scholarly journals Study of the stress-strain state of ribbed cylindrical shells by the finite elements method

1985 ◽  
Vol 17 (8) ◽  
pp. 1166-1169
Author(s):  
P. Z. Menabdishvili ◽  
M. Ya. Kodner ◽  
V. B. Babaev
Keyword(s):  
Finite Elements ◽  
Strain State ◽  
Cylindrical Shells ◽  
Finite Elements Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Ribbed Cylindrical Shells

scholarly journals STUDY OF STRESS-STRAIN STATE OF MATHEMATICAL MODEL OF JAWS USING THE FINITE-ELEMENTS METHOD

2019 ◽  
Vol 19 (1-2) ◽  
pp. 131-139
Author(s):  
D. A Trunin ◽  
A. V Revyakin ◽  
M. A Postnikov ◽  
I. N Kolganov ◽  
I. A Zakharova ◽  
...  
Keyword(s):  
Finite Elements ◽  
Strain State ◽  
Soft Tissues ◽  
Finite Elements Method ◽  
Stress Strain ◽  
Jaw Bones ◽  
Stress Strain State ◽  
Lower Jaw ◽  
Characteristic Features ◽  
Bone Structures

This work is devoted to the study of the stress-strain state (SSS) model by using the finite-elements method (FEM) of jaw-bones (the system of lower jaw (LJ) - upper jaw (UJ)) and is the next step in understanding the mechanism of mastication as one of the main functions of the maxillofacial system (MFS). At the same time, reliable information about SSS of the LJ and UJ bones with account of the peculiarities of their anatomical and topographical structure will, firstly, reveal the main regularities of the jaw bone deformations. It will make possible to choose prosthetic appliances that will provide the minimum level of intensity of atrophic processes in supporting tissues and the most favorable biomechanical interaction of bone structures, soft tissues and elements of the prosthetic appliance. The results of mathematical calculations allowed to identify the characteristic features of the deformation and interaction of the LJ and UJ bones, which will ensure a scientifically based choice of those prosthetic appliances contributing to the most prolonged and normal functioning of the maxillofacial system in general.

Research of opening reliability of blast easily disposable systems with honeycomb polycarbonate sheets by finite elements method

2020 ◽  
pp. 107-115
Author(s):  
Yu.Yu. Pidhoretskyi ◽  
Keyword(s):  
Finite Elements ◽  
Strain State ◽  
Numerical Algorithms ◽  
Honeycomb Structure ◽  
Geometrical Parameters ◽  
Stress Strain ◽  
Stress Strain State ◽  
Relief Elements ◽  
Explosion Overpressure ◽  
Applied Approach

In the article, the author presents results of mathematical modeling of operation of the venting relief structures made of honeycomb polycarbonate sheets and fixed in the standard window profiles, under the effect of explosion. In order to reproduce the explosion effect on venting relief structures, an approach to modeling dynamic systems was applied, which used a finite element method to approximate the basic general equations of dynamics added by the equations of the stress-strain state of a solid body. The applied approach differs by reproduction of the explosion process impact on the venting relief structures of this type by using equations which describe the motion of the dynamic system with accounting a contact interaction with the friction of honeycomb polycarbonate sheets and corresponding surfaces of the standard window profile locks. The honeycomb structure of the polycarbonate sheet was modeled by appropriate finite elements with considering the polycarbonate elastic properties. In order to implement numerical algorithms of this approach, a program code of the LS-DYNA computer system was used. The conducted numerical experiment on reproducing the explosion effect on the relief elements of this type of the venting relief structures made it possible to trace all stages of the honeycomb polycarbonate sheets deforming and moving under the action of explosion up to the exit of their edges from the window profile locks with the study of the corresponding stress-strain state parameters. By using this approach, reliably disclosure of the venting relief structures based on honeycomb polycarbonate sheets was investigated, and conditions for their reliable disclosure were identified with considering geometrical parameters of such type of venting relief structures opening and thickness of the honeycomb polycarbonate sheets. Results of the research have shown that reliable disclosure of the honeycomb polycarbonate sheets occurs within the range of the explosion overpressure, hence, confirming the effectiveness of such type of the venting relief structures used for protecting buildings against the explosion action.

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.

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