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.

scholarly journals Mechanisms of construction machines and selection of steels for the manufacture of welded metal structures

2020 ◽  
Vol 1001 ◽  
pp. 012012
Author(s):  
Alexander Scherbakov ◽  
Anna Babanina ◽  
Elena Solovyeva ◽  
Maxim Aleksandrovskiy
Keyword(s):  
Metal Structures ◽  
Selection Of

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.

scholarly journals COMPARATIVE ANALYSIS AND SELECTION OF TECHNOLOGY OF DEVICE OF FENCING METAL STRUCTURES IN CONSTRUCTION OF UNDERGROUND STRUCTURES

2021 ◽  
Vol 9 (1) ◽  
pp. 26-30
Author(s):  
Elena Korol ◽  
Zarina Chipova
Keyword(s):  
Underground Structures ◽  
Engineering Structures ◽  
Metal Structures ◽  
Large Cities ◽  
Long Time ◽  
Complex Engineering ◽  
Transport Problems ◽  
The Cost ◽  
Transport Complex ◽  
Selection Of

Urban motor transport complex engineering structures, the construction of which is carried out for a long time, and the cost is often tunnels of structures. Despite this, urban tunnels remain in demand as a means of solving transport problems, especially for large cities, in areas with dense urban development or an established architectural appearance, the violation of which is unacceptable. The construction of tunnels makes it possible to increase the throughput of highways, especially in places of large intersections, one of the diverting high-intensity transit traffic flows underground, making them invisible on the surface and thus not disrupting the existing historical appearance of the area.

scholarly journals Calibration and measurement capability (CMC) and customer technical qualification

2019 ◽  
Author(s):  
Suelí Fischer Beckert ◽  
Renan Ednan Flôres
Keyword(s):  
Measuring Range ◽  
Measurement Capability ◽  
Normative Documents ◽  
Calibration Methods ◽  
Accredited Laboratories ◽  
Accredited Laboratory ◽  
Effective Use ◽  
Formal Recognition ◽  
Selection Of ◽  
Calibration And Measurement Capability

In the context of metrological confirmation, calibration is an essential process in all quality assurance efforts. Several organizations choose to outsource this activity to accredited laboratories in accordance with the requirements set forth in ISO/IEC 17025: 2017. Companies understand that accredited laboratory has formal recognition of its technical competence to perform the services within its scope of accreditation. The document ILAC P14: 2013 sets out guidelines for the presentation of Calibration and Measurement Capability (CMC). However, when analysing the scope of accredited laboratories in some national calibration bodies, it is possible to observe that, for the same instrument and the same measuring range, different values are attributed to CMC. If the CMC should result from normal calibration operations on the best existing device, what causes this dispersion? How can the customer make effective use of the information contained in accreditation scopes? In order to further standardize the presentation of CMC in accreditation scopes, calibration methods adopted by laboratories should be required to meet the maximum permissible errors established by manufacturers or normative documents. Companies can outsource calibration activities. But the selection of service provider and the interpretation of the results remains a customer assignment. The paper presents an analysis of accreditation scopes of different national calibration bodies and discusses the qualification of those in charge of metrology management, regarding the knowledge and skills required for activity.

Measurement of Weld Mechanical Properties Using an Instrumented Indentation Technique

2017 ◽  
Vol 754 ◽  
pp. 383-386
Author(s):  
Kee Nam Song
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Weld Zone ◽  
Base Material ◽  
Metal Structure ◽  
Instrumented Indentation ◽  
Welded Structures ◽  
Indentation Technique ◽  
Lower Confidence ◽  
Welded Structure

Different microstructures in the weld zone of a metal structure including a fusion zone and a heat affected zone, are formed as compared to the base material. Consequently, the mechanical properties in the weld zone are different from those in the base material to a certain degree owing to different microstructures and residual welding stresses. When a welded structure is loaded, the mechanical behavior of the welded structure might be different from the case of a structure with homogeneous mechanical properties. It is known that obtaining the mechanical properties in the weld is generally difficult owing to the narrow regions of the weld and interfaces. As an alternative way to obtain the weld mechanical properties, the weld mechanical properties of Alloy800HT, SUS316L, and Alloy617, were recently measured using an instrumented indentation technique, and the representative weld mechanical properties of these materials were estimated with a 95% lower confidence level for later structural analyses of the welded structures.

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 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.

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.

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.

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