Experimental Tests of White UHPC Plates Reinforced by PVA Fibres and Textile Glass Reinforcement

2015 ◽  
Vol 1124 ◽  
pp. 83-88 ◽  
Author(s):  
Tomáš Bittner ◽  
Petr Tej ◽  
Miroslav Vokáč ◽  
Petr Bouška ◽  
Šárka Nenadálova
Keyword(s):  
Experimental Tests ◽  
Lower Surface ◽  
Automatic Measuring ◽  
Numeric Model ◽  
Four Point Bending ◽  
Glass Reinforcement ◽  
Acting Force ◽  
Measuring Unit

The paper is about a research focused on a development of thin slabs made from white UHPC. These slabs are reinforced by scattered PVA fibres and textile glass reinforcement in form of 2D net. The aim of the experiment is the development of tin slabs that can be used as facade or roof panels. The course of the experimental tests of these slabs and its correspondence with the numeric analysis made with ATHENA software is in the paper. Three slab specimens with size of 750 x 125 x 15 mm were tested in four-point bending. The white UHPC matrix was reinforced by the scattered PVA fibres and the 2D textile glass reinforcement with mesh 20 x 20 mm. The used 2D reinforcement was coated against alkali conditions, so called AR - Glass with 2400 TEX fineness. The reinforcement was placed and fixed near the lower surface of the slabs. The course of the tests was continually monitored by an automatic measuring unit where especially the acting force, the deformation in the middle of the span, the deformation in the supports and the progressive formation and development of cracks were detected. The numeric model was created in 3D surroundings of Gid 2011 program and then converted into ATENA software.

scholarly journals Flexural behavior of sandwich panels with cellular wood, plywood stiffener/foam and thermoplastic composite core

2017 ◽  
Vol 21 (2) ◽  
pp. 784-805 ◽  
Author(s):  
Edgars Labans ◽  
Kaspars Kalnins ◽  
Chiara Bisagni
Keyword(s):  
Mechanical Performance ◽  
Sandwich Panels ◽  
Experimental Tests ◽  
Design Tool ◽  
Thermoplastic Composite ◽  
Flexural Behavior ◽  
Four Point Bending ◽  
Reliable Design ◽  
Sufficient Strength ◽  
Core Part

A series of experimental tests have been carried out on three types of novel sandwich panels mainly designed for application in lightweight mobile housing. Two types of the panels are manufactured entirely from wood-based materials while the third one presents a combination of plywood for surfaces and corrugated thermoplastic composite as a core part. All sandwich panels are designed to allow rapid one-shot manufacturing. Mechanical performance has been evaluated in four-point bending comparing the data to the reference plywood board. Additionally, finite element simulations were performed to evaluate global behavior, stress distribution and provide the basis for a reliable design tool. Obtained results show sufficient mechanical characteristics suitable for floor and wall units. Compared to a solid plywood board, sandwich alternative can reach up to 42% higher specific stiffness, at the same time maintaining sufficient strength characteristics.

Experimental Tests of I Profile Made from UHPC Reinforced with Textile Glass Fibres

2016 ◽  
Vol 249 ◽  
pp. 261-266
Author(s):  
Tomáš Bittner ◽  
Petr Bouška ◽  
Šárka Nenadálová ◽  
Milan Rydval ◽  
David Čítek
Keyword(s):  
Experimental Testing ◽  
Experimental Tests ◽  
Loading Capacity ◽  
Test Results ◽  
Glass Fibres ◽  
Material Characteristics ◽  
Recorded Data ◽  
Glass Reinforcement ◽  
Metal Wires ◽  
3D Profile

This abstract is summarizing production and subsequent experimental testing of 3D profile of the symmetrical I shape concrete from UHPC matrix and reinforced with textile glass fibres. Upper and bottom covering strips of this profile are at the outside fibres reinforced with textile glass reinforcement. Position of this reinforcement is fixed in the distance of about 3 mm from outside fibres and is connected with reinforcement of the profile stem located in its axis. Such prepared beams were tested with four-point flexure evenly loaded until fracture. Course of the measurement was continuously recorded by the automatic logger, where mostly increase of the force in relation to deflection in the middle of the span and change of position of supports were recorded. From the recorded data were prepared graphic outputs compared with the same experiments performed on I profile which is not reinforced, i.e. only UHPC matrix, and for comparison also on the profile made from UHPC matrix with use of metal wires. In the conclusion were compared achieved test results. Mainly suitability and loading capacity of individual beam types was compared. Within the experiment were performed supporting tests based on which were determined material characteristics of tested matrix and textile glass reinforcement. Tests were performed in the Klokner Institute within solution of the grant project GACŘ 13-12676S.

Fatigue Properties of Dynamically Loaded Self-Compacting Concrete

2010 ◽  
Vol 452-453 ◽  
pp. 633-636
Author(s):  
Wouter de Corte ◽  
Veerle Boel
Keyword(s):  
Dynamic Loading ◽  
Experimental Tests ◽  
Reinforced Concrete Beams ◽  
Fatigue Properties ◽  
Single Type ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Lower Shear ◽  
Four Point Bending ◽  
Static And Dynamic Loading

Many civil structures are subjected to dynamic loading with load cycles exceeding 100.000 to 100.000.000 or more depending on the type of structure. At such high amounts of load cycles concrete can fail due to fatigue damage. The phenomenon is well understood and documented in the literature for traditional concrete. It remains unclear whether these conclusions can be transferred to self-compacting concrete (SCC), due to changes in concrete composition, decrease in the size of the coarse aggregates in combination with the addition of filler and superplasticizer. For this paper several reinforced concrete beams with varying reinforcement ratios are subjected to dynamic loads in a four point bending rig until failure. The imposed stress levels for the dynamic loading range between 0,80fcc and 0,85fcc. The main conclusions of the experimental tests are (1) clearly different failure mechanisms determine the static and dynamic loading for a single type of beam, (2) SCC appears to have a somewhat lower shear resistance during fatigue, (3) the differences in flexural degradation between SCC and TC beams are rather small.

scholarly journals Modeling of Fracture Propagation in Concrete Structures Using a Constitutive Relation with Embedded Discontinuity

2015 ◽  
Vol 36 (4) ◽  
pp. 27-33 ◽  
Author(s):  
Stanisław Pietruszczak ◽  
Ehsan Haghighat
Keyword(s):  
Mixed Mode ◽  
Concrete Beam ◽  
Concrete Structures ◽  
Fracture Propagation ◽  
Experimental Tests ◽  
Constitutive Law ◽  
Extended Finite Element ◽  
Localized Deformation ◽  
Four Point Bending ◽  
Discrete Nature

Abstract In this paper, the problem of modeling of mixed mode cracking in concrete structures is addressed within the context of a constitutive law with embedded discontinuity (CLED). This approach, which was originally developed for describing the propagation of localized deformation in a “smeared” sense, is enhanced here to model a discrete nature of crack propagation. The latter is achieved by coupling the CLED approach with the level-set method, which is commonly used within the framework of Extended Finite Element (XFEM). Numerical simulations of experimental tests conducted at Delft University, which involve four-point bending of a notched concrete beam under the action of two independent actuators, are presented. The results based on enhanced CLED approach are directly compared with XFEM simulations. The predictions from both these methodologies are quite consistent with the experimental data, thereby giving advantage to CLED scheme in view of its simplicity in the numerical implementation.

scholarly journals Experimental and Numerical Analysis of the Deformation Behavior of Adaptive Fiber-Rubber Composites with Integrated Shape Memory Alloys

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 582
Author(s):  
Felix Lohse ◽  
Karl Kopelmann ◽  
Henriette Grellmann ◽  
Moniruddoza Ashir ◽  
Thomas Gereke ◽  
...  
Keyword(s):  
Shape Memory ◽  
Biomedical Applications ◽  
Experimental Tests ◽  
Rubber Matrix ◽  
Fiber Reinforced ◽  
Rubber Composites ◽  
Four Point Bending ◽  
Glass Fiber Reinforced ◽  
Liquid Silicone ◽  
Good Agreement

Fiber-reinforced rubber composites with integrated shape memory alloy (SMA) actuator wires present a promising approach for the creation of soft and highly elastic structures with adaptive functionalities for usage in aerospace, robotic, or biomedical applications. In this work, the flat-knitting technology is used to develop glass-fiber-reinforced fabrics with tailored properties designed for active bending deformations. During the knitting process, the SMA wires are integrated into the textile and positioned with respect to their actuation task. Then, the fabrics are infiltrated with liquid silicone, thus creating actively deformable composites. For dimensioning such structures, a comprehensive understanding of the interactions of all components is required. Therefore, a simulation model is developed that captures the properties of the rubber matrix, fiber reinforcement, and the SMA actuators and that is capable of simulating the active bending deformations of the specimens. After model calibration with experimental four-point-bending data, the SMA-driven bending deformation is simulated. The model is validated with activation experiments of the actively deformable specimens. The simulation results show good agreement with the experimental tests, thus enabling further investigations into the deformation mechanisms of actively deformable fiber-reinforced rubbers.

scholarly journals Fatigue investigation of threaded pipe connections

2010 ◽  
Vol 1 (1) ◽  
pp. 182-189
Author(s):  
Jeroen Van Wittenberghe ◽  
Jan De Pauw ◽  
Patrick De Baets ◽  
Wim De Waele ◽  
Wouter Ost ◽  
...  
Keyword(s):  
Load Distribution ◽  
Crack Opening ◽  
Experimental Tests ◽  
Fe Analysis ◽  
Small Scale ◽  
Line Pipe ◽  
Bending Fatigue ◽  
Four Point Bending ◽  
Threaded Connections ◽  
Drill Pipes

Threaded pipe connections are used to connect well casing, well tubing, drill pipes and risers.For many of these applications fatigue resistance plays an important role. In this study the fatigueproperties of threaded connections are studied using a combination of finite element modelling andexperimental testing. Using 2D axisymmetric FE analysis several connections are compared. It is shownthat the load distribution over the engaged threads is an important feature. Experimental tests are carriedout on three setups. A small scale four-point bending setup is used to develop S-N curves. An S-N curve fora standard API Line Pipe connection is compared to an S-N curve for a connection that showed animproved load distribution over the engaged threads in the FE analysis. On a medium scale four-pointbending setup, strains together with crack opening are measured. The strain measurements are comparedwith the strains obtained by the numerical model. Finally a full scale resonant bending fatigue setup ispresented, which will be used in future testing of pipe connections ranging from 168 mm (6”) to 508 mm(20”) in diameter.

scholarly journals Lightweight Ribs for the Strengthening of Single Leaf Vaults Undergoing Seismic Actions

2010 ◽  
Vol 133-134 ◽  
pp. 923-928 ◽  
Author(s):  
Luca Ferrario ◽  
Egidio Marchina ◽  
Alessandra Marini ◽  
Marco Preti ◽  
Ezio Giuriani
Keyword(s):  
Experimental Tests ◽  
Numerical Analyses ◽  
Collapse Mechanism ◽  
Seismic Loads ◽  
Single Leaf ◽  
Numeric Model ◽  
Innovative Technique ◽  
Non Linear ◽  
Load Conditions

In this paper the behavior and the collapse mechanism of single leaf vaulted structures undergoing seismic loads are discussed, and an innovative technique based on the use of lightweight ribs is proposed. The efficiency of the solution is verified by means of non linear numerical analyses on a strengthened single leaf vaulted structure. The numeric model is validated through comparison with the results of experimental tests performed on lightweight ribs subjected to cyclic, unsymmetrical load conditions.

scholarly journals The effect of surface roughness of the impeller to the performance of pump as turbine pico power plant

2019 ◽  
Vol 13 (1) ◽  
pp. 4693-4703 ◽  
Author(s):  
D. L. Zariatin ◽  
Dwi Rahmalina ◽  
Eko Prasetyo ◽  
A. Suwandi ◽  
M. Sumardi
Keyword(s):  
Surface Roughness ◽  
Low Cost ◽  
Electrical Power ◽  
Performance Testing ◽  
Experimental Tests ◽  
Lower Surface ◽  
Hydropower Plant ◽  
Average Surface Roughness ◽  
Average Surface ◽  
Low Performance

Pump as Turbine (PAT) is one of a hydropower plant that applies a pump with a reversed flow, working as a turbine to generate electrical power. It has the advantages of low-cost, widely available in the market and user-friendly. However, like other hydropower plants, PAT technology has low performance in term of power output. The impeller surface roughness is one of critical aspect, which influences PAT performance because poor surface roughness causes losses and cavitation. The objective of the research is to increase the PAT performance by improving the quality of the surface roughness and validate by the experimental tests. A low-cost and customize hand grinding process was applied to produce five impellers with three different levels of surface roughness (average surface roughness of 0.16 mm, 0.24 mm, and 0.40 mm), an edge rounded impeller, and a varnish lacquer coated impeller. All of the impellers undergo performance testing. The performance of the original impeller (without modification) used as a comparison. The experiment result shows that an impeller with a lower surface roughness (lower Ra number) has a higher performance. An impeller with an average surface roughness of 0.16 mm improved 10.9% of its initial performance. Additional edge rounding for a 0.16 mm surface roughness impeller would improve its performance by 13.1%.  The optimum turbine efficiency of 15.45% was achieve-able by implementing an impeller with the lowest surface roughness.

scholarly journals A Novel Implementation of the LDEM in the Ansys LS-DYNA Finite Element Code

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7792
Author(s):  
Andrea Zanichelli ◽  
Angélica Colpo ◽  
Leandro Friedrich ◽  
Ignacio Iturrioz ◽  
Andrea Carpinteri ◽  
...  
Keyword(s):  
Finite Element ◽  
Fracture Behaviour ◽  
Sandwich Panels ◽  
Experimental Tests ◽  
Finite Element Code ◽  
Three Point Bending ◽  
Four Point Bending ◽  
Experimental Findings ◽  
The University ◽  
Bending Failure

In this paper, a novel implementation of the Lattice Discrete Element Method (LDEM) is proposed: in particular, the LDEM is implemented in the Ansys LS-DYNA finite element code. Such an implementation is employed to evaluate the fracture behaviour of sandwich panels under bending. First, the novel hybrid model proposed is validated by simulating some three-point bending experimental tests carried out at the University of Parma, and then it is used to model the fracture behaviour of sandwich panels under four-point bending. Failure mechanisms, damage locations, and load-deflection curves are numerically determined by employing such a novel model, and the results show a good agreement with the available experimental findings.

Finite Element Formulation of a Piezoelectric Continuum and Performance Studies of Laminar PZT-Patch-Modules

2005 ◽  
Vol 881 ◽  
Author(s):  
Monika Gall ◽  
Bärbel Thielicke ◽  
Christophe Poizat ◽  
Sven Klinkel
Keyword(s):  
Finite Element ◽  
Experimental Tests ◽  
Bending Test ◽  
Failure Behavior ◽  
Element Formulation ◽  
Sensors And Actuators ◽  
Mechanical Coupling ◽  
Sensor Performance ◽  
Four Point Bending ◽  
And Performance

AbstractEfficient application of piezoelectric sensors and actuators requires extensive investigations of their loading limits, failure-behavior and life-span under service conditions. Here the performance of laminar PZT-patch-modules is studied, applying a combined approach of experimental and numerical tests. Four-point bending tests are used to evaluate the sensor performance. Linear electro-mechanical coupling is implemented in an 8-node brick user element of the research finite element code FEAP to develop a flexible FE-tool for piezoelectric problems. Comparative FE-analyses of the bending test are carried out in order to assess the capability of the implemented FEAP user element versus the commercially available FE-code ABAQUS. FE-results show good agreement with the experimental tests, different element types yield slight deviations which are discussed.

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