Wyniki wyszukiwania - BazTech

1

Seismic behavior of interior polyvinyl chloride-carbon fiber-reinforced polymer-confined concrete column-ring beam joints

Yu Feng, Wang Shisi, Fang Yuan, Zhang Nannan, Wang Yan, Nuermaimaiti Maimaiti

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e49, 2023

EN

Eleven interior polyvinyl chloride (PVC)-carbon fiber-reinforced polymer (CFRP)-confined concrete (PCCC) column-ring beam joints are fabricated and experimentally investigated. The impacts of axial compression ratio, frame beam reinforcement ratio, CFRP strips spacing, ring beam width and ring beam reinforcement ratio, on seismic behaviors are analyzed. All specimens show obvious failure signs, and the frame beam reinforcement ratio exerts a degree of effect on failure positions, exhibiting different failure modes, such as shear failure in the joint zone, shear-bending failure at the junction and bending failure at the frame beam. The experimental results show that the hysteresis curves are relatively full, which have roughly experienced four stages as elastic, elastic-plastic, stable and decline stages, reflecting that the interior joints have considerable seismic behavior. The increment of ring beam reinforcement ratio or ring beam width enhances the load capacity, mitigates degradation of strength and stiffness. The peak load increases by 38.63% as the ring beam reinforcement ratio increases from 0.88 to 1.5%. When the ring beam width increases from 75 to 125 mm, the peak load increases by 37.24%. Appropriately increasing axial compression ratio can raise the load capacity, alleviate strength degradation, and enhance the initial stiffness. As the axial compression ratio increases from 0.2 to 0.4, the peak load increases by19.41%. The joints with larger frame beam reinforcement ratio show higher load capacity, while the frame beam reinforcement ratio exerts marginal impacts on strength and initial stiffness degradation. The existing classical shear models and specification design formulae are used to evaluate the shear capacity of the interior joints, and the reasons for the deviations of prediction results are expounded, which provides the theoretical basis and useful reference for the subsequent establishment of a new shear capacity formula of the joints.

2

Effect of corrosion on the buckling behaviour of cold‑formed steel channel section columns under axial compression

Nie Biao, Xu Shanhua, Chen Huapeng, Wang Youde

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e70, 2023

EN

This paper presents an experimental and numerical investigation on the buckling behaviour of corroded cold-formed steel (CFS) channel section columns under axial compression. 7 stub columns and 7 medium long columns were accelerated corrosion by the outdoor periodic spray test. Prior to compression tests, the mass, residual thickness, surface morphology and initial geometric imperfection of the corroded CFS columns were measured. The failure modes, load-strain curves and load-axial displacement curves obtained from axial compression tests were discussed. Based on the corrosion morphology, the non-linear finite element (FE) model for the corroded CFS columns was then developed. Finally, the calculation method for corroded CFS channel section columns was proposed. The results indicated that with the increasing mass loss rate, the irregularity of residual thickness increased rapidly at first, and then increased slowly due to uniform corrosion. The failure mode of the corroded specimens may change from distortional buckling to local buckling as the mass loss rate increased. With the increase in mass loss rate, the buckling critical load, ultimate load, post-buckling strength and axial displacement corresponding to ultimate load decreased. The failure positions of distortional buckling and local buckling were mainly related to the corrosion degree of the flange and web, respectively. The FE results were compared against the experiment results showing a good match in terms of both the ultimate strength and failure modes.

3

Overall buckling performance of high strength steel welded I-sections under combined axial compression and bending

Huang Bin, Zhang Wen-Fu

Archives of Civil Engineering

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2022

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Vol. 68, nr 3

369--384

EN

This paper presents a numerical investigation into the high strength steel (HSS) welded I-section overall buckling performance with respect to the major axis under combined axial compression and bending. The validation of FE models compared with the existing test data to verify the appropriateness of the element division and boundary condition was firstly conducted. In line with the FE arrangement verified, separate 890 numerical models, covering a broader range of eight steel grades (460 MPa, 500 MPa, 550 MPa, 620 MPa, 690 MPa, 800 MPa, 890 MPa and 960 MPa), different overall slenderness and various eccentricities were designated. Subsequently, the comparison of the resistance prediction codified design rules in EN 1993-1-1, ANSI/AISC 360-10 and GB50017-2017 was preferentially operated, by the instrumentality of the normalized axial compression-bending moment curves. The results graphically revealed that, the provision given in ANSI/AISC 360-10 concerned in the present work was the most loose, whereas, the corresponding content set out in EN 1993-1-1 and GB50017-2017 was relatively on the safe side. Taking account of the FE results, the conservative shortcomings of the considered rules in EN 1993-1-1 and GB50017-2017 were further highlighted. Especially, the disparity of EN 1993-1-1 and numerical results was higher to 27%, from the perspective of a definition given in the present work. In contrast, the provision in ANSI/AISC 360-10 yielded a relatively accurate prediction, on average. Based on the numerical program, an alternative formula for the HSS welded I-section beam-columns with a general expression form was sought, which intimately reflected the effect of overall slenderness.

4

Performance of circular stainless‑carbon steel tube confned concrete stubs under axial compression

Gao Shan, Guo Lanhui, Zhang Sumei

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e104

EN

To increase the usage cost-efectiveness of stainless steel in structural members, a bimetallic tube composed of an external thin-walled stainless steel tube and an internal relatively thick-walled carbon steel tube is proposed. Fifteen stub specimens including nine stainless-carbon steel tube confned concrete (SCTCC) stubs and six concrete-flled stainless-carbon steel tubes (CFSCT) were tested and analyzed in detail. The results show that both SCTCC stubs and CFSCT stubs exhibit good mechanical performance and shear failure modes. The axial strength of SCTCC stubs is higher than that of CFSCT stubs. Regarding SCTCC stubs, the exterior stainless-steel tube would yield before the interior carbon-steel one. The parametric analysis shows that the rising in the thickness ratio of stainless steel tube would decrease the axial capacity of SCTCC model, but also cause the decrease in the axial resistance of the model beyond the peak to become more subtle. The predicting method regarding the capacity of SCTCC stub under axial compression is proposed based on the current design standard and test results.

5

Experimental investigation and analysis on the axial compressive performance of recycled concrete‑filled corroded steel tubular columns

Hui Cun, Li Yonggang, Li Ke, Liu Cong, Hai Ran, Li Chunqing

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 2

art. no. e97, 1--22

EN

In this study, the axial compressive performance of recycled concrete-filled corroded steel tubular columns was assessed with different concrete strength grades (C30, C45, C60) and different corrosion degrees (0%, 5%, 10%, 15%, 20%). Axial compression tests on 15 specimens were conducted, and the corresponding load-displacement curves, skeleton curves, stiffness degradation curves, characteristic load, characteristic displacement, failure modes, and the stress-strain distribution in steel tube and concrete specimens were obtained and thoroughly analyzed. The load-bearing capacity of the specimens was calculated by the typical local and international standards. The static calculation model of the specimens was built by the finite element software, and the load-bearing capacity and deformation performance were evaluated and compared with the test results. The results showed that with the increase of corrosion degree under the same load, the specimen deformation and central bulge are more prominent, whereas the load-bearing capacity and stiffness decrease. As the concrete strength increased, the load-bearing capacity of specimens increased significantly. The calculated load-bearing capacity values and the finite element analysis results agree well with the test values. The findings of this research can be used in different engineering applications.

6

Utrata stateczności osiowo ściskanych słupów dwugałęziowych

Piotrowski Rafał, Siedlecka Monika

Inżynieria i Budownictwo

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2021

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R. 77, nr 5-6

242--246

PL

Przedstawiono wyniki analitycznych i numerycznych rozważań dotyczących formy lokalnej i globalnej utraty stateczności osiowo ściskanych bisymetrycznych prętów dwugałęziowych połączonych sztywnymi przewiązkami, w jednej lub dwu płaszczyznach, bądź przeponami. Poza oczywistym wpływem sposobu podparcia końców pręta na postać wyboczenia, uwzględniono także rozstaw gałęzi i ilość połączeń między nimi.

EN

The analysis covers the forms of local and global loss of stability of axially compressed bisymmetric two-branch bars connected with rigid lacings, in one or two planes, or with diaphragms. Apart from the obvious influence of the method of supporting the bar ends on the buckling form, the branch spacing and the number of connections between them were also taken into account.

7

Wpływ owalizacji na nośność ściskanych osiowo stalowych powłok walcowych

Hotała E., Kozikowski D.

Materiały Budowlane

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2018

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nr 4

100--102

PL

W artykule przedstawiono wyniki numerycznych analiz stateczności walcowych powłok stalowych ściskanych osiowo, w których oprócz imperfekcji w postaci wgnieceń wystąpiły również imperfekcje w postaci owalizacji o znacznej wartości. Owalizacja walcowych powłok silosów, zbiorników i innych stalowych konstrukcji powłokowych jest powszechną i trudną do uniknięcia odchyłką wykonawczą. Wyniki przeprowadzonych analiz wskazują, że imperfekcje geometryczne w postaci owalizacji dwukrotnie większych niż normowe wartości dopuszczalne mogą nie mieć istotnego wpływu na nośność ściskanych osiowo powłok walcowych. Może to ułatwić podejmowanie racjonalnych decyzji podczas procedur odbiorczych stalowych konstrukcji powłokowych.

EN

Paper presents results from numeric analysis of stability of cylindrical steel shells under axial compression, in which except dents, out-of-roundness imperfections of substantial values were taken into account. Out-of-roundness in cylindrical silos, tanks and other steel structures is seldom and hard to eliminate in construction rising. Outcomes of undertaken analysis has shown that out-of-roundness imperfections with dimension twice as high as acceptable according to norm classes can have no significant influence on bearing capacity of axially compressed cylindrical steel shells. This conclusion can ease taking reasonable decisions in construction release to use.

8

O wyznaczaniu temperatury krytycznej stalowych słupów ściskanych ogarniętych pożarem

Maślak M., Suchodoła M.

Inżynieria i Budownictwo

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2018

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R. 74, nr 2

99--104

PL

Omówiono sposób wyznaczania temperatury krytycznej eksponowanego na działanie ognia stalowego słupa osiowo ściskanego. Wskazano na ograniczenia w stosowaniu do tego celu uproszczonej formuły normowej opartej na specyfikacji wskaźnika wykorzystania nośności. Zaproponowano skorygowane postępowanie iteracyjne pozwalające na oszacowanie poszukiwanej temperatury, gdy bezpośrednie wykorzystanie wskazanej zależności nie jest miarodajne.

EN

A procedure for determining the critical temperature of axially compressed steel column when exposed to fire was presented and discussed in detail. The limitations for the use in this purpose a simplified standard formula which is based on the specification of degree of utilization index were identified. A revised iterative procedure has been proposed to evaluate the sought temperature level in the case when the direct use of such the formula is not reliable.

9

Numerical Simulation of Axially Compressed Cylindrical Shells with Circular Cutouts

Lykhachova O.

Mechanics and Mechanical Engineering

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2016

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Vol. 20, nr 3

309--320

EN

The present paper deals with FEM modelling of Tennyson’s famous experiment: the buckling problem of axially compressed elastic cylindrical shells with small single circular cutouts. It is completed using ANSYS software package in geometrically linear and nonlinear formulations for three different loading schemes. Two of the loading schemes provide an upper and lower bounds for buckling loads. The third loading scheme corresponds to the experiment and gives an excellent agreement of numerical results with the experimental data. The influence of shell thickness on buckling load is studied in addition to common non–dimensional geometrical shell parameter. Decrease of a shell thickness about two times leads to decrease of buckling load parameter about 7 % in the studied range of cutouts. The efficiency of ANSYS software is proved for the buckling design of shells with highly non–homogeneous stress strain state.

10

Axial splitting of empty and foam-filled circular composite tubes – An experimental study

Rezaei B., Niknejad A., Assaee H., Liaghat G. H.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 3

650--662

EN

This paper studies the effects of polyurethane foam-filler on the axial splitting process of circular composite tubes under the axial quasi-static loading, experimentally. A shear mode of failure in circular composite tubes is initiated by crushing the tube onto a conical die to absorb the energy. The effects of conical die angle, number of fiber fabric layers, resin type and also, diameter and fiber fabric type of the tubes on axial load, energy absorption and specific absorbed energy by the structure are studied. Experimental results show that the polyurethane foam-filler increases energy absorption capability by the tubes. Also, it is found that in the investigated domain, composite tubes with smaller diameters are better energy absorbers, comparing with the composite tubes with larger diameters. Experiments show that foam-filled circular tubes under the axial compression in the splitting process works as good energy dissipater.

11

Quasi-static and dynamic properties of the intervertebral disc : experimental study and model parameter determination for the porcine lumbar motion segment

Araujo A. R. G., Peixinho N., Pinho A. C. M., Claro J. C. P.

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 4

59--66

EN

Purpose: The study of axial loading is essential to determine the properties of intervertebral disc. The objectives of this work are (1) to quantify the mechanical properties of porcine lumbar intervertebral discs under static and cyclic compressive loading, and (2) to determine the parameters of a five-parameter rheological model for porcine and compare them with those obtained for human lumbar intervertebral discs. Methods: Thus, the porcine lumbar motion segments were subjected to quasi-static and dynamic compression tests. The quasi-static tests were used to obtain the static stiffness coefficient at different strain rates, while the data from the cyclic compressive tests were used to both determine the dynamic stiffness coefficient and to be fitted in a 5-parameter model, in order to simulate the creep response of the porcine intervertebral discs. Results: The results demonstrated that dynamic stiffness coefficient of porcine discs is between four and ten times higher than the static stiffness coefficient, depending on load applied. The parameters of the rheological model suggested a low permeability of nucleus and endplate during the fast response of porcine discs. In addition, the fast response in terms of displacement is four times higher than those documented for human discs. Conclusions: This study revealed that care must be taken on the comparison between porcine and human discs, since they present different behaviour under quasi-static and dynamic compressive loading.

12

Nośność i wytężenie osiowo ściskanych polimerowych rur grubościennych wypełnionych betonem

Abramski M., Korzeniowski P., Wesołowski M.

Inżynieria i Budownictwo

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2014

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R. 70, nr 5

280--284

PL

Przedstawiono wyniki badań i porównano je z podobnymi badaniami polimerowych rur cienkościennych. Stwierdzono, że grubość płaszcza w znacznym stopniu wpływa na zachowanie pokrytyczne słupów oraz rozwój odkształceń podłużnych i obwodowych płaszcza w trakcie procesu obciążania. Próbę wykorzystania zaczerpniętej z Eurokodu 4 procedury obliczania stalowo-betonowych słupów zespolonych do wyznaczania nośności badanych słupów uznano za nieudaną.

EN

In the paper results of experimental investigation carried out on axially loaded polymer thick-walled tubes filled out with concrete are discussed. Comparing this investigation with other tests carried out on similar, but thin-walled tubes authors realize significant differences in post-critical behavior as well as strain development in tube in both longitudinal and circumferential directions. A trial of adaptation of Eurocode 4 procedure of calculating composite steel-concrete columns for the tested columns was made. However load-carrying capacities obtained using this approach differ from the experimental results in authors’ opinion too much.

13

Odkształcalność ściskanego osiowo betonu z kruszywem styropianowym

Rucińska T., Kiernożycki W.

Cement Wapno Beton

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2014

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R. 18/80, nr 1

33--39

PL

W pracy przedstawiono wyniki badań odkształcalności betonu z kruszywem styropianowym o różnych klasach wytrzymałości oraz gęstości objętościowej, poddawanych jednoosiowemu ściskaniu. Wyniki badań wykazują, że poziom naprężenia inicjującego styrobetonów σi/ƒcm mieści się w granicach 35% ÷ 45% naprężeń niszczących, podobnie jak w przypadku betonów zwykłych. Natomiast poziom naprężenia krytycznego σcr/ƒcm wynosi 60%÷75% i jest nieco niższy od betonów zwykłych. Współczynnik Poissona ma wartość około 0,22 i jest zbliżony do betonów zwykłych.

EN

In the paper the results of strain investigation of concrete with styrofoam aggregate of different strength classes and bulk densities subjected to uniaxial compression is presented. The obtained results are showing that the initiating stress of styrofoam concretes σi/ƒcm is in the range 35% ÷ 45% of destructive stress, similarly to ordinary concrete. However the critical stress level σcr/ƒcmis in the range 60%÷75%, slightly lower than for ordinary concrete. Poisson s ratio of stryfoam concrete is about 0.22, similar to ordinary concrete.

14

Pręty kompozytowe GFRP jako zbrojenie elementów betonowych obciążonych siłą podłużną i momentem zginającym

Szymczak P., Olbryk P, Kamińska M.

Budownictwo i Architektura

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2014

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Vol. 13, nr 3

167--174

PL

Referat dotyczy betonowych elementów zbrojonych wewnętrznie prętami kompozytowymi GFRP (Glass Fibre Reinforced Polymer), zawierającymi włókna szklane zatopione w matrycy żywicznej. Skupiono się na elementach obciążonych siłą podłużną i momentem zginającym. Omówiono doświadczalne badania czterech słupków obciążonych ściskającą siłą osiową, zbrojonych podłużnie i poprzecznie prętami GFRP. Słupki miały kształt walców o nominalnej średnicy 200mm i wysokości 600mm. Zbrojenie podłużne było stałe i składało się z sześciu prętów o średnicy 11mm, zbrojenie poprzeczne wykonano jako ciągłe w postaci spirali z prętów o średnicy 4mm lub 8mm, o rozstawie 45mm i 60mm. Zależność σ – ε prętów kompozytowych zbrojenia podłużnego była określona doświadczalnie, zarówno przy rozciąganiu, jak i ściskaniu. Badania wykazały, że zbrojenie GFRP bardzo dobrze współpracuje z betonem, a w stanie zniszczenia osiąga naprężenia adekwatne do podłużnych odkształceń elementu. Wykazano, że na podstawie stanów odkształcenia przekroju takich jak przyjmowane dla przekrojów żelbetowych, zgodnie z EC2, można sporządzić krzywe interakcji Nu-Mu.

EN

This paper discusses concrete members reinforced internally with composite GFRP bars (Glass Fibre Reinforced Polymer). The studies are focused on members under axial force and bending moment. Experimental studies of 4 RC columns loaded with compressive axial force, longitudinally and transversally reinforced with GFRP bars were discussed. Columns had cylinder shape with the nominal diameter of 200mm and height of 600mm. Longitudinal reinforcement contained six bars with 11mm diameter and transversal reinforcement of continuous spiral bars # 4 and #8 with spacing equal to 45mm and 60mm. Studies show that the GFRP reinforcement has very good adhesion to concrete and,in failure state reaches stresses adequate to longitudinal strains of members. This paper proves that the interaction curves can be determined on the same strain state basis as used in RC members according to EC2.

15

Investigation on corroded hss tubular members under compression strengthened with CFRP composites

Sundarraja M. C., Sriram P.

Archives of Civil Engineering

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2014

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Vol. 60, nr 1

145--159

EN

The main objective of this investigation is to assess the feasibility of strengthening of corroded (damaged) square hollow steel tubular sections subjected to compression and to develop or predict the suitable wrapping scheme of fibre reinforced polymer (FRP) to enhance the structural behaviour of it. For this study, compact mild steel tubes were used with the main variable being FRP characteristics. Carbon fibre reinforced polymer (CFRP) fabrics was used as horizontal strips (lateral ties) with other parameters such as the number of layers and spacing of strips. Among fourteen specimens, six were externally bonded by CFRP strips having a constant width of 50mm with a spacing of 20mm and the remaining six were externally bonded by CFRP strips having a constant width of 70mm with a spacing of 20mm, two columns were unbonded. Experiments were undertaken until the failure of columns to fully understand the influence of FRP characteristics on the compressive behaviour of the square sections including their failure modes, axial stress-strain behaviour, enhancement in the load carrying capapcity, and effect of distribution of CFRP layers. Finally, the behaviour of externally bonded hollow tubular sections was compared with one another and also with the control specimens. Evaluation of the results will lead to optimum CFRP jacketing/ wrapping arrangements for the steel tubes considered here.

16

Projektowanie elementów rozciąganych i ściskanych osiowo według PN-EN 1993-1-1 i PN-EN 1993-1-5

Giżejowski M., Król P., Ślęczka L.

Inżynieria i Budownictwo

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2008

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R. 64, nr 3

126-134

PL

Przedstawiono zagadnienia projektowania elementów osiowo rozciąganych i ściskanych wg części 1-1 i 1-5 PN-EN 1993. Zamieszczono przykłady liczbowe takie same jak w artykule dotyczącym wdrożenia (w 1990 r.) normy polskiej PN-90/B-03200, co umożliwiło pokazanie analogii i różnic w określaniu nośności wg tej normy polskiej i Eurokodu 3 wdrażanego w Polsce jako normy PN-EN z odpowiednimi załącznikami krajowymi.

EN

Design procedures of axially loaded tension and compression members according to parts 1-1 and 1-5 of PN-EN 1993, from the package of eurocodes implemented in Poland for design of steel structures, are presented. Illustrative examples, the same as presented in the paper concerned with the introduction of national code PN-90/B-03200, are included in order to show the analogies and differences in the determination of member resistances according to currently used national codes and Eurocode 3 parts being now implemented in Poland together with relevant National Annexes.

17

Obliczanie słupów zespolonych. Cz.1. Słupy osiowo ściskane

Kucharczuk W., Labocha S.

Konstrukcje Stalowe

|

2007

|

nr 3

42-44

18

Kryteria nośności stalowych słupów obetonowanych

Szumigała M.

Przegląd Budowlany

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2006

|

R. 77, nr 7-8

20-24

19

Ocena odporności ogniowej stalowych słupów ściskanych osiowo. Przykłady obliczeń

Maślak M.

Inżynieria i Budownictwo

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2006

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R. 62, nr 4

206-209

PL

Przykłady ilustrują wybrane podejścia do oceny odporności ogniowej słupów stalowych. Pokazano wpływ, jaki na wartość badanej odporności ma stopień skrępowania potencjalnych odkształceń termicznych.

EN

Numerical examples presented in this paper illustrate selected engineering approaches to the assessment of steel column fire resistance. The influence of constrainment of possible thermal deformations on this resistance has been taken into account. Theoretical foundations of the applied methods of analysis have been presented in the previous part of this article.

20

Duże deformacje osiowo ściskanych elementów cienkościennych

Cieśla P., Dacko A., Dacko M., Nowak J.

Biuletyn Wojskowej Akademii Technicznej

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2006

|

Vol. 55, nr 4

209-220

PL

W artykule przedstawiono wyniki badań doświadczalnych i symulacji numerycznych procesu ściskania osiowego elementów cienkościennych. Badania doświadczalne przeprowadzono przy obciążeniu quasi-statycznym i przy obciążeniu falą uderzeniową wybuchu MW. Obliczenia numeryczne wykonano metodą elementów skończonych w modelach złożonych z elementów powłokowych i trójwymiarowych. Uzyskano dobrą zgodność w zakresie maksymalnej wartości siły zgniatającej próbkę i postaci deformacji próbki w próbach doświadczalnych i symulacjach numerycznych.

EN

The paper presents the results of experimental investigations and numerical simulations of axial compression of thin-walled structural elements. Experiments were carried out for quasistatic loads and the load of shockwave of explosion. The numerical analyses were based on both shell- and solid-element models. Good correlation of maximum axial force for specimen crush and deformation shape was obtained in experiments and numerical simulation.