scholarly journals Numerical analysis of torsional tangent rigidity of reinforced concrete waffle slab

2019 ◽  
Vol 12 (6) ◽  
pp. 1454-1467
Author(s):  
C. C. NUNES
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Structural Engineering ◽  
Research Work ◽  
Experimental Tests ◽  
Breaking Load ◽  
The Finite Element Method ◽  
Torsion Rigidity ◽  
Waffle Slab ◽  
Geometric Nonlinear Analysis

Abstract This research work deals with the analysis of torsional tangent rigidity of reinforced concrete waffle slabs by comparisons of the numerical analysis with results of experimental tests, with calculations performed using the ATENA program. This program was specially developed for the calculation of reinforced concrete structures, considering the physical and geometric nonlinear analysis using the finite element method. Numerical analysis considered the tensile strength of the concrete and consequently the fracture energy. Numerical situations were tested to obtain the calibration of the numerical analysis with the laboratory tests. After the calibrations, the results were extrapolated to extreme situations to infer tangent torsion rigidity in new situations. It is concluded that, for waffle slabs, near the rupture, the torsional tangent rigidity should be 5% of the torsional tangent rigidity to the initial torsion. In service, considering one third of the total breaking load, the torsional tangent rigidity should be 85% of the torsional tangent rigidity to the initial twist. This great torsional tangent rigidity in service is another parameter that guarantees the structural efficiency of the waffle slabs and can be used in the most diverse applications of structural engineering.

scholarly journals NUMERICAL ANALYSIS OF CORRUGATED STEEL PLATE BRIDGE WITH REINFORCED CONCRETE RELIEVING SLAB

2015 ◽  
Vol 22 (5) ◽  
pp. 585-596 ◽  
Author(s):  
Damian BEBEN ◽  
Adam STRYCZEK
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Steel Plate ◽  
Numerical Models ◽  
Experimental Tests ◽  
Bridge Engineering ◽  
Steel Plates ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Rc Slab

The paper presents a numerical analysis of corrugated steel plate (CSP) bridge with reinforced concrete (RC) relieving slab under static loads. Calculations were made based on the finite element method using Abaqus software. Two computation models were used; in the first one, RC slab was used, and the other was without it. The effect of RC slab to deformations of CSP shell was determined. Comparing the computational results from two numerical models, it can be concluded that when the relieving slab is applied, substantial reductions in displacements, stresses, bending mo­ments and axial thrusts are achieved. Relative reductions of displacements were in the range of 53–66%, and stresses of 73–82%. Maximum displacements and bending moments were obtained at the shell crown, and maximum stresses and axial thrusts at the quarter points. The calculation results were also compared to the values from experimental tests. The course of computed displacements and stresses is similar to those obtained from experimental tests, although the absolute values were generally higher than the measured ones. Results of numerical analyses can be useful for bridge engineering, with particular regard to bridges and culverts made from corrugated steel plates for the range of necessity of using additional relieving elements.

scholarly journals Numerical Evaluation of Structural Safety of Linear Actuator for Flap Control of Aircraft Based on Airworthiness Standard

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 104
Author(s):  
Dong-Hyeop Kim ◽  
Young-Cheol Kim ◽  
Sang-Woo Kim
Keyword(s):  
Numerical Analysis ◽  
Analytical Method ◽  
Safety Evaluation ◽  
Experimental Tests ◽  
Structural Safety ◽  
Linear Actuator ◽  
The Finite Element Method ◽  
Margin Of Safety ◽  
Verification Methodology ◽  
The Given

Airworthiness standards of Korea recommend verifying structural safety by experimental tests and analytical methods, owing to the development of analysis technology. In this study, we propose a methodology to verify the structural safety of aircraft components based on airworthiness requirements using an analytical method. The structural safety and fatigue integrity of a linear actuator for flap control of aircraft was evaluated through numerical analysis. The static and fatigue analyses for the given loads obtained from the multibody dynamics analysis were performed using the finite element method. Subsequently, the margin of safety and vulnerable area were acquired and the feasibility of the structural safety evaluation using the analytical method was confirmed. The proposed numerical analysis method in this study can be adopted as an analytical verification methodology for the airworthiness standards of civilian aircraft in Korea.

scholarly journals Numerical Structural Analysis of NPP Reinforced Concrete Structures Under Seismic Loading / Numeryczna Analiza Strukturalna Żelbetowych Konstrukcji Elektrowni Jądrowych W Warunkach Obciążeń Sejsmicznych

2012 ◽  
Vol 23 (1) ◽  
pp. 29-44
Author(s):  
Vladimir Aleshin ◽  
Vadim Seleznev
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Nuclear Power ◽  
Ground Surface ◽  
Seismic Load ◽  
Reinforced Concrete Structure ◽  
The Finite Element Method ◽  
Nonlinear Statement ◽  
Reactor Building ◽  
Seismic Loadings

Abstract The paper describes an approach to the numerical analysis of response of nuclear power plant buildings including soil-structure interaction effects. A reinforced concrete structure of an NPP reactor building under operating and seismic loadings is considered. The simulated seismic load corresponds to a maximum designed earthquake of magnitude 7 (the peak ground surface acceleration is 0.12 g). The numerical analysis was performed by the finite element method in a 3D nonlinear statement using the FEM-programs ANSYS and LS-DYNA. Review of the numerical analysis results demonstrated that the presented technique can be successfully applied to seismic design of NPP structures.

scholarly journals EXPERIMENTAL AND NUMERICAL STUDIES OF THE CARRYING CAPACITY OF A CIRCULAR ARCH UNDER HYDROSTATIC PRESSURE

2020 ◽  
pp. 50-58
Author(s):  
M.G. Surianinov ◽  
◽  
S.P. Neutov ◽  
I.B. Korneieva ◽  
D.O. Kirichenko ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Hydrostatic Pressure ◽  
Bearing Capacity ◽  
Cross Sections ◽  
Experimental Studies ◽  
Breaking Load ◽  
Domestic Literature ◽  
Numerical Studies ◽  
Steel Fiber Concrete

Abstract. The results of a numerical and experimental study of the bearing capacity of a circular concrete arch loaded with hydrostatic pressure are presented. To implement the specified scheme of loading arches, the authors made a stand that allows you to determine the bearing capacity of models of concrete, reinforced concrete, steel-fiber concrete and wooden arches. For experiments, a double-hinged arch was made of concrete С16/20. At the same time, samples-cubes with an edge size of 10 cm were prepared from the same batch, which were tested for compression in accordance with the current regulatory documents. During the tests, the load was applied in small steps for a detailed study of the arch deformation process. At each stage, the readings of the measuring devices, dial indicators and strain gauges, were recorded. For computer modeling and numerical analysis by the finite element method, the software LIRA-SAPR was used. It is noted that, despite the widespread use of arched structures made of reinforced concrete, there are still no generalizing conclusions and recommendations for determining their actual bearing capacity and strengthening methods in the domestic literature. During the tests, a breaking load of 600 kN was achieved, that is, the bearing capacity of the arch, determined experimentally, was 0.845 of the value obtained by numerical analysis, although, as a rule, in our experimental studies of other structures, the theoretical value of the bearing capacity turned out to be lower than the actual one. In this case, the destruction occurred in the support part, i.e. at the junction of the support (heel) and the arch, which is explained by the lack of reinforcement of the heel. The results of experimental and numerical studies of a concrete arch indicate that under this loading scheme, almost equal stresses arise in all cross sections of the arch. Obviously, the bearing capacity of the structure can be increased due to the uniform dispersed reinforcement of the arch and reinforcement of the heel with bar reinforcement, which determines the direction of our further research.

An innovative prefabricated building system for the seismic regions

2020 ◽  
pp. 127-129
Author(s):  
Ž. P. Cuckič
Keyword(s):  
Reinforced Concrete ◽  
Return Period ◽  
Research Work ◽  
Construction Behaviour ◽  
Building System ◽  
Seismic Regions ◽  
Earthquake Effects ◽  
Precast Elements ◽  
Prefabricated Building

At the end of a decade-long research work at the Moravamont plant in Gnjilane, a new completely prefabricated building system was created from reinforced concrete and prestressed precast elements on the track, which was called Moravamont 2000. Presented in paper final results demonstrates that the construction is well and rationally designed, that the construction behaviour for the maximum expected earthquake effects with a return period of 500 years, according to the criterion of regulation, is resistant and resistant to an earthquake without major damage.

On axial compressive behavior of steel fiber reinforced concrete confined by FRP

2021 ◽  
pp. 136943322098165
Author(s):  
Hossein Saberi ◽  
Farzad Hatami ◽  
Alireza Rahai
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Steel Fiber ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Frp Confinement

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-confined specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

scholarly journals Different Techniques to Mitigate Partial Shading in Photovoltaic Panels

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3863
Author(s):  
Tiago Alves ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas ◽  
Carlos A. F. Fernandes
Keyword(s):  
Cell Model ◽  
Research Work ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Pv System ◽  
Partial Shading ◽  
System Architectures ◽  
Pv Systems ◽  
Advantages And Disadvantages ◽  
Pv Panel

The effect of partial shading in photovoltaic (PV) panels is one of the biggest problems regarding power losses in PV systems. When the irradiance pattern throughout a PV panel is inequal, some cells with the possibility of higher power production will produce less and start to deteriorate. The objective of this research work is to present, test and discuss different techniques to help mitigate partial shading in PV panels, observing and commenting the advantages and disadvantages for different PV technologies under different operating conditions. The motivation is to contribute with research, simulation, and experimental work. Several state-of-the-artsolutions to the problem will be presented: different topologies in the interconnection of the panels; different PV system architectures, and also introducing new solution hypotheses, such as different cell interconnections topologies. Alongside, benefits and limitations will be discussed. To obtain actual results, the simulation work was conducted by creating MATLAB/Simulink models for each different technique tested, all centered around the 1M5P PV cell model. The several techniques tested will also take into account different patterns and sizes of partial shading, different PV panel technologies, different values of source irradiation, and different PV array sizes. The results will be discussed and validated by experimental tests.

scholarly journals Experimental tests of PVD AlCrN-coated planer knives on planing Scots pine (Pinus sylvestris L.) under industrial conditions

2021 ◽  
Author(s):  
Krzysztof Nadolny ◽  
Wojciech Kapłonek ◽  
Marzena Sutowska ◽  
Paweł Sutowski ◽  
Piotr Myśliński ◽  
...  
Keyword(s):  
Research Work ◽  
Experimental Tests ◽  
Technical Condition ◽  
Cutting Edge ◽  
Raw Material ◽  
Edge Condition ◽  
Wear Area ◽  
Pine Wood ◽  
Wood Processing ◽  
Machining Operations

AbstractRaw pine wood processing and especially its mechanical processing constitute a significant share among technological operations leading to obtaining a finished product. Stable implementation of machining operations, ensuring long-term repeatable processing results depends on many factors, such as quality and invariability of raw material, technical condition of technological equipment, adopted parameters of work, qualifications and experience of operators, as well as preparation and properties of the machining tools used. It seems that the greatest potential in the search for opportunities to increase the efficiency of machining operations has the modification of machining tools used in it. This paper presents the results of research work aimed at determining how the life of cutting tools used in planing operations of wet pine wood is affected by the application of chromium aluminum nitride (AlCrN) coating to planar industrial planing knives in the process of physical vapour deposition. For this purpose operational tests were carried out under production conditions in a medium-sized wood processing company. The study compares the effective working time, rounding radius, the profile along the knife (size of worn edge displacement, wear area of the cutting edge), selected texture parameters of the planar industrial planing knife rake face and visual analyses of cutting edge condition of AlCrN-coated planar knives and unmodified ones. The obtained experimental results showed the possibility of increasing the life of AlCrN-coated knives up to 154% compared to the results obtained with uncoated ones. The proposed modification of the operational features of the knives does not involve any changes in the technological process of planing, does not require any interference with the machining station nor its parameters, therefore enabling rapid and easy implementation into industrial practice.

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