scholarly journals METHODS DEVELOPMENT OF STRENGTH AND RELIABILITY ANALYSIS OF ROLLING-STOCK BEARING STRUCTURE USING MATHEMATICAL MODELING METHODS

2020 ◽  
Vol 2020 (3) ◽  
pp. 29-37
Author(s):  
Vladimir Kobishchanov ◽  
Dmitriy Antipin ◽  
Dmitriy Rasin ◽  
Marina Manueva
Keyword(s):  
Mathematical Modeling ◽  
Finite Element ◽  
Fatigue Life ◽  
Strain State ◽  
Rolling Stock ◽  
Finite Element Models ◽  
Stress Strain ◽  
Stress Strain State ◽  
Bearing Structure ◽  
Pivot Joint

The purpose of the work is a procedure formation for the analysis of strength and reliability of rolling-stock bearing structure using methods of mathematical modeling. Its appraisal is shown by the example of improvements in a universal gondola car bearing structure. The procedure offered is formed by a mathematical modeling of bearing structure dynamic loading in the rolling-stock operation including shunting movement encounters. At the first stage of the procedure the dynamic computer simulations of a rail crew movement on way roughness are under development. As a result of modeling there are defined dynamic loads influencing a bearing structure in operation. The analysis of the stress-strain state of the bearing structure is carried out on the basis of detailed shell finite element models. The computation is carried out in a dynamic position through the method of the direct integration of nodal-relocation equations. The estimate of bearing structures fatigue life in a pivot area was carried out on the basis of the linear hypothesis of fatigue damages summation, the power approximation of a material fatigue curve and scheming dynamic stresses affecting the structure through the method of complete cycles. Within the limits of the procedure the history of loading was presented as a step function. On the basis of the results of a stress-strain state in the bearing structure of a gondola car body in a static and dynamic location there is carried out the analysis of fatigue life in a pivot area of the gondola car and the conclusions were drawn regarding crack-like defect occurrence in a center plate arrangement of a frame. There are offered three versions for updating the pivot joint of a gondola car with the purpose of its fatigue life increase. For each version of updating there are developed corresponding detailed finite element models of the pivot area and on their basis the analysis of strength and fatigue life is performed. On the basis of computation results and taking into account the manufacturability of center plate arrangement production an efficient version is recommended for updating a pivot joint of a gondola car. The pivot joint modernization according to the version offered allowed decreasing maximum acting stresses in the pivot joint by 27% and increasing service life of the welded joint elements up to 29 years.

scholarly journals REGULARITIES OF THE LINING STRESS-STRAIN STATE DURING OF THE PYLON METRO STATION CONSTRUCTION

2021 ◽  
pp. 19-27
Author(s):  
D. O. BANNIKOV ◽  
V. P. KUPRII ◽  
D. YU. VOTCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Elements ◽  
Strain State ◽  
Finite Element Models ◽  
Bending Moments ◽  
Stress Strain ◽  
Normal Forces ◽  
Stress Strain State ◽  
Station Structure

Purpose. Perform numerical analysis of the station structure. Take into account in the process of mathematical modeling the process of construction of station tunnels of a three-vaulted station. Obtain the regularities of the stress-strain state of the linings, which is influenced by the processes of soil excavation and lining construction. Methodology. To achieve this goal, a series of numerical calculations of models of the deep contour interval metro pylon station was performed. Three finite-element models have been developed, which reflect the stages of construction of a three-vaulted pylon station. Numerical analysis was performed on the basis of the finite element method, implemented in the calculation complex Lira for Windows. Modeling of the stress-strain state of the station tunnel linings and the soil massif was performed using rectangular, universal quadrangular and triangular finite elements, which take into account the special properties of the soil massif. Station tunnel linings are modeled by means of rod finite elements. Findings. Isofields of the stress-strain state in finite-element models reflecting the stages of construction are obtained. The vertical displacements and horizontal stresses that are characteristic of a three-vaulted pylon station are analyzed. The analysis of horizontal stresses proved that at the stage of opening of the middle tunnel the scheme of pylon operation is rather disadvantageous. The analysis of bending moments and normal forces was also carried out and the asymmetry of their distribution was noted. Originality. Based on the obtained patterns of distribution of stress-strain state and force factors, it is proved that numerical analysis of the station structure during construction is necessary to take measures to prevent or reduce deformation of frames that are in unfavorable conditions. Practical value. In the course of research, the regularities of changes in stresses, displacements, bending moments and normal forces in the models of the pylon station, which reflect the sequence of its construction, were obtained.

scholarly journals ANALYSIS OF FEATURES OF APPLIED SOFTWARE “LIRA” IN CALCULATIONS OF NON-CIRCULAR TUNNEL LININGS

2019 ◽  
pp. 41-50
Author(s):  
V. P. KUPRIY ◽  
O. L. TIUTKIN ◽  
P. YE. ZAKHARCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Software Package ◽  
Strain State ◽  
Element Model ◽  
Finite Element Models ◽  
Stress Strain ◽  
Stress Strain State ◽  
The Finite Element Model

Purpose. The article examines the effect on the stress-strain state of the parameters of the finite-element model created in the “Lira” software package in a numerical analysis of non-circular outlined tunnels. Methodology To achieve this goal, the authors developed finite element models of the calotte part of the mine during the construction of a double track railway tunnel using “Lira” software. In each of the models in the “Lira” software package, the interaction zone with temporary fastening was sampled in a specific way. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. In the finite element models, the values of deformations and stresses in the horizontal and vertical axes, as well as the maximum values of the moments and longitudinal forces in the temporary fastening were obtained. A comparative analysis of the obtained values of the components of the stress-strain state with a change in the parameters of the finite element model was carried out. The graphs of the laws of these results from the discretization features of the two models were plotted. The third finite element model with a radial meshing in the zone of interaction of temporary support with the surrounding soil massif was investigated. Originality It has been established that in the numerical analysis of the SSS of a tunnel lining of a non-circular outline, its results substantially depend on the shape, size and configuration of the applied finite elements, on the size of the computational area of the soil massif, and also on the conditions for taking into account the actual (elastic or plastic) behavior of the soil massif.  Practical value. The features of discretization and the required dimensions of the computational area of the soil massif were determined when modeling the “lining – soil massif” system, which provide sufficient accuracy for calculating the parameters of the stress-strain state of the lining.

scholarly journals Elaboration of testing technique of flat slabs on punching shear strength using finite element modeling

2018 ◽  
Vol 196 ◽  
pp. 02048
Author(s):  
Valery Filatov ◽  
Zulfat Galyautdinov ◽  
Alexander Suvorov
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Strain State ◽  
Concrete Slabs ◽  
Finite Element Models ◽  
Bending Moments ◽  
Stress Strain ◽  
Stress Strain State ◽  
Reinforced Concrete Slabs

The results of researches on finite-element models of stress-strain state of flat reinforced concrete slabs of beamless frame under punching by columns of square and rectangular cross-section are presented. The purpose of the study was to develop a technique for testing samples plates for punching in the presence of bending moments in a column. The results of the study of deflections of reinforced concrete slabs, the distribution of bending moments in the punching zone of the plate under various loading schemes are presented. Variable parameter was the ratio of the sides of the column cross-section. Comparative analysis of studies results on finite element models has made it possible to choose the optimal variant of applying the load to the test samples, depending on the aspect ratio of rectangular section of column. Results of the conducted research will allow simulating the stress-strain state in the punching zone of natural reinforced concrete slabs of monolithic beamless frame during the test of samples.

scholarly journals Load simulation of a base station chassis of the mobile transport and overloading rope complex

2021 ◽  
Vol 7 (2) ◽  
pp. 166-175
Author(s):  
V.I. Tarichko ◽  
◽  
P.I. Shalupina ◽  
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Metal Structure ◽  
Base Station ◽  
Finite Element Models ◽  
Stress Strain ◽  
Grid Model ◽  
Stress Strain State ◽  
Load Simulation

The article deals with the issues of modeling the stress-strain state of a chassis designed to accommodate the equipment of a mobile transport and overloading rope complex. The main computational cases are determined. Geometric and computational finite element models are constructed, taking into account the features of the metal structure and suspension elements. The method of gluing elements of the grid model is applied. On the basis of the performed calculations, conclusions are drawn about the compliance of the developed structure with the requirements of strength and rigidity.

scholarly journals Stress-strain state of reinforced concrete structures of the LN-1 and LN-2 retaining walls of Zagorskaya PSPP taking into account the opening of interblock joints and the formation of secondary cracks

2021 ◽  
Vol 17 (4) ◽  
pp. 324-334
Author(s):  
Nartmir V. Khanov ◽  
Fedor A. Pashchenko
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Strain State ◽  
Retaining Walls ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Structures ◽  
Finite Element Models ◽  
Computational Studies ◽  
Stress Strain ◽  
Stress Strain State

Relevance. The lower retaining walls of the water intake of the Zagorskaya PSPP perform the important function of protecting the pressure water conduits from the collapse of the soil massif. Two of them (LN-2 and LN-3) were reinforced with anchor rods. Considering the long period of operation (more than 25 years), certain deviations in the work during examinations and field observations were revealed. So, on the front face of the walls, extended horizontal cracks were recorded (opening of horizontal interblock joints and the emergence of secondary oblique cracks on the front surface of the walls). To carry out computational studies of the stress-strain state of the downstream retaining walls was required. The purpose of the work was to determine the stress-strain state of the lower retaining walls of the water intake of the Zagorskaya PSPP taking into account the opening of interblock joints and the formation of secondary oblique cracks. Methods. Computational studies of the stress-strain state of retaining walls were carried out within the framework of the method of numerical modeling of reinforced concrete structures of hydraulic structures based on finite element models. In finite element models, structural features of retaining walls were reproduced, including anchor rods, horizontal interblock joints, actual reinforcement, secondary oblique cracks. Results. The stress-strain state of the retaining walls was obtained. The stresses in the longitudinal and transverse reinforcement were determined, including when the structure was changed due to anchor rods. In horizontally transverse reinforcement, tensile stresses exceeding the yield point are recorded. It took the development of measures to strengthen the lower retaining walls.

Incidence of the boundary condition between bone and soft tissue in a finite element model of a transfemoral amputee

2012 ◽  
Vol 36 (4) ◽  
pp. 405-414 ◽  
Author(s):  
Juan Fernando Ramírez ◽  
Jaime Andrés Vélez
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Soft Tissue ◽  
Lower Limb ◽  
Strain State ◽  
Soft Tissues ◽  
Finite Element Models ◽  
Residual Limb ◽  
Stress Strain ◽  
Stress Strain State

Background: Many finite element investigations have been made in the field of lower limb prosthetics; however, friction between bone and soft tissues as a boundary condition has not been considered. Objectives: To establish whether the change in the contact boundary condition between bone and soft tissues in a transfemoral amputee affects the stress-strain state on the residual limb. Study Design: Finite element analysis comparison. Methods: Finite element models of four transfemoral amputees were developed. In these models the socket, soft tissues and femur were included and two simulations were made for each model, in one of them the interaction between bone and soft tissues was defined as tied (there is no relative displacement between surfaces) and in the other it was defined as a friction boundary condition. Results: The von Mises stress and strain peaks are higher when the friction definition is used than for tied contact definition. The distribution pattern of stresses and strains also change when the contact definition varies from tied to friction. Conclusions: It was concluded that the friction between bone and soft tissues have a significant impact on the results of finite element models of lower limb prosthetic systems, and therefore in its predictive capabilities. Clinical relevance Understanding the bone-soft tissue interaction can lead to more realistic and accurate finite element models used to predict the stress-strain state in the residual limb of prosthetic users and therefore predict the occurrence of deep tissue injuries.

Finite Element Models of Disk Tools with Attachment Points on Triangular Prisms

2015 ◽  
Vol 770 ◽  
pp. 429-433 ◽  
Author(s):  
A.A. Khoreshok ◽  
L.E. Mametyev ◽  
A.Yu. Borisov ◽  
A.V. Vorobyov
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Finite Element Models ◽  
Stress Strain ◽  
Rock Face ◽  
Stress Strain State ◽  
Disk Tool

The paper presents simulation of the stress-strain state of various designs of disk tool attachment points on triangular prisms of radial bits of the roadheaders working body when cutting of coal and rock face.

scholarly journals Load simulation of a semi-trailer of the mobile transport and overloading rope complex

2021 ◽  
Vol 7 (1) ◽  
pp. 73-81
Author(s):  
V.I. Tarichko ◽  
◽  
P.I. Shalupina ◽  
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Metal Structure ◽  
Finite Element Models ◽  
Stress Strain ◽  
Grid Model ◽  
Stress Strain State ◽  
Load Simulation

The article deals with the issues of modeling the stress-strain state of a semi-trailer designed to accommodate the equipment of a mobile transport and overloading rope complex. The main computational cases are determined. Geometric and computational finite element models are constructed, taking into account the features of the metal structure and suspension elements. The method of gluing elements of the grid model is applied. On the basis of the performed calculations, conclusions are drawn about the compliance of the developed structure with the requirements of strength and rigidity.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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