scholarly journals Instrumentation used for vibration monitoring on the supports of the tank scales of the port transshipment complex

2021 ◽  
Vol 2061 (1) ◽  
pp. 012021
Author(s):  
R G Dubrovin ◽  
N I Nikolaev ◽  
V V Gerasidi
Keyword(s):  
Metal Structure ◽  
Longitudinal Direction ◽  
Vibration Monitoring ◽  
Time Signal ◽  
Valve Mechanism ◽  
Resonant Frequencies ◽  
Metal Structures ◽  
Main Thing ◽  
A Chain ◽  
Vibration Measuring

Abstract The main thing for rotating equipment is to measure vibration, since, in the process of irreversible state change, a chain of defects always occurs and at least one of them significantly changes the vibration of the equipment. Using tank scales for static equipment, the vibration measuring makes it possible to determine the actual values of the levels and compare them with the maximum permissible values set by the manufacturer or regulatory documents. Also, the measurement of vibration levels in the time signal allows determining resonant frequencies at which vibration levels significantly increase due to the coincidence of the natural frequencies of the equipment with external workers, which can lead to increased loads on the supporting metal structures, suspended equipment and subsequently to fatigue destruction of the latter. Results of the work: the excess of the measured vibration levels on the supports of the hopper scales No. 28.1 was recorded by vibration acceleration in pt.11 (longitudinal direction) from twelve measurements; the excess of the measured vibration levels on the supports of the hopper scales No. 28.2 was not recorded, but increased levels of vibration speed were observed in pt. 11 and pt. 12; excessive vibration levels at the same measurement points on different scales may indicate that it is necessary to conduct a survey of the operation of the valve mechanism for smooth running and to monitor the condition of the metal structure under the fourth supports; it is recommended to perform a repeated measurement of the vibration of the hopper scales after inspection and repair of the structures of the scales.

Economical design for long-span soil – metal structures

1996 ◽  
Vol 23 (4) ◽  
pp. 838-849 ◽  
Author(s):  
Hesham Mohammed ◽  
John B. Kennedy
Keyword(s):  
Dimensional Analysis ◽  
Structural Engineering ◽  
Three Dimensional ◽  
Metal Structure ◽  
Reinforced Soil ◽  
Soil System ◽  
Metal Structures ◽  
Long Span ◽  
Economical Design ◽  
Soil Metal

Soil – metal structures consisting of metal conduits covered with soil have been used extensively for short-span bridges. Recently, some designers ventured into utilizing them for longer spans with shallow soil cover which has led to some failures. Long-span soil – metal structures are often designed with transverse stiffeners attached to the metal structure. Another approach is the use of a reinforced-soil system in which the surrounding soil is reinforced and the metal conduit is tied into the soil. In this paper, a three-dimensional analysis of long-span soil – metal structures is carried out using these two approaches. The analysis is verified and substantiated by results from laboratory models. The structural responses from the two designs show that the latter design approach leads to a more economical structure. A design example based on the Cheese Factory Bridge built in Ontario in 1984 is presented. Key words: bridges, design, long span, reinforced soil, soil – metal structures, structural engineering, three-dimensional analysis.

Hydraulic Mental Structure Health Diagnosis Weighting Method

2014 ◽  
Vol 494-495 ◽  
pp. 925-931
Author(s):  
Kun Yang ◽  
Guang Ming Yang ◽  
Yong Huang ◽  
Pan De Jing
Keyword(s):  
Information Diffusion ◽  
Information Gain ◽  
Fuzzy Theory ◽  
Metal Structure ◽  
Weighting Method ◽  
Metal Structures ◽  
New Ideas ◽  
Multi Level ◽  
Weighting Methods ◽  
Health Diagnosis

By means of inductive analysis the health diagnosis weighting methods in engineering, this paper discusses the basic principle, advantages, disadvantages and applicable scope of weighting methods. On the basis, combining with multi-level, multi-standard and multi-factor characteristic of hydraulic metal structures health diagnosis, the methods of AHP, information gain, information diffusion and improved entropy are studied, which are applicable to hydraulic metal structures health diagnosis weighting. Based on fuzzy theory, the fuzzy multi-level comprehensive weighting method is put forward and studied, which combined both subjective and objective method advantages and its complementary. In addition, it provides the necessary theory foundation and new ideas for the development of hydraulic metal structure health diagnosis technology.

scholarly journals Research on Construction and Sizing of the Metal Structure of a Winding Installation

2021 ◽  
Vol 44 (2) ◽  
pp. 11-16
Author(s):  
Marin-Silviu NAN ◽  
Dorina BĂDIȚĂ (POPESCU) ◽  
Danut GRECEA ◽  
Cosmin VITAN ◽  
Bogdan BRĂNIȘTEANU
Keyword(s):  
Analytical Calculation ◽  
Metal Structure ◽  
Metal Structures ◽  
The Real

The paper focuses on the design of the metal tower for the sinking of Netiș de-ventilating shaft in Râul Mare Retezat hydro-energetic setup. The analytical calculation of sizing and verification of the metal structure is doubled by the graphic simulation with speciality software, in view of obtaining results as close as possible to the real exploitation conditions of the tower. The tower of the de-ventilating shaft is considered to be a temporary construction, and its component parts will be decommissioned once the sinking is finalized. The tower is made up of metal structures in four transoms, 3 being mounted with junction plates and screws, the fourth being the roof.

scholarly journals Comparative study of selected bearing vibration measuring systems

Mechanik ◽  
2018 ◽  
Vol 91 (7) ◽  
pp. 498-500 ◽  
Author(s):  
Stanisław Adamczak ◽  
Mateusz Wrzochal
Keyword(s):  
Comparative Study ◽  
Roller Bearing ◽  
Rolling Bearing ◽  
Vibration Monitoring ◽  
Monitoring Systems ◽  
Measuring Systems ◽  
Bearing Vibration ◽  
Vibration Measuring

Roller bearing manufacturers have individual bearing vibration monitoring systems, consisting of several key components. Despite the fact that the principle of operation of these systems is the same, they differ from each other with some constructional solutions, whereas the type of construction used has an impact on the accuracy of measuring vibrations of a rolling bearing.

scholarly journals Technical condition of welded load-bearing metal structures of operated agricultural hoisting cranes

2020 ◽  
Vol 175 ◽  
pp. 11005
Author(s):  
Alexander Scherbakov ◽  
Anna Babanina ◽  
Ivan Kochetkov ◽  
Pavel Khoroshilov
Keyword(s):  
Plastic Deformation ◽  
Metal Structure ◽  
Technical Condition ◽  
Technical Diagnostics ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Load Bearing ◽  
Metal Structures ◽  
Elastic Plastic ◽  
Alloy Steels

The paper considers the methodology for assessing the technical condition of welded load-bearing metal structures of operated agricultural hoisting cranes. In the course of the study, the relationship between structural, mechanical and magnetic parameters was established during cyclic elastic-plastic deformation of low-carbon and low alloy steels. Based on the analysis, it was concluded that the dependence of the minimum values of the magnetic parameter on the acting stresses Нр(σ) is influenced by the metal structure and its chemical composition. It has been established that the coarser-grained structure of the studied steels under elastic-plastic deformation contributes to a shift in the minimum values of Нр towards lower acting stresses; an increase in the strength characteristics of steels shifts the minimum of Нр toward large values of s, which must be taken into account when conducting technical diagnostics of the elements of the operating metal structures of hoisting cranes. Based on the results of the study, a method for determining the acting stresses in the elements of the metal structures of hoisting cranes was developed, which, by the nature and magnitude of the change in the residual magnetization of the scattering field during their stepwise loading (unloading), allows judging the magnitude of the acting stresses. The work also presents a methodology for assessing the technical condition of welded load-bearing metal structures of hoisting cranes based on the integrated use of passive flux-gate and other control methods, which allows determining the acting stresses used in strength calculations in the identified hazardous zones of concentration of stresses in the elements of metal structures.

scholarly journals The strength of welded structures at low climatic temperatures

2018 ◽  
Vol 245 ◽  
pp. 08001
Author(s):  
Sergey Sokolov ◽  
Ivan Vasilyev ◽  
Konstantin Manzhula
Keyword(s):  
Metal Structure ◽  
Welded Structures ◽  
Metal Structures ◽  
Steel 09G2s ◽  
Normative Documents ◽  
Selection Of

Methods for the selection of steels for metal structures were analyzed in accordance with the normative documents GOST 32578-2013, ISO 20332-2015 and F.E.M.1.001. As the example the choice of steel 09G2S was confirmed for a metal structure of a crane, operated at a temperature of minus 55° C. To confirm the correctness of the choice of steel for this design and justify the allowable size of defects, welded samples were tested at temperatures from plus 20 to minus 60° C.

Theory and Application of a Bi-Metal Ring-Stiffened Cylinder Under External Pressure

1989 ◽  
Vol 33 (04) ◽  
pp. 291-297
Author(s):  
A. Moshaiov ◽  
E. R. Joelson
Keyword(s):  
Metal Structure ◽  
Failure Criteria ◽  
External Pressure ◽  
Pressure Vessels ◽  
Metal Ring ◽  
Principal Stresses ◽  
Collapse Pressure ◽  
Metal Structures ◽  
Young’S Moduli ◽  
Metal Case

Ring-stiffened pressure vessels have historically been constructed of one material only (for example, steel); this is especially true in naval submarines. Existing codes for the design of pressure vessels subjected to external pressure such as ASME and the British Standard BS5500 refer explicitly to unimetal designs only where the stiffening rings and the shell are made of one material only. Bi-metal structures are not accommodated in the design codes. A bi-metal structure would have one type of metal for the shell plating and another type for the ring stiffeners, possibly differing both in Young's modulus and material yield stress. An analytical study of the axisymmetric elastic deformations and stresses in a bi-metal ring-stiffened cylindrical shell under external hydrostatic pressure is given. A closedform solution to the governing differential equation for the bi-metal case is obtained and compared with the uni-metal case. A parametric study is conducted by varying the Young's moduli ratio for the shell and stiffeners of a typical design. Trends in the vessel's critical collapse pressure, shell deflection, and principal stresses are analyzed and the significance of different failure criteria is examined. An approach for modifying current uni-metal design methodologies to accommodate bi-metal structures is suggested. Preliminary comparisons of resulting bi-metal designs with "equivalent" uni-metal designs indicate that a bi-metal pressure hull can have significant advantages. Finally, recommendations for further research studies are made.

A Framework of Assessing Remaining Fatigue Life of Aged Crane Structures

2012 ◽  
Vol 226-228 ◽  
pp. 1141-1144
Author(s):  
Kai Qi ◽  
Wei Xiong Wang ◽  
Xin Hua Wang ◽  
Ai Hua Jiang ◽  
Bai Qing Liu
Keyword(s):  
Fatigue Life ◽  
Steel Structure ◽  
Metal Structure ◽  
Gantry Crane ◽  
Metal Structures ◽  
Analysis Process ◽  
Element Simulation ◽  
Fatigue Life Estimation ◽  
Fatigue Life Evaluation ◽  
Remaining Fatigue Life

The fatigue life of crane steel structure will inevitably decrease in the course of work, which directly affects the work of crane. So the correct fatigue life evaluation is necessary. Based on crack propagation theory, a framework of assessing remaining fatigue life of crane metal structures is built in this paper. Moreover, in order to descript the analysis process, an example about fatigue life estimation of a shipbuilding gantry crane whose maximum hoist 100 ton was shown. During assessment of remaining fatigue life of aged crane structure, some important indexes were inspected such as corrosion，strength and defection in focused weld joints, besides of finite element simulation of structure. The results can also be used to evaluate the whole metal structure of this crane.

scholarly journals Influence of metal bar lever-arm on screws detorque for dental prosthesis implant supported

2020 ◽  
Vol 49 ◽  
Author(s):  
Wilson MATSUMOTO ◽  
Ana Paula MACEDO ◽  
Rossana Pereira de ALMEIDA ◽  
Anselmo Agostinho SIMIONATO ◽  
Takami Hirono HOTTA
Keyword(s):  
Metal Structure ◽  
Application Site ◽  
Metal Structures ◽  
Chewing Simulation ◽  
Cantilever Length ◽  
Significant Difference ◽  
Two Factors ◽  
Torque Loss ◽  
Fixed Prosthesis ◽  
Moisture Conditions

Abstract Introduction The cantilever length of implant-supported fixed prosthesis metal structure has been considered an important factor to transfer occlusion forces to the dental implant. Objective This study evaluated the influence of different extensions of cantilevers of Branemark protocol implant prosthesis when submitted to mechanical thermocycling by screw loosening evaluation. Material and method The groups G10 (n = 5), G15 (n = 5) and G20 (n = 5) were formed according to the distance in millimeters between the force application site in the cantilever and the center of the last implant. All metal structures (n = 15) were submitted to a 120 N cyclic vertical load in a chewing simulation machine (MSM-Elquip, São Carlos-SP, Brazil) under controlled temperature and moisture conditions. Two hundred and fifty thousand mechanical cycles were performed with a frequency of 2 Hz that simulates a masticatory activity similar to 3 months. To compare the data obtained regarding the loosening of the metal structure screws, implant position and sites of load application, the analysis of variance with two factors and the Tukey test were performed. Result Statistical analysis showed that the G10 group presented greater torque loss, statistically different from G15 (p = 0.001) and G20 (p = 0.002), and there was no significant difference between groups G15 and G20. Conclusion It can be concluded from the results that all the screws presented torque loss after simulation of 3 month masticatory activity, suggesting the need for periodical evaluation to prevent failures in the treatment.

scholarly journals ANÁLISE DE SOLDA EM ESTRUTURA METÁLICA

2019 ◽  
Vol 10 (2) ◽  
pp. 33
Author(s):  
Thomas Röhsig ◽  
Sandra Raquel Kunst ◽  
Leonardo Félix Scheffel ◽  
Luciane Taís Fuhr ◽  
Carlos Leonardo Pandolfo Carone ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Low Cost ◽  
Welding Process ◽  
Metal Structure ◽  
Metallurgical Industry ◽  
Market Segments ◽  
Metallic Structures ◽  
Metal Structures ◽  
Eds Analysis ◽  
Microstructural Behavior

O processo de soldagem em estruturas metálicas possui destaque dentro da indústria metalúrgica, pois é a melhor maneira de unir materiais com baixo custo, quando comparado a outros métodos. Diversos são os segmentos de mercado onde se faz necessário o uso de estruturas metálicas soldadas. Estruturas metálicas possuem algumas vantagens sobre os sistemas construtivos convencionais, tais como precisão, devido ao fato de os elementos serem produzidos em fábrica, possibilidade de seções menores, construções com maiores vãos e rapidez na execução da obra. A soldagem de estruturas metálicas pelo processo MIG/MAG tem se mostrado muito eficiente, sendo o método mais utilizado nas soldas de emendas dessas estruturas. O presente trabalho relata uma análise laboratorial através de metalografia da solda em questão, avaliando o seu comportamento microestrutural e sua composição química em diferentes zonas. Portanto, este trabalho tem como objetivo geral analisar a microestrutura formada em determinada parte de uma estrutura metálica soldada. Para tanto, inicialmente foi realizado o acompanhamento termográfico da estrutura durante o processo de soldagem, seguido da retirada dos corpos de prova. O processo metalográfico possibilitou análises de microscopia ótica, microscopia eletrônica de varredura e análises de EDS. Os resultados mostraram um crescimento já esperado dos grãos na região da solda e apresentaram variações em relação à composição química ao longo da área soldada.Palavras-chave: Estruturas metálicas. Soldagem. Corrosão.ABSTRACTThe welding process in metal structures is prominent within the metallurgical industry, as it is the best way to join materials with low cost when compared to other methods. Several are the market segments where it is necessary to use welded metal structures. Metal structures have some advantages over conventional constructional systems, such as accuracy due to the fact, that the elements are produced in the factory, smaller sections are possible, constructions with bigger spans besides the speed in the execution of the work. The welding of metallic structures by the MIG / MAG process has been proved very efficient and is the most used method for this purpose in the welds of joints of these structures. The present work reports a laboratory analysis through metallography of the weld in question, evaluating its microstructural behavior and its chemical composition in different zones. Therefore, this work has as general objective to analyze the microstructure formed in certain part of a welded metal structure. To do this, the thermographic monitoring of the structure was carried out during the welding process, followed by the removal of the samples. The metallographic process allowed the analysis of optical microscopy, scanning electron microscopy and EDS analysis. The results showed an expected growth of the grains in the region of the weld and showed variations in relation to the chemical composition along the welded area. Keywords: Metal structures. Welding. Corrosion.

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