scholarly journals Some Comments on Designing of Steel Structures According to European Standards

2019 ◽  
Vol 18 (2) ◽  
pp. 113-120
Author(s):  
Y. Y. Davydov
Keyword(s):  
Steel Structures ◽  
Load Combination ◽  
Load Factors ◽  
Partial Load ◽  
Calculated Load ◽  
Similar Materials ◽  
Technical Specifications ◽  
The Republic ◽  
European Standards ◽  
Materials Used

Critical comments on the European standards for designing steel structures including welded and bolted joints have been given on the basis of application experience and executed analysis. Comments are presented in comparison with similar regulatory documents which are in effect in Belarus. European standards concerning loads (determination of calculated load values and drawing up of design load combination) have been also analyzed. Particular attention has been paid to the analysis of European standard requirements to steel and welding materials and their comparison with mechanical characteristics of similar materials used for manufacture of steel structures in Belarus. The paper gives notice to the rules which are accepted in the European norms and the rules being compared with the similar rules used in Construction rules and regulations (SNiP) lead to a significant increase in material consumption of steel structures. First of all, it concerns assignment of partial load factors and classification of sections for ensuring local stability of compressed and partially compressed elements. The paper pays a special notice to the rules of Eurocodes that do not meet requirements of State standards and technical specifications operating in the Republic of Belarus. Significant limitations of some European rules regarding calculation of centrally and eccentrically compressed elements, absence of rules for testing overall stability of through and step columns which are widely used while implementing projects Belarus have been described in the paper. Conclusions have been made on the basis of the analysis results and according to them application of European standards for designing steel structures has significant limitations on the territory of the Republic of Belarus.

The Method Research for Appraisal of Reliability of Existing Lightweight Steel Structures

2014 ◽  
Vol 578-579 ◽  
pp. 1562-1566
Author(s):  
Zhong Yang Liu ◽  
Wei Chen ◽  
Li Jun Zhang
Keyword(s):  
Structural Analysis ◽  
Steel Structures ◽  
Conversion Factors ◽  
Lightweight Steel ◽  
Load Factors ◽  
Partial Load

Combined with the characteristics of existing lightweight steel structures, the paper gives an adapted method and flowchart for appraisal of reliability of these structures, and explains objectives appraisal of existing lightweight steel structures. It indicates that assessment based on structural analysis is the available method for scientific and saving, according to the demond of market and owner. It also discussed the central technique and the main problems of appraisal in current, such as revision of partial load factors, consideration of conversion factors, etc.

scholarly journals Limit states design of antenna towers

1994 ◽  
Vol 21 (6) ◽  
pp. 913-923 ◽  
Author(s):  
Yohanna M. F. Wahba ◽  
Murty K. S. Madugula ◽  
Gerard R. Monforton
Keyword(s):  
Direct Interaction ◽  
Steel Structures ◽  
Ice Accretion ◽  
Structural Behaviour ◽  
Limit States ◽  
Working Stress ◽  
Load Factors ◽  
Partial Load ◽  
Wind Pressures ◽  
Supporting Structures

The Canadian Standard CAN/CSA-S37-M86 “Antennas, towers and antenna supporting structures” follows a quasi-limit states approach in which the member forces determined for specified loads are multiplied by a unified factor and compared with factored resistances given in CAN3-S16.1-M84. This results in designs basically the same as those resulting from a working stress design with a factor of safety of 5/3. Such structures exhibit a non-linear structural behaviour even under service loads. Thus the effect of ice accretion and direct interaction between wind and ice does not permit the load factors specified in CAN/CSA-S16.1-M89 “Limit states design of steel structures” to be directly applied to antenna supporting structures.In this study, 41 different towers (representing various heights and designed for different ice classes and wind pressures) were analyzed under specified loads and then under a set of factored loads. From the comparison of the design forces in the towers with those calculated according to the existing standard, a set of partial load factors was derived. The new load factors to be used in the 1993 edition of S37 are presented and justified. Key words: antenna towers, guyed towers, ice and wind loads, limit states design, self-supporting towers, working stress design.

Genetic Algorithm-Based Searching Method for Piping Path Routing in Coal-Fired Boiler Buildings

2011 ◽  
Author(s):  
Naohiro Kusumi ◽  
David E. Goldberg ◽  
Noriyuki Ichinose
Keyword(s):  
Genetic Algorithm ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Search Space ◽  
Design System ◽  
Dynamic Programming Method ◽  
Plant Design ◽  
Technical Specifications ◽  
The Many ◽  
Searching Method

Power plant design using digital engineering based on 3-D computer-aided design has become a mainstream technology because of possessing higher speed and improvement in design accuracy. To take a coal-fired boiler building as an example, it has many complex structures with several million parts including the boiler itself, large fans, steel structures, and piping in varying sizes. Therefore, it is not easy to maintain integrity of the whole design throughout all the many engineering processes. We have developed a smart design system for coal-fired boiler buildings to solve the integrity problem. This system is capable of creating and allocating 3-D models automatically in accordance with various technical specifications and engineering rules. Lately, however, there has been a growing demand for more effectiveness of the developed system. We have begun to look into the feasibility of further improvements of the system function. The first point to note, when considering effectiveness, is the piping path routing process in the coal-fired boiler building. The quantity of piping is large, and it has a considerable impact on performance of the whole plant because hot steam is fed into the steam turbine and cold steam is taken from it through the piping. A considerable number of studies have been made on automatic searching methods of piping path routing. Although, the decision of piping path routing by using the Dynamic Programming method is most commonly, a previously decided routing becomes an interference object because of the single searching method. Therefore, basically, the later the order of the routing becomes, the longer the length of the routing becomes. To overcome this problem, in this paper we have proposed a new searching method based on the Genetic Algorithm (GA). The GA is a multipoint searching algorithm based on the mechanics of natural selection and natural genetics. Virtual prohibited cells are introduced into the proposed search method as a new idea. The virtual prohibited cells are located in a search space. The different paths are generated by avoiding the virtual prohibited cells while searching for the piping path routing. The optimum locations of the prohibited cells which are expressed in a genotype are obtained by using the GA in order to get a lot of paths independent of the order of the routing. The proposed method was evaluated using a simple searching problem. The results showed that many effective paths are generated by making the virtual prohibited cells.

scholarly journals INFORMATION TECHNOLOGIES IN THE FINANCING OF POLITICAL PARTIES (CASE STUDY OF THE REPUBLIC OF MOLDOVA)

2019 ◽  
Vol 2 (1(31)) ◽  
pp. 57-65
Author(s):  
Rodica Svetlicinâi ◽  
Mariana Iațco ◽  
Tatiana Turco
Keyword(s):  
Political Parties ◽  
Information Technologies ◽  
A Priori ◽  
Financial Reports ◽  
Political Actors ◽  
Republic Of Moldova ◽  
Financial Activity ◽  
Electoral Campaign ◽  
The Republic ◽  
European Standards

The issue of reporting on the financial activity of political parties is crucial for any democratic society. At the same time, the presentation of financial reports by political parties is a mandatory element in ensuring greater transparency of their activity as a whole. Transparency of party financing activities is necessary to protect voters' rights to obtain the necessary information on financial support to political parties as well as the costs associated with running the electoral campaign, etc., which ensures a more trained and informed voter for the exercise of his / her rights in a democratic system. One way to increase the transparency of political parties' funding is the system of online reporting of political party incomes and expenditures. For the Republic of Moldova this is an a priori, given that our society has set its course towards European standards and values, and the political arena is characterized by the diversity of political actors segmented according to the ideals claimed in their platform and status.

scholarly journals Early-Age Thermal-Shrinkage Cracking in Deep Foundations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Łukasz Grabowski ◽  
Monika Mitew-Czajewska
Keyword(s):  
Thermal Shrinkage ◽  
Future Research ◽  
Early Age ◽  
Deep Foundations ◽  
Shrinkage Cracking ◽  
The United Kingdom ◽  
Normative Requirements ◽  
Geotechnical Design ◽  
European Standards ◽  
Materials Used

Abstract With the growing rate of urbanisation, deep foundations are playing an ever-larger role in the development of cities, reaching deeper than before to fulfil the requirements of new constructions. While current European standards include design procedures for structural and geotechnical design, they lack provisions for massive deep foundations with regard to early-age thermal effects. This paper presents aspects of the phenomenon especially important for deep foundations and discusses normative requirements that influence their thermal behaviour. Further, the paper describes the methods and results of the research carried out in the United Kingdom on 1.50-m-thick diaphragm walls of a deep circular shaft. Shaft features are described, as well as the materials used. The measurements were carried out using vibrating wire strain gauges coupled with temperature readings. The results presented refer to one of the test panels concreted in January 2020. The temperature results are analysed together with the influence of work scheduling on the readings. Strain results that indicate contractive behaviour of the test panel are investigated together with the possible causes leading to such readings. Plans and directions for future research are discussed.

scholarly journals Elaboration and industrial implementation of lean alloy steel rolled stock production for structures of road bridges

2020 ◽  
Vol 76 (3) ◽  
pp. 228-233
Author(s):  
A. A. Pridein ◽  
L. V. Prokopenko ◽  
O. V. Samokhina ◽  
S. P. Zubov ◽  
D. A. Shablya ◽  
...  
Keyword(s):  
Alloy Steel ◽  
Minimum Temperature ◽  
Steel Production ◽  
Steel Structures ◽  
Weather Conditions ◽  
Rolled Stock ◽  
Steel Bridge ◽  
Welding Technology ◽  
Trial Batch ◽  
Technical Specifications

Within the national project “Safe and quality automobile roads” realization a big number of bridge passages will be constructed, including steel road bridges with small (14–42 m) spans instead of reinforced concrete bridges. Application of metal rolled products of 10ХСНД, 15ХСНД, 10ХСНДА, 15ХСНДА steels in the steel structures of bridges with small spans results in unreasonable increase the costs of the bridges structures. This circumstance stipulates necessity to elaboration and implementation of cheap lean alloy steel for manufacturing standard short-spanned bridges. The steel production should involve minimal and lean alloying method and ensure complex of operation properties in normalized state. At JSC “Ural Steel” an experiment work was accomplished for elaboration lean alloy steel 12Г2СБД due to STO 13657842-1 having standard yield strength 345 MPa. In cooperation with NIZ “Mosty”, OJSC “CNIIS” and CNIIchermet after I.P. Bardin technical specifications of plates for short-spanned bridges were elaborated and approved. Comprehensive technology of 12Г2СБД steel plate production was elaborated. A trial batch of 12Г2СБД steel plates was produced and shipped to ZAO “Kurganstalmost”. Study of welding and technological characteristics of the trial batch plates was carried out. The study showed, that the plates of 12Г2СБД steel have low sensitiveness against heat action of a welding thermal cycle and can be used in welding structures of steel bridge spans providing keeping the plant and assembling welding technology by standard regimes (due to welding technology of steel 10–15ХСНД). Application of the plant and assembling technology at welding by standard regimes makes it possible to use the plates of the elaborated steel for manufacturing metal structures of short-spanned metal bridges for various weather conditions. The plated can be used for both a regular performance (the calculated minimum temperature is down to –40 °С inclusive) and a northern performance Zone A (the calculated minimum temperature is down to –50 °С inclusive).

COMMUNICATION SYSTEMS OF POLISH MILITARY CONTINGENTS IN PEACEKEEPING OPERATIONS AND STABILIZATION MISSIONS

2012 ◽  
Vol 164 (2) ◽  
pp. 104-115
Author(s):  
Maciej MARCZYK
Keyword(s):  
Communication Networks ◽  
Communication Systems ◽  
Ad Hoc ◽  
Armed Forces ◽  
Military Operations ◽  
Peacekeeping Operations ◽  
National Security Strategy ◽  
International Operations ◽  
Technical Specifications ◽  
The Republic

Polish soldiers have long participated in international operations under the auspices of various organizations, primarily the UN. However, since Poland’s accession to NATO and the adoption of our country to European Union, the activities of our military contingents have focused primarily on participation in international operations, organized by the two organizations and under the terms of their procedures. Poland, as part of joint and several actions to ensure common security, has actively been engaged in military operations and non-military missions of various international organizations, as well as local actions in the ad hoc coalition created. The degree of involvement and geographical areas are determined by the current capabilities of the armed forces and the clearly defined objectives coincide with the Polish raison d'etat, as defined in the National Security Strategy of the Republic of Polish and expressed in their efforts to strengthen Poland’s international position. This paper presents the results of research on the functioning of NEC communication network (the Polish military contingent) in military operations abroad. The research was carried out among the soldiers-specialists who were involved in international operations and it focused on the organizational requirements: the technical specifications for the NEC communication networks. Also, the research concerned the organization and operation of communication networks and its services as well as the means of communication and IT used by the staff, users, soldiers and NEC employees.

Use Wear on Bone and Antler Tools from the Mackenzie Delta, Northwest Territories

1994 ◽  
Vol 59 (2) ◽  
pp. 316-334 ◽  
Author(s):  
Genevieve M. LeMoine
Keyword(s):  
Northwest Territories ◽  
Experimental Results ◽  
Fish Scales ◽  
Mackenzie Delta ◽  
Use Wear ◽  
Similar Materials ◽  
Series Of Experiments ◽  
Materials Used ◽  
Historical Accounts ◽  
Lines Of Evidence

A series of experiments making and using bone and antler tools show that functional identifications of these tools can be made with confidence in some circumstances. Using principles from the field of tribology, the experiments demonstrate that different uses leave different microscopic traces on bone and antler. They also show that when the materials used are similar, the wear produced will be similar. In particular, wet materials, including snow, ice, wet hide, and wet antler all produce nearly identical microscopic patterns. Other groups of similar materials, such as bone, antler, and wood, or fish scales and hair, present the same problem. Although differences can be detected, these may not be preserved on archaeological tool specimens. Application of the experimental results to bone and antler tools from the Mackenzie Delta illustrates that functional identifications of tools can be made with confidence, despite the problem of similar microscopic patterns, when other lines of evidence (ethnographic and historical accounts, distribution of wear) are taken into account. When such information is lacking, functional identifications are more difficult and must be made with more caution.

Influence of Predetermined Surface Defect to the Bendability of Ultra-High-Strength Steel

2012 ◽  
Vol 504-506 ◽  
pp. 901-906 ◽  
Author(s):  
Antti Määttä ◽  
Antti Järvenpää ◽  
Matias Jaskari ◽  
Kari Mäntyjärvi ◽  
Jussi A. Karjalainen
Keyword(s):  
Surface Defects ◽  
High Strength Steels ◽  
Steel Structures ◽  
High Strength ◽  
Crack Size ◽  
Critical Crack ◽  
Bending Radius ◽  
Ultra High Strength Steels ◽  
Materials Used ◽  
Critical Crack Size

The use of ultra-high-strength steels (UHS) has become more and more popular within last decade. Higher strength levels provide lighter and more robust steel structures, but UHS-steels are also more sensitive to surface defects (e.g. scratches). Practically this means that the critical crack size decreases when the strength increases. The aim of the study was to study if the formula of critical crack size is valid on forming processes of UHS-steels. Surface cracks with different depths were created by scratching the surface of the sheet by machining center. Effect of the scratch depth was determined by bending the specimens to 90 degrees. Bents were then visually compared and classified by the minimum achieved bending radius. Test materials used were direct quenched (DQ) bainitic-martensitic UHS steels (YS/TS 960/1000 and 1100/1250). Results from the bending tests were compared to the calculated values given by the formula of critical crack size.

Transforming the Moldovan Prosecution Service: Can the Eyes of the State Become the Voice of the People?

2012 ◽  
Vol 12 (3) ◽  
pp. 491-518 ◽  
Author(s):  
John Pearson
Keyword(s):  
European Union ◽  
Legal Institutions ◽  
The European Union ◽  
Reform Initiatives ◽  
Republic Of Moldova ◽  
The People ◽  
Political Interference ◽  
The Republic ◽  
European Standards ◽  
The Voice

The Republic of Moldova yearns for the embrace of the European Union. But before this can happen, Moldova must first transform its legal institutions to approximate European standards. This article focuses on one of Moldova’s most powerful legal institutions, the Office of the Prosecutor General. It asks whether this office can be transformed from a militarized relic of the Soviet past to a modern prosecution service. Many daunting challenges will have to be overcome, including the spectre of political interference; an overly broad mandate; deep seated public mistrust; the corruption entrenched in Moldova’s legal institutions; and the absence of cross-sector justice reform initiatives.

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