Wyniki wyszukiwania - BazTech

1

Analysis of the use of a hexagonal tubular section in a beam using the finite element method

Jaskot Anna

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2023

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Z. 29 (179)

20--26

EN

A static and strength analysis of a simply supported steel beam with a special cross-section has been described in this work. The system has been subjected to a static load. On this basis the basic strength parameters of a beam with a hexagonal tubular section compared to a beam with a circular tubular section have been determined. The analysis consisted of assessing the possibility of using the proposed beam with a particular emphasis on the limitation of deflection compared to a beam with a circular tubular cross-section. The analytical calculations of the deflection and results from a program used for numerical calculations by the finite element method have been included. The values of reduced stresses and strains were compared according to the Huber von Mises hypothesis. Based on the results obtained, it was found that the use of a hexagonal cross-section is more effective than the comparison beam due to its smaller deflection. The conclusions also indicate the direction of further research.

PL

Przeprowadzono analizę statyczno-wytrzymałościową stalowej belki swobodnie podpartej o specjalnym przekroju. Poprzez dobór obciążenia statycznego możliwe było zbadanie podstawowych parametrów wytrzymałościowych belki o przekroju rurowym heksagonalnym w porównaniu do belki o przekroju rurowym okrągłym. Analiza polegała na ocenie możliwości stosowania proponowanej belki ze szczególnym wskazaniem ograniczenia ugięcia w porównaniu do belki o przekroju okrągłym rurowym. W pracy zawarto obliczenia analityczne strzałki ugięcia oraz wyniki z programu do obliczeń numerycznych z wykorzystaniem metody elementów skończonych. Porównano wartości zredukowanych naprężeń i odkształceń wg hipotezy Hubera von Misesa. Na podstawie otrzymanych wyników stwierdzono, że wykorzystanie przekroju heksagonalnego jest bardziej efektywne, ze względu na mniejsze ugięcie, niż w przypadku belki porównawczej. W podsumowaniu wskazano kierunek dalszych badań.

2

A method for comparison of large deflection in beams

Taghipour Yasser, Darfarin Sara

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 4

179--193

EN

The deflection analysis of beams has been recently an active area of research. The large deflection of beams refers to deflections occurring due to large displacements and small strains. This type of deflection has been one of the areas of interest in the development of beam deformation methods. The wide diversity of beam deformation methods highlights the importance of their comparison to further elucidate the properties and features of each method and determine their benefits and limitations. In this study, a new comparison model is introduced which involves three steps, instead of only comparing final results for verification in common studies. In the first step, a complete comparison is made based on the assumptions and approximations of each method of the kinematics of deformation, displacement, and strain fields. After selecting the most accurate method in the first step, the displacement functions are determined by polynomial approximation under different loading and support conditions based on the selected method. In the third step, the displacement functions are used to calculate the strains in each method. The conclusion is based on comparing the strains. This comparative model can be used as a benchmark to compare different theories of deformation analysis.

3

Multi-criteria diagnostics of historic buildings with the use of 3D laser scanning (a case study)

Szymczak-Graczyk Anna, Walczak Zbigniew, Ksit Barbara, Szyguła Zdzisław

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 2

art. no. e140373

EN

The protection and use of historic buildings is a difficult and costly task. Most often, these objects are under conservatory protection and any interference in their structure requires appropriate consent. On the other hand, conducting construction works on historic buildings carries a high risk of their damage or even destruction. Therefore, proper prior diagnostics is an extremely important factor affecting the scope and manner of works to be conducted. The paper presents the use of 3D scanning to determine the deflection of the ceiling under the Column Hall of the historic Palace, the floor of which showed elasticity, recorded during changing service loads. After identifying the places with the greatest deflections, based on data from 3D laser scanning, test holes were made and wood samples from the ceiling were taken to perform moisture content and mycological tests. An endoscopic inspection camera was inserted into test holes, providing the basis for recognizing the structure of the ceiling, i.e. arrangement of layers as well as dimensions and spacing of ceiling beams. Strength calculations were made with the limit state method resulted in the determination of the maximum permissible service load on the ceiling. The presented course of action in diagnostics of the analysed historic building may be an example of a preliminary procedure to be taken before deciding on changes in the manner of use of historic buildings or the functionalities of their individual parts.

4

Geometric optimization of a beam detector for a WIM system

Nieoczym Aleksander, Drozd Kazimierz, Wójcik Andrzej

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 3

233--241

EN

Weigh-in-Motion (WIM) systems are designed for weighing vehicles driving across a measurement site. Because during measurements the vehicle has to come in physical contact with the components of the system, WIM systems always use built-in sensors installed in road pavement. Each WIM system consists of force sensors placed in one, two or even several lines, perpendicular to the direction of traffic. The idea behind WIM systems is to measure the dynamic loads that the wheels of a moving vehicle exert on the road surface and, on this basis, to estimate static wheel loads as well as gross vehicle weight.

5

Test results of the damaged T-section beams

Ismael A. M.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2013

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Z. 19 (169)

20--25

EN

The aim of the paper is the experimental determination of residual bearing capacity prototypes - beams with damaged shelf. Tests conducted to study the effect of beam damage on its residual load carrying capacity. In this paper it is proved that the type of damage affects the residual load-bearing captivity, the nature of the occurrence and the further development of cracks, the beam deflection.

PL

W artykule przedstawiono wyniki badań doświadczalnych belek teowych z uszkodzoną półką. Badania wykonano w celu przestudiowania wpływu uszkodzeń na resztkową nośność belek. Udowodniono, że rodzaj uszkodzenia wpływa na resztkową nośność, charakter występowania i dalszy rozwój rys oraz ugięcie belek.

6

Modelowanie belek pięciowarstwowych

Magnucki K., Jasion P., Smyczyński M.

Modelowanie Inżynierskie

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2012

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T. 14, nr 45

90--98

PL

W pracy przedstawiono model belki trójwarstwowej, w którym uwzględniono cienkie warstwy kleju łączące okładziny z rdzeniem. Sformułowano całkowitą energię potencjalną belki, a z zasady stacjonarności tej energii wyznaczono układ równań różniczkowych równowagi. Układ ten rozwiązano i wyznaczono ugięcie belki. Wyniki rozwiązania analitycznego porównano z wynikami numerycznymi MES. Zamieszczono przegląd literatury z uwzględnieniem współczesnych badań.

EN

The subject of the paper is an analysis of deflection of a five layer sandwich beam. The mechanical and physical properties vary through the thickness of the beam and depend on the material of each layer, which are: the metal face, binding material (the glue) and metal foam core. The main aim of the paper is to present an analytical model of the five layer beam and to compare the results of the analyses obtained theoretically and numerically. Moreover, the proposed model is compared with a three layer sandwich beam model. In the paper a mathematical model of the field of displacements, which include a share effect and a bending moment, is presented. The system of partial differential equations of equilibrium for the five layer sandwich beam is derived on the basis of the principle of stationary total potential energy. The equations are analytically solved and deflection is obtained. The influence of the binding layer thickness and Young’s modulus on the value of deflection is analysed. Comparison of the results obtained in the analytical and numerical (MES) analysis are shown in graphs and figures.

7

Model zależności moment-krzywizna dla belek żelbetowych : ocena ciągliwości

Korentz J.

Drogi : lądowe, powietrzne, wodne

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2010

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[nr] 6 (26)

22-31

PL

Przedstawiamy propozycję trzyliniowego modelu zależności moment-krzywizna, który może mieć zastosowanie do analizy deformacji belek żelbetowych. Model ten pozwala na ocenę ciągliwości i obliczanie ugięcia.

EN

A trilinear moment-curvature model is constructed by presenting each of uncracked, cracked, and yielded behavior of reinforced concrete beams as linear segments. The trilinear moment-curvature relationship considered here is defined by the points of cracking, yielding and ultimate. The curvature at first yield and the ultimate curvature are applied in ductility calculations. Furthermore this moment-curvature relationship can be apply to deflection calculations of beams. The obtained theoretical moment-curvature curve fits well with experimental data.

8

Examination of gases with the photothermal method

Pieszyński K.

Scientific Bulletin. Physics / Lodz University of Technology

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2002

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Vol. 22

83-88

EN

The work presents the possibilities of the application of photothermal phenomena for the examination of gases and the processes taking place in the gas. The obtained results for nitrogen peroxide in different temperatures are described.

PL

W pracy pokazano możliwości wykorzystania zjawiska fototermicznego do badań własności gazów i procesów w nich zachodzących. Przedstawiono to na przykładzie przeprowadzonych pomiarów z użyciem tlenków azotu.

9

Model belki Eulera z lokalną, skokową zmianą sztywności na zginanie

Kasprzyk S.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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1999

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z. 52 [174]

401-408

EN

The note presents four some types of distributions couples of forces for Euler beam with constant flexural rigidity. These couples of forces bring about antideflection of the beam on interval (c, d) ⊂ (0,l). The effect of this antideflection should be such that real line deflection of axis of the beam on interval (c,d) is rectilinear or aproximativery rectilinear. Line deflection on interval (0,l) obtained must be identical or almost identical with line deflection of the beam with local absolute stiffnesson interval (0,l).