scholarly journals Experimental tests of post-tensioned girders strengthened with prestressed CFRP composites

2014 ◽  
Vol 13 (3) ◽  
pp. 159-166
Author(s):  
Michał Staśkiewicz ◽  
Renata Kotynia ◽  
Julien Michels ◽  
Christoph Czaderski ◽  
Masoud Motavalli
Keyword(s):  
Materials Science ◽  
Load Capacity ◽  
Experimental Tests ◽  
Field Application ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
University Of Technology ◽  
Federal Laboratories ◽  
Real Scale ◽  
Post Tensioned

The paper presents a research carried out within the framework of the Polish-Swiss “Tulcoempa” project, carried out by Lodz University of Technology and EMPA Swiss Federal Laboratories for Materials Science and Technology. The main goal of the project was to perform the first field application of an innovative, anchorless flexural strengthening with use of prestressed CFRP laminates on an existing bridge in Poland. Laboratory tests were conducted to verify the efficiency of the strengthening of two real-scale, 18.4m long, post-tensioned bridge girders reconstructed at EMPA institute. Flexural strengthening was successful and resulted in an increase of the member’s load capacity by 24% and reduction of the midspan deflection by more than 60%.

Flexural strengthening of continuous unbonded post-tensioned concrete beams with end-anchored CFRP laminates

2015 ◽  
Vol 53 (6) ◽  
pp. 1083-1104 ◽  
Author(s):  
Saeed Ghasemi ◽  
Ali A. Maghsoudi ◽  
Habib A. Bengar ◽  
Hamid R. Ronagh
Keyword(s):  
Concrete Beams ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Post Tensioned

scholarly journals Flexural Performance of RC Beams Strengthened with Externally-Side Bonded Reinforcement (E-SBR) Technique Using CFRP Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2809
Author(s):  
Md. Akter Hosen ◽  
Fadi Althoey ◽  
Mohd Zamin Jumaat ◽  
U. Johnson Alengaram ◽  
N. H. Ramli Sulong
Keyword(s):  
Absorption Capacity ◽  
Experimental Program ◽  
Rc Beams ◽  
Rc Structures ◽  
Functional Changes ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Flexural Performance ◽  
Design Loads ◽  
Predicted Values

Reinforced concrete (RC) structures necessitate strengthening for various reasons. These include ageing, deterioration of materials due to environmental effects, trivial initial design and construction, deficiency of maintenance, the advancement of design loads, and functional changes. RC structures strengthening with the carbon fiber reinforced polymer (CFRP) has been used extensively during the last few decades due to their advantages over steel reinforcement. This paper introduces an experimental approach for flexural strengthening of RC beams with Externally-Side Bonded Reinforcement (E-SBR) using CFRP fabrics. The experimental program comprises eight full-scale RC beams tested under a four-point flexural test up to failure. The parameters investigated include the main tensile steel reinforcing ratio and the width of CFRP fabrics. The experimental outcomes show that an increase in the tensile reinforcement ratio and width of the CFRP laminates enhanced the first cracking and ultimate load-bearing capacities of the strengthened beams up to 141 and 174%, respectively, compared to the control beam. The strengthened RC beams exhibited superior energy absorption capacity, stiffness, and ductile response. The comparison of the experimental and predicted values shows that these two are in good agreement.

scholarly journals The Effect of Process Parameters in Helical Rolling of Balls on the Quality of Products and the Forming Process

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak
Keyword(s):  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Helical Rolling ◽  
Forming Process ◽  
University Of Technology ◽  
Quality Of Products ◽  
Skew Rolling

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.

scholarly journals Mechanical-Level Hardware-In-The-Loop and Simulation in Validation Testing of Prototype Tower Crane Drives

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5727
Author(s):  
Michał Michna ◽  
Filip Kutt ◽  
Łukasz Sienkiewicz ◽  
Roland Ryndzionek ◽  
Grzegorz Kostro ◽  
...  
Keyword(s):  
Laboratory Testing ◽  
Environmental Parameters ◽  
Experimental Tests ◽  
Drive System ◽  
Hardware In The Loop ◽  
Dynamic Simulations ◽  
Tower Crane ◽  
University Of Technology ◽  
New Type ◽  
Drive Systems

In this paper, the static and dynamic simulations, and mechanical-level Hardware-In-the-Loop (MHIL) laboratory testing methodology of prototype drive systems with energy-saving permanent-magnet electric motors, intended for use in modern construction cranes is proposed and described. This research was aimed at designing and constructing a new type of tower crane by Krupiński Cranes Company. The described research stage was necessary for validation of the selection of the drive system elements and confirmation of its compliance with applicable standards. The mechanical construction of the crane was not completed and unavailable at the time of testing. A verification of drive system parameters had to be performed in MHIL laboratory testing, in which it would be possible to simulate torque acting on the motor shaft. It was shown that the HIL simulation for a crane may be accurate and an effective approach in the development phase. The experimental tests of selected operating cycles of prototype crane drives were carried out. Experimental research was performed in the LINTE^2 laboratory of the Gdańsk University of Technology (Poland), where the MHIL simulator was developed. The most important component of the system was the dynamometer and its control system. Specialized software to control the dynamometer and to emulate the load subjected to the crane was developed. A series of tests related to electric motor environmental parameters was carried out.

scholarly journals Numerical Analysis of the Perforated Steel Sheets Under Uni-Axial Tensile Force

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 632 ◽  
Author(s):  
Ahmed M. Sayed
Keyword(s):  
Load Capacity ◽  
Tensile Force ◽  
Three Dimensional ◽  
Tensile Load ◽  
Experimental Tests ◽  
Strain Engineering ◽  
Uniaxial Tensile ◽  
Fe Model ◽  
Stress Strain ◽  
Steel Sheets

The perforated steel sheets have many uses, so they should be studied under the influence of the uniaxial tensile load. The presence of these holes in the steel sheets certainly affects the mechanical properties. This paper aims at studying the behavior of the stress-strain engineering relationships of the perforated steel sheets. To achieve this, the three-dimensional finite element (FE) model is mainly designed to investigate the effect of this condition. Experimental tests were carried out on solid specimens to be used in the test of model accuracy of the FE simulation. Simulation testing shows that the FE modeling revealed the ability to calculate the stress-strain engineering relationships of perforated steel sheets. It can be concluded that the effect of a perforated rhombus shape is greater than the others, and perforated square shape has no effect on the stress-strain engineering relationships. The efficiency of the perforated staggered or linearly distribution shapes with the actual net area on the applied loads has the opposite effect, as it reduces the load capacity for all types of perforated shapes. Despite the decrease in load capacity, it improves the properties of the steel sheets.

Flexural strengthening of pre-cracked RC slabs with prestressed NSM CFRP laminates and evaluation of strain loss

2021 ◽  
pp. 136943322110105
Author(s):  
M.R. Mostakhdemin Hosseini ◽  
Salvador J.E. Dias ◽  
Joaquim A.O. Barros
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Transfer Length ◽  
Rc Structures ◽  
Cracked Concrete ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Load Carrying ◽  
Rc Slabs

The strengthening intervention of RC structures often involves already cracked concrete. To evaluate the effect of the level of damage prior to the strengthening (pre-cracks) on the behavior of the flexurally strengthened RC slabs with prestressed NSM CFRP laminates, an experimental research was carried out. Two pre-cracking levels of damage were analyzed and, for each one, three levels of prestress were tested (0%, 20% and 40%). The obtained results showed that the strengthening of damaged RC slabs with prestressed NSM CFRP laminates results in a significant increase on the load carrying capacity at serviceability limit states. Pre-cracked RC slabs strengthened with prestressed NSM CFRP laminates presented a load carrying capacity almost similar to the corresponding uncracked strengthened slabs. To determine the effective prestress level in CFRP laminates, the variation of strain over the length of the CFRP and over time was experimentally recorded. The prestress transfer length was also evaluated. The experimental results revealed that the transfer length of CFRP laminates was less than 150 mm, and the maximum value of strain loss out of transfer length (around 14%) was measured close to the cracked section of the damaged RC slabs. Significant part of strain loss in CFRP laminates occurred during 24 h after releasing the prestress load.

scholarly journals Experimental tests on real-scale EBF structures with horizontal and vertical links

Data in Brief ◽  
2018 ◽  
Vol 21 ◽  
pp. 1246-1257
Author(s):  
Silvia Caprili ◽  
Francesco Morelli ◽  
Nicola Mussini ◽  
Walter SALVATORE
Keyword(s):  
Experimental Tests ◽  
Real Scale

scholarly journals Introduction

2003 ◽  
Vol 9 (4) ◽  
pp. 336-336
Author(s):  
Michal Zelechower ◽  
Pawel Zieba ◽  
Clive Walker
Keyword(s):  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Materials Science ◽  
Polish Academy ◽  
Science Institute ◽  
Materials Engineering ◽  
University Of Technology ◽  
Regional Workshop ◽  
Analysis Society ◽  
Microbeam Analysis Society

This issue of Microscopy and Microanalysis contains selected papers from the fifth Regional Workshop of the European Microbeam Analysis Society (EMAS) on Electron Probe Microanalysis—Practical Aspects that took place May 22–25, 2002 at Szczyrk, Poland. The meeting was organized by the Polish National Branch of EMAS in collaboration with the Silesian University of Technology (Faculty of Materials Engineering and Metallurgy) and the Polish Academy of Science (Institute of Metallurgy and Materials Science).

Influence of the Parameter of Ductility of Reinforcing Steel on the Behaviour of a Narrow Three-Span Reinforced Concrete Slab Based on Experimental Investigations

2015 ◽  
Vol 240 ◽  
pp. 218-224 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Building Structures ◽  
Reinforced Concrete Slab ◽  
Tension Member ◽  
Test Models ◽  
Reinforced Steel

In the time of the exploitation of building structures frequently situations do occur, in which due to failures they are exposed to much higher loads than has been originally predicted. In a state of emergency due to overloading of the structure, significant reserves of load capacity may be appear in the case of a self-acting tension member work. The aim of the paper was to demonstrate the influence of reinforced steel parameters and its quantity on the mechanism of destruction of four three-span models of reinforced concrete strips with the dimensions 7140×500×190 mm. The paper contains the description of the test stand and test models and the results of experimental tests which were compared with the results of the calculations based on traditional methods.

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