Dissertations / Theses: 'Fibre reinforced plastics testing'

1

Saka, Kolawole. "Dynamic mechanical properties of fibre reinforced plastics." Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:0514854d-36db-4cc1-b377-03a75550ab76.

Full text

Abstract:

A small gas gun, capable of accelerating a projectile 1m long by 25.4mm diameter to about 50 m/s, and an extended split Hopklnson bar apparatus have been designed and constructed for the tensile impact testing of fibre reinforced composite specimens at strain rates of the order of 1000/s. Elastic strain measurements derived from the Hopkinson bar analysis are checked, using strain gauges attached directly to the specimen and the validity of the elastic moduli determined under tensile impact is confirmed. Epoxy specimens reinforced with plain-weave fabrics of either carbon or glass or with several hybrid combinations of the two in various lay-ups, giving five different weight fractions of reinforcement from all-carbon to all-glass, have been tested in tension at three strain rates, nominally, ~10^-3/s, ~10/s and ~10³/s. The effect of both hybrid composition (volume fraction of carbon reinforced plies) and applied strain rate on the tensile modulus, the tensile strength and the strain to fracture is determined and a limited hybrid effect is observed in specimens with a carbon volume fraction in the approximate range 0.6 to 0.7 where, at all three strain rates there is an enhancement of the failure strain over that for the all-carbon plies and an increased failure strength, most marked in the impact tests, over that predicted by the rule of mixtures. The fracture surfaces of specimens are examined by optical and scanning electron microscopy and the failure process in the hybrid composites is related to that found in the all-carbon and the all-glass specimens. The classical laminated plate theory and the Tsai-Wu strength criterion are used to predict the stiffness and strength of the hybrid composites from the elastic and strength properties of the constituent plies. Analytical predictions are in good agreement with experimental measurements.

APA, Harvard, Vancouver, ISO, and other styles

2

Kelly, Gordon. "Joining of Carbon Fibre Reinforced Plastics for Automotive Applications." Doctoral thesis, KTH, Aeronautical and Vehicle Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3819.

Full text

Abstract:

The introduction of carbon-fibre reinforced plastics in loadbearing automotive structures provides a great potential toreduce vehicle weight and fuel consumption. To enable themanufacture and assembly of composite structural parts,reliable and cost-effective joining technologies must bedeveloped. This thesis addresses several aspects of joining andload introduction in carbon-fibre reinforced plastics based onnon-crimp fabric reinforcement.

The bearing strength of carbon fibre/epoxy laminates wasinvestigated considering the effects of bolt-hole clearance.The laminate failure modes and ultimate bearing strength werefound to be significantly dependent upon the laminate stackingsequence, geometry and lateral clamping load. Significantreduction in bearing strength at 4% hole deformation was foundfor both pin-loaded and clamped laminates. The ultimatestrength of the joints was found to be independent of theinitial bolt-hole clearance.

The behaviour of hybrid (bolted/bonded) joints wasinvestigated both numerically and experimentally. Athree-dimensional non-linear finite element model was developedto predict the load transfer distribution in the joints. Theeffect of the joint geometry and adhesive material propertieson the load transfer was determined through a parameter study.An experimental investigation was undertaken to determine thestrength, failure mechanisms and fatigue life of hybrid joints.The joints were shown to have greater strength, stiffness andfatigue life in comparison to adhesive bonded joints. However,the benefits were only observed in joint designs which allowedfor load sharing between the adhesive and the bolt.

The effect of the environment on the durability of bondedand hybrid joints was investigated. The strength and fatiguelife of the joints was found to decrease significantly withincreased ageing time. Hybrid joints demonstrated increasedfatigue life in comparison to adhesive bonded joints afterageing in a cyclic freeze/thaw environment.

The strength and failure mechanisms of composite laminatessubject to localised transverse loading were investigatedconsidering the effect of the specimen size, stacking sequenceand material system. Damage was found to initiate in thelaminates at low load levels, typically 20-30% of the ultimatefailure load. The dominant initial failure mode wasintralaminar shear failure, which occurred in sub-surfaceplies. Two different macromechanical failure modes wereidentified, fastener pull-through failure and global collapseof the laminate. The damage patterns and ultimate failure modewere found to depend upon the laminate stacking sequence andresin system. Finite element analysis was used to analyse thestress distribution within the laminates and predict first-plyfailure.

Keywords:Composite, laminate, bearing strength,joining, load introduction, hybrid joint, finite elementanalysis, mechanical testing.

APA, Harvard, Vancouver, ISO, and other styles

3

Haberle, Jurgen. "Strength and failure mechanisms of unidirectional carbon fibre-reinforced plastics under axial compression." Thesis, Imperial College London, 1992. http://hdl.handle.net/10044/1/11390.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Barkley, David. "Instrumentation of impact testing and evaluation of fibre reinforced injection moulded thermoplastics by process-structure-properties correlation." Thesis, Open University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328827.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Sabat, Philippe Jacques. "Evaluation of fiber-matrix interfacial shear strength in fiber reinforced plastics." Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/77733.

Full text

Abstract:

The role of the interphase in fiberglass reinforced composites was studied by a combination of theoretical analysis, mechanical tests, and several high-resolution analytical techniques. The interphase was varied in composition by using epoxy and polyester matrix polymers with and without added coupling agents, as well as four fiber surface modifications. Different coupling agents on the fibers were shown to change the fiber tensile strength markedly. Filament wound unidirectional composites were tested in short beam "shear." Corresponding samples were fabricated by embedding one to seven fibers in the center of polymer dogbone specimens that were tested in tension to determine critical fiber lengths. Those values were used in a new theoretical treatment (that combines stress gradient shear-lag theory with Weibull statistics) to evaluate "interfacial shear strengths". The fact that results did not correlate with the short beam data was examined in detail via a combination of polarized light microscopy, electron microscopy (SEM) and spectroscopy (XPS or ESCA) and mass spectroscopy (SIMS). When the single fiber specimens were unloaded, a residual birefringent zone was measured and correlated with composite properties, as well as with SIMS and SEM analysis that identified changes in the locus of interphase failure. Variations in the interphase had dramatic effects upon composite properties, but it appears ·that there may be an optimum level of fiber-matrix adhesion depending upon the properties of both fiber and matrix. Fiber-fiber interactions were elucidated by combining tensile tests on multiple fiber dogbone specimens with high-resolution analytical techniques. In general, this work exemplifies a multidisciplinary approach that promises to help understand and characterize the structure and properties of the fiber-matrix interphase, and to optimize the properties of composite materials.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles

6

Littles, Jerrol W. Jr. "Ultrasonic characterization of Fiber Reinforced Polymeric (FRP) composites." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/19160.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Carlin, Daniel Edward. "Experimental and numerical characterization of damage in FRP beams." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/21465.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Butz, Travis M. "Tests on pultruded square tubes under eccentric axial load." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/21800.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Sasher, William C. "Testing, assessment and FRP strengthening of concrete T-beam bridges in Pennsylvania." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5876.

Full text

Abstract:

Thesis (M.S.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains viii, 177 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 130-136).

APA, Harvard, Vancouver, ISO, and other styles

10

Kumar, Rajesh S. "Effects of damage and viscoelasticity on the constitutive behavior of fiber reinforced composites." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/13013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Bangalore, Gurudutt S. "Nondestructive evaluation of FRP composite members using infrared thermography." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2419.

Full text

Abstract:

Thesis (M.S.)--West Virginia University, 2002.
Title from document title page. Document formatted into pages; contains viii, 101 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 98-101).

APA, Harvard, Vancouver, ISO, and other styles

12

Li, Xin. "Eddy current techniques for non-destructive testing of carbon fibre reinforced plastic (CFRP)." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/eddy-current-techniques-for-nondestructive-testing-of-carbon-fibre-reinforced-plastic-cfrp(e8aa9a3f-108d-49a4-9f32-2e6118195898).html.

Full text

Abstract:

AbstractThis thesis describes research on the use of eddy current techniques for nondestructivetesting of carbon fibre reinforced plastic (CFRP). The research hasinvolved bulk conductivity testing, fibre direction characterization and 3D FEMmodeling of the CFPR and eddy current probes geometry. In the conductivity testing,how the sample thickness, fibre volume content and fibre conductivity affects thesignal from the eddy current has been evaluated. Eddy current testing shows gooddirectionality as CFRP is an anisotropic material, thus is very suitable to characterizethe fibre orientation. Direction sensitive probes have been developed and tested toreveal information about the fibre direction and layer. Computer FEM software hasbeen used to analyze the magnetic field inside the sample and probes. Specific probegeometries have been designed depending on the electrical properties of thecomposites and testing requirement. The experiment, simulation and analysis resultsshow very good agreement. However, when the measuring frequency increases, noisesand parasitic capacitance inevitably become significant and have a negative influenceon the results. Improvements and further research are proposed which are believed tomake eddy-current techniques a more feasible and efficient measurement method, willcontribute to the development and maintenance of light weight CFRP composites.

APA, Harvard, Vancouver, ISO, and other styles

13

Justice, Adam L. "Testing and assessment of FRP strengthened concrete T-beam bridges in Pennsylvania." Morgantown, W. Va. : [West Virginia University Libraries], 2010. http://hdl.handle.net/10450/11255.

Full text

Abstract:

Thesis (M.S.)--West Virginia University, 2010.
Title from document title page. Document formatted into pages; contains ix, 223 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 138-141).

APA, Harvard, Vancouver, ISO, and other styles

14

Sheats, Matthew Reed. "Rehabilitation of reinforced concrete pier caps using carbon fiber reinforced composites." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/19490.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Van, der Westhuizen Artho Otto. "Impact response of a continuous fibre reinforced thermoplastic from a soft bodied projectile." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80095.

Full text

Abstract:

Thesis (MScEng)--Stellenbosch University, 2013.
AFRIKAANSE OPSOMMING: Saamgestelde materiale het baie gewilde materiale in die lugvaart- en motor industrië geword as gevolg van die gewigsbesparende voordele wat dit inhou. Kostes en ander verwerkingsprobleme het tradisioneel die wydverspreide gebruik van spesifiek termoplasties-versterkte vesels in hierdie areas verhinder. Baie van die vervaardigingsprobleme (spesifiek lang siklusse) is aangespreek met die aanvang van termoplastiese matriks materiaal soos Polyphenolien Sulfied (PPS). Hierdie materiaal voldoen ook aan die lugvaart-industrie se brand-, rook- en giftigheidstandaarde. Termoplastiese saamgestelde materiale kan byvoorbeeld gevind word op komponente in vliegtuie se binneruimtes en ook die voorste rand van die vlerke. Hierdie komponente is hoogs vatbaar vir impakskade. Die hoë sterkte en styfheid tot gewig verhoudings van saamgestelde materiale laat toe vir dun materiaal dwarssnitte. Komponente is dus kwesbaar vir uit-vlakkige impak beladings. Saamgestelde materiale kan ook intern deur hierdie beladings beskadig word en kan nie met die blote oog waargeneem kan word nie. Dit is dus nodig om die skade weens hierdie beladings tydens normale gebruik akkuraat te voorspel. Verder sal dit nuttig wees om die struktuur se gedrag te bepaal in toepassings waar byvoorbeeld passasier veiligheid krities is, soos op vliegtuig ruglenings tydens noodlandings. In hierdie studie is die potensiële vervaardigingsvoordele van termoplastiese saamgestelde materiale gedemonstreer. Daarbenewens is 'n uit-vlakkige impak deur 'n sagte liggaam herbou in 'n laboratorium omgewing. Die primêre doelwit van hierdie studie was om die impak numeries te modelleer. Vervaardigingsvoordele van `n vesel versterkte termoplastiese laminaat is gedemonstreer deur die vervaardiging van 'n konkawe, agt laag laminaat uit 'n vooraf gekonsolideerde geweefde doek. Die totale verwerkingstyd van die plat laminaat na 'n konkawe laminaat was minder as vyf minute. 'n Eenvoudige plat laminaat en 'n konkawe laminaat is onderwerp aan 'n lae snelheid impak deur 'n sagte projektiel. Die impak is gemodelleer deur die evaluering van drie modelleringsmetodes vir die saamgestelde paneel. Die evalueringskriteria het o.a. ingesluit of laminaat se volle gedrag suksesvol gemodelleer kon word met behulp van slegs 2D dop elemente. Die reaksie van die saamgestelde paneel en gepaardgaande faling is met wisselende vlakke van sukses deur die drie geëvalueerde modelle voorspel. Die faling van tussen-laminêre bindings (verwys na as delaminasie) kon nie deur enige van die modelle voorspel word nie. Twee van die modelle het egter in-vlak faling met redelike akkuraatheid voorspel.
ENGLISH ABSTRACT: Due to weight saving advantages composite materials have become a highly popular material in the aerospace and automotive industries. Traditionally processing difficulties and costs have been a barrier to widespread composite material use in these industries. With the advent of thermoplastic matrix materials such as Polyphenoline Sulphide (PPS) the processing difficulties (especially long cycle times) experienced with traditional thermosetting resins can be addressed while maintaining aerospace Fire-Smoke and Toxicity (FST) approval. Thermoplastic composites can for example be found on aircraft interior components and leading edges of the wings. These areas are highly susceptible to impact damage. The high strength- and stiffness to weight ratios of composites allows for thin material cross sections. This leaves the components vulnerable to out-of-plane impact loads. Composite materials may also be damaged internally by these loads, leaving the damage undetectable through visual inspections. It may therefore be necessary to predict the amount of damage a component would sustain during normal operation. Additionally, it would be useful to predict structural response of these materials in applications where passenger safety is crucial, such as aircraft seat backrests during emergency landings. In this study the potential processing benefits of thermoplastic composite materials were demonstrated. Additionally an out-of-plane impact from a soft bodied projectile was reconstructed in a laboratory environment. The primary objective was to numerically model the impact event. Processing benefits of thermoplastics were demonstrated by producing a single curvature eight layered laminate from a pre-consolidated woven sheet. The total processing time from flat panel to a single curvature panel was below five minutes. A simple flat laminate and a single curvature laminate were subjected to a low velocity drop weight impact load from a soft bodied projectile. These impact events were modelled by evaluating three modelling methods for the composite panel structural response and damage evolution. Part of the evaluation criteria included whether laminate failure could be modelled successfully using only 2D shell elements. The response of the composite panel and accompanying failure were predicted with varying levels of success by the three evaluated models. The failure of interlaminar bonds (referred to as delamination) could not be predicted by either model. However two of the models predicted in-plane failure with reasonable accuracy.

APA, Harvard, Vancouver, ISO, and other styles

16

Engindeniz, Murat. "Acceptance criteria for fiber-reinforced polymeric bridge deck panels." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/21507.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Zerkane, Ali S. H. "Cyclic Loading Behavior of CFRP-Wrapped Non-Ductile Reinforced Concrete Beam-Column Joints." PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/3000.

Full text

Abstract:

Use of fiber reinforced polymer (FRP) material has been a good solution for many problems in many fields. FRP is available in different types (carbon and glass) and shapes (sheets, rods, and laminates). Civil engineers have used this material to overcome the weakness of concrete members that may have been caused by substandard design or due to changes in the load distribution or to correct the weakness of concrete structures over time specially those subjected to hostile weather conditions. The attachment of FRP material to concrete surfaces to promote the function of the concrete members within the frame system is called Externally Bonded Fiber Reinforced Polymer Systems. Another common way to use the FRP is called Near Surface Mounted (NSM) whereby the material is inserted into the concrete members through grooves within the concrete cover. Concrete beam-column joints designed and constructed before 1970s were characterized by weak column-strong beam. Lack of transverse reinforcement within the joint reign, hence lack of ductility in the joints, and weak concrete could be one of the main reasons that many concrete buildings failed during earthquakes around the world. A technique was used in the present work to compensate for the lack of transverse reinforcement in the beam-column joint by using the carbon fiber reinforced polymer (CFRP) sheets as an Externally Bonded Fiber Reinforced Polymer System in order to retrofit the joint region, and to transfer the failure to the concrete beams. Six specimens in one third scale were designed, constructed, and tested. The proposed retrofitting technique proved to be very effective in improving the behavior of non-ductile beam-column joints, and to change the final mode of failure. The comparison between beam-column joints before and after retrofitting is presented in this study as exhibited by load versus deflection, load versus CFRP strain, energy dissipation, and ductility.

APA, Harvard, Vancouver, ISO, and other styles

18

Carmichael, Benjamin Mark. "Fiber-reinforced polymer strengthening of War Memorial Bridge installation, load testing, and analysis /." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Thesis/CARMICHAEL_BENJAMIN_2.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Mercer, Anthony Scott. "Autonomous unmanned ground vehicle for non-destructive testing of fiber reinforced polymer bridge decks." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4943.

Full text

Abstract:

Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains x, 100 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 83-86).

APA, Harvard, Vancouver, ISO, and other styles

20

Fason, William Ernest Barnes Robert W. "Static load testing of a damaged, continuous prestressed concrete bridge." Auburn, Ala, 2009. http://hdl.handle.net/10415/1582.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Cherif, Chokri, Rico Hickmann, Andreas Nocke, Matthias Schäfer, Klaus Röbenack, Sven Wießner, and Gerald Gerlach. "Development and testing of controlled adaptive fiber-reinforced elastomer composites." Sage, 2018. https://tud.qucosa.de/id/qucosa%3A35534.

Full text

Abstract:

The integration of shape memory alloys (SMAs) into textile-reinforced composites produces a class of smart materials whose shape can be actively influenced. In this paper, Ni-Ti SMA wires are inserted during the weaving of a glass fiber reinforcement textile. This ‘‘active’’ reinforcement is then combined with an elastomeric matrix to produce a highly flexible composite sheet, which maintains high rigidity in the longitudinal direction. By activating the SMAs, high deflection ratios of up to 35% (relative to the component’s length) are achieved. To adjust the composite’s deflection to defined values, a closed-loop control is set up to adjust the current flow through the SMA wires. A control algorithm is designed and evaluated for several test cases. The high deformability and the controllable behavior show the high potential of these materials for applications such as aerodynamic flow control, automation and architecture.

APA, Harvard, Vancouver, ISO, and other styles

22

Javidinejad, Amir. "An experimental stress analysis approach for pure shear testing and analysis of a fiber reinforced plastic composite." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/20706.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Al-Obaidi, Salam. "Behavior of Reinforced Concrete Beams Retrofitted in Flexure Using CFRP-NSM Technique." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2294.

Full text

Abstract:

A variety of retrofitting methods are used to upgrade existing structures. For example, steel plates and Fiber Reinforced Polymer (FRP) jackets are externally bonded to members to increase their capacity in flexure and shear. However, due to the issue of corrosion these strengthening systems may lose their efficiency with time. FRP materials have been used to strengthen many structural components of different shapes and types. FRP jackets, FRP Strips, and FRP rods have commonly been used to rehabilitate existing structural components. The many advantages of using FRP as strengthening materials have made this material an attractive alternative: advantages such as lightweight, high strength, and ease of setting up. Among the many applications using FRP, Near Surface Mounted -- Fiber Reinforced polymer (NSM-FRP) is a promising technique used to strengthen concrete members. However, de-bonding issues have to be overcome to make this technique efficient and reliable. The NSM-FRP technique consists of making a groove along the surface of the concrete member to be retrofitted with depth less than the cover of the member. After cleaning the groove, epoxy paste is used to fill two-thirds of the groove's depth. The FRP element is then mounted in the groove. Finally, the groove is filled with epoxy and the excessive epoxy is leveled with surface of the concrete. This technique makes the FRP material completely covered by epoxy in the cover of the concrete. This method can be used for strengthening both the positive and negative moment regions of girders and slabs. Groove size, paste, concrete, and rods properties are the main variables that control the efficiency of the NSM-FRP rods. The main objective of this research project is to determine the behavior of reinforced concrete beams that are strengthened with NSM-CFRP reinforcement bars. In this research project, the bond characteristics of NSM-CFRP reinforcement bars are first determined from pullout tests. Then, NSM-CFRP rods are installed in reinforced concrete beams and the beams are tested. Loads, strains, and deflections are measured and theoretical and measured capacities are compared. Finally, the reliability and efficiency of using NSM-CFRP rods technique in retrofitting existing structures is observed.

APA, Harvard, Vancouver, ISO, and other styles

24

Aules, Wisam Amer. "Behavior of Non-Ductile Slender Reinforced Concrete Columns Retrofit by CFRP Under Cyclic Loading." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/4804.

Full text

Abstract:

In the Middle East region and many countries in the world, older reinforced concrete (RC) columns are deemed to be weak in seismic resistance because of their low amount of reinforcement, low grades of concrete, and large spacing between the transverse reinforcement. The capacity of older RC columns that are also slender is further reduced due to the secondary moments. Appropriate retrofit techniques can improve the capacity and behavior of concrete members. In this study, externally bonded Carbon Fiber Reinforced Polymer (CFRP) retrofit technique was implemented to improve the behavior of RC columns tested under constant axial load and cyclic lateral load. The study included physical testing of five half-scale slender RC columns, with shear span to depth ratio of 7. Three specimens represented columns in a 2-story, and two specimens represented columns in a 4-story building. All specimens had identical cross sections, reinforcement detail, and concrete strength. Two specimens were control, two specimens were retrofit with CFRP in the lateral direction, and one specimen retrofit in the longitudinal and lateral directions. A computer model was created to predict the lateral load-displacement relations. The experimental results show improvement in the retrofit specimens in strength, ductility, and energy dissipation. The effect of retrofitting technique applied to two full-scale prototype RC buildings, a 2-story and a 4-story building located in two cities in Iraq, Baghdad, and Erbil, was determined using SAP2000.

APA, Harvard, Vancouver, ISO, and other styles

25

Alteri, Nicholas James. "Flexural Behavior of Laterally Damaged Full-Scale Bridge Girders Through the Use of Carbon Fiber Reinforced Polymers (CFRP)." UNF Digital Commons, 2012. http://digitalcommons.unf.edu/etd/412.

Full text

Abstract:

ABSTRACT The repair and strengthening of concrete bridge members with CFRP has become increasingly popular over recent years. However, significant research is still needed in order to develop more robust guidelines and specifications. The research project aims to assist with improving design prosedures for damaged concrete members with the use of CFRP. This document summarizes the analysis and testing of full-scale 40’ foot long prestressed concrete (PSC) bridge girders exposed to simulated impact damage and repaired with carbon fiber reinforced polymers (CFRP) materials. A total of five AASHTO type II bridge girders fabricated in the 1960’s were taken from an existing bridge, and tested at the Florida Department of Transportation FDOT structures lab in Tallahassee, Florida. The test specimens were tested under static loading to failure under 4-point bending. Different CFRP configurations were applied to each of the girders. Each of the test girders performed very well as each of them held a higher capacity than the control girder. The repaired girders 5, 6 and 7 surpassed the control girder’s capacity by 10.88%, 15.9% and 11.39%. These results indicate that repairing laterally damaged prestressed concrete bridge girders with CFRP is an effective way to restore the girders flexural capacity.

APA, Harvard, Vancouver, ISO, and other styles

26

Warner, Wyatt Young. "Characterization of Local Void Content in Carbon Fiber Reinforced Plastic Parts Utilizing Observation of In Situ Fluorescent Dye Within Epoxy." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7772.

Full text

Abstract:

Experimentation exploring the movement of voids within carbon fiber reinforced plastics was performed using fluorescent dye infused into the laminates observed through a transparent mold under ultraviolet light. In situ photography was used as an inspection method for void content during Resin Transfer Molding for these laminates. This in situ inspection method for determining the void content of composite laminates was compared to more common ex-situ quality inspection methods i.e. ultrasonic inspection and cross-section microscopy. Results for localized and total void count in each of these methods were directly compared to test samples and linear correlations between the three test methods were sought. Test coupons were then cut from these laminates and were used to calculate the interlaminar shear strength at certain locations throughout the laminates. Although this research did not adequately observe correlations between results obtained from ultrasonic C-scans, cross-sectional microscopy and in situ photography of the surface, it was seen that the fluid dynamics of the thermosetting epoxy used in this experimentation correlated to results obtained from previous experimentation performed by students at Brigham Young University using vegetable oil as a substitute for resin.

APA, Harvard, Vancouver, ISO, and other styles

27

Kaza, Avinash. "Preparation of acoustic emission data for neural network analysis using AWK and C programs." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3896.

Full text

Abstract:

Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xiv, 189 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 157-160).

APA, Harvard, Vancouver, ISO, and other styles

28

Kochan, Antje. "Untersuchungen zur zerstörungsfreien Prüfung von CFK-Bauteilen für die fertigungsbegleitende Qualitätssicherung im Automobilbau." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-77530.

Full text

Abstract:

Ein großer Vorteil von Kunststoffbauteilen ist neben funktionellen Vorzügen die Kosten- und Gewichtsreduzierung durch integrale Gestaltungsmöglichkeiten. Es können Geometrien umgesetzt werden, die mit metallischen Werkstoffen nur unter hohem Aufwand realisierbar sind. Insbesondere im Bereich der Faser-Kunststoff-Verbunde (FKV) gibt es hohen Forschungsbedarf hinsichtlich Reduzierung von Herstellungskosten, Erhöhung der Langlebigkeit aber auch der Reparaturfähigkeit. Die Erkennung von Defekten ist dabei eine grundlegende Voraussetzung. Für einen FKV-Serieneinsatz im Automobilbau gibt es jedoch kein bekanntes und ausreichendes Prüfkonzept der Schadenserkennung für die geforderten Stückzahlen. Die aus der Luft- und Raumfahrt bekannten Methoden lassen sich aufgrund ihres hohen apparativen Aufwandes und der eingeschränkten Tauglichkeit bezüglich geometrisch komplexer Bauteile nicht unmittelbar übernehmen. Es bestehen andere Anforderungen an ein Prüfkonzept für FKV-Bauteile im Automobilbau. Im Rahmen dieser Arbeit wurden zerstörungsfreie Prüfmethoden hinsichtlich ihrer Eignung zur Detektion nicht sichtbarer Schäden systematisch untersucht und bewertet. Der Fokus lag dabei auf Bauteilen aus kohlenstofffaserverstärkten Kunststoffen des Automobils, die sowohl eine flächige als auch eine mehrfach gekrümmte Bauteilstruktur mit nicht-homogenen Wanddicken aufweisen können. In Abhängigkeit von der Art der Schädigung, etwa Einschlüsse, Zwischenfaserrisse oder Delaminationen wurden die unterschiedlichen Verfahren vergleichend in Hinblick auf Detektionssicherheit, -grenzen und Einschränkungen durch gegebene geometrische sowie werkstoffliche Bauteilausführungen bewertet und ein Konzept für eine fertigungsbegleitende Qualitätssicherung entwickelt.

APA, Harvard, Vancouver, ISO, and other styles

29

Renner, Axel, Uwe Marschner, and Wolf-Joachim Fischer. "A new imaging approach for in situ and ex situ inspections of conductive fiber–reinforced composites by magnetic induction tomography." Sage, 2014. https://tud.qucosa.de/id/qucosa%3A35619.

Full text

Abstract:

Fiber-reinforced plastics for industrial applications face constantly increasing demands regarding efficiency, reliability, and economy. Furthermore, it was shown that fiber-reinforced plastics with tailored reinforcements are superior to metallic or monolithic materials. However, a trustworthy description of the load-specific failure behavior and damage evolution of composite structures can hardly be given, because these processes are very complex and are still not entirely understood. Among other things, several research groups have shown that material damages like fiber fracture, delamination, matrix cracking, or flaws can be discovered by analyzing the electrical properties of conductive composites, for example, carbon fiber–reinforced plastics. Furthermore, it was shown that this method could be used for structural health monitoring or nondestructive evaluation. Within this study, magnetic induction tomography, which is a new imaging approach, is introduced in the topic of nondestructive evaluation of carbon fiber–reinforced plastics. This non-contacting imaging method gains the inner spatial distribution of conductivity of a specimen and depicts material inhomogeneity, like damages, not only in two-dimensional images but also in three-dimensional images. Numerical and experimental investigations are presented, which give a first impression of the performance of this technique. It is demonstrated that magnetic induction tomography is a promising approach for nondestructive evaluation. Potentially, it can be used for fabrication quality control of conductive fiber–reinforced plastics and as a structural health monitoring system using an integrated or superficially applied magnetic induction tomography setup.

APA, Harvard, Vancouver, ISO, and other styles

30

Warraich, Daud Sana Mechanical &amp Manufacturing Engineering Faculty of Engineering UNSW. "Ultrasonic stochastic localization of hidden discontinuities in composites using multimodal probability beliefs." Publisher:University of New South Wales. Mechanical & Manufacturing Engineering, 2009. http://handle.unsw.edu.au/1959.4/43719.

Full text

Abstract:

This thesis presents a technique used to stochastically estimate the location of hidden discontinuities in carbon fiber composite materials. Composites pose a challenge to signal processing because speckle noise, as a result of reflections from impregnated laminas, masks useful information and impedes detection of hidden discontinuities. Although digital signal processing techniques have been exploited to lessen speckle noise and help to localize discontinuities, uncertainty in ultrasonic wave propagation and broadband frequency based inspections of composites still make it a difficult task. The technique proposed in this thesis estimates the location of hidden discontinuities stochastically in one- and two-dimensions based on statistical data of A-Scans and C-Scans. Multiple experiments have been performed on carbon fiber reinforced plastics including artificial delaminations and porosity at different depths in the thickness of material. A probabilistic approach, which precisely localizes discontinuities in high and low amplitude signals, has been used to present this method. Compared to conventional techniques the proposed technique offers a more reliable package, with the ability to detect discontinuities in signals with lower intensities by utilizing the repetitive amplitudes in multiple sensor observations obtained from one-dimensional A-Scans or two-dimensional C-Scan data sets. The thesis presents the methodology encompassing the proposed technique and the implementation of a system to process real ultrasonic signals and images for effective discontinuity detection and localization.

APA, Harvard, Vancouver, ISO, and other styles

31

Baylis, E. R. "Wave propagation in fibre-reinforced laminates." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373799.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Boniface, Lynn. "Damage development in fibre-reinforced plastics' laminates." Thesis, University of Surrey, 1989. http://epubs.surrey.ac.uk/843993/.

Full text

Abstract:

Tensile static and tension-tension fatigue behaviour has been studied in coupon specimens made from continuous fibre reinforced glass/epoxy and carbon/epoxy laminates of various lay-ups, including a series of GFRP and CFRP 0,90,0 cross-ply laminates with different 90° ply thicknesses and CFRP 0, 90, +/-45 laminates with different ply stacking sequences. A variety of techniques has been used to monitor the accumulation of damage; microscopy on the polished edge of coupons, penetrant-enhanced X-radiography for CFRP laminates and visual observations for the transparent GFRP laminates. Under static loading, mechanical properties and damage thresholds are established for the onset of events such as cracking in the 90' and 45° plies and delamination. The experimentally determined 90° ply cracking threshold strains agree with predictions based on fracture mechanics, provided residual thermal strains are taken into account. Fatigue failure data are obtained for the CFRP laminates and plotted as conventional S-logN curves. The fatigue behaviour of the CFRP laminates has also been described qualitatively using a form of fatigue life representation in terms of the predominant damage mechanisms observed during cyclic loading. A detailed study of transverse ply matrix cracking showed that the mode of crack propagation depended on the type of loading. Crack growth across the width of the ply was instantaneous under static loading and at high cyclic stresses. At low cyclic stresses, i.e. below the static cracking threshold, cracks initiated only after a number of cycles (dependent on the stress level) and then grew slowly across the width of the ply throughout the course of loading. Slow crack growth was also observed at high cyclic stresses when the density of full width cracks was high and the crack spacing was small. The crack growth rate was found to be independent of crack length and to depend on crack spacing and hence was strongly influenced by interactions between neighbouring cracks. Fatigue growth of individual cracks was modelled using an approach based on an expression for the stress intensity factor at the tip of a transverse ply crack and a Paris fatigue crack growth relationship.

APA, Harvard, Vancouver, ISO, and other styles

33

Kanellopoulos, V. N. "Hygrothermal characteristics of carbon fibre reinforced plastics." Thesis, University of Salford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356171.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Cushley, Anna T. "The prediction of fibre orientation in short fibre reinforced thermoplastic injection mouldings." Thesis, Cranfield University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281060.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Symons, Digby Duncan. "Impact damage tolerance of carbon fibre reinforced plastics." Thesis, University of Oxford, 1998. https://ora.ox.ac.uk/objects/uuid:1db49475-ac42-4259-91aa-b84ee6718875.

Full text

Abstract:

Carbon fibre reinforced plastic (CFRP) is a composite composed of very high strength and stiffness carbon fibres within a polymer matrix. Low mass and cost make CFRP attractive for aerospace applications. At present application of CFRP is limited by the poor residual strength and fatigue properties of the material following impact damage, and because of the limited understanding of the problem. Damage to CFRP results in a combination of fibre fracture and matrix cracking. The strength of CFRP perpendicular to the fibre direction is relatively poor and so the material is generally used as a laminate of unidirectional plies of different fibre orientations. Laminates are particularly prone to delamination, this is matrix cracking which separates plies. In this thesis techniques for measurement of damage type and severity in CFRP are evaluated. These are used to quantify the distribution of damage resulting from hard body impacts at high, low and quasi-static incident velocities. A composite material damage model in a dynamic finite element analysis computer program (DYNA 3D) was used to predict the experimentally measured impact damage. However the prediction was found to be insufficiently accurate for reliable use by designers. Recommendations are made for improvements in the numerical modelling of impact damage in CFRP. Mechanical tests that provide data on the effect of impact damage on the residual strength of CFRP specimens are reported. These show that providing impact damage is limited to delamination, with little fibre fracture ocurring, the compressive residual strength will be more severely reduced than the tensile property. Strain gauge measurements show that this effect is caused by local compressive buckling of the delaminated plies in the impact damaged area. Lquivalent hole sizes, causing the same residual strengths as in the impact damaged specimens, are given. Cyclic load tests were conducted providing stress-life data for impact damaged specimens of CFRP. The data fit a stress-life diagram divided into three scatter band regions: static fracture; cycle dependent damage growth; and infinite life. Qualitative and quantitative observations are given of the progression of damage in a fatigue after impact damage test. Strain gauge and force/extension measurements show the presence of creep and energy absorption in undamaged and impact damaged CFRP. Much of the observed behaviour may be explained by a viscoelastic model. Because of the presence of viscoelastic creep it is suggested that the fatigue mechanism must depend on interacting cycle dependent and time dependent mechanisms.

APA, Harvard, Vancouver, ISO, and other styles

36

Makhdum, Farrukh. "Ultrasonically-assisted drilling of carbon fibre-reinforced plastics." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/14721.

Full text

Abstract:

Carbon fibre-reinforced plastics (CFRP) are widely used in aerospace, automobile and other structural applications due to their superior mechanical and physical properties. CFRP outperform conventional metals in high strength-to-weight ratio. Usually, CFRP parts are manufactured near to net-shape;however,machining is unavoidable when it comes to assembly. Drilling the holes are essential to facilitate riveting and bolting of the components. However, conventional drilling (CD) induces different types of damages such as cracking, fibre pull-out, sprintling and delamination due to the abrasive nature, inhomogeneity and anisotropy of CFRP. A novel technique, ultrasonically-assisted drilling (UAD) is hybrid machining technique in which highfrequency (typically above 20 kHz) vibration are superimposed on a standard twist drill bit in axial direction using ultrasonic transducer. UAD has shown several advantages such as thrust force reduction, improving surface quality and lower bur-formation in drilling of conventional metals. UAD has also effectively been used for drilling brittle materials.

APA, Harvard, Vancouver, ISO, and other styles

37

Shipton, Paul David. "The compounding of short fibre reinforced thermoplastic composites." Thesis, Brunel University, 1988. http://bura.brunel.ac.uk/handle/2438/5788.

Full text

Abstract:

It is generally accepted that the mechanical properties of short fibre reinforced thermoplastics do not correspond with the high mechanical properties of fibres used to reinforce them. A study is made into the methods of compounding reinforcing fibres into thermoplastics to produce short fibre reinforced thermoplastics of enhanced properties. The initial method chosen for investigation is the twin screw extrusion compounding process. Variables such as fibre feeding arrangement and extrusion screw design are found to be factors influencing the properties of carbon and glass reinforced nylon 6,6. Use is made of computer programs to predict properties, assess compound quality and estimate fibre-matrix bond strength. Investigations indicate that the presence of reinforcing fibres with enhanced lengths does not result in the predicted property increases. The reasons for this shortfall are believed to lie in unfavourable fibre orientation in injection mouldings and the reduced strain to break of these materials. Short Kevlar reinforced thermoplastics are compounded and their mechanical properties assessed. The reasons for the poor mechanical properties for these materials are identified as a poor bond strength between fibre and matrix, the formation of points of weakness within the fibres by the compounding and moulding processes and the coiled arrangement of fibres present in injection mouldings. A method suitable for the routine assessment of fibre-matrix bond strength is used to examine combinations of fibre and thermoplastic matrix. A comparison is made of the values derived from this method with values calculated from stress-strain curves of injection mouldings. This allows an understanding of the nature of the fibre-matrix bond yielded by compounding and injection moulding steps. A description is given of a novel method designed to overcome the limitations of conventional compounding routes to produce long fibre reinforced injection moulding feedstock. Further work is necessary before this method is a feasible production technique.

APA, Harvard, Vancouver, ISO, and other styles

38

Holden, Andrew Mark. "Multiple live-feed moulding of fibre reinforced thermoplastics." Thesis, Brunel University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292992.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Grove, Stephen Michael. "Anisotropy of heat conduction in fibre-reinforced composites." Thesis, University of Plymouth, 1985. http://hdl.handle.net/10026.1/2749.

Full text

Abstract:

Fibre-reinforced composites usually exhibit anisotropy of thermal as well as mechanical properties. For example, in a unidirectional carbon fibre-reinforced plastic of 60% volume fraction, the longitudinal thermal conductivity may be greater than that in the transverse direction by a factor of 50, and greater than that of the unreinforced polymer by more than two orders of magnitude. In order to evaluate the engineering applications of thermal anisotropy, this thesis concentrates on the development and validation of a generalised finite element model of heat conduction in an anisotropic medium. This uses a variational formulation of the anisotropic time-dependent heat conduction equation, and is implemented for two and threedimensional quadratic finite elements. The model may be used for the solution of problems having any combination of steady or time-dependent boundary conditions (fixed temperature, convection, radiation, heat flux and internal heat generation), as well as nonlinear properties. Anisotropy is specified by the components of the two or threedimensional thermal conductivity tensor; efficient representation of nonhomogeneous materials is achieved by the specification of properties at element integration points. Theoretical validation of the model is carried out by means of a number of mathematical solutions to orthotropic and anisotropic problems. Experimental validation is performed by comparison of calculations with measured steady-state surface temperatures on a cylindrical specimen of unidirectional carbon fibre-reinforced epoxy resin. The thermal property data for this exercise are obtained from measurements of principal thermal conductivities on absolute and comparative steady-state apparatus. The use of the finite element model in two industrial applications is briefly described. These concern thermal cycling during composite fabrication with reinforced thermoplastic tape, and an analysis of heat transfer in a composite propeller blade.

APA, Harvard, Vancouver, ISO, and other styles

40

Spickenheuer, Axel. "Zur fertigungsgerechten Auslegung von Faser-Kunststoff-Verbundbauteilen für den extremen Leichtbau auf Basis des variabelaxialen Fadenablageverfahrens Tailored Fiber Placement." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-147748.

Full text

Abstract:

Seitdem Faser-Kunststoff-Verbunde (FKV) als Leichtbauwerkstoffe für Hochleistungsanwendungen im Luftfahrzeug-, Automobil- und Sportgerätebau eingesetzt werden, erfolgt dies vorrangig mit Hilfe multiaxialer Mehrlagenlaminate. Vergleichsweise neue Fertigungstechnologien, wie die Tailored Fiber Placement (TFP-)Technologie, eröffnen jedoch die Möglichkeit einer gekrümmten, auch als variabelaxial bezeichneten, Ablage von Verstärkungsfäden. Der zugewonnene Freiheitsgrad, den Verstärkungsfasern an jeder beliebigen Stelle eine neue Richtung zuweisen zu können, bedingt aber auch ein komplexes Verständnis für eine beanspruchungsgerechte Auslegung von Faserverbundbauteilen. Ziel ist es dabei, die Fäden so zu orientieren, dass sie die angreifenden mechanischen Lasten mit einer möglichst gleichmäßigen Beanspruchung übertragen und das notwendige Matrixmaterial nur geringen Belastungen ausgesetzt ist. Nach einer Analyse bestehender theoretischer Auslegungsstrategien werden Vor- und Nachteile von reinen Materialoptimierungsansätzen bzw. in Kombination mit einer vorgeschalteten Topologieoptimierung diskutiert. Experimentelle Nachweise werden am Beispiel einer Zugscheibe mit ungleich breiten Einspannbereichen und einem steifigkeitsdimensionierten Fahrradbauteil (Brake Booster) erbracht. Dabei wird insbesondere das hohe Leichtbaupotential einer topologisch optimierten variabelaxialen FKV-Struktur gegenüber einer multiaxialen Laminatgestaltung herausgestellt. Anhand der TFP-Prozesskette wird deutlich gemacht, dass für eine numerische Auslegung variabelaxialer Strukturbauteile neue Softwarewerkzeuge sowie ein hinreichend genaues Analysemodell notwendig sind. Mit Hilfe des in der vorliegenden Arbeit entwickelten Softwarewerkzeugs AOPS kann die Auslegung beanspruchungsgerechter Strukturbauteile zukünftig effizienter erfolgen. Einen wesentlichen Bestandteil bildet dabei der vorgestellte Modellierungsansatz für die Finite Elemente Analyse. Damit ist es erstmals möglich ausgehend von einem beliebigen TFP-Ablagemuster, die spätere Struktursteifigkeit eines komplexen variabelaxialen TFP-Bauteils vorauszusagen. Der entwickelte Modellansatz konnte anhand der durchgeführten experimentellen Untersuchungen erfolgreich validiert werden.

APA, Harvard, Vancouver, ISO, and other styles

41

Graeff, Matthew Kent. "The Repair of Laterally Damaged Concrete Bridge Girders Using Carbon Fiber Reinforcing Polymers (CFRP)." UNF Digital Commons, 2012. http://digitalcommons.unf.edu/etd/592.

Full text

Abstract:

In recent years the use of carbon fiber reinforcing polymers (CFRP) to repair damaged structural components has become more accepted and practiced. However, the current reference for designing FRP systems to repair and strengthen reinforced concrete (RC) and prestressed concrete (PSC) girders has limitations. Similarly, very few resources address solutions for the debonding problem associated with CFRP laminates or the use of CFRP laminates to repair structural members with pre-existing damage. The included experimental program consists of testing both RC and PSC girders with simulated lateral damage and CFRP repairs. A total of 34 RC beams were statically tested under a 4-point loading until failure and had cross-section dimensions of 5” x 10” (14cm x 25.4cm), were 8’ long (2.44m), and were reinforced with either #3 or #4 mild steel rebar. 13 PSC girders having cross-section dimensions representing a half-scaled AASHTO type II shape, were 20’ long (6.1m), and were prestressed with five 7/16” (11.1mm) diameter low-lax 7-wire strands. Ten of the PSC girders were statically loaded until failure under a 4-point testing setup, but 3 PSC girders were dynamically tested under fatigue loading using a 3-point arrangement. Different configurations of CFRP laminates, number and spacing of CFRP transverse U-wraps, and amount of longitudinal CFRP layers are studied. The results present the flexural behavior of all specimen including load-deflection characteristics, strain characteristics, and modes of failure. Ultimately, results are used to recommend important considerations, needed criteria, and proper design procedures for a safe and optimized CFRP repair configuration.

APA, Harvard, Vancouver, ISO, and other styles

42

Funke, Henrik, Sandra Gelbrich, Lars Ulke-Winter, Lothar Kroll, and Carolin Petzoldt. "An application of asymmetrical glass fibre-reinforced plastics for the manufacture of curved fibre reinforced concrete." Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-178054.

Full text

Abstract:

There was developed a novel technological and constructive approach for the low-cost production of curved freeform formworks, which allow the production of single and double-curved fibre reinforced concrete. The scheduled approach was based on a flexible, asymmetrical multi-layered formwork system, which consists of glass-fibre reinforced plastic (GFRP). By using of the unusual anisotropic structural behavior, these GFRP formwork elements permitted a specific adjustment of defined curvature. The system design of the developed GFRP formwork was examined exhaustively. There were designed, numerically computed and produced prototypical curved freeform surfaces with different curvature radii. The fibre reinforced concrete had a compressive strength of 101.4 MPa and a 3-point bending tensile strength of 17.41 MPa. Beyond that, it was ensured that the TRC had a high durability, which has been shown by the capillary suction of de-icing solution and freeze thaw test with a total amount of scaled material of 874 g/m² and a relative dynamic E-Modulus of 100% after 28 freeze-thaw cycles.

APA, Harvard, Vancouver, ISO, and other styles

43

Mohd, Ishak Zainal Afirin. "Mechanical properties of short carbon fibre reinforced nylon 6.6." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.256817.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Svecova, Dagmar Carleton University Dissertation Engineering Civil and Environmental. "Serviceability and strength of concrete parking structures reinforced by fibre-reinforced plastics." Ottawa, 1994.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

45

Kretsis, George. "Mechanical characterisation of hybrid glass/carbon fibre-reinforced plastics." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/46982.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Ratner, Alon. "Hybrid steel wire strands with carbon fibre reinforced plastics." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12477/.

Full text

Abstract:

It has been hypothesised that weight reduction in ropes can be realised by the hybridisation of steel strands with non-metallic carriers in order to improve the efficiency of hoisting processes, most notably in mining applications. While this has been attempted by replacing steel central wires with unreinforced polymers and parallel fibre cores, this investigation has considered the replacement of steel wires with carbon fibre reinforced plastic rods. Fibre reinforced plastics are valued for their high strength-to-weight ratios and ubiquity. Since load sharing is maximal between materials of similar stiffness in a hybrid system, high strength carbon fibres were identified as the most feasible reinforcements for achieving compatible mechanical properties with those of high strength steel wires. A nylon polymer matrix was chosen to provide a reasonable balance between toughness, environmental stability and cost. A pultruder was designed and constructed in order to produce carbon fibre/nylon 12 rods for the creation of novel steel/CFRP hybrid strands. Development of the pultruder highlighted challenges in manufacturing that have been solved for industrial processes but remain underrepresented in academic research. Cost effective and flexible laboratory-scale techniques included fibre spreading by rollers, powder impregnation and the use of heating strips. Superior consolidation of the polymer matrix was obtained in rods pultruded from commingled stretch-broken carbon fibre/nylon tows, which emerged as the most appropriate feedstock. The Young's modulus and tenacity of hybrid carbon fibre/vinyl ester central rods were found to exceed that of standard steel strands, which in turn were higher than that of hybrid strands produced with in-house pultruded rods. Although this identified a need for the refinement of manufacturing conditions, it identified a lower bound of material properties required of the central rod in order to improve the tenacity of a hybrid strand. The finding of higher tenacity for the hybrid carbon fibre/vinyl ester strands demonstrated the feasibility of hybridising steel wire strands with non-metallic rods as a novel means of increasing the strength-to-weight ratio of strands. Finite element modelling of strands with a range of non-metallic core materials confirmed the material selection process by predicting the suitability of carbon fibre reinforced plastics over other core materials in improving the tenacity of hybrid strands.

APA, Harvard, Vancouver, ISO, and other styles

47

Wells, Garry Michael. "The transverse mechanical behaviour of glass fibre reinforced plastics." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380692.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Berg, Jolyon. "The role of fibre coatings on interphase formation in glass fibre epoxy resin composites." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245546.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

McClelland, Alan Nigel Robert. "The injection moulding of long glass fibre reinforced thermoplastic materials." Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235520.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

De, Rose David. "The rehabilitation of a concrete structure using fibre reinforced plastics." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29388.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Fibre reinforced plastics testing'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles