieve the required level of reliability of the building constructions and soil of base of the structure.


2019 ◽  
Vol 97 ◽  
pp. 04032
Author(s):  
Nikolay Trekin ◽  
Dmitrii Pekin

The analysis of various regulatory methods for calculating reinforced concrete slabs for pushing and comparing with experiment results is made. The tested sample, measuring equipment and test bench are described. Sizes and materials for experimental prototype were chosen by existing beamless and capless slabs of monolithic reinforced concrete superstructures with column grid from 8×8 to 9×9 m. Experimental research results of reinforcing concrete plate structure are presented for study purpose of stress-strain state when punching shear collapse occurring. Various aspects and observations obtained during the test are given. The comparison of the tested slab fragment with the complete response of slab structure is performed. Analysis of tested sample stress-strain state and punching bearing capacity calculations results in according to existing regular standards were made. Main criterias of punching shear collapse were determined and new procedure for punching calculation of RC concrete slabs was offered basing on significantly new approach in punching bearing capacity defining.


2020 ◽  
Vol 17 (1) ◽  
pp. 199-210
Author(s):  
Anton Egorov ◽  
Vitaly Egorov

PurposeThe purpose of this paper is to expand possibilities of stability computing method when performing a dynamic analysis of bar- or rod-shaped elements for actual structures.Design/methodology/approachThe methodology is based on the changes of stress–strain state of the bar-shaped elements at the moment of buckling. The proposed method is based on three assumptions. Firstly, the spatial stress–strain state is determined in the bar. Secondly, technological deviations inherent in real structures are introduced into the bar. Thirdly, mechanical behaviour of the bar is investigated in the mode of real time, which makes it possible to take into account wave deformation processes in the bar. To implement the suggested method of analysis, LS-DYNA package was selected in a dynamic formulation using solid finite elements.FindingsValidity of the proposed method is shown by an example of dynamic stability analysis of a steel flat thin bar with two types of loads: short-time and long-term axial compressions. Comparison of the results showed different nature of the mechanical behaviour of the bar: wave processes are observed under short-time loading, and continuous monotone ones are stated under long-term loads.Practical implicationsResearch results are applicable in the rocket and space industry.Originality/valueA new computer-based methodology for dynamic analysis of heterogeneous elastic-plastic bar-, rod-shaped structures under shock axial compressive loads is proposed.


1981 ◽  
Vol 15 (6) ◽  
pp. 360-365 ◽  
Author(s):  
I. F. Blinov ◽  
E. M. Mirzak ◽  
Yu. P. Shaikin

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