scholarly journals Numerical Modeling of Stress-Strain State of a Deep Beam

2019 ◽  
Vol 221 ◽  
pp. 01032
Author(s):  
Nikita Mescheulov ◽  
Vladimir Barashkov

The article presents calculation results for model elastic problem of defining stress-strain state of a deep beam preformed in 3D and 2D statements with the use of ANSYS software package. Geometric relations are taken in the form of Cauchy equations. The purpose of the study is to assess error in the results obtained for the two statements and to draw a conclusion on the possibility of using 2D statement for the deep beam under study. Based on 3D statement calculation results one may observe a short area near the support surface of a deep beam with the maximum load across the entire thickness. In this area the concentration of maximum stress values and maximum linear and angular deformations in the structure material are observed. The area is located on the axis of symmetry of the deep beam near the inner edge of support surface. It is found that the stress intensity values obtained for the two statements have considerable differences in this area, for that reason 3D statement shall be used when performing calculations for the deep beam. This way of solving the problem is illustrative of stress-strain state parameters distribution across the thickness of the structure, which is necessary for its strength evaluation.

2018 ◽  
Vol 243 ◽  
pp. 00021
Author(s):  
Pavel Pisarev ◽  
Aleksandr Anoshkin ◽  
Vladislav Ashihmin

In this research we developed a technique for calculating the stress-strain state of a model construction from a thermoplastic composite material with an embedded piezoactuator. Numerical simulations of the model construction stress-strain state with different arrangement of piezoactuators: upper and middle,-were performed. Numerical simulations were carried out in a three-dimensional setting taking into account the complete technological scheme of laying and anisotropy of the properties of reinforcing layers. The results of numerical experiments revealed the areas of maximum stress. Recommendations for the MFC’s embedding into composite materials were formulated.


Author(s):  
Yifang Sun ◽  
А. А. Вендин

Fitting joints are widely used in aircraft structures, and they are responsible for the interconnection of important components. The stress-strain state analysis of the fitting joint must be carried out before the performance analysis of the fitting joint. With the help of 3D modeling software (CATIA) and finite element analysis software (ANSYS), the stress-strain state of each component in the fitting joint of outer wing section was calculated in this paper. In the CATIA, the solid model is simplified and segmented according to the size of the cross section and the height of the center of gravity of the model. In the ANSYS, the beam elements are used to replace the simplified segmented model to obtain the internal force distribution of the solid model and to determine the magnitude and change law of the stress applied to the end of the solid model. When calculating the force transmitted by the fastener, the pre-tightening force of the bolt and the interaction between the surfaces of the component are taken into account, so as to simulate the real force situation well. Therefore, it is a very feasible method to use the CATIA and ANSYS to obtain the stress-strain state of components in the fitting joint of center wing section and outer wing section.The results show that under the working conditions of the fitting joint (130Mpa), the fitting of outer wing section with center section has a maximum stress of 245.79Mpa and a maximum strain of 0.0035, the stringer of outer wing section has a maximum stress of 293.17Mpa and a maximum strain of 0.0047, the lower panel of outer wing section has a maximum stress of 289.53Mpa and a maximum strain of 0.0042. The connecting bolts (M8 and M6) have a maximum stress of 686.81Mpa and a maximum strain of 0.0063, which meets the design requirements. In addition, according to the analysis results of the stress-strain state of the fitting joint of outer wing section, the force distribution of the bolts in the fitting joint of outer wing section with center section was obtained in this paper. It has been confirmed that due to the different positions and force areas of the bolts, the force distribution between rows of bolts is uneven, and the first row of bolts has a more force.


2021 ◽  
Vol 22 (1) ◽  
pp. 36-42
Author(s):  
Andrey A. Chistyakov ◽  
Valery P. Timoshenko

In this work, the most rational schemes to designing the skin of a full-turning vertical empennage element (stabilator) have been studied. Skin designing schemes were chosen according to aero-spacecraft operating conditions in the re-entry trajectory. During designing process, the requirements for reusable structures of tourist-class aero-spacecrafts were taken into account, such as: maximum simplicity and endurance of the product. To determine the mechanical loads acting on the keel during its movement in the air, a numerical simulation of the aerodynamic flow-around the stabilator profile at 5 arbitrary points on the flight path was carried out. The parameters used for the analysis are: flight velocity, density and viscosity of the air. Of the 5 obtained fields of dynamic pressure acting on the stabilator, the field that creates the largest distributed load was used as the boundary condition for the analysis of the stress-strain state of the structure. The problem of mechanical loading of the stabilator was solved separately for each of the previously studied structural schemes of the skin. Based on the obtained calculation results the optimal skin structural scheme was chosen by comparing the displacements on the line connecting ribs.


2020 ◽  
Vol 18 (2) ◽  
pp. 68-81
Author(s):  
I. S. Bondar ◽  
M. Ya. Kvashnin ◽  
D. T. Aldekeeva

Beam spans are the most vulnerable elements of the bridge system, as they are exposed to direct effects of mobile load, environmental and climatic factors (temperature and humidity effects, including freezing and thawing, shrinkage, humidity, etc.). Appearance of defects of the structure is inevitable; the refore civil engineers face a topical problem of strengthening of damaged structures of bridges. The article discusses some results of calculated values and instrumental measurements of stress-strain state (SSS) of reinforced concrete beam span structures of railway overpass under operational load caused by different rolling stock units. The objective of this study is to control stress-strain state of railway overpass for identification and elimination of defects at early stages. The calculation results obtained, carried out by finite-element method (FEM) in the program ABAQUS/Standard correlate well with experimental data. These results can be used for monitoring the state of artificial structures on main lines of JSC NC KTZ.


2021 ◽  
Vol 24 (3) ◽  
pp. 45-51
Author(s):  
Viktor H. Subotin ◽  
◽  
Oleksandr S. Burakov ◽  
Oleksii V. Dushyn ◽  
Viktor M. Iefymenko ◽  
...  

An analysis of the existing and prospective blade seal designs for Kaplan runners was performed. The selected design type provides the maximum ecological safety for Kaplan runners. A 3D model of runner hub sector with the trunnion, inner and outer bushes of blade trunnion was generated taking into account the cyclic symmetry of the runner design based on the modern automated design engineering system. A diagram of application of external loads from the blade and lever to the given 3D model of the Kaplan runner hub segment was developed. The contact problem was formulated to determine the stress-strain state as well as the contact pressures at the inner and outer bronze bushes of the Kaplan runner blade trunnions in different operating conditions. The problem was formulated for the finite element method, taking into consideration the diagram of external load application and contact restraints to the given 3D model of the Kaplan runner hub sector in the software package for engineering calculations. Using calculation results, principal stress distribution diagrams and the distribution diagram for the contact pressure at the outer and inner bronze bushes of blade trunnions were obtained. Strength calculation results were processed using the data of principal stress distribution diagrams, and the contact pressure values at the inner and outer bronze bushes of blade trunnions were determined. A methodology for further use of the given analytical model in the evaluation of stress-strain state of Kaplan runners involving modern automated design engineering systems and software package for engineering calculations was developed. The comparison of stress-strain states of the blade trunnion bushes was performed for the old and new designs of the Kaplan runner seal.


Author(s):  
Barkov Barkov ◽  
Oleg Veretelnik ◽  
Mykola Tkachuk ◽  
Mykola А. Tkachuk ◽  
Victor Veretelnik

Objective. To study the stress-strain state of the elements of the human lumbar spine when we use the transpedicular system, taking into account different angular values of segmental and total lumbar lordosis. Methods. For computer modeling of the stress-strain state of the elements of the human lumbar spine after mono- and polysegmental fixation, the Workbench product was used, and for the construction of parametric three-dimensional geometricmodels — the SolidWorks computer-aided design system was used. 4 groups of decisions were studied, which differed in angular values of segmental and total lumbar lordosis. In each group, 11 models were analyzed that describe the lumbar segments after mono- and polysegmental fixation in various configurations of the sagittal alignment of the lumbar spine. Results. It was found that the maximum stress on the cortical bone is concentrated on the base of the LV in case of the «pathological» intervertebral disc LV–S in the group of patients with hyperlordosis. At polysegmental fixation of the LI – S, there is a redistribution of stress on the cortical bone of all vertebrae, the maximum values of which is present in the bodies of the LV and S vertebrae. And only in the group with hypolordosis this stress is minimal. The maximum stress was always on the overlying intervertebral disc during transpedicularfixation. Significant increasing of cartilage stress in the facet joints of the LIV–LV segment was recorded during fixation of the LV–S segmentin case of hyperlordosis. The maximum stress on the rods was identified in the group of patients with hyperlordosis and polysegmentalfixation of the LI –S, on screws — on LV, LIV, LIII vertebrae during fixation in all groups, except for hypolordosis. Conclusions. Increasing in angular values (hyperlordosis), which describe segmental and total lumbar lordosis, leads to the stress elevation in the fixing elements and structures of the spinal motor segments, and, conversely, a decreasing in angular values (hypolordosis) causes the stress falling.


Author(s):  
I. Pozhueva ◽  
Т. Levitskaya

Purpose of work. Construction of method for calculating the stress-strain state of cylindrical shell with small initial deflection, to which an end load is applied, using the method of characteristics. Comparison of the calculation results of the obtained model with the works of other authors in this area. Research methods. For the calculation, the equations of motion of the Timoshenko type shell were used, taking into account both the shear deformation and inertia of rotation, and some nonlinear terms, to which the method of characteristics was applied. To obtain the equations of shell motion, the Hamilton-Ostrogradsky variational principle was used. Results method is proposed for calculating the stress-strain state of a cylindrical shell with a small initial deflection using characteristics. Comparative analysis of the calculation results with research in this area by other authors, which showed the effectiveness of the proposed method. Scientific novelty. The equations of the classical theory of shells, based on the Kirchhoff-Love hypotheses, which do not take into account the shear deformation and inertia of rotation, as well as linear equations of the Timoshenko type, have become widespread. In this work, a model of the stress-strain state of an axisymmetric shell with small initial deflections is constructed, taking into account both shear deformation and rotational inertia, and some nonlinear terms. Practical value. The proposed method can be used to calculate the stress-strain state of structures in which thin shells are present as elements, taking into account small initial deflection. This method makes it possible to study the influence of the characteristics of the initial deflection on the stress-strain state of the entire structure.


2021 ◽  
Vol 2021 (8) ◽  
pp. 77-86
Author(s):  
Oleg Voron

There are considered analysis results of stress-strain state in the load-bearing structure of three versions of refrigerator cars with different arrangement solutions of refrigerating-heating plants (RHP) and a thermos car at its cooling with liquid nitrogen. By means of the “APM WinMachine” application there are presented model parameters of a basic universal body. The analysis of calculation results has shown sufficient strength and potentialities for updating an available car metal structure for the application as a universal body of a refrigerator car. Work purpose: the estimation of a stress-strain state in the load-bearing structure of a basic body for insulated cars of different types of refrigerator- and thermos cars. Investigation methods: for the analysis of the stress-strain state in a load-bearing structure in three versions of the bodies of refrigerator- and thermos cars under loads with “Normal” modes there was used the “APM WinMachine” software complex realizing a finite element method. Results and novelty: for the first time there are offered arrangement solutions for the location of refrigeration-heating plants earlier not used for refrigeration rolling-stock (RRS). A stress-strain state of the body of the thermos car at the impact of overpressure upon it of gaseous nitrogen evaporated in cargo compartment is estimated. Conclusions: the analysis of calculation results for all three versions of the RHP arrangement and a solid body of a thermos car has shown sufficient strength and possibility regarding simple updating an available body metal structure which may be used as a universal car set.


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