scholarly journals Сalculation methodology and determination of efforts in vault

2021 ◽  
Vol 2 (92) ◽  
pp. 85
Author(s):  
Olena Yaremenko
Keyword(s):  
Spatial Structure ◽  
Abstract Problem ◽  
Term Operation ◽  
Unit Width ◽  
Methods Of Calculation ◽  
Central Forces ◽  
Circular Curve

Abstract. Problem. In this article we offer the meth-odology of calculation, based on the idea of dismem-berment of vault on the separate archs of single width. It is recommended for the estimation of efforts in the designed and damaged vaults. Also offered a methods of calculation effort in serried vaults. As spatial inflexibility of cross vault below than inflexi-bility of serried vault, then it is necessary to execute the calculation of the cheek arch abstracted from the tray of cross vault also. If the outline of tray is exe-cuted on a circular curve, then it is possible to take methodology of calculation of archs with the outline of axis a curve as catenoid. Goal. The proposed methodology for calculating closed and cross vaults is also based on the idea of dividing the arch into separate arches of unit width. The results of studies of efforts and rational forms of arches of V.A. Kiselev [1]. Methodology. Calculation based on the idea of dismemberment of vault on the separate archs of single width. Recommended for the estimation of efforts in the designed and damaged vaults. A method over of calculation of dome is brought for determina-tion of effort in serried vaults. Results. At the choice of outline of axis of arch it is necessary aspires to that an axis, on possibility, coincided with the curve of pressure. Such outline of axis is rational, as there are only central forces of N in an arch. Flexion mo-ments M and transversal forces of Q are equal to the zero. The coincidence of axis of arch with the curve of pressure can be got for the three-hinged arch. For the statically undetermined arch of complete coinci-dence of axis with the curve of pressure attaining is impossible, so that the origin of flexion moments at any her outline is inevitable. Originality. The tech-nique based on the separation of flat elements from the spatial structure does not show the reserves of strength of the structure. Experience of long-term operation of vaulted structures designed or verified by calculation using similar methods [2], [9] shows caution and reliability. Practical value. The tech-nique is also suitable for assessing the strength of damaged vaults with collapsed corners or walms.

Determination of Actual Tensile and Fracture Characteristics of Critical Components of Industrial Plants Under Long Term Operation by SPT

2012 ◽  
Author(s):  
Karel Matocha
Keyword(s):  
Mechanical Properties ◽  
Residual Lifetime ◽  
Test Technique ◽  
Fracture Characteristics ◽  
Industrial Plants ◽  
Term Operation ◽  
Critical Components ◽  
Time Of Operation

The assessment of the residual lifetime of critical components of industrial plants requires the knowledge of mechanical properties prior to operation, respecting all technological operations realized throughout the manufacture of the component, and the knowledge of mechanical properties after actual time of operation (actual mechanical properties). Small Punch (SP) test technique enables measurement of the realistic material properties at the critical locations in the component both prior and after long-term operation. The paper shows the examples of the sampling of testing material from the critical components of the industrial plants and the procedures for determination of tensile and fracture characteristics by SP tests at ambient and low temperatures. The special attention is devoted to the test specimen orientation for determination of SP fracture energy ESP.

Determination of Tensile Properties of Power Plant Steels by Testing of Miniature Specimens

2013 ◽  
Author(s):  
Ivan Klevtsov ◽  
Andrei Dedov
Keyword(s):  
Mechanical Properties ◽  
Power Plant ◽  
Flat Plate ◽  
Tensile Properties ◽  
Standard Size ◽  
Term Operation ◽  
University Of Technology ◽  
Miniature Specimens

Long-term operation of the power plant components in the conditions of the creep leads to the degradation of the short-term mechanical properties of the material. Therefore, in order to predict the degree of the metal degradation and integrity of the component the determination of the mechanical properties of the actual component in service material is required. Since the standard tests requiring a significant volume of sample material cannot be applied the technique of the tensile testing of miniature flat plate specimens has been developed in Tallinn University of Technology and described in this paper. The results of the tests of miniature flat plate specimens have been compared with testing results of cylindrical specimens with standard size and at the same time the comparison has shown a good agreement of the results. The data analysis has also shown the high repeatability of the tests results of miniature specimens. Thus, the developed technique of the miniature flat plate specimens testing could be considered as accurate and reliable method and could be definitely used for evaluation of the tensile properties of the metal.

Research Advances in the Interaction among Stratum-Ground Fissure-Tunnel under Subway Dynamic Loading

2012 ◽  
Vol 226-228 ◽  
pp. 1513-1516 ◽  
Author(s):  
Li Qun Yuan ◽  
Hong Jia Liu ◽  
Yu Ming Men
Keyword(s):  
Dynamic Loading ◽  
Dynamic Interaction ◽  
Subway Tunnel ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Term Operation ◽  
Geological Disaster ◽  
Under Construction

Ground fissure is a kind of serious geological disaster. There will be more unprecedented challenges during the construction of the urban subway in ground fissures-developed zone. How to ensure the long-term operation safety of the subway crossing ground fissure belts are the first problems for the subway under construction in the cities with ground fissure developed. One of the important problems is that dynamic interaction and disaster effect control among ground fissure-stratum-subway tunnel under subway dynamic loading, which is also the important problem to be solved in the engineering. This problem involves the following three aspects: (a) the determination of subway dynamic loading; (b) the structure dynamic response of subway tunnel; (c) the interaction among stratum-ground fissure-subway tunnel. According to make a comment on these researches, some issues which are necessary to carry out in this field are suggested.

The study of regularities of changes in acoustic characteristics depending on microstructure parameters and development of acoustic limit state criterion

2020 ◽  
pp. 32-42
Author(s):  
V. N. Gadalov ◽  
S. V. Safonov ◽  
E. A. Filatov ◽  
O. N. Boldyreva ◽  
I. A. Makarova
Keyword(s):  
Structural Damage ◽  
Limit State ◽  
Acoustic Characteristics ◽  
Term Operation ◽  
Long Run ◽  
Microstructure Parameters ◽  
State Criterion ◽  
Good Agreement

The studies of the dependence of acoustic characteristics on the microstructure of chromium-molybdenum-vanadium steels in various structural states after long term operation are presented. The meaning of the acoustic limit state criterion, which represents a relative assessment of accumulated structural damage of the long run metal for the time delay of ultrasonic Rayleigh waves and determination of the limit state of the material, is revealed. It is established that at the acoustic criterion of the limit state of ≥0.7, the metal is in the state of avalanche creep and reaches the limit state. Measurements of acoustic characteristics gave a good agreement with the results of metallographic studies conducted on sections of metal cuttings. In addition, the criterion was tested when diagnosing technical devices made of steel 15X1M1F, 12X2MFSR, 17GS, 09G2S.

Determination of VVER-440/ V-213 long-term operation induced activity

2021 ◽  
Author(s):  
Michal Šnírer ◽  
Kristína Krištofová ◽  
Gabriel Farkas ◽  
Peter Hausner ◽  
Vladimír Slugeň
Keyword(s):  
Term Operation

Determination of DMFC deterioration during long-term operation

2006 ◽  
Vol 160 (1) ◽  
pp. 440-445 ◽  
Author(s):  
Ho Kim ◽  
Se-Jong Shin ◽  
Young-gil Park ◽  
Joohan Song ◽  
Hee-tak Kim
Keyword(s):  
Term Operation

Texturing of Magnetite Forming during Long-Term Operation of a Pipeline of 10CrMo9-10 Steel

2013 ◽  
Vol 203-204 ◽  
pp. 121-124 ◽  
Author(s):  
Monika Gwoździk ◽  
Zygmunt Nitkiewicz
Keyword(s):  
Cross Section ◽  
Oxide Surface ◽  
Initial State ◽  
Radiation Beam ◽  
X Ray ◽  
Term Operation ◽  
Magnetite Layer ◽  
Anode Tube

The paper presents results of X-ray measurements of the texture of a magnetite (Fe3O4) layer formed on 10CrMo9-10 steel during 100,000 hours operation at the temperature of 575°C (in a flowing medium environment). The formed oxide layer was ≈140µm thick. Measurements of texturing were performed on the oxide surface and also at the depth of ≈50µm from the surface (1st polishing) and ≈100µm (2nd polishing). X-ray studies were carried out using the radiation of a cobalt anode tube, λCo=0.17902nm, for (311) and (400) Fe3O4 reflections, using a radiation beam collimated to φ=2mm. The study was aimed at determination of correlation between the texturing and the structure on the magnetite layer cross-section. A clear texturing of {111} and {111} type for the magnetite in the initial state and after the second polishing was found. Instead, after the first polishing there was a substantial texturing of {034} and {015} type. A different nature of the texture may result from a diversified morphology of magnetite at various depths (caused inter alia by a differentiated temperature on the tube wall cross-section during the material operation), which is related among other things to the crystallites size. The magnetite structure and texture changes can affect the magnetite porosity and cleavage.

scholarly journals Application of the classical Payout Ratio Model and determination of the limitations of the Lintner Model demonstrated on the example of Komerční banka, PLC

2021 ◽  
Vol 91 ◽  
pp. 01043
Author(s):  
Veronika Machova ◽  
Tereza Geierova
Keyword(s):  
Annual Reports ◽  
Ratio Model ◽  
Company Strategy ◽  
Term Operation ◽  
Long Run

Initial determination of the payout ratio should be an integral part of each company strategy; it is a cornerstone of a long-term operation of any company. The aim of this contribution is to analyse the possibilities of determining the payout ratio of the company using dividend models and to design the most optimal application of the dividend model, and to define the limitations for the application. The data required for the application of the dividend models are obtained from the annual reports of Komerční banka, PLC. for the years of 2006-2018. The obtained data are used to calculate the classical payout ratio model, and subsequently to determine the payout ratio according to the Lintner model. Using the method of comparison, the obtained results for the application of the pay ratio are contrasted. The classic payout ratio model coincided directly with the results of the payout ratios of Komerční banka, PLC. and therefore turned out to be optimal for the application. The Lintner model is considered in literature to be very well functioning. However, this research confirmed that the resulting values of payout ratios after the application of the Lintner model are unacceptable in the long run.

scholarly journals Design and Development of Sustainable Product Service Systems Based on Design-Centric Complexity

2021 ◽  
Vol 13 (2) ◽  
pp. 532
Author(s):  
Peng Zhang ◽  
Shaohua Jing ◽  
Zifeng Nie ◽  
Boyuan Zhao ◽  
Runhua Tan
Keyword(s):  
Design Stage ◽  
Functional Requirements ◽  
Early Design Stage ◽  
Term Operation ◽  
Development Framework ◽  
Design Attributes ◽  
Product Service ◽  
Operation Stability

Product-service system (PSS) complexity is rapidly increasing in order to meet complex user requirements. Increased complexity leads to PSSs failing to meet sustainability requirements in their initial design. To enhance PSS sustainability and support social benefits, this paper proposes a sustainable PSS development framework based on design-centric complexity (DCC) theory. In the early design stage of a PSS, DCC theory is used to analyze the complexity of the system. Determination of the types of complexity in the system and the corresponding problems is then performed. By combining the sub-field model of TRIZ, the problems can be converted and solved, and the functional periodicity may be established to reduce system complexity. By using this development framework, the conflicts and potential problems of design attributes can be reduced and the possibility of achieving PSSs functional requirements (FRs) can be enhanced. This will maintain the long-term operation stability for the system and enhance the sustainability of the PSS. Finally, the feasibility of the development framework is verified here through the case analysis of a bicycle sharing service and management system.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

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