scholarly journals Stress-deformed state of the shell with a small initial deflection under the action of the end load

2021 ◽  
pp. 67-72
Author(s):  
I. Pozhueva ◽  
Т. Levitskaya
Keyword(s):  
Cylindrical Shell ◽  
Shear Deformation ◽  
Strain State ◽  
Method Of Characteristics ◽  
Initial Deflection ◽  
Stress Strain ◽  
The Method Of Characteristics ◽  
Stress Strain State ◽  
Timoshenko Type ◽  
Calculation Results

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.

scholarly journals Stress-Strain State of a Cylindrical Shell of a Tunnel Using Construction Stage Analysis

2019 ◽  
Vol 21 (3) ◽  
pp. 72-76
Author(s):  
Sergey B. Kosytsyn ◽  
Vladimir Y. Akulich
Keyword(s):  
Cylindrical Shell ◽  
Comparative Analysis ◽  
Static Analysis ◽  
Strain State ◽  
Computational Models ◽  
Stress Strain ◽  
Construction Stage ◽  
Stress Strain State ◽  
Slurry Shield ◽  
Stage Analysis

The work is aimed at research of the stress-strain state of a cylindrical shell of a tunnel using the non-linear static analysis and construction stage analysis. Research is carried out on the example of determining the stress-strain state of the tubing (shells) of the main line tunnel, constructed using a tunnel powered complex (slurry shield). Based on obtained results, a comparative analysis of the computational models with the corresponding conclusions is presented.

scholarly journals Stress-strain state analysis of the design of full-turning vertical empennage for aero-spacecraft

2021 ◽  
Vol 22 (1) ◽  
pp. 36-42
Author(s):  
Andrey A. Chistyakov ◽  
Valery P. Timoshenko
Keyword(s):  
Numerical Simulation ◽  
Strain State ◽  
Dynamic Pressure ◽  
Operating Conditions ◽  
Structural Scheme ◽  
Stress Strain ◽  
Mechanical Loads ◽  
Stress Strain State ◽  
Distributed Load ◽  
Calculation Results

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.

scholarly journals Stress-strain state of a three-layer cylindrical shell under internal axisymmetric pulse load

2020 ◽  
pp. 145-151
Author(s):  
Viktor Gaidaichuk ◽  
Kostiantyn Kotenko
Keyword(s):  
Finite Element ◽  
Cylindrical Shell ◽  
Strain State ◽  
Layer Structure ◽  
Three Dimensional ◽  
Pulse Load ◽  
Geometrical Parameters ◽  
Time Interval ◽  
Stress Strain ◽  
Stress Strain State

The problem of dynamic deformation of a three-layer cylindrical shell under non-stationary loads in the case of rigid clamping of the shell ends is considered. The article presents the results of assessing the stress-strain state of a three-layer cylindrical shell, taking into account its structural feature, the ratio of the sheathing thickness and the physical and mechanical characteristics of a one-piece polymer filler. Calculations were performed by software complex Nastran. The values of displacements and stresses were calculated by the algorithm of direct transient dynamic process. The step duration of the time interval was 0.0000025 s, and the total number of steps was 200. The choice of the type of three-dimensional finite element was due to obtaining more detailed and accurate calculation results. The finite element model included 19000 three-dimensional finite elements and numbered 20800 nodes. The influence of geometrical parameters of shell layers with different physical and mechanical properties of one-piece filler on the stress-strain state under axisymmetric internal impulse load is investigated. Numerical results on the dynamics of the three-layer structure, obtained by the finite element method, allow to characterize the stress-strain state of the three-layer elastic structure of the cylindrical type at any time in the studied time interval. Optimization of the shell design is recommended. Changing the ratio of the thickness of the internal and external shells of the shell significantly affects the stress-strain state of the shell and its performance. Increasing the thickness of the internal layer of the shell significantly contributes to the increase of the latter. Comparison of the given results with materials of other similar researches and positions, testify to objectivity of the made approach.

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