Nauki Techniczne

Archives of Civil Engineering

Zawartość

Archives of Civil Engineering | 2017 | No 2 |

Abstrakt

Cold-formed structure connections utilizing gusset plates are usually semi-rigid. This paper investigates the behaviours of rectangular gusset plates in cold-formed connections of elements whose columns and beams are made with lipped back-to-back C-sections. Methods of calculating strength and stiffness are necessary for such semi-rigid joints. The main task of this paper is to determine a method capable of calculating these characteristics. The proposed analytical method could then be easily adapted to the component method that is described in part 1993-1-8 of the Eurocode. This method allows us to calculate both the strength and stiffness of rectangular gusset plates, assuming that the joint deforms only in plane. This method of design moment resistance calculation was presented taking into account that an entire cross-section shall reach its yield stress. A technique of stiffness calculation was presented investigating the sum of deformations acquired at the bending moment and from shear forces which are transmitted from each beam bolt group. Calculation results according to the suggested method show good agreement of laboratory experimental results of specimens with numerical simulations. Two specimens of beam-to-column connections were tested in the laboratory. Lateral supports were used on the specimens to prevent lateral displacements in order to better investigate the behaviour of the rectangular gusset plate in plane. Experiments were simulated by modelling rectangular gusset plates using standard finite element software ANSYS Workbench 14.0. Three-dimensional solid elements were used for modelling and both geometric and material nonlinear analysis was performed.

Przejdź do artykułu

Abstrakt

This study aims to design a novel air cleaning facility which conforms to the current situation in China, and moreover can satisfy our demand on air purification under the condition of poor air quality, as well as discuss the development means of a prototype product. Air conditions in the operating room of a hospital were measured as the research subject of this study. First, a suitable turbulence model and boundary conditions were selected and computational fluid dynamics (CFD) software was used to simulate indoor air distribution. The analysis and comparison of the simulation results suggested that increasing the area of air supply outlets and the number of return air inlets would not only increase the area of unidirectional flow region in main flow region, but also avoid an indoor vortex and turbulivity of the operating area. Based on the summary of heat and humidity management methods, the system operation mode and relevant parameter technologies as well as the characteristics of the thermal-humidity load of the operating room were analyzed and compiled. According to the load value and parameters of indoor design obtained after our calculations, the airflow distribution of purifying the air-conditioning system in a clean operating room was designed and checked. The research results suggested that the application of a secondary return air system in the summer could reduce energy consumption and be consistent with the concept of primary humidity control. This study analyzed the feasibility and energy conservation properties of cleaning air-conditioning technology in operating rooms, proposed some solutions to the problem, and performed a feasible simulation, which provides a reference for practical engineering.

Przejdź do artykułu

Abstrakt

Heating of steel or structural aluminum alloys at a speed of 2 to 50 K/min – characterizing the fire conditions – leads to a reduction in mechanical properties of the analyzed alloys. The limit of proportionality fp, real fy and proof f₀₂ yield limit, breaking strength fu and longitudinal limit of elasticity E decrease as the temperature increases. Quantitative evaluation of the thermal conversion in strengths of structural alloys is published in Eurocodes 3 and 9, in the form of dimensionless graphs depicting reduction coefficients and selected (tabulated) discrete values of mechanical properties. The author’s proposal for an analytical formulation of code curves describing thermal reduction of elasticity modulus and strengths of structural alloys recommended for an application in building structures is presented in this paper.

Przejdź do artykułu

Abstrakt

Construction risk assessment is the final and decisive stage of risk analysis. When highly changeable conditions of works execution are predicted, risk should be evaluated in the favorable, moderate, and difficult random conditions of construction. Given the random conditions, the schedule and cost estimate of the construction are developed. Based on these values, the risk of final deadline delay and the risk of total cost increase of construction completion are calculated. Next, the charts of the risks are elaborated. Risk changes are shown in the charts and are analyzed in the range [1, 0].

Przejdź do artykułu

Abstrakt

The preliminary stage of asphalt mixture production involves the drying and dedusting of coarse aggregates. The most common types of coarse aggregates used are limestone and basalt. In the process of drying and dedusting the dryer filter accumulates large quantities of waste in the form of mineral powder.

This paper introduces an investigation into limestone powder waste as a potential microfiller of polymer composites. Physical characteristics such as the granulation the of powder collected from the filter - in terms of the season of its collection and the type of input materials used - were analysed. A scanning electron microscope (SEM) was used for the investigation described within this paper. The obtained results were compared against those of other materials which can be used as polymer composites microfillers.

Przejdź do artykułu

Abstrakt

This paper deals with the prevention of failure of structural elements made of reinforced concrete. It discusses preservice cracks in the concrete decks of an underground parking facility. The cracks were assessed by analyzing their morphology. The results were used to determine the crack causes and the mechanisms of their initiation and growth. Some design solutions to prevent or reduce the occurrence of pre-service cracks are also presented.

Przejdź do artykułu

Abstrakt

This paper presents new procedure modeling based on finite element method analysis of wood-framed timber structures. The fasteners linking boards of sheathing with the timber frame both modeled applying shell finite element, with individual material parameters, remain the main objective of this manuscript. Material parameters are obtained from experimental tests and numerical identification. The main objective of the paper is the elaboration of the numerical model with high precision of mapping, and, at the same time, diminishing the number of the unknown simplifying the process of the modeling of timber structures. The new presented method leads to a simplification of analysis of multistory wood-framed multifamily building structures.

Przejdź do artykułu

Abstrakt

Insufficient due planning policy in Poland is subject to widespread and justified criticism. This applies to all levels of spatial management. Legal instruments governing spatial planning in Poland are passive - setting out only the legal framework corresponding to a particular area. They regulate what might be developed within its boundaries, however, they do not specify how it is to be accomplished. Therefore, there is a need to develop an integrated spatial development planning, in which also investors and/or stakeholders would be involved. Apart from answering to the question of what is going to be developed, it will also provide a very comprehensive and flexible implementation strategy having regard to different timelines and local amenities (facilities). This paper also brings an example showing how the spatial planning strategy was conducted for the development of the "Fort Bema" housing estates in the Warsaw district of Bemowo. It highlights the relevance of the planning phase for the subsequent in-use (operating) phase.

Przejdź do artykułu

Abstrakt

This paper presents research results of composite tubes filled with self-compacting concrete. The impact of the selected materials and geometric factors on resistance to the vertical shear was evaluated in this study. The resistance of the tested members was compared with recommendations given in Eurocode PN-EN 1994-1-1. From the results obtained in the tests it can be deduced that more parameters should be taken into consideration when determining resistance to the vertical shear in the interface between steel and concrete than PN-EN 1994-1-1 recommends.

Przejdź do artykułu

Abstrakt

This article shows incidents associated with the use of gas as an energy carrier. It presents selected incidents which have occurred in Poland and around the world in recent decades. Based on this, consequences of gas and air mixture explosions were analysed as well. The article presents the main causes of gas incidents which have taken place, as per instances which are similar worldwide. Incidents associated with the use of gas are not frequent, but at the same time very tragic as they often lead to illness or even death. In Poland, in the last twenty years, construction area disasters caused by gas explosions account for only 5% of all which have occurred, but the number of fatalities resulting from these cases is approximately 14%. The number of individuals injured reached 39% of all construction disaster victims. Considering all these facts, it is necessary to undertake wide preventive measures in order to increase safety in the use of gaseous fuels.

Przejdź do artykułu

Abstrakt

The protection of Polish architectural heritage in the former eastern borderlands, accomplished through the conservation and technical securing of historical structures, constitutes one of the main programmes that are implemented by the Ministry of Culture and National Heritage. Currently, many Polish historical buildings in the former eastern borderlands are in a very bad technical condition. The load-bearing systems of these elements, as well as elements of their finish, require immediate emergency securing work. The basic steps that precede conservation work are emergency structural works, which guarantee the durability and stability of the entire historical substance. The specifics and complexity of the problem of the failure of historical buildings often demands an in-depth analysis of a series of factors that are difficult to measure and which are responsible for the cause and effect relationship during the early stage of the technical evaluation of a structure. The analyses of failures of numerous historical structures, for instance that were carried out by the authors, have become the inspiration for the search for effective methods of analysis that would allow for an in-depth analysis of the causes and effects of the failures in question. The DEMATEL method (Decision Making Trial and Evaluation Laboratory) that has been presented in this work, and its fuzzy extension, has lately become one of the more popular methods used in the cause-and-effect analysis of various phenomena. The authors demonstrated how this method works on the example of the evaluation and securing of the load-bearing system of the XVII Collegiate church of the Holy Trinity in the town of Olykha in the Volhynskiy Oblast, Ukraine.

Przejdź do artykułu

Abstrakt

This paper addresses the problem of road safety regarding barrier placement as relative to the curb. A short summary of existing regulations is presented. Numerical simulations using the explicit finite element system Ls-Dyna are shown. In the analysis, variable distance between the barrier and the curb is assumed. The obtained result reveals that the distance has little impact on the working width of the barrier.

Przejdź do artykułu

Redakcja

Editor-in-Chief
Henryk Zobel


Deputy Editor-in-Chief
Mariola Książek


Scientific Advisory Committee
:
Andrzej M. Brandt
Werner Brilon (Germany)
Jacek Chróścielewski
Luc Courard (Belgium)
Andrzej Garbacz
Andrzej Garstecki
Wojciech Gilewski
Marian Giżejowski
Oleg Kapliński
Piotr Konderla
Aleksander Kozłowski
Marian Kwietniewski
Zbigniew Młynarek
Andrzej S. Nowak (USA)
Anna Siemińska-Lewandowska
Jan Szwabowski
Waldemar Świdziński
Andrew P. Tarko (USA)
Marian Tracz
Edmundas K. Zavadskas (Lithuania)
Jerzy Ziółko

Secretary
Katarzyna Orzeł

Kontakt

 

Politechnika Warszawska

Wydział Inżynierii Lądowej

Al. Armii Ludowej 16, 00-637 Warszawa, Polska Pokój 618; Telefon 22 234 62 84

e-mail: ace@il.pw.edu.pl;

website: http://ace.il.pw.edu.pl

 

 

 

Instrukcje dla autorów

GUIDELINES FOR AUTHORS

1. Preparation of the paper

General: Author is responsible for the Paper contents including copyrights and text formatting. The manuscript should be written in English. It should be typed using 12 p TNR font with 1.5 line spacing, on single-sided A4 sheets with 2 cm margins. The paper should not exceed 10 pages including tables and figures plus 2 pages of an extended summary (TNR 10 pt. justify align), started from new page at the end of the manuscript. Summary in Polish for Polish natives only, others - summary in English.

The first page and the main text: The first page of the article should contain: (1) the title of the article, (2) the name, academic merits, affiliation and e-mail of each author, (3) the name and the address of the author to whom correspondence, proofs and reprints should be sent, (4) a summary of 50-150 words, (5) a list of key words (not to exceed 8). The main text should be divided into numbered (1, 2, etc.) and titled sections and, if needed, into subsections (1.1, 1.2, ... in Section 1, 2.1, 2.2, ... in Section 2, etc.). The abstract of 50-150 words is required on a separate sheet. Polish natives authors only are requested to enclose Polish translation of the abstract, others - abstract in English.

Tables and figures: Tables and figures should be inserted into the text (black-and-white figures and glossy photographs),numbered consecutively and titled. They should be referred to in the text as Fig. 1, Fig. 2, ..., Table 1, Table 2. A list of figures and tables captions (TNR 11 pt. left align, in Polish - for Polish natives only and in English) should be provided on separate sheet(s) at the end of the manuscript beforean extended summary. Colour figures will be accepted only if the colour is essential for the explanation.

Units and mathematical formulae: SI units and abbreviations are obligatory. Mathematical formulae should be typewritten and centred. The formulae referred to in the text are to be numbered consecutively in each Section, i.e. (1.1), (1.2), ... in Section 1, (2.1), (2.2), ... in Section 2, etc. The numbers should be placed in parentheses ( ) at the left margin. The formulae are to be referred to in the text as Eq. (1.1),, Eq. (1.2), ..., Eq. (2.1), Eq. (2.2), ..., etc. The formulae not referred to in the text should not be numbered.

Bibliography: References are to be listed at the end of the paper in the alphabetical order and consecutively numbered. A reference to a published paper should be referred to in the text by the last name(s) of author(s) and the reference's number in brackets [ ]. Each item should contain full bibliographical data in the format illustrated by the following examples:

[1] M. Abramowitz and I. A. Stegun, Eds. Handbook of Mathematical Functions (Applied Mathematics Series 55). Washington, DC: NBS, 1964, pp. 32-33.

[2] M. Gorkii, “Optimal design”, Dokl. Akad. Nauk SSSR, vol. 12, pp. 111-122, 1961.

(Transl.: in L. Pontryagin, Ed., The Mathematical Theory of Optimal Processes. New York: INTERSCIENCE, 1962, Ch. 2, sec. 3, pp. 127-135).

[3] B. Klaus and P. Horn, Robot Vision. Cambridge, MA: MIT Press, 1986.

[4] E. F. Moore, “Gedanken-experiments on sequential machines”, in Automata Studies

(Ann. of Mathematical Studies, no. 1), C. E. Shannon and J. McCarthy, Eds. Princeton, NJ: Princeton Univ. Press, 1965, pp. 129-153.

[5] R. L. Myer, “Parametric oscillators and nonlinear materials”, in Nonlinear Optics, vol. 4, P. G. Harper and B. S. Wherret, Eds. San Francisco, CA: Academic, 1977, pp. 47-160.

[6] L. Stein, “Random patterns”, in Computers and You, J. S. Brake, Ed. New York: Wiley, 1994, pp. 55-70.

[7] Westinghouse Electric Corporation (Staff of Technology and Science, Aerospace Div.), Integrated Electronic Systems. Englewood Cliffs, NJ: Prentice-Hall, 1970.

[8] G. O. Young, “Synthetic structure of industrial plastics”, in Plastics, vol. 3, Polymers of Hexadromicon, J. Peters, Ed., 2nd ed. New York: McGraw-Hill, 1964, pp. 15-64.

In special cases, other formats related to codes, reports, dissertations, etc. will be accepted.

Layout of the text can be downloaded from ace website: http://ace.il.pw.edu.pl

2. Submission of the paper

Two electronic versions of the manuscript (DOC and PDF file) and License to publish should be submitted and sent directly to the Editor-in-chief by e-mail to: ace@il.pw.edu.pl

Signing license agreement is required.

3. Proof read: Proofs will be sent to the corresponding author to correct any typesetting errors. Alterations to the original manuscript at this stage will not be accepted. Corrected proofs page must be mailed to the Editorial Office as soon as possible.

4. Copyright: Submission of a paper to Archives of Civil Engineering implies that the material is an original and unpublished work, not under consideration for publication elsewhere. If permission for publication of any material is required, it should be obtained from appropriate sources by the author. The corresponding author is responsible for the other authors' approval of the paper publication.

5. Reprints: The corresponding author will receive ten reprints and PDF file of the published paper free of charge.

6. Other information: Apart from research papers, other articles such as review papers, brief notes, discussions and reports may be published in the journal. Monographic papers and state-of-the-art papers are accepted after prior approval of the Editor. Reports on important conferences held in Poland may also be published. Editor decides whether the paper fulfil all requirements i.e. formal and scientific. Editor nominates two reviewers, who shall forward reviews of the accepted publication.

The paper will be published in ACE provided that the reviews are positive. If reviewers have some comments authors have to correct the paper. Papers are subject to open discussion. All letters should be addressed to the Editorial Office and will be published together with the authors' response.

7. Fees: Submission of the paper is free of charge. Submitted papers are accepted for publication after a positive opinion of two independent reviewers. When publication accepted Author will be informed by email about article processing charge incl. amount and payment deadline. ACE is non for profit and all fees are calculated to cover operational costs only. Payment is required to the following bank account:

OFICYNA WYDAWNICZA POLITECHNIKI WARSZAWSKIEJ

ul. Polna 50, 00-644 WARSAW

PKO IV Department in WARSAW

Number: PL 84 1240 1053 1111 0000 0500 5707

with annotation: "Author(s) name and surname, ACE"

Ta strona wykorzystuje pliki 'cookies'. Więcej informacji