Wyniki wyszukiwania - BazTech

1

Thin-walled cross section shape influence on steel member resistance

Urbańska-Galewska E., Deniziak P., Gordziej-Zagórowska M., Łukowicz A.

Advances in Science and Technology. Research Journal

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2016

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Vol. 10, nr 29

41--45

EN

This work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into account local, distortional and overall buckling. The results are presented in a tabular and a graphical way and clearly confirm that cross-section forming distinctly impact the cold-formed member resistance. The authors choose these cross-sections that work better in compression state and the other (those slender and high) that function more efficiently are subjected to bending.

2

Analiza porównawcza metod zwiększania nośności i sztywności stalowych, doczołowych węzłów śrubowych

Deniziak P.

Zeszyty Naukowe Politechniki Gdańskiej. Inżynieria Lądowa i Wodna

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2015

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Nr 3 (637)

33--41

PL

Innowacyjna, w porównaniu z dotychczas stosowanym sposobem, metoda obliczania nośności stalowych węzłów została wdrożona wraz z normami europejskimi. Pozwala ona dokładniej odwzorować rzeczywistą pracę poszczególnych części węzła, gdyż wynik obliczeń uzależniony jest od znacznie większej liczby zmiennych. Dzięki postępowi technologicznemu w zakresie metalurgii oraz badaniom naukowym możliwe jest obecnie wzmacnianie połączeń dwuteowych słupów z ryglami nie tylko za pomocą często do tej pory wykorzystywanych żeber poprzecznych, ale także za pomocą dodatkowych nakładek, które spawane lokalnie wzdłuż środnika słupa zwiększają jego nośność. Artykuł stanowi analizę porównawczą wymienionych metod wzmacniania środnika opartą o procedury opisane w Eurokodzie 3. Otrzymane wyniki zestawiono również z połączeniami, które pozbawione są wszelkich dodatkowych blach, gdyż jest to coraz częściej obserwowany - ze względu na uniknięcie czasochłonnego spawania na placu budowy - zabieg projektowy. Celem poszukiwań jest wskazanie optymalnej, w zakresie prowadzonych obliczeń, metody wzmacniania węzłów stalowych ze względu na efektywność oraz pracochłonność zastosowanych rozwiązań.

EN

Method presented in EN 1993-1-8 [7] is a result of long-term studies focused on calculating moment resistance and stiffness of joints. Design calculations shown in this article are based on resistance and stiffness growth analysis applying supplementary web plates and traditional transverse web stiffeners extending beam flanges. Author considers validity of those solutions due to construction effort and building durability remembering about minimization of the costs. A connection of beam and column is usually a critical point in steel frames made of H or I sections where beam height is decisive. Designing full-strength joints (it means that joint design moment resistance M j, Rd, is higher than plastic moment resistance of beam Mb, pl, Rb) is not possible applying joints bereft reinforcements. There is also a possibility to increase the number of bolts in each rows from two to four. This increase is available only when width of the H or I section beams reaches at least 300 mm. This article shows exact designs examples which are inviting construction engineers to apply supplementary web plates or transverse web stiffeners increasing the resistance and rotational stiffness of column panel in shear, transverse compression and tension. Applying such supplementary web plates is nearly as laborious as welding transverse web stiffeners so it's contrary to the basic semi-rigid joints assumption focused mainly on production costs minimization. Taken parametric analysis explicitly confirms high effectiveness of applying supplementary web plates reinforcing the column web panel. This effect is impossible to attain using traditional transverse web stiffeners extending beam flanges.

3

Analizy wpływu współpracy blach poszycia z konstrukcją nośną na wartości sił wewnętrznych i przemieszczeń hali stalowej

Deniziak P., Urbańska-Galewska E., Migda W.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2015

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z. 62, nr 4

43--53

PL

W niniejszej pracy, wykorzystując możliwości programu Dlubal RFEM 5.04, przedstawiono efekty uwzględniania współpracy konstrukcji nośnej hali z poszyciem wykonanym z blach trapezowych. Przeprowadzono analizy obliczeniowe kilku wariantów modelu 3D przykładowej hali stalowej. Wyniki obliczeń oraz wnioski zestawiono w tablicach.

EN

Previous construction analysing methods were based on 2D models what is inaccurate and does not give a possibility to use a full, precise members mutual cooperation. In this article authors show an influence of taking into consideration the cooperation between trapezoidal sheeting and structural beam members illustrated with an example of a single storey buildings. This analysis was carried out in the state of the art computer program called Dlubal RFEM 5.04. This paper shows the stiffening profiled sheeting application impact on a general construction mass. 3D numerical calculations were based on a frame construction with 10 metre-high columns and a span of 12 m. Hot rolled truss-column system made out of S235 steel with stiff base in the foundation was used here. Steel profiled sheeting were assumed as an orthotropic surfaces, called diaphragm. Those 3 separate numerical models were analysed. The first one did not consider the cooperation between trapezoidal sheets and the structure. The second did consider the cooperation but only on the roof and the last one account the full integration (on the roof and on longitudinal walls as well). Calculations gave a surprising results. The displacement decreased by about 90% between the first and the second numerical models. Authors also noticed the decrease of general mass by 26%.

4

Classification of restraints in the optimization problem of a cold-formed profile

Łukowicz A., Urbańska-Galewska E., Deniziak P., Gordziej-Zagórowska M.

Advances in Science and Technology. Research Journal

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2015

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Vol. 9, nr 28

61--67

EN

This work describes the restraints in the optimization problem. This is an important and complicated issue because it requires taking into account a vast range of information related to the design and production. In order to describe the relations of a specific optimization problem, it is essential to adopt appropriate criteria and to collect information on all kinds of restraints, i.e. boundary conditions. The following paper verifies the various restraints and defines three subsets: design assumptions, technological limitations and standard conditions. The provided classification was made with reference to the analysis of the construction applicability of the newly patented cold-formed profile.

5

The influence of applying supplementary web plates on structural joint moment resistance and rotational stifness

Urbańska-Galewska E., Deniziak P.

Structure and Environment

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2014

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Vol. 6, no. 2

11--17

PL

Continual trend to simplify structural elements and find less time-consuming solutions on construction site as well as inevitable increase in labour costs determine for instance elimination of those technological steps that are difficult to automation. Welding additional reinforcements and web stiffeners are great examples of such a step. The method presented in EN 1993-1-8 [8] is a result of long-term studies focused on calculating the moment resistance and stiffness of joints without transverse web stiffeners. Design calculations shown in this paper are based on resistance and stiffness growth analysis applying supplementary web plates. Authors consider validity of this solution due to construction effort and building durability remembering about minimization of the costs.