scholarly journals DEFORMATION AND BUCKLING ANALYSIS OF SHALLOW CONICAL SHELLS BASED ON IMPROVED MODEL OF WIND LOAD USING ENVIRONMENT ANSYS

2021 ◽  
pp. 20-27
Author(s):  
Y.O. Bessmertnyi ◽  
◽  
V.L. Krasovsky ◽  
Keyword(s):  
Previous Investigation ◽  
Linear Problem ◽  
Wind Load ◽  
Uniform Stress ◽  
Shell Surface ◽  
Conical Shells ◽  
Pressure Application ◽  
Improved Model ◽  
Parameter Influence

The process of deformation and buckling of shallow thin-walled elastic conical shells has been investigated for the case of significantly non-uniform stress-strain state due to the action of wind load based on improved model of pressure application schema to the surface of shallow shell and for hinged hedge of border. An improved model of wind load was based on data presented in terms [5, 6] and was a logical continuation of previous investigation of wind action on shallow conical shells based on model of first approach [3]. Deformation and buckling process investigation has been carried out using software ANSYS which effectivity was approved by the fact of being used by NASA for its aerospace projects. A model of shallow conical shell has been made using four-corner finite element SHELL 281 with 8 nodes that let us obtain not only symmetrical relatively to the axis of rotation buckling form but an asymmetrical too. Two types of computation have been made during numerical modeling – linear bifurcation computation with determination of linear pressure qcr value and corresponding to it buckling form, and computation of geometrically non-linear problem of deformation with determination of limit pressure qlim and corresponding buckling form. Obtained buckling forms have been compared to the deformed shape of shell surface when aerodynamic computations have been carried out using software ANSYS. An estimation analysis has been made for case of application of improved model of wind load in comparison to the previous investigation according to the values of baring capacity and buckling shape coherence during resolution of static tasks and comparison to the results of aerodynamic solution. An analysis of base parameter influence has been carried out for the model of first approach and current improved model according to the bearing capacity value and local extremums on schema of pressure intensity distribution of wind load. Specific moments of deformation process computations based on improved model using environment ANSYS have been mentioned and of further analysis on the basis of improved model with it specifics have been given too.

Energy for crack growth in model rubber components

1972 ◽  
Vol 7 (2) ◽  
pp. 132-140 ◽  
Author(s):  
P B Lindley
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Crack Surface ◽  
Uniform Stress ◽  
Numerical Techniques ◽  
Surface Displacements ◽  
Tearing Energy ◽  
Crack Growth Rates ◽  
Essential Prerequisite

The determination of tearing energy, i.e. the energy available for crack growth, is an essential prerequisite for the estimation of the fatigue life of rubber components. Three methods of determining tearing energy are considered: from changes in total energy, from crack surface displacements, and by comparison with known values for the same crack growth rates. It is shown by applying experimental and numerical techniques to plane-stress testpieces, not necessarily of uniform stress or thickness, that the methods are satisfactory.

Application of 3D-printing technologies for production of master-model in engineering industry

2021 ◽  
Vol 0 (9) ◽  
pp. 17-21
Author(s):  
O. A. Dvoryankin ◽  
◽  
N. I. Baurova ◽  
Keyword(s):  
3D Printing ◽  
Layer Thickness ◽  
Ultimate Strength ◽  
3D Models ◽  
Engineering Industry ◽  
Master Model ◽  
Parameter Influence ◽  
Printing Parameter

Analysis of 3D-printing methods used in the molding production to manufacture master-models has been carried out. The technology was selected, which allowed one to make high-precision parts, combining the molding and the 3D-printing. Factors effecting on the quality of 3D-models printed by this technology were analyzed. Experimental studied for determination of the printing parameter influence (layer thickness, filling percentage, printing velocity) on ultimate strength of specimens made of ABS-plastic were carried out.

scholarly journals EVALUATION OF THE VITALITY OF A FLANGED CONNECTION WITH A STEEL TOWER STRUCTURE WITH ACCOUNT OF EXPERIMENTAL DETERMINATION OF AERODYNAMIC COEFFICIENTS

2020 ◽  
Vol 82 (2) ◽  
pp. 215-224
Author(s):  
V.I. Erofeev ◽  
I.A. Samokhvalov
Keyword(s):  
Bearing Capacity ◽  
Numerical Study ◽  
Wind Load ◽  
Aerodynamic Coefficients ◽  
Metal Structures ◽  
Equivalent Stresses ◽  
Tower Structure ◽  
Calculation Results ◽  
Design Calculations

A numerical study of the survivability of the flange assembly is carried out upon reaching a critical load and in the presence of a defect in one of the design areas, taking into account the calculated values of the aerodynamic coefficients. An experiment is being carried out to determine the values of the wind load acting on the supporting legs of a metal tower. The calculation of the stressstrain state is performed using software system as SCAD Office and IDEA StatiCa 10.0. After calculating the forces in the core model of the structure, a threedimensional plate model of the assembly is formed and prepared for calculation. According to the results of the experiment, a graph was compiled with the values of aerodynamic coefficients, which were used in calculating the stressstrain state of the node. The analysis of the calculation results revealed that in the design (defectfree) state of the structure, the safety factor of the bearing units and elements is 35-40% (equivalent stresses were 165 MPa). If there is a defect in the metal structures of the belt in the region of the flange, the equivalent stresses increase to 247.6 MPa in the region of the cleavage (defective hole), thus, the margin in bearing capacity drops to 0.4%. As a result of the assessment of the survivability of the flange connection, it was revealed that the connection has a high potential survivability, in turn, the flange itself is able to work in the presence of some defects without reducing its bearing capacity to a critical level. The aerodynamic coefficients obtained in this work will determine the wind load on this type of profile and can be used in design calculations of tower structures for wind loads.

scholarly journals Improved model-independent determination of the strong-phase difference between D0 and D¯0→KS,L0K+K− decays

2020 ◽  
Vol 102 (5) ◽  
Author(s):  
M. Ablikim ◽  
M. N. Achasov ◽  
P. Adlarson ◽  
S. Ahmed ◽  
M. Albrecht ◽  
...  
Keyword(s):  
Phase Difference ◽  
Strong Phase ◽  
Independent Determination ◽  
Model Independent ◽  
Improved Model

scholarly journals Peculiarities of improvement of the national system of education quality assessment in the conditions of implementation of the curriculum of public secondary education integrated with the curriculum of professional training

2020 ◽  
pp. 96-105
Author(s):  
Anastasiya Andreevna Rudakova ◽  
Anna Semenovna Zaitseva
Keyword(s):  
Secondary Education ◽  
General Education ◽  
Quality Assessment ◽  
Professional Training ◽  
Educational Institution ◽  
Education Quality ◽  
Managerial Decision ◽  
National System ◽  
Improved Model

This article thoroughly examines such aspects of the topic as determination of new trends and approaches towards ensuring systematicity and comprehensiveness of functionality of the national system of education quality assessment; effective managerial decision-making via development and implementation of the local normative acts under the authority of educational institution with regards to education quality control. In the conditions of establishment of the unified system of education quality assessment in the Russian education and limitations of resources (organizational, personnel, methodological, normative, motivational, etc.), the heads of educational institution are aware of the need and importance of improvement of the national system of education quality assessment . This article examines the key stages in improvement of the national system of education quality assessment in the context of implementation of curriculum of public secondary education integrated with the curriculum of professional training on the disciplines “Horticulturist”. The novelty of this research consists in the fact that systematic gathering and analysis of information on the content, students’ performance, and conditions for implementation of the curriculum of public secondary education integrated with the curriculum of professional training on the profession “Horticulturist”, with subsequent determination of the problems, contributed to the making effective management decisions aimed at elimination of the “problem areas”. The expected result of improvement of the model of national system of education quality assessment consists in quality improvement of the public general education. The authors’ special contribution into the research of this topic lies in obtainment of practical results in the course of implementation of the improved model of the national system of education quality assessment on the level of administration, bodies of state administration, pedagogical personnel of the educational institution.

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