Wyniki wyszukiwania - BazTech

1

Mathematical modelling of stress-strain state of steel-concrete beams with combined reinforcemenent

Selejdak Jacek, Bobalo Taras, Blikharskyy Yaroslav, Dankevych Iryna

Production Engineering Archives

|

2023

|

Vol. 29, Iss. 1

108--115

EN

Most of the modern computer software for the building structures` calculation is based on mathematical dependencies which make it possible to analyse rather complex stress-strain state of structures subjected to loading. As a rule, the calculation is based on the finite element method and is reduced to the calculation of deformations arising in structures due to the action of external forces with the use of real strain diagrams of materials, σ-ε diagrams for concrete and reinforcement. Modern normative regulations for reinforced concrete structures` calculation are also based on the deformation model using material deformation diagrams, which are as close to the real ones, as possible. Therefore, this study was aimed to investigate in more detail the stress-strain state and the physical essence of the processes occurring in reinforced concrete structures with combined reinforcement according to mathematical approaches and regulations of DBN B.2.6-98:2009 and DSTU B. In 2.6-156:2010. Namely, in the research is analysed the combined reinforcement of S245 steel tapes and A1000 rebar, which is used in the production of reinforced concrete elements. The results of mathematical modelling were compared with the calculation results, according to DBN B.2.6-98: 2009 and DSTU B. B 2.6-156:2010, as well as with field experimental data. Therefore, the conclusion could be made, whether it is possible to use this technique with sufficient accuracy to calculate reinforced concrete structures with combined reinforcement.

2

Ocena wybranych normowych modeli przyczepności kompozytów FRP do wzmacniania betonu

Krzywoń Rafał

Inżynieria i Budownictwo

|

2023

|

R. 79, nr 9-10

533--537

PL

Przyczepność jest jednym z kluczowych czynników decydujących o efektywności zewnętrznego wzmocnienia kompozytowego konstrukcji betonowej. Wykorzystywane w projektowaniu normy stosują różne modele matematyczne do wyznaczania siły przyczepności taśm i mat FRP. Otrzymywane w obliczeniach wyniki mogą różnić się nawet ponad dwukrotnie. Artykuł przedstawia ocenę dokładności przewidywania siły przyczepności dla wybranych wytycznych projektowania w świetle badań przyczepności ponad 800 próbek. Wyniki analiz metodą Demerit wskazują, że najlepsze modele przyczepności proponują szwajcarska norma SIA 166 i włoska CNR-DT200.

EN

Bond is one of the key issues determining the effectiveness of external composite strengthening of a concrete structure. The standards used in designing use various mathematical models to predict the bond strength of FRP overlays. The results obtained in the calculations may differ even two times. The paper presents an assessment of the accuracy of bond force prediction for selected design guidelines. The results of over 800 samples taken from the literature were used for comparison. The results of analyses show that the best bond model is recomended by the Swiss standard SIA 166 and CNR-DT200.

3

Computer modelling of RC beams reinforced with high strength rebars and steel plate

Bobalo Taras, Blikharskyy Yaroslav, Krainskyi Pavlo, Volynets Myhailo

Quality Production Improvement - QPI

|

2019

|

Vol. 1, Iss. 1

304--310

EN

The use of computers provides the opportunity to analyse and design complex structures, taking into account the geometric and physical nonlinearity of construction materials. In the article the study of stress-strain state of mixed steelconcrete beams, were presented. The results of this study showed that the method of calculation according to designe codes gave satisfactorily results of calculated strength compared with experiments. However, these methodes do not provide complete information of structural performance at all levels of load. For a more complete study of the stress-strain state and the physical nature of the processes occurring in steel-concrete structures reinforced with a mixed reinforcement, the calculation method using "Lira" software complex is proposed. The method of calculation is based on the finite element method. The calculation is made taking into account physical nonlinearity and real diagrams of σ-ε of materials using the nonlinear deformation law №14 of "Lira" software complex. The proposed method of calculation allows to determine the values of bearing capacity, the development of deformations and the beginning of crack formation, as well as stresses at all load levels.

4

Badanie nośności belek żelbetowych dozbrojonych stalowymi siatkami cięto-ciągnionymi

Burchenya S., Dobryanskyy I., Famulyak Y., Sobczak-Piąstka J.

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

|

2016

|

z. 63, nr 1/I

237--245

PL

W artykule przedstawiono wyniki badań nośności oraz momentu pojawienia się pęknięć i odkształceń konstrukcji żelbetowych zginanych belek ze wzmocnieniem zewnętrznym w formie stalowej siatki cięto-ciągnionej. Rozpatrzono przypadek umieszczenia siatki bez warstwy ochronnej z betonu oraz z warstwą ochronną w postaci betonu (otuliny). We wcześniejszych badaniach eksperymentalnie potwierdzono, że siatka cięto-ciągniona zapewnia bardziej niezawodną sczepność z powierzchnią betonu, niż beton z arkuszem blachy falistej lub gładkiej i systemem dospawanych kotew.

EN

The results of the bearing capacity, cracks formation moment and stress-strain behavior of the reinforced bending beam structures with the external reinforcement in the form of steel cut and stretchy sheet which is placed with and without the protective layer of concrete are presented in the article. It is experimentally confirmed that the cut and stretchy sheet provides better adhesion with an array of concrete than a similar solid corrugated sheet or flat sheet with a system of welded anchors.

5

Obchislennja zginal'nikh momentihv u nerozrihznikh stalebetonnikh balkakh z vrakhuvannjam najavnostih trishhin ta deformihvnikh vlastivostejj betonu ih stalih

Barabash V., Vars'kijj V.

Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

|

2000

|

z. 32[180], cz.1

33-40

EN

It is shown the description of an algorithm calculation of the unslitted steel concrete beams with the external reinforcing on electronic calculating machine. In the mathematical model are regarded the real deformation properties of the materials - concrete and steel from which are made the beams and the influence of the deformation and the process of the formation of cracks and hardness of cutting. In accordance to changing the hardness ot cutting is carried out the calculation out the calculation sizes of bending moments and are estimated the opportunities of their redistribution compared to flexible diagram. It is noted that the opportunity of redistribution of their efforts depends on deformation properties of fittings.

6

Mshhnihst' ta deformashhjjnihst' trisharovikh zalihzobetonnikh balkovikh konstrukcihjj ihz zovnihshnihm listovim armuvannjam

Barabash V. M., Shmig R.

Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

|

2000

|

z. 32[180], cz.1

25-32

EN

The thesis comprising the experimental theoretical investigations of new common and preliminary tensed complex concrete reinforced constructions. The basis of the suggested solution is the panel construction which is composed of the reinforced pressed up layer and the stretched lower layer reinforced with the external band skeleton frame construction, the space between which is filled with the light heat isolation keramzite-concrete. It was estimated that the great importance for the proper work with the bend three-layer steel concrete constructions is the connection between the layers of different concrete, the presence of space frame systems on the supporting and the bend anchors in their flight of cutting. The suggested mathematic model according to the method of final elements defines the tense-deformed state of the complex concrete reinforced constructions regarding the real programs of materials deformation at all loading stages.