scholarly journals Regarding the strength calculationof thin-walled shells

2021 ◽  
Vol 18 (5) ◽  
pp. 70-76
Author(s):  
Kh. M. Khanukhov ◽  
Keyword(s):  
Economic Effect ◽  
Membrane Theory ◽  
Shell Wall ◽  
Thin Walled ◽  
Internal Volume

Based on the analysis of Pascal's law and the hydraulic paradox applied to vertical cylindrical, conical and spherical tanks, as well as using the hypothesis of flat sections according to the membrane theory of thin-walled shells, the author makes the following proposal: the pressure on the shell wall, according to the hypothesis of flat sections, is not produced by the entire mass of the liquid, limited by its height and area, but only by an annular shell balanced by the internal volume of the liquid. On this basis, in the formula for calculating the strength of the tank walls, correcting coefficients are supposed to be introduced. In case of these assumptions being confirmed through testing, an economic effect is expected in the most metal-intensive industry, namely, in tank construction and capacitive equipment.

Membrane theory for thin-walled circular cylinders and spheres

2021 ◽  
pp. 231-242
Author(s):  
Carl Ross ◽  
John Bird ◽  
Andrew Little
Keyword(s):  
Circular Cylinders ◽  
Membrane Theory ◽  
Thin Walled ◽  
Cylinders And Spheres

scholarly journals ANALYSES OF THE STRESS INTENSITY OF THE CYLINDRICAL TANK WALL AT THE PLACE OF THE GEOMETRICAL DEFECT

2010 ◽  
Vol 16 (2) ◽  
pp. 209-215 ◽  
Author(s):  
Konstantin Rasiulis ◽  
Kęstutis Gurkšnys
Keyword(s):  
Strain State ◽  
Individual Case ◽  
Tank Wall ◽  
Cylindrical Tank ◽  
Membrane Theory ◽  
Operation Period ◽  
The Common ◽  
Thin Walled ◽  
Cylindrical Tanks ◽  
The Ideal

Major repair or regular inspection of the large capacity thin‐walled tankages is very expensive. Steel cylindrical tanks are an individual case of the thin‐walled tankages. The common calculation of the tanks by analytical and numerical methods is not difficult. Strengthening the places, where a perfect calculated form is disturbed, that is, at the spots of in‐cuts, hatches, defects etc. is a responsible part of the design of such constructions. The problems of prevention of defects during the operation period and repairs, as well as possibility to assure quickly the safety of defective places of the constructions are more important than the common calculations. The main objective of the presented investigations is to identify stress/strain state of the wall tank with local imperfections from the ideal cylindrical surface, taking into account the membrane theory of the shells by using the finite element's method. Santrauka Didelio tūrio statiniu remontai arba net profilaktines apžiūros yra gana brangūs procesai. Metalines cilindrines talpyklos priskiriamos prie atskiros tūriniu plonasieniu konstrukciju grupes. Talpyklu reguliariu konstrukciju analitiniai ar skaitiniai skaičiavimai nera sudetingi. Bet tokiu vietu, kaip konstrukciju jungčiu bei technologines irangos prijungimo projektavi‐mas ar konstrukciju defektu analize yra gerokai svarbesne projektavimo dalis. Defektu prevencija naudojant talpyklas, taip pat defektuotu vietu sustiprinimas yra svarbesnis nei bendrieji talpyklu skaičiavimai. Šio darbo tikslas ‐ nustatyti realaus objekto cilindrines talpyklos sieneles su geometrinemis lokaliomis nuokrypomis itempiu ir deformaciju būvi pagal memb‐ranine kevalu skaičiavimo teorija, taikant baigtiniu elementu metoda.

On the Statics of Supports and the Geometry of Wrinkling of Large Spherical Pressure Vessels

1988 ◽  
Vol 110 (4) ◽  
pp. 387-392 ◽  
Author(s):  
W. Szyszkowski ◽  
P. G. Glockner
Keyword(s):  
Pressure Vessels ◽  
Curvilinear Coordinates ◽  
Solution Technique ◽  
Membrane Theory ◽  
Stress Concentrations ◽  
Eulerian Formulation ◽  
Key Variables ◽  
Thin Walled ◽  
Spherical Pressure ◽  
Large Spherical

Thin-walled spherical pressure vessels, the bending and compressive stiffnesses of which are small in comparison with their tensile stiffness, are discussed using membrane theory. In the first part of the paper linear membrane theory is used to analyze the statics of supports for large spherical pressure vessels. The reactions from such supports which are tangential or almost tangential to the pressure vessel surface, require reinforcements so as to distribute the reactions into the wall without causing undue stress concentrations and/or wrinkling. The size and contour of such reinforcing elements depend, of course, on the magnitude of the reactions as well as the internal pressure. In the second part of the paper, nonlinear membrane theory is used to analyze the geometry of wrinkled domains in such membrane pressure vessels. Using an Eulerian formulation, the parameters of the first and second fundamental forms of the surface are treated as key variables and are determined from the analysis as functions of the curvilinear coordinates referred to the current deformed configuration. The solution technique is applied to a simple example.

Architecture of Radiolitid Rudist (Mollusca) Shell-Wall Structures and its Phylogenetic Implications

1975 ◽  
Vol 33 ◽  
pp. 686-687
Author(s):  
David H. Sturm ◽  
Bob F. Perkins
Keyword(s):  
Phylogenetic Relationships ◽  
Outer Wall ◽  
Shell Microstructure ◽  
Shell Wall ◽  
Wall Structures ◽  
Phylogenetic Implications ◽  
Cellular Wall ◽  
Superfamily Analysis ◽  
Central Texas

Each of the seven families of rudists (Mollusca, Bivalvia, Hippuritacea) is characterized by distinctive shell-wall architectures which reflect phylogenetic relationships within the superfamily. Analysis of the complex, calcareous, cellular wall of the attached valve of the radiolite rudist Eoradiolites davidsoni (Hill) from the Comanche Cretaceous of Central Texas indicates that its wall architecture is an elaboration of the simpler monopleurid rudist wall and supports possible radiolite-monopleurid relationships.Several well-preserved specimens of E. davidsoni were sectioned, polished, etched, and carbon and gold coated for SEM examination. Maximum shell microstructure detail was displayed by etching with a 0.7% HC1 solution from 80 to 100 seconds.The shell of E. davidsoni comprises a large, thick-walled, conical, attached valve (AV) and a small, very thin, operculate, free valve (FV) (Fig. 1a). The AV shell is two-layered with a thin inner wall, in which original structures are usually obliterated by recrystallization, and a thick, cellular, outer wall.

An experience of elaboration and implementation of systems of slag-forming mixtures mechanized feeding into CCM moulds

2020 ◽  
Vol 76 (10) ◽  
pp. 994-1003
Author(s):  
S. P. Eron’ko ◽  
M. Yu. Tkachev ◽  
E. V. Oshovskaya ◽  
B. I. Starodubtsev ◽  
S. V. Mechik
Keyword(s):  
Economic Effect ◽  
Three Dimensional ◽  
Movable Part ◽  
High Quality ◽  
Working Zone ◽  
Fine Material ◽  
Mixing Chamber ◽  
Field Samples ◽  
Technical Solutions ◽  
Feeding Systems

Effective application of slag-forming mixtures (SFM), being fed into continuous castingg machine (CCM) moulds, depends on their even distribution on the melt surface. Manual feeding of the SFM which is widely usedd does not provide this condition, resulting in the necessity to actualize the work to elaborate systems of SFM mechanized feedingg into moulds of various types CCM. A concept of the designing of a system of SFM feeding into CCM moulds presented with the ratte strictly correspondent to the casting speed and providing formation of an even layer of fine material of given thickness on the whoole surface of liquid steel. The proposed methods of designing of the SFM mechanized feeding systems based on three-dimensional computer simulation with the subsequent verification of the correctness of the adopted technical solutions on field samples. Informattion is presented on the design features of the adjusted facilities intended for continuous supply of finely granulated and powder mixtuures on metal mirror in moulds at the production of high-quality billets, blooms and slabs. Variants of mechanical and pneumo-mechaanical SFM supply elaborated. At the mechanical supply the fine material from the feeding hopper is moved at a adjusted distance bby a rigid horizontally located screw. At the pneumo-mechanical supply the metered doze of the granular mixture is delivered by a sshort vertical screw, the lower part of which is located in the mixing chamber attached from below to the hopper and equipped with ann ejector serving for pneumatic supply of the SFM in a stream of transporting gas. It was proposed to use flexible spiral screws in the ffuture facilities of mechanical SFM feeding. It will enable to eliminate the restrictions stipulated by the lack of free surface for locatiion of the facility in the working zone of the tundish, as well as to decrease significantly the mass of its movable part and to decreaase the necessary power of the carriage moving mechanism driver. The novelty of the proposed technical solutions is protected by thhree patents. The reduction of 10–15% in the consumption of slag-forming mixtures during the transition from manual to mechanizeed feeding confirmed. The resulting economic effect from the implementation of technical development enables to recoup the costs inncurred within 8–10 months.

New algorithms and formulas for calculation the volume of a ball and its surface area for the development of students' creative thinking and practical application

2020 ◽  
pp. 32-41
Author(s):  
V. P. Zudin
Keyword(s):  
Surface Area ◽  
Creative Thinking ◽  
Economic Effect ◽  
Educational Institutions ◽  
Practical Application ◽  
Microsoft Word ◽  
Ball Surface ◽  
Visual Basic For Application ◽  
Application Programs ◽  
Development Of Students

The article presents new, more accurate algorithms and formulas for calculating the area of a circle, volume of a ball, surface area of a ball. To prove these algorithms and formulas and their practical application, programs have been developed in the Visual Basic for Application in Microsoft Word. These algorithms and formulas should be studied and applied in all educational institutions, as they are closer to the truth. From a more accurate calculation using these formulas, you can get an economic effect when calculating trajectories of movements in space, on the surface of the globe, in the construction and maintenance of products in the form of a circle or a ball. The study of this material in informatics lessons contributes to the development of students' creative thinking, increasing their motivation to study informatics and IT.

Translucent Glass Roofs For Large-Span Coverings

2019 ◽  
pp. 23-28
Keyword(s):  
Warm Season ◽  
Natural Light ◽  
Labor Costs ◽  
Main Bearing ◽  
Large Span ◽  
Glass Panels ◽  
Technical Properties ◽  
Internal Volume ◽  
Basic Approaches ◽  
Smoke Removal

The article deals with the issues of glass use in the enclosing structures of large-span coverings, which have such advantages as ensuring the penetration of natural light, tightness, minimum labor costs for repair and maintenance. Design shortcomings: the high cost, the need for protection of the internal volume against the penetrating sun rays in the warm season (hothouse effect); arrangement of devices for operation of a roof. The key technical properties and characteristics of glass panels and pane-glass sets, constructive decisions, including interface to the main bearing structures of a large-span covering are given. Peculiarities of their design with due regard for ventilation and smoke removal, a drainage of condensate, ways of fight against frosting and snow drifts on the roof are reflected. Features of the account of loadings, the basic approaches to their calculation are considered. Various design solutions for the spatial metal trussed systems with the original nodal connections are presented. Information on modern solutions of translucent roofs using glass for large-span coverings is given.

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