Name: artificial thermal ageing of polyester reinforced and polyvinyl chloride coated technical fabric
Uploaded: 2020-01-29T15:00:00
Description: Watch this Scientific Journal Video about Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric at JoVE.com

The publication of this work was supported by the Faculty of Civil and Environmental Engineering at Gdansk University of Technology.

1. Accelerated thermal ageing experiments on technical fabric
<ol>
	<li>Overall preparation
	<ol>
		<li>Prepare a testing machine with proper software (in order to provide constant strain rate tests) and a video extensometer.</li>
		<li>Prepare a thermal chamber providing constant temperature of 80 &#176;C (&#177; 1 &#176;C) and 90 &#176;C (&#177;1 &#176;C) for at least 12 weeks.</li>
	</ol>
	</li>
	<li>Specimen preparation
	<ol>
		<li>Unroll the technical fabric AF9032 bale. Draw the desired shapes (300 mm x 50 mm) wi...

<ol>
	<li>Ambroziak, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+properties+of+Precontraint+1202S+coated+fabric+under+biaxial+tensile+test+with+different+load+ratios.">Mechanical properties of Precontraint 1202S coated fabric under biaxial tensile test with different load ratios.</a> Construction and Building Materials. 80, 210-224 (2015).</li><li>&#379;erdzicki, K., K&#322;osowski, P., Wo&#378;nica, K., Pietraszkiewicz, W., Witkowski, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+cyclic+load-unload-reload+tests+of+VALMEX+aged+fabric.">Analysis of the cyclic load-unload-reload tests of VALMEX aged fabric.</a> Shell Structures: Theory and Applications. , 477-480 (2017).</li><li>Cash, C. G., Bailey, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Predictive service life tests for roofing membranes: Phase 2. Durability of Building Materials and Components. , (2014).</li><li>Yin, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aging+behavior+and+lifetime+prediction+of+PMMA+under+tensile+stress+and+liquid+scintillator+conditions.">Aging behavior and lifetime prediction of PMMA under tensile stress and liquid scintillator conditions.</a> Advanced Industrial and Engineering Polymer Research. 2 (2), 82-87 (2019).</li><li>Swedish Standards Insitute. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Buildings+And+Constructed+Assets+-+Service+Life+Planning+-+Part+7:+Performance+Evaluation+For+Feedback+Of+Service+Life+Data+From+Practice.">Buildings And Constructed Assets - Service Life Planning - Part 7: Performance Evaluation For Feedback Of Service Life Data From Practice.</a> International Organization of Standardization. , 15686-15687 (2017).</li><li>&#352;ar&#353;ounov&#225;, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Inconveniences+Related+to+Accelerated+Thermal+Ageing+of+Cables.">The Inconveniences Related to Accelerated Thermal Ageing of Cables.</a> Transportation Research Procedia. 40, 90-95 (2019).</li><li>Gong, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+study+on+different+methods+for+determination+of+activation+energies+of+nuclear+cable+materials.">Comparative study on different methods for determination of activation energies of nuclear cable materials.</a> Polymer Testing. 70, 81-91 (2018).</li><li>Vega, A., Yarahmadi, N., Jakubowicz, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimal+conditions+for+accelerated+thermal+ageing+of+district+heating+pipes.">Optimal conditions for accelerated thermal ageing of district heating pipes.</a> Energy Procedia. 149, 79-83 (2018).</li><li>Redondo-Iglesias, E., Venet, P., Pelissier, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eyring+acceleration+model+for+predicting+calendar+ageing+of+lithium-ion+batteries.">Eyring acceleration model for predicting calendar ageing of lithium-ion batteries.</a> Journal of Energy Storage. 13, 176-183 (2017).</li><li>Panjan, P., Virtanen, V., Sesay, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+stability+characteristics+for+electrochemical+biosensors+via+thermally+accelerated+ageing.">Determination of stability characteristics for electrochemical biosensors via thermally accelerated ageing.</a> Talanta. 170, 331-336 (2017).</li><li>Martin, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Ageing of Composites. , (2008).</li><li>Mouzakis, D. E., Zoga, H., Galiotis, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accelerated+environmental+ageing+study+of+polyester/glass+fiber+reinforced+composites+(GFRPCs).">Accelerated environmental ageing study of polyester/glass fiber reinforced composites (GFRPCs).</a> Composites Part B: Engineering. 39 (3), 467-475 (2008).</li><li>Rosato, D., Rosato, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Plastic product material and process selection handbook. , (2004).</li><li>Brebu, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+the+natural+ageing+of+PVC+insulation+for+electrical+cables.">Study of the natural ageing of PVC insulation for electrical cables.</a> Polymer Degradation and Stability. 67 (2), 209-221 (2000).</li><li>Martienssen, W., Warlimont, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Condensed Matter and Materials Data. , (2005).</li><li>Berard, M. T., Daniels, C. A., Summers, J. W., Wilkes, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> PVC Handbook. , (2005).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Rubber - or plastics-coated fabrics - Determination of tensile strength and elongation at break. , (2017).</li><li>Systat Software, Inc. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> SigmaPlot 12.0 User's Guide. , (2015).</li><li>Ambroziak, A., K&#322;osowski, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+testing+of+technical+woven+fabrics.">Mechanical testing of technical woven fabrics.</a> Journal of Reinforced and Plastic Composites. 32 (10), 726-739 (2013).</li><li>Bodner, S. R., Partom, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Constitutive+equations+for+elastic-viscoplastic+strain-hardening+materials.">Constitutive equations for elastic-viscoplastic strain-hardening materials.</a> Journal of Applied Mechanics. 42, 385-389 (1985).</li><li>Andersson, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+implicit+formulation+of+the+Bodner-Partom+constitutive+equations.">An implicit formulation of the Bodner-Partom constitutive equations.</a> Computers and Structures. 81 (13), 1405-1414 (2003).</li><li>K&#322;osowski, P., Zagubie&#324;, A., Woznica, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+on+rheological+properties+of+technical+fabric+"Panama".">Investigation on rheological properties of technical fabric "Panama".</a> Archive of Applied Mechanics. 73 (9-10), 661-681 (2004).</li><li>Za&#239;ri, F., Na&#239;t-Abdelaziz, M., Woznica, K., Gloaguen, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Constitutive+equations+for+the+viscoplastic-damage+behaviour+of+a+rubber-modified+polymer.">Constitutive equations for the viscoplastic-damage behaviour of a rubber-modified polymer.</a> European Journal of Mechanics, A/Solids. 24 (1), 169-182 (2005).</li><li>Klosowski, P., Zerdzicki, K., Woznica, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+Bodner-Partom+model+parameters+for+technical+fabrics.">Identification of Bodner-Partom model parameters for technical fabrics.</a> Computers and Structures. 187, (2017).</li><li>Zerdzicki, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Durability evaluation of textile hanging roofs materials. , (2015).</li><li>Bystritskaya, E. V., Pomerantsev, A. L., Rodionova, O. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prediction+of+the+aging+of+polymer+materials.">Prediction of the aging of polymer materials.</a> Chemometrics and Intelligent Laboratory Systems. 47 (2), 175-178 (1999).</li><li>Hukins, D. W. L., Mahomed, A., Kukureka, S. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accelerated+aging+for+testing+polymeric+biomaterials+and+medical+devices.">Accelerated aging for testing polymeric biomaterials and medical devices.</a> Medical Engineering and Physics. 30 (10), 1270-1274 (2008).</li><li>Zerdzicki, K., Klosowski, P., Woznica, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+service+ageing+on+polyester-reinforced+polyvinyl+chloride-coated+fabrics+reported+through+mathematical+material+models.">Influence of service ageing on polyester-reinforced polyvinyl chloride-coated fabrics reported through mathematical material models.</a> Textile Research Journal. 89 (8), 1472-1487 (2019).</li><li>Klosowski, P., Zerdzicki, K., Woznica, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+artificial+thermal+ageing+on+polyester-reinforced+and+polyvinyl+chloride+coated+AF9032+technical+fabric.">Influence of artificial thermal ageing on polyester-reinforced and polyvinyl chloride coated AF9032 technical fabric.</a> Textile Research Journal. 89 (21-22), 4632-4646 (2019).</li><li>Firdosh, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Durability+of+GFRP+nanocomposites+subjected+to+hygrothermal+ageing.">Durability of GFRP nanocomposites subjected to hygrothermal ageing.</a> Composites Part B: Engineering. 69, 443-451 (2015).</li><li>Le Saux, V., Le Gac, P. 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This article incudes a detailed experimental protocol to simulate the laboratory accelerated experiments on polyester reinforced and PVC coated fabrics for civil engineering applications. The protocol describes the case of artificial thermal ageing only by the means of raising the ambient temperature. This is an obvious simplification of real weather conditions, as UV radiation and water influence play an additional role in material service ageing.
Generally, the conditions of accelerated agei...

Polyester based architectural fabrics are commonly used for construction of hanging roofs1. Being relatively cheap with good mechanical properties, they can be employed in long-term exploitation (e.g., the hanging roof of the Forest Opera in Sopot - Poland). Unfortunately, weather conditions, ultraviolet radiation, biological reasons, and operational purposes (season pre-stressing and loosening2) can affect their mechanical properties. Hanging roofs made of AF9032 are typically seasonal structures subjected to high temperature (especially during sunny days in the summer), regular pre-tensioning and loosening. In order to properly design a hanging roof, fabric parameters must be determined not only at the beginning of exploitation, but also after several years of use.
Ageing analysis measures the ageing indicator and compares the initial and final values of the parameters to assess the impact of ageing. Cash et al.3 proposed one of the simplest methods by comparative analysis of 12 different types of roofing membranes. These membranes were exposed to outdoor weathering for 2 or 4 years. The authors used a rating system of several properties to assess fabric durability. In order to provide an analysis of polymer thermal ageing, the time-temperature superposition principle (TTSP) can be applied4. This principle states that the behavior of a material at low temperature and under low strain level resembles its behavior at high temperature and high strain level. The simple multiplicative factor can be used to relate the current temperature properties with the properties at the reference temperature. Graphically, it corresponds to the curve shift on the log time scale. Regarding the temperature, two methods are proposed to combine the shift factor and the ageing temperature: the Williams-Landel-Ferry (WLF) equations, and the Arrhenius law. Both methods are included in the Swedish standard ISO 113465 to estimate the lifetime and maximum operational temperature for rubber, or vulcanized and thermoplastic, materials. Recently, thermal ageing and Arrhenius methodology have been used in the cable lifetime prediction6,7, heating pipes8, and polymer glue PMMA4. An extension of the Arrhenius law is the Eyring law that takes into account other ageing factors (e.g., voltage, pressure, etc.)9. Alternatively, other studies propose and verify simple linear models for a description of ageing (e.g., biosensor ageing10). Although the Arrhenius method is commonly used, there is discussion on its relevance in the lifetime prediction of every material. Hence, the method must be used with care, especially in terms of initial assumptions and experimental conditions6.
Similar to most polymers, the polyester fabrics used in the current research exhibit two distinct transition phases defined by the melting temperature (Tm) and the glass transition temperature (Tg). The melting temperature (Tm) is the temperature when a material changes from its solid state to the liquid one, and the glass transition temperature (Tg) is the boundary between the glass and rubber states11. According to manufacturer&#39;s data, the AF9032 fabric is made from polyester threads (Tg = 100&#8722;180 &#176;C12, Tm = 250&#8722;290 &#176;C13) and PVC coating (Tg = 80&#8722;87 &#176;C14,15, Tm = 160&#8722;260 &#176;C16). The ageing temperature T&#945; should be selected below Tg. During sunny days, the temperature on the top surface of a hanging roof may even reach 90 &#176;C; thus, two ageing temperatures (80 &#176;C and 90 &#176;C) are tested here. These temperatures are below the thread Tg and close to the coating Tg.
The performance of the accelerated ageing protocol on technical fabrics is presented in the current work. Artificial thermal ageing is used to predict changes of the material properties. The article illustrates appropriate laboratory testing routines and a way to extrapolate relatively short-term experimental results.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>AF 9032 technical fabric</td>
			<td>Shelter-Rite Seaman Corporation</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>knife of scisors</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>marker</td>
			<td></td>
			<td></td>
			<td>pernament</td>
		</tr>
		<tr>
			<td>ruler</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sigma Plot</td>
			<td>Systat Software Inc.</td>
			<td>v. 12.5</td>
			<td></td>
		</tr>
		<tr>
			<td>Testing machine Z020</td>
			<td>Zwick Roell</td>
			<td>BT1-FR020TN.A50</td>
			<td></td>
		</tr>
		<tr>
			<td>TestXpert II program</td>
			<td>Zwick Roell</td>
			<td>v. 3.50</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermal chamber</td>
			<td>Eurotherm Controls</td>
			<td>2408</td>
			<td></td>
		</tr>
		<tr>
			<td>tubular spanner</td>
			<td></td>
			<td></td>
			<td>13 mm</td>
		</tr>
		<tr>
			<td>Video extensometer</td>
			<td>Zwick Roell</td>
			<td>BTC-EXVIDEO.PAC.3.2.EN</td>
			<td>Instead of video extensometer, a mechanical one can be used</td>
		</tr>
		<tr>
			<td>VideoXtens</td>
			<td>Zwick Roell</td>
			<td>5.28.0.0 SP2</td>
			<td></td>
		</tr>
	</tbody>
</table>

artificial thermal ageing of polyester reinforced and polyvinyl chloride coated technical fabric

Architectural fabric AF9032 has been subjected to artificial thermal ageing to determine changes of the material parameters of the fabric. The proposed method is based on the accelerated ageing approach proposed by Arrhenius. 300 mm x 50 mm samples were cut in the warp and fill directions and placed in a thermal chamber at 80 &#176;C for up to 12 weeks or at 90 &#176;C for up to 6 weeks. Then after one week of conditioning at ambient temperature, the samples were uniaxially tensioned at a constant strain rate. Experimentally, the parameters were determined for the non-linear elastic (linear piecewise) and viscoplastic (Bodner&#8211;Partom) models. Changes in these parameters were studied with respect to the ageing temperature and ageing period. In both cases, the linear approximation function was successfully applied using the simplified methodology of Arrhenius. A correlation was obtained for the fill direction between experimental results and the results from the Arrhenius approach. For the warp direction, the extrapolation results exhibited some differences. Increasing and decreasing tendencies have been observed at both temperatures. The Arrhenius law was confirmed by the experimental results only for the fill direction. The proposed method makes it possible to predict real fabric behavior during long term exploitation, which is a critical issue in the design process.

Figure 2 juxtaposes the stress-strain curves for the warp and fill directions of AF9032 fabric obtained at different ageing times, in the 80 &#176;C temperature level for a strain rate of 0.001 s-1. The difference between the 1 h ageing period (reference test) and the rest of the ageing periods is clear. The ageing time does not seem to substantially affect the material response in the warp direction, as the stress&#8211;strain curves are highly repetitive, showing no important di...

Watch this Scientific Journal Video about Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric at JoVE.com

Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric

Here, we simulate accelerated thermal ageing of technical fabric and see how this ageing process influences the mechanical properties of the fabric.

Architectural fabric AF9032 has been subjected to artificial thermal ageing to determine changes of the material parameters of the fabric. The proposed ...

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Horizontal and vertical electrohydrodynamic liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields and polar dielectric liquids. The construction of basic apparatus and operational examples, including thermographic images, for three liquids (e.g., water, DMSO, and glycerol) is presented.

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Two types of surfaces, polyester-coated steel and polyester coated with a layer of silica nanoparticles, were studied. Both surfaces were exposed to sunlight, which was found to cause substantial changes in the chemistry and nanoscale topography of the surface.

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Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous light irradiation. The photo-excitation of dopants that can quickly dissipate light into heat, coupled with anisotropic thermal expansion and self-shadowing of the film, gives rise to the self-sustained deformation. The oscillations observed are influenced by the dimensions and the modulus of the film, and by the directionality and intensity of the light. The system developed offers applications in energy conversion and harvesting for soft-robotics and automated systems.
The general method described here consists of creating free-standing liquid crystalline films and characterizing the mechanical and thermal effects observed. The molecular alignment is achieved using alignment layers (rubbed polyimide), commonly used in the display manufacturing industry. To obtain actuators with large deformation, the mesogens are aligned and polymerized in a splay/bend configuration, i.e., with the director of the liquid crystals (LCs) going gradually from planar to homeotropic through the film thickness. Upon irradiation, the mechanical and thermal oscillations obtained are monitored with a high-speed camera. The results are further quantified by image analysis using an image processing program.

The goal of the protocol is to create liquid crystalline polymer films that can mechanically oscillate under continuous light irradiation. We describe in great detail the conception of free-standing films, from the liquid crystal alignment method to the photo-actuation. The experimental protocol applied to prepare this material is broadly applicable.

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous ...

Preparation of Aligned Steel Fiber Reinforced Cementitious Composite and Its Flexural Behavior

The aim of this work is to present an approach, inspired by the way in which a compass needle maintains a consistent orientation under the action of the Earth&#39;s magnetic field, for manufacturing a cementitious composite reinforced with aligned steel fibers. Aligned steel fiber reinforced cementitious composites (ASFRC) were prepared by applying a uniform electromagnetic field to fresh mortar containing short steel fibers, whereby the short steel fibers were driven to rotate in alignment with the magnetic field. The degree of alignment of steel fibers in hardened ASFRC was assessed both by counting steel fibers in fractured cross-sections and by X-ray computed tomography analysis. The results from the two methods show that the steel fibers in ASFRC were highly aligned while the steel fibers in non-magnetically treated composites were randomly distributed. The aligned steel fibers had a much higher reinforcing efficiency, and the composites, therefore, exhibited significantly enhanced flexural strength and toughness. The ASFRC is thus superior to SFRC in that it can withstand greater tensile stress and more effectively resist cracking.

This protocol describes an approach for manufacturing aligned steel fiber reinforced cementitious composite by applying a uniform electromagnetic field. Aligned steel fiber reinforced cementitious composite exhibits superior mechanical properties to ordinary fiber reinforced concrete.

The aim of this work is to present an approach, inspired by the way in which a compass needle maintains a consistent orientation under the action of the ...

Installation Method to Enhance Quality Control for Fiber Reinforced Polymer Spike Anchors

Fiber reinforced polymer (FRP) anchors are a promising way to enhance the performance of externally-bonded FRPs applied to existing structures, as they can delay or even prevent debonding failure. However, a major concern faced by designers is the premature failure of the anchors due to stress concentration. Poor installation quality and preparation of the clearance holes can result in stress concentration that provokes this premature failure. This paper deals with an installation method that aims to reduce the impact of the stress concentration and to provide a proper quality control of the preparation of the drill hole. The method involves three parts: the drilling and cleaning of the holes, the smoothing of the hole edges with a customized drill bit, and the installation of the anchor itself, including the impregnation of the anchor dowel and its insertion. Anchor fans (the free length of the spikes) are then bonded to the external FRP reinforcement. For the end anchorage, and in the case of reinforcements with multiple plies, it is recommended that the anchor fan be inserted between two plies to assist the stress-transfer mechanism. 
The proposed procedure is complemented with a design approach for spike anchors, based on an extensive database. It is proposed that the design follow a number of steps, namely: selection of the anchor diameter and subsequent tensile strength of the connector (that is to say, the anchor before fanning out the free end), evaluation of the reduction in the tensile strength due to bending, provision of enough embedment to prevent slippage failure, and consideration of the number and spacing of anchors for a given reinforcement. In this sense, it should be noted that further research is needed in order to obtain a general expression for the contribution of spike anchors to overall bond strength of FRP reinforcements.

This manuscript presents a method for controlling the quality of installation for spike anchors designed to delay delamination of externally bonded fiber reinforced polymers. The protocol includes the preparation of the drill hole and the insertion process. The most influential parameters on the efficiency of the anchors are discussed.

Fiber reinforced polymer (FRP) anchors are a promising way to enhance the performance of externally-bonded FRPs applied to existing structures, as they ...

Cutting Procedures, Tensile Testing, and Ageing of Flexible Unidirectional Composite Laminates

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, where the yarns in each layer are oriented parallel to each other and held in place using binder resins and thin polymer films. The armor is constructed by stacking the unidirectional layers in different orientations. To date, only very preliminary work has been performed to characterize the ageing of the binder resins used in unidirectional laminates and the effects on their performance. For example, during the development of the conditioning protocol used in the National Institute of Justice Standard-0101.06, UD laminates showed visual signs of delamination and reductions in V50, which is the velocity at which half of the projectiles are expected to perforate the armor, after ageing. A better understanding of the material property changes in UD laminates is necessary to comprehend the long-term performance of armors constructed from these materials. There are no current standards recommended for mechanically interrogating unidirectional (UD) laminate materials. This study explores methods and best practices for accurately testing the mechanical properties of these materials and proposes a new test methodology for these materials. Best practices for ageing these materials are also described.

The goal of the study was to develop protocols to prepare consistent specimens for accurate mechanical testing of high-strength aramid or ultra-high-molar-mass polyethylene-based flexible unidirectional composite laminate materials and to describe protocols for performing artificial ageing on these materials.

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, ...

Fabric Moisture Uniform Control to Study the Influence of Air Impingement Parameters on Fabric Drying Characteristics

Impinging dryness is now a widely used and effective way for fabric drying due to its high heat and mass transfer coefficient. Previous studies on fabric drying have neglected the contributions of moisture uniformity and diffusion coefficient to the drying process; though, they have recently been shown to have a significant influence on drying characteristics. This report outlines a step-by-step procedure to investigate the effects of air impingement parameters on a fabric&#39;s drying characteristics by controlling the uniformity of its area moisture distribution. A hot air blower unit equipped with an angle adjustable nozzle is used to generate air flow with different velocities and temperatures while the drying process is recorded and analyzed using an infrared thermograph. In addition, a uniform padder is adapted to ensure the fabric&#39;s moisture uniformity. Impinging drying is studied under different initial conditions by changing the air flow temperature, velocity, and direction, then the applicability and suitability of the protocol are evaluated.

Presented here is a protocol that guarantees uniform distribution of initial moisture inside of a fabric and investigates the effects of hot-air thermodynamic parameters (velocity, temperature, and direction) and thickness on the fabric&#39;s drying characteristics (e.g., temperature variation) under the condition of air impingement.

Impinging dryness is now a widely used and effective way for fabric drying due to its high heat and mass transfer coefficient. Previous studies on fabric ...

Advanced Self-Healing Asphalt Reinforced by Graphene Structures: An Atomistic Insight

Graphene can improve the self-healing properties of asphalt with high durability. However, the self-healing behaviors of graphene-modified asphalt nanocomposite and the role of incorporated graphene are still unclear at this stage. In this study, the self-healing properties of pure asphalt and graphene-modified asphalt are investigated through molecular dynamics simulations. Asphalt bulks with two crack widths and locations for graphene are introduced, and the molecular interactions among asphalt components and the graphene sheet are analyzed. The results show that the location of graphene significantly affects the self-healing behaviors of asphalt. Graphene near the crack surface can greatly accelerate the self-healing process by interacting with the aromatic molecules through &#960;-&#960; stacking, while graphene at the top area of the crack tip has a minor impact on the process. The self-healing process of asphalt goes through the reorientation of asphaltene, polar aromatic, and naphthene aromatic molecules, and the bridging of saturate molecules between crack surfaces. This in-depth understanding of the self-healing mechanism contributes to the knowledge of the enhancement for self-healing properties, which will help to develop durable asphalt pavements.

Graphene-modified asphalt nanocomposite has shown an advanced self-healing ability compared to pure asphalt. In this protocol, molecular dynamics simulations have been applied in order to understand the role of graphene in the self-healing process and to explore the self-healing mechanism of asphalt components from the atomistic level.