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1

Bending behaviour of thin-walled perforated channel beams with modified cross-sectional shape – Part 1: experimental tests and FSM

Paczos Piotr, Pawlak Aleksandra M., Jasion Paweł, Plust Michał

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2025

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Vol. 73, nr 3

art. no. e153830

EN

The subject of this study is thin-walled channel sections with a modified cross-sectional shape. The investigation involved six beams, three of which had perforations on the web, while the other three had a flat, solid web. The beams were subjected to four-point bending tests. Experimental tests were conducted using both electronic and optical methods, with a test setup specifically designed for this investigation. Additionally, numerical analyses were performed using the finite strip method. The primary objective of the research was to determine the impact of web perforations on the strength and stability of the bent beams. The perforation of the web also resulted in a reduction in the overall weight of the structure, thereby decreasing material consumption. Based on the research, the critical forces and maximum forces at which total loss of load-bearing capacity occurred were determined. Furthermore, the buckling modes of the beams were identified. The study revealed that the critical and maximum forces for beams with perforated webs were lower compared to beams with a flat, solid web. However, the significant reduction in weight for the perforated beams suggests that their use remains advantageous. The results of FEM and analytical analyses, essential for modelling and understanding complex behaviours in thin-walled structures, will be presented in the second part of this publication to maintain clarity and accessibility.

2

A comparative study between beam and pull-out tests on bond behavior of ribbed GFRP bar in concrete conforming to RILEM standards

Rahimi Mehran, Davoodi Mohammad-Reza, Nematzadeh Mahdi, Yousefpour Hossein, Azarbera Mahdi, Fattahi Zahra

Archives of Civil and Mechanical Engineering

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2025

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Vol. 25, no. 1

art. no. e37, 2025

EN

Different researchers have perused the bond behavior of concrete and rebar employing the beam or pull-out tests; nonetheless, results were not precisely comparable owing to different test methods. Hence, a comprehensive research study is necessary in this field. In contrast to steel bars, there is no standard approach for FRP bar surface characterization. Moreover, previous studies reveal that FRP bars with different surfaces exhibit various bonding mechanisms. Therefore, determining the bond characteristics of various FRP bars with different surfaces is essential for their application in structures. A recent study experimentally compared beam and pull-out test results for ribbed GFRP bars, with and without anchors, conforming to RILEM standards. The variables included two different test methods (beam test and pull-out test), steel anchor (presence and absence of anchor), and concrete compressive strength level (25 and 45 MPa). It was found that the maximum transferred stress in the ribbed GFRP bar from the beam test was higher than in the pull-out test for all specimens. On average, they are about 24% higher than the pull-out test values. In the pull-out test, the bar slip threshold stress and the initial slope of the stress–slip graph were higher than in the beam test for all specimens. A comparative analysis was conducted on studies using beam and pull-out test results without anchors. The impact of anchors on reducing development length was evaluated by comparing the existing length with the straight and hook development lengths specified by ACI 440.1R-15. The difference suggests a conservative approach in the code.

3

Formulation of the critical lateral buckling moment of a steel I-beam

Derlatka Anna, Gao Shan

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2024

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Z. 30 (180)

23--28

EN

The paper presents an analysis of the method of formulation of the critical lateral moment during buckling of an I-beam. Three methods of determining the critical moment were considered: commonly known analytical formulas, the Robot Structural Analysis Professional 2024 program and the finite element method implemented in the ADINA program. The subject of the analysis was the steel beam with a cross-section of IPE 200. Two simply supported beams were considered. The first one was loaded with a concentrated force and the second one was loaded with an evenly distributed load.

PL

Przedstawiono analizę sposobu obliczania momentu krytycznego przy zwichrzeniu belki dwuteowej. Rozważano trzy sposoby wyznaczania momentu krytycznego: powszechnie znane wzory analityczne, program Robot Structural Analysis Professional 2024 oraz metodę elementów skończonych zaimplementowaną w programie ADINA. Przedmiotem analizy była belka stalowa o przekroju IPE 200. Rozważano dwie belki swobodnie podparte. Pierwszą obciążono siłą skupioną, a drugą obciążono obciążeniem równomiernie rozłożonym.

4

Assessment of reinforced concrete beams cracking depending on the concrete class

Derlatka Anna, Jrethi Yassin Ali

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2024

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Z. 30 (180)

29--34

EN

Cracks in reinforced concrete are a common concern that can arise from various causes such as concrete shrinkage, temperature differences, and structural loads. The aim of the study was an analysis of cracks in concrete on which the reinforcement concrete beam was made. The beam was loaded with an evenly distributed load and subjected to bending. Depending on the concrete class (C20/25, C25/30 and C30/37), the cracks in the concrete, the deflection at a load of 5.35 kN/m2 and the beam’s load-bearing capacity, i.e. the value of the load that the beam can withstand without any cracks were assessed.

PL

Pęknięcia w żelbecie są powszechnym problemem, który może wynikać z różnych przyczyn, takich jak skurcz betonu, różnice temperatur i obciążenia konstrukcyjne. Celem pracy była analiza pęknięć w betonie, z którego wykonano belkę żelbetową. Belka została obciążona równomiernie rozłożonym obciążeniem i poddana zginaniu. Analizowano trzy klasy betonu C20/25, C25/30 i C30/37. W zależności od klasy betonu oceniano pęknięcia w betonie, ugięcie przy obciążeniu 5.35 kN/m2 i nośność belki, tj. wartość obciążenia, jakie belka może wytrzymać bez pęknięć.

5

Modeling and control of a combined inverted pendulum on beam system

Choukri Bensalah, Amal Choukchou Braham, Rida Mokhtari

Przegląd Elektrotechniczny

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2024

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R. 100, nr 9

213--218

EN

This paper addresses a novel structure for an underactuated system. It involves the combination of two well-known underactuated systems: the inverted pendulum-cart and the ball and beam. In this configuration, the cart in the first system replaces the role of the ball in the second. The primary focus lies in controlling the balancing beam, which is the key element of the system. The complete system is modeled using Lagrangian formulation, resulting in a set of coupled and highly nonlinear dynamical equations. Additionally, structural analysis of the corresponding control flow diagram is discussed. To control the entire system, an LQR controller with a PI controller in a cascade structure is employed. Simulation results demonstrate the stabilization performance of the proposed controller and its capability to address tracking problems.

PL

W artykule tym omówiono nową strukturę niedostatecznie aktywowanego układu. Obejmuje ona połączenie dwóch dobrze znanych niedostatecznie aktywowanych układów: odwróconego wózka wahadłowego oraz kuli i belki. W tej konfiguracji wózek w pierwszym układzie zastępuje rolę kuli w drugim. Główny nacisk położony jest na sterowanie belką równoważącą, która jest kluczowym elementem układu. Cały układ jest modelowany przy użyciu formuły Lagrange’a, co skutkuje zestawem sprzężonych i wysoce nieliniowych równań dynamicznych. Ponadto omówiono analizę strukturalną odpowiadającego schematu przepływu sterowania. Aby sterować całym układem, zastosowano regulator LQR z regulatorem PI w strukturze kaskadowej. Wyniki symulacji pokazują wydajność stabilizacji proponowanego regulatora i jego zdolność do rozwiązywania problemów ze śledzeniem.

6

Obiekt mostowy MS-35 w ciągu drogi ekspresowej S1

Kloc Ewelina, Strama Paweł, Łazarowicz Maksymilian, Kozieł Grzegorz

Mosty

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2024

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nr 3

40--42

PL

W artykule przedstawiono budowę metodą dziesięcioprzęsłowego obiektu mostowego MS-35 metodą nasuwania podłużnego, położonego w łuku pionowym, łuku poziomym oraz na krzywej przejściowej nad linią kolejową, stawem, przejściem dla zwierząt oraz drogą powiatową.

EN

The article presents the construction of the bridge superstructure as a ten-span free supported beam with the use of the incremental launching method. The structure is located within the vertical curve, horizontal curve and on the transition curve and crosses the railway line, a pond, an animal crossing and a county road.

7

Research into the bearing capacity of reinforced concrete bent elements strengthened by the FRCM system

Tereshko Andriy, Blikharskyy Yaroslav

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

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2024

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Vol. 13

246-252

EN

This article presents the experimental results of reinforced concrete beams strengthened by the FRCM system. To realize the set goal of the work, 4 reinforced concrete beams of real dimensions 2100 mm × 180 mm × 140 mm were manufactured. Exhaustion of the load-bearing capacity of all samples occurred due to the fluidity of the reinforcement. After the moment of reaching the flow of the reinforcement, physical destruction occurred in all samples due to the fragmentation of the compressed zone of concrete. Studies of reinforced samples showed that the non-shearing capacity was 16 % higher compared to non-reinforced control samples.

8

Study on the working mechanism of self-resetting performance of superelastic SMA fiber-reinforced ECC beams

Yang Zhao, Wu Qing, Qi Xiaolong, Xiang Jichao

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 3

art. no. e180, 2024

EN

This study aimed to master the self-resetting performance and working mechanism of superelastic shape memory alloy fibers reinforced engineered cementitious composite (SMAF-ECC) beams. Four SMAF-ECC pre-cut beams were fabricated. The three-point bending test was used to analyze the changes in mid-span deflection and crack width under different shape memory alloy (SMA) fibers lengths and end forms. And the stress of SMA fiber was analyzed by ABAQUS. Finally, the working mechanism of SMA fiber was revealed. The results showed that SMAF-ECC specimens perform well in deformation recovery and crack closure. Among them, the maximum deflection self-recovery rate of the specimen was 83.6%. And compared to the engineered cementitious composite (ECC) specimen, the residual crack width was reduced by 76.62% to 84.01%. In addition, reducing the length and diameter of the SMA fiber increased its stress. However, the length of SMA fiber had little effect on the deflection self-recovery rate of SMAF-ECC specimens, and the maximum difference between the specimens with different SMA fiber lengths was only 1.1%. The working mechanism of SMA fiber included four stages: linear elastic, descent, platform, and deformation strengthening stage. After the SMA fiber entered the platform phase, the residual deformation of the specimen was significantly reduced. When entering the deformation strengthening stage, the SMA fiber not only improved the bearing capacity of the specimen, but also provided greater restoring force, considerably improved the specimen’s self-resetting performance. This paper offered a theoretical basis for the design of self-resetting beams.

9

An experimental assessment on the seismic behaviour of precast hollowcore slab to beam connection with different connection details

Vinutha D., Vidjeapriya R., Jaya K. P.

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 3

art. no. e167, 2024

EN

This study evaluates the cyclic response of the Precast Hollow Core Slab (PHCS) to the beam connection by proposing a novel connection detail. The evaluation involved, three different connection details, namely, (1) Continuity rebar and U-type Core Rebar Discrete with 100 mm ledge width (CUCRD_100); (2) continuity rebar and Core Rebar Combined with 100 mm ledge width (CCRC_100); and (3) continuity rebar and Core Rebar Combined with Ties along with 100 mm ledge width (CCRCT_100) were experimentally validated. These were validated through experimental testing, comparing their performance with a reference specimen that adhered to New Zealand guidelines using Continuity rebar and Core Rebar Discrete with 100 mm ledge width (CCRD_100). Displacement controlled reverse cyclic loading, following the ACI T1.1–0.1 protocol, was applied to the end of a hollow core slab for the experimental testing. The structural performance of all four connections considered failure pattern, strength, hysteretic behaviour, energy dissipation, displacement ductility, stiffness degradation, and equivalent viscous damping. The overall seismic efficiency of the connections was assessed using ACI 374.1–05 approval criteria. The experimental results proved that the peak load-carrying capacity for CCRCT_100 specimen was observed to be greater in both directions of loading (positive and negative) when compared with the other connection detailing. The presence of transverse reinforcement enhanced the confining capacity of the concrete in the joint region which substantially increased the ductility and dissipation of energy in CCRCT_100 specimen. The seismic performance of every connection specimen was favourable, and they all met the ACI 374.1–05 approval standards.

10

Uwiarygodnienie koncepcji „projektowania plastycznego” belek mostowych zgodnie z Eurokodem 4: Badania niszczące w skali naturalnej zespolonych belek mostowych złożonych z dwuteownika HL1100 i płyty betonowej

Marcinczak Krzysztof, Kożuch Maciej, Lorenc Wojciech, Zannon Riccardo, Ochojski Wojciech

Mosty

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2023

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nr 3

47--50

PL

W artykule przedstawiono wyniki eksperymentów niszczących, które rzucają nowe światło na projektowanie mostów zespolonych w Polsce. Różnica między tradycyjnymi normami a nowoczesnym podejściem opartym na Eurokodzie 4 jest widoczna. Wyniki badań opisane przez autorów stanowią solidny argument za zmianą tradycyjnych praktyk.

EN

The article presents the results of destructive experiments, which shed new light on the design of composite bridges in Poland. The difference between traditional norms and a modern approach based on Eurocode 4 is evident. The test findings described by the authors provide a strong argument for changing traditional practices.

11

Wykorzystanie zdolności pochłaniania energii do wyznaczania wytrzymałości resztkowych fibrokompozytów

Głodkowska Wiesława, Laskowska-Bury Joanna, Lehmann Marek

Materiały Budowlane

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2023

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nr 3

1--4

PL

W artykule omówiono sposób wyznaczania wytrzymałości resztkowych z wykorzystaniem zdolności pochłaniania energii przez fibrokompozyt. Badania przeprowadzono przez zginanie płyt o przekroju kwadratowym podpartych przegubowo na obwodzie. Określone w ten sposób wytrzymałości resztkowe cechują się znacznie mniejszym współczynnikiem zmienności niż wyznaczone wg PN-EN 14651:2007. Opisane badanie jest alternatywą dla 3-punktowego zginania belek i pozwala na wyznaczenie tej cechy z większą wiarygodnością.

EN

The article discusses the method of determining residual strength using the energy absorption capacity of fibrecomposite. The research was carried out by bending square cross-section plates simply supported at the perimeter. The residual strengths determined in this way are characterized by a much lower coefficient of variation than those determined using the normative method according to PN-EN 14651:2007. The described test is an alternative to 3-point bending of beams and allows to determine this feature with greater reliability.

12

A posteriori error estimates for beams with inexact flexural stiffness representation

Torii André J., Gracite Paula M.A., Miguel Leandro F.F., Lopez Rafael H.

Journal of Applied Mathematics and Computational Mechanics

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2023

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Vol. 22, nr 2

62--74

EN

In this work, we present a posteriori error estimates for the Euler-Bernoulli beam theory with inexact flexural stiffness representation. This is an important subject in practice because beams with non-uniform flexural stiffness are frequently modeled using a mesh of elements with constant stiffness. The error estimates obtained in this work are validated by means of two numerical examples. The estimates presented here can be employed for adaptive mesh refinement.

13

Influence of material distribution and damping on the dynamic stability of Bernoulli-Euler beams

Garus Sebastian, Garus Justyna, Sochacki Wojciech, Nabiałek Marcin, Petru Jana, Borek Wojciech, Šofer Michal, Kwiatoń Paweł

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 4

art. no. e145567

EN

The study analyzed the influence of materials and different types of damping on the dynamic stability of the Bernoulli-Euler beam. Using the mode summation method and applying an orthogonal condition of eigenfunctions and describing the analyzed system with the Mathieu equation, the problem of dynamic stability was solved. By examining the influence of internal and external damping and damping in the beam supports, their influence on the regions of stability and instability of the solution to the Mathieu equation was determined.

14

Numerical failure analysis of laminated beams using a refined finite element model

Layachi Maroua, Khechai Abdelhak, Ghrieb Abderrahmane, Layachi Safa

Advances in Materials Science

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2023

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Vol. 23, nr 1(75)

32--57

EN

In the present investigation, laminated composite beams subjected to a bending static loading are studied in order to determine their failure mechanisms and the first ply failure (FPF) load. The FPF analysis is performed using a refined rectangular plate element. The present element is formulated based on the classical lamination theory (CLT) to calculate the in-plane stresses. To achieve this goal, several failure criterions, including Tsai-Wu, Tsai-Hill, Hashin, and Maximum Stress criteria, are used to predict failure mechanisms. These criterions are implemented within the finite element code to predict the different failure damages and responses of laminated beams from the initial loading to the final failure. The numerical results obtained using the present element compare favorably with those given by the analytic approaches. It is observed that the numerical results are very close to the analytical results, which demonstrates the accuracy of the present element. Finally, several parameters, such as fiber orientations, stacking sequences, and boundary conditions, are considered to determine and understand their effects on the strength of these laminated beams.

15

Influence of the PZT actuator asymmetry on the LQR control parameters in the active reduction vibrations of beams

Kuras Romuald

Vibrations in Physical Systems

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2022

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Vol. 33, nr 3

art. no. 2022305

EN

The paper deals with the active reduction of beam vibrations using piezoelectric transducers (PZT). The LQR parameters of the control of an asymmetric actuator (a-PZT) depending on the length of its arms were analysed. The results were compared to those of the symmetrical PZT (s-PZT), so far used as standard. The actuator is modeled with two bending moments or two pairs of forces. The design of the LQR controller also took into account the location of the PZT on the beam. The reduction efficiency can also be increased by using asymmetrical PZT. To obtain the vibration asymmetry of the beam, simply supported at both ends, an asymmetrically point mass was added. The LQR control was applied to an asymmetric actuator on the beam. Two-parameter optimization was used to find the optimal proportions of the a-PZT arms. For such a problem, the LQR control parameters were found, which ensure the highest efficiency of vibration reduction.

16

Analysis of deflection in visco-thermoelastic beam resonators subjected to harmonic loading

Chopra Deepti, Singh Prince

International Journal of Applied Mechanics and Engineering

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2022

|

Vol. 27, no. 2

35--52

EN

This paper analyses the transverse deflection in a homogeneous, isotropic, visco-thermoelastic beam when subjected to harmonic load. The ends of the beam are considered at different boundary conditions (both axial ends clamped, both axial ends simply supported and left end clamped and right end free). The deflection has been studied by using the Laplace transform. Numerical computation of analytical expression of deflection obtained after Inverse Laplace transform has been done using MATLAB software. The graphical observations have been discussed under various boundary conditions for different values of time and length. The above work has applications in design of resonators.

17

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

|

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.

18

Porównanie wybranych metod oceny momentu krytycznego zwichrzenia belek o zmiennej wysokości środnika

Czepiżak Dariusz, Machowiak Adam

Inżynieria i Budownictwo

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2021

|

R. 77, nr 5-6

269--274

PL

Porównano sprężyste momenty krytyczne belek ze zbieżnym środnikiem, obliczone metodami analitycznymi i numerycznymi przedstawionymi w ostatnich latach przez badaczy zajmujących się tym zagadnieniem z obliczeniami własnymi, przeprowadzonymi dostępnymi narzędziami. Głównym celem było zweryfikowanie dokładności i zbieżności wyników otrzymanych różnymi metodami i różnymi prętowymi elementami skończonymi 1D o 7 stopniach swobody w węźle (7DOF).

EN

In this article, the elastic critical bending moments of the web-tapered I-beams calculated by the analytical and numerical solutions developed last years by researchers involved in the topic were compared with own calculations carried out with available common tools. The main goal was to verify the accuracy and convergence of the results provided by different modern methods and different finite bar elements 1D with 7 degrees od freedom at the node (7DOF).

19

A new index for damage identification in beam structures based on modal parameters

Taghipour Reza, Nashta Mina Roodgar, Bozorgnasab Moshen, Mirgolbabaei Hessam

Archive of Mechanical Engineering

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2021

|

LXVIII, nr 4

375--394

EN

The structural damages can lead to structural failure if they are not identified at early stages. Different methods for detecting and locating the damages in structures have been always appealing to designers in the field. Due to direct relation between the stiffness, natural frequency, and mode shapes in the structure, the modal parameters could be used for the purpose of detecting and locating the damages in structures. In the current study, a new damage indicator named “DLI” is proposed, using the mode shapes and their derivatives. A finite element model of a beam is used, and the numerical model is validated against experimental data. The proposed index is investigated for two beams with different support conditions and the results are compared with those of two well-known indices – MSEBI and CDF. To show the capability and accuracy of the proposed index, the damages with low severity at various locations of the structures containing the elements near the supports were investigated. The results under noisy conditions are investigated by considering 3% and 5% noise on modal data. The results show a high level of accuracy of the proposed index for identifying the location of the damaged elements in beams.

20

The impact of the agressive acid environment on RC constructions

Blikharskyy Yaroslav, Khmil Roman, Blikharskyy Zinoviy, Shnal Taras

System Safety : Human - Technical Facility - Environment

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2020

|

Vol. 2, nr 1

223--229

EN

The main issue of the article is the corrosion of the reinforced concrete elements by the co-influence of the aggressive and power factors. The problem of corrosion is extremely actual one. Therefore the tests were carried out upon the specimens considering the corrosion in the acid environment, namely 10 % H2SO4. The acid environment H2SO4 was taken as a model of the aggressive environment. Conclusions concerning the corrosion model of the cross section and investigation of stress-strain state have been made. That material concerns the problem of the reinforced concrete corrosion as a whole construction. Reinforced concrete beams were tested with and without the co-action of the aggressive environment and power factor.