Vai ai contenuti. | Spostati sulla navigazione | Spostati sulla ricerca | Vai al menu | Contatti | Accessibilità

| Crea un account

Belmonte, Enrico (2016) Multi-scale modeling of the fatigue behavior for short fiber reinforced thermoplastics. [Tesi di dottorato]

Full text disponibile come:

[img]
Anteprima
Documento PDF (PhD Thesis) - Versione sottomessa
22Mb

Abstract (inglese)

This PhD thesis deals with the investigation of damage initiation in a short glass fiber reinforced polyamide under fatigue loading. This material belongs to Short Fiber Reinforced Plastics (SFRPs) and is widely used in load-bearing applications in the automotive sector. Lifetime prediction models represent a powerful tool for optimizing structural parts in the early stage of a project reducing the number of prototypes needed before the series production. Multi scale predictive models aim to integrate the relevant damage mechanisms in order to obtain accurate estimation of the lifetime to failure reducing empirical parameters and assumptions. The aim of this PhD thesis is to gain insight into the conditions for damage initiation in a short glass fiber reinforced polyamide under fatigue loading in order to prepare the basis for the development of a multi-scale, mechanism-based lifetime prediction model. This objective was addressed through three main activities: 1) The quantification of the lifetime to crack initiation during fatigue tests (Chapter 4); 2) The investigation of the fatigue damage mechanisms (Chapter 5 - 6); 3) The study of the local stress concentrations at crack initiation (Chapter 7).
Chapter 4 describes the development of an optical method for the quantification of the lifetime to crack initiation during fatigue tests. Using the proposed experimental method, it was possible to generate a set of fatigue data to crack initiation for the calibration of a lifetime prediction model.
The investigation of the damage mechanisms constitutes a major part of the PhD. In Chapter 5 an extensive damage investigation on PA66-GF35 plain and notched specimens is presented. In Chapter 6 the influence of the fiber volume fraction on the damage mechanisms is investigated. Fatigue damage mechanisms were studied at multiple scales by means of Field Emission Scanning Electron Microscopy (FESEM). Damage investigation was carried out analyzing either the fracture surface of failed specimens or the polished side surface of specimens subjected to interrupted fatigue tests. Specific fractographic features were analyzed and compared with the results from the literature. These are: ductile / brittle matrix fracture behavior, fiber failure / pull out, degree of fiber-matrix interfacial adhesion. Particular attention was devoted to the analysis of the fiber-matrix interface. Mirror-clean fibers on the fracture surface indicate fiber-matrix debonding. By contrast, fibers covered by a resin layer suggest the damage occurs in form of matrix-cracking in the resin, at a certain distance from the interface.
In Chapter 7, the influence of the fiber distribution on the local stress concentrations at crack initiation is studied. Stress concentrations are potential locations for damage initiation. In SFRPs, fiber-fiber and fiber-matrix interactions lead to stress concentrations at micro-scale. X Ray Computed Tomography (X-Ray CT) was used for the quantitative description of the fiber distribution around a molded notch, at crack initiation. For this purpose, a fatigue test of a notched specimen was interrupted before failure. A sample surrounding the notch and including a crack propagated during the fatigue test was scanned by means of X-Ray CT. A manual procedure for reconstructing the real fiber orientation distribution around the notch is proposed. The reconstructed volume was simulated with the FEM code ABAQUS with the aim to study the stress concentrations at crack initiation.
Finally, the findings of the experimental and modeling activities were used for the development of a preliminary multi-scale approach for the prediction of the crack initiation in a short glass fiber reinforced polyamide under fatigue loading. This activity is presented in Chapter 8.

Abstract (italiano)

Il tema del presente dottorato di ricerca è lo studio della nucleazione del danneggiamento in una poliammide rinforzata con fibre di vetro corte soggetta a un carico di fatica. La poliammide è un materiale termoplastico molto utilizzato nell’industria automobilistica per applicazioni strutturali sotto il cofano della vettura. Questo materiale è caratterizzato da ottime proprietà meccaniche e da un’elevata resistenza ad alte temperature e alla corrosione. Inoltre è leggero contribuendo in questo modo a ridurre il peso dell’autovettura. I componenti strutturali realizzati con questo materiale sono soggetti in esercizio a sollecitazioni cicliche di natura termica e meccanica che provocano una rottura a fatica. Lo sviluppo di modelli previsionali è pertanto di fondamentale importanza perché permette una stima della vita a fatica nella fase di progettazione riducendo il numero di prototipi necessari prima dell’avvio della produzione in serie. Lo sviluppo di questi modelli richiede la comprensione dei meccanismi di danneggiamento che causano l’innesco di una cricca e la sua propagazione fino alla rottura finale.
L’obiettivo che si pone questo dottorato di ricerca è la comprensione del fenomeno di nucleazione del danneggiamento in una poliammide rinforzata con fibre di vetro corte, soggetta a un carico di fatica al fine di porre le basi per lo sviluppo di un modello previsionale basato sui meccanismi di danneggiamento. Le tre principali attività svolte sono: 1) L’identificazione dell’inizio cricca durante test di fatica (Capitolo 4); 2) L’analisi dei meccanismi di danneggiamento (Capitolo 5 - 6); 3) Lo studio dei campi tensione locali a inizio cricca (Capitolo 7).
Il Capitolo 4 descrive lo sviluppo di un metodo ottico per l’identificazione dell’inizio cricca durante i test di fatica. È stata condotta una campagna sperimentale di test a fatica su provini lisci e intagliati. Lo sviluppo della tecnica sperimentale ha reso possibile lo studio dell’effetto della frazione di volume sulla vita a innesco della poliammide. In questo modo è stato generato un set di dati sperimentali per lo sviluppo di un modello previsionale a inizio cricca.
L’analisi dei meccanismi di danneggiamento copre una parte importante del dottorato. Nel Capitolo 5 è presentata l’analisi del danneggiamento su provini lisci e intagliati per una poliammide rinforzata con il 35 % (in peso) di fibre. Nel Capitolo 6, l’analisi del danneggiamento è estesa a diverse frazioni di volume. È stato utilizzato un microscopio a scansione ad alta risoluzione. L’analisi del danneggiamento è stata condotta analizzando o la superficie di frattura di provini giunti a rottura durante test di fatica o la superficie laterale di provini soggetti a test di fatica interrotti. I meccanismi di danneggiamento sono stati studiati analizzando specifiche evidenze frattografiche: il comportamento duttile / fragile della matrice; la presenza di fibre rotte o estratte intere dalla superficie di frattura; il grado di adesione fibra-matrice. In particolare, l’evidenza sulla superficie di frattura di fibre pulite o coperte da un strato di resina è importante nell’ottica di sviluppo modello. Nel primo caso il danneggiamento avviene all’interfaccia in forma di debonding. Nel secondo caso, il danneggiamento avviene fuori dall’interfaccia in uno strato di resina che potrebbe essere stato modificato chimicamente dal sizing usato durante il processo di formatura delle fibre per migliorarne l’adesione con la matrice.
Il Capitolo 7 tratta l’effetto dell’orientazione delle fibre sui campi di tensione locali a inizio cricca. Le concentrazioni di tensione rappresentano potenziali fonti di innesco di una cricca. Nei materiali plastici rinforzati, l’interazione tra fibre e matrice su scala microscopica dà luogo a concentrazioni di tensione. È stato condotto un test di fatica su un provino intagliato fino alla comparsa di una cricca. A questo punto, il test è stato interrotto e un volume di materiale attorno all’intaglio e comprendente la cricca è stato fresato dal provino e analizzato con un tomografo computerizzato. In seguito, la reale distribuzione delle fibre a bordo intaglio è stata riprodotta manualmente in un software agli elementi finiti con l’obiettivo di studiare i campi di tensione locali nella matrice che possono causare l’innesco di una cricca.
Infine i risultati dell’attività sperimentale e di modellazione sono stati utilizzati per lo sviluppo di un approccio multi scala per la previsione della vita a innesco di cricca in una poliammide rinforzata soggetta a un carico di fatica. Quest’attività è presentata nel Capitolo 8.

Statistiche Download - Aggiungi a RefWorks
Tipo di EPrint:Tesi di dottorato
Relatore:Quaresimin, Marino
Dottorato (corsi e scuole):Ciclo 28 > Scuole 28 > INGEGNERIA MECCATRONICA E DELL'INNOVAZIONE MECCANICA DEL PRODOTTO
Data di deposito della tesi:25 Gennaio 2016
Anno di Pubblicazione:26 Gennaio 2016
Parole chiave (italiano / inglese):Short Fiber Reinforced Plastics, Damage Mechanisms, Fatigue, Interface / Interphase, Micro-tomography, Polyamide
Settori scientifico-disciplinari MIUR:Area 09 - Ingegneria industriale e dell'informazione > ING-IND/22 Scienza e tecnologia dei materiali
Struttura di riferimento:Dipartimenti > Dipartimento di Tecnica e Gestione dei Sistemi Industriali
Codice ID:9104
Depositato il:21 Ott 2016 10:48
Simple Metadata
Full Metadata
EndNote Format

Bibliografia

I riferimenti della bibliografia possono essere cercati con Cerca la citazione di AIRE, copiando il titolo dell'articolo (o del libro) e la rivista (se presente) nei campi appositi di "Cerca la Citazione di AIRE".
Le url contenute in alcuni riferimenti sono raggiungibili cliccando sul link alla fine della citazione (Vai!) e tramite Google (Ricerca con Google). Il risultato dipende dalla formattazione della citazione.

[1] American Chemistry Council, Economics ad Statistics Deparment, Plastics and Polymer Composites in Light Vehicles (2014). Cerca con Google

[2] E. Carlson, K. Nelson, Nylon Under-the-Hood: A History of Innovation, Automotive Engineering (1996) 84-89. Cerca con Google

[3] M. De Monte, E. Moosbrugger, M. Quaresimin, Influence of temperature and thickness on the off-axis behaviour of short glass fibre reinforced polyamide 6.6 – Quasi-static loading, Composites Part A: Applied Science and Manufacturing. 41 (2010) 859-871. Cerca con Google

[4] M. De Monte, E. Moosbrugger, M. Quaresimin, Influence of temperature and thickness on the off-axis behaviour of short glass fibre reinforced polyamide 6.6 – cyclic loading, Composites Part A: Applied Science and Manufacturing. 41 (2010) 1368-1379. Cerca con Google

[5] L.E. Asp, L.A. Berglund, R. Talreja, A criterion for crack initiation in glassy polymers subjected to a composite-like stress state, Composites Sci. Technol. 56 (1996) 1291-1301. Cerca con Google

[6] P. Lazzarin, R. Zambardi :, A finite-volume-energy based approach to predict the static and fatigue behavior of components with sharp V-shaped notches, International Journal of Fracture. 12 (2001) 275-298. Cerca con Google

[7] P. Lazzarin, F. Berto, Some Expressions for the Strain Energy in a Finite Volume Surrounding the Root of Blunt V-notches, International Journal of Fracture. 135 (2005) 161-185. Cerca con Google

[8] B. Atzori, F. Berto, P. Lazzarin, M. Quaresimin, Multi-axial fatigue behaviour of a severely notched carbon steel, Int. J. Fatigue. 28 (2006) 485-493. Cerca con Google

[9] M. De Monte, M. Quaresimin, P. Lazzarin, Modelling of fatigue strength data for a short fiber reinforced polyamide 6.6 based on local strain energy density. Proceedings of ICCM16, 16th International Conference on Composite Materials (2007). Cerca con Google

[10] A. Schaaf, M. De Monte, E. Moosbrugger, M. Vormwald, M. Quaresimin, Life estimation methodology for short fiber reinforced polymers under thermo-mechanical loading in automotive applications, Materialwissenschaft und Werkstofftechnik. 46 (2015) 214-228. Cerca con Google

[11] C.M. Sonsino, E. Moosbrugger, Fatigue design of highly loaded short-glass-fibre reinforced polyamide parts in engine compartments, Int. J. Fatigue. 30 (2008) 1279-1288. Cerca con Google

[12] H. Huang, R. Talreja, Numerical simulation of matrix micro-cracking in short fiber reinforced polymer composites: Initiation and propagation, Composites Sci. Technol. 66 (2006) 2743-2757. Cerca con Google

[13] J.J. Horst, N.V. Salienko, J.L. Spoormaker, Fibre-matrix debonding stress analysis for short fibre-reinforced materials with matrix plasticity, finite element modelling and experimental verification, Composites Part A: Applied Science and Manufacturing. 29 (1998) 525-531. Cerca con Google

[14] S. Hoffmann, Computational Homogenization of Short Fiber Reinforced Thermoplastic Materials (2012). Cerca con Google

[15] D.A. Jesson, J.F. Watts, The Interface and Interphase in Polymer Matrix Composites: Effect on Mechanical Properties and Methods for Identification, - Polymer Reviews. 52 (2012) 321-354. Cerca con Google

[16] W.N. Findley, J.S. Lai, K. Onaran, Creep and relaxation of nonlinear viscoelastic materials with an introduction to linear viscoelasticity, Amsterdam : New York :North-Holland Pub. Co. ; American Elsevier Pub. Co., 1978. Cerca con Google

[17] J.L. Thomason, Structure-property relationships in glass-reinforced polyamide, part 1: The effects of fiber content, Polymer Composites. 27 (2006) 552-562. Cerca con Google

[18] L.E. Nielsen, R.F. Landel, Mechanical Properties of Polymers and Composites, Second Edition, Marcel Deckker, New York, 1994. Cerca con Google

[19] J.F. Mandell, F.J. McGarry, D.D. Huang, C.G. Li, Some effects of matrix and interface properties on the fatigue of short fiber-reinforced thermoplastics, Polymer Composites. 4 (1983) 32-39. Cerca con Google

[20] H. Voss, K. Friedrich, On the wear behaviour of short-fibre-reinforced peek composites, Wear. 116 (1987) 1-18. Cerca con Google

[21] J.L. Thomason, The influence of fibre properties of the performance of glass-fibre-reinforced polyamide 6,6, Composites Sci. Technol. 59 (1999) 2315-2328. Cerca con Google

[22] J.L. Thomason, L.J. Adzima, Sizing up the interphase: an insider's guide to the science of sizing, Composites Part A: Applied Science and Manufacturing. 32 (2001) 313-321. Cerca con Google

[23] J.L. Thomason, Interfaces and interfacial effects in glass reinforced thermoplastics - Keynote Presentation (2007). Cerca con Google

[24] J.L. Thomason, Glass Fibre Sizing : A Review of Size Formulation Patents (2015). Cerca con Google

[25] J.L. Thomason, G.E. Schoolenberg, An investigation of glass fibre/polypropylene interface strength and its effect on composite properties, Composites. 25 (1994) 197-203. Cerca con Google

[26] L.E. Asp, L.A. Berglund, L. Talreja, Effects of fiber and interphase on matrix-initiated transverse failure in polymer composites, Composites Sci. Technol. 56 (1996) 657-665. Cerca con Google

[27] A. Bergeret, M.P. Bozec, J.-. Quantin, A. Crespy, J.-. Gasca, M. Arpin, Study of interphase in glass fiber-reinforced poly(butylene terephthalate) composites, Polymer Composites. 25 (2004) 12-25. Cerca con Google

[28] L. Yang, J.L. Thomason, Interface strength in glass fibre–polypropylene measured using the fibre pull-out and microbond methods, Composites Part A: Applied Science and Manufacturing. 41 (2010) 1077-1083. Cerca con Google

[29] P.J. Herrera-Franco, L.T. Drzal, Comparison of methods for the measurement of fibre/matrix adhesion in composites, Composites. 23 (1992) 2-27. Cerca con Google

[30] S. Zhandarov, E. Mäder, Characterization of fiber/matrix interface strength: applicability of different tests, approaches and parameters, Composites Sci. Technol. 65 (2005) 149-160. Cerca con Google

[31] L. Yang, J.L. Thomason, Development and application of micromechanical techniques for characterising interfacial shear strength in fibre-thermoplastic composites, Polym. Test. 31 (2012) 895-903. Cerca con Google

[32] L. Yang, J.L. Thomason, Interface strength in glass fibre–polypropylene measured using the fibre pull-out and microbond methods, Composites Part A: Applied Science and Manufacturing. 41 (2010) 1077-1083. Cerca con Google

[33] A. Bergeret, L. Ferry, P. Ienny, Influence of the fibre/matrix interface on ageing mechanisms of glass fibre reinforced thermoplastic composites (PA-6,6, PET, PBT) in a hygrothermal environment, Polym. Degrad. Stab. 94 (2009) 1315-1324. Cerca con Google

[34] J.L. Thomason, L. Yang, Temperature dependence of the interfacial shear strength in glass–fibre polypropylene composites, Composites Sci. Technol. 71 (2011) 1600-1605. Cerca con Google

[35] H.M. Brodowsky, W. Jenschke, E. Mäder, Characterization of interphase properties: Microfatigue of single fibre model composites, Composites Part A: Applied Science and Manufacturing. 41 (2010) 1579-1586. Cerca con Google

[36] J.L. Thomason, Micromechanical parameters from macromechanical measurements on glass reinforced polyamide 6,6, Composites Sci. Technol. 61 (2001) 2007-2016. Cerca con Google

[37] J.L. Thomason, Interfacial strength in thermoplastic composites - at last an industry friendly measurement method?, Composites Part A: Applied Science and Manufacturing. 33 (2002) 1283-1288. Cerca con Google

[38] D.V. Rosato, D.V. Rosato, M.G. Rosato, Injection Molding Handbook, 3 ed., Springer US, 2000. Cerca con Google

[39] A. Bernasconi, P. Davoli, A. Basile, A. Filippi, Effect of fibre orientation on the fatigue behaviour of a short glass fibre reinforced polyamide-6, Int. J. Fatigue. 29 (2007) 199-208. Cerca con Google

[40] M. Laspalas, C. Crespo, M.A. Jiménez, B. García, J.L. Pelegay, Application of micromechanical models for elasticity and failure to short fibre reinforced composites. Numerical implementation and experimental validation, Comput. Struct. 86 (2008) 977-987. Cerca con Google

[41] M.F. Arif, N. Saintier, F. Meraghni, J. Fitoussi, Y. Chemisky, G. Robert, Multiscale fatigue damage characterization in short glass fiber reinforced polyamide-66, Composites Part B: Engineering. 61 (2014) 55-65. Cerca con Google

[42] J.J. Horst, J.L. Spoormaker, Mechanisms of fatigue in short glass fiber reinforced polyamide 6, Polymer Engineering & Science. 36 (1996) 2718-2726. Cerca con Google

[43] Y. Zhou, P.K. Mallick, A non-linear damage model for the tensile behavior of an injection molded short E-glass fiber reinforced polyamide-6,6, Materials Science and Engineering: A. 393 (2005) 303-309. Cerca con Google

[44] M.F. Arif, F. Meraghni, Y. Chemisky, N. Despringre, G. Robert, In situ damage mechanisms investigation of PA66/GF30 composite: Effect of relative humidity, Composites Part B: Engineering. 58 (2014) 487-495. Cerca con Google

[45] J. Karger-Kocsis, Effects of processing induced microstructure on the fatigue crack propagation of unfilled and short fibre-reinforced PA-6, Composites. 21 (1990) 243-254. Cerca con Google

[46] K. Friedrich, J. Karger-Kocsis, Fracture and fatigue of unfilled and reinforced polyamides and polyesters, in: J.M. Schultz, S. Fakirov (Eds.), <br />Solid state behavior of linear polyesters and polyamides, Prentice Hall Inc., Englewood Cliffs, 1990, pp. 249-322. Cerca con Google

[47] S.G. Advani, C.L. Tucker, The Use of Tensors to Describe and Predict Fiber Orientation in Short Fiber Composites, Journal of Rheology (1978-present). 31 (1987) 751-784. Cerca con Google

[48] A. Bernasconi, F. Cosmi, Analysis of the dependence of the tensile behaviour of a short fibre reinforced polyamide upon fibre volume fraction, length and orientation, Procedia Engineering. 10 (2011) 2129-2134. Cerca con Google

[49] A. Pegoretti, T. Riccò, Fatigue crack propagation in polypropylene reinforced with short glass fibres, Composites Sci. Technol. 59 (1999) 1055-1062. Cerca con Google

[50] B. Mouhmid, A. Imad, N. Benseddiq, S. Benmedakhène, A. Maazouz, A study of the mechanical behaviour of a glass fibre reinforced polyamide 6,6: Experimental investigation, Polym. Test. 25 (2006) 544-552. Cerca con Google

[51] J.L. Thomason, G. Kalinka, A technique for the measurement of reinforcement fibre tensile strength at sub-millimetre gauge lengths, Composites Part A: Applied Science and Manufacturing. 32 (2001) 85-90. Cerca con Google

[52] S. Wilberforce, S. Hashemi, Effect of fibre concentration, strain rate and weldline on mechanical properties of injection-moulded short glass fibre reinforced thermoplastic polyurethane, Journal of Materials Science. 44 (2009) 1333-1343. Cerca con Google

[53] J.F. Mandell, D.D. Huang, F.J. McGarry, Fatigue of glass and carbon fiber reinforced engineering thermoplastics, Polymer Composites. 2 (1981) 137-144. Cerca con Google

[54] S.Y. Fu, B. Lauke, Y.H. Zhang, Y.-. Mai, On the post-mortem fracture surface morphology of short fiber reinforced thermoplastics, Composites Part A: Applied Science and Manufacturing. 36 (2005) 987-994. Cerca con Google

[55] K. Tanaka, T. Kitano, N. Egami, Effect of fiber orientation on fatigue crack propagation in short-fiber reinforced plastics, Eng. Fract. Mech. 123 (2014) 44-58. Cerca con Google

[56] R. Pyrz, Microstructural Description of Composites, Statistical Methods, in: H.J. Böhm (Ed.), Mechanics of Microstructured Materials, Springer Vienna, 20014, pp. 173-233. Cerca con Google

[57] K. Friedrich, R. Walter, H. Voss, J. Karger-Kocsis, Effect of short fibre reinforcement on the fatigue crack propagation and fracture of PEEK-matrix composites, Composites. 17 (1986) 205-216. Cerca con Google

[58] A. Bernasconi, P. Davoli, C. Armanni, Fatigue strength of a clutch pedal made of reprocessed short glass fibre reinforced polyamide, Int. J. Fatigue. 32 (2010) 100-107. Cerca con Google

[59] Y. Zhou, P.K. Mallick, Fatigue performance of an injection-molded short E-glass fiber-reinforced polyamide 6,6. I. Effects of orientation, holes, and weld line, Polymer Composites. 27 (2006) 230-237. Cerca con Google

[60] J. Segurado, J. LLorca, Computational micromechanics of composites: The effect of particle spatial distribution, Mech. Mater. 38 (2006) 873-883. Cerca con Google

[61] Q. Yang, Q. Qin, Modelling the effective elasto-plastic properties of unidirectional composites reinforced by fibre bundles under transverse tension and shear loading, Materials Science and Engineering: A. 344 (2003) 140-145. Cerca con Google

[62] S. Mortazavian, A. Fatemi, Fatigue behavior and modeling of short fiber reinforced polymer composites including anisotropy and temperature effects, Int. J. Fatigue. 77 (2015) 12-27. Cerca con Google

[63] K. Friedrich, Microstructure and fracture mechanical properties of short fiber reinforced thermoplastic P.E.T., Colloid and Polymer Science. 259 (1981) 808-811. Cerca con Google

[64] M.G. Wyzgoski, G.E. Novak, Fatigue fracture of nylon polymers: Part II. Effect of glass-fibre reinforcement, Journal of Materials Science. 26 (1991) 6314-6324. Cerca con Google

[65] W.J. Evans, D.H. Isaac, K.S. Saib, The effect of short carbon fibre reinforcement on fatigue crack growth in PEEK, Composites Part A: Applied Science and Manufacturing. 27 (1996) 547-554. Cerca con Google

[66] A. Bernasconi, F. Cosmi, E. Zappa, Combined Effect of Notches and Fibre Orientation on Fatigue Behaviour of Short Fibre Reinforced Polyamide, Strain. 46 (2010) 435-445. Cerca con Google

[67] A. Avanzini, G.Donzella, D. Gallina, Fatigue damage modelling of PEEK short fibre composites, Procedia Engineering. 10 (2011) 2052-2057. Cerca con Google

[68] K. Friedrich, R. Walter, H. Voss, J. Karger-Kocsis, Effect of short fibre reinforcement on the fatigue crack propagation and fracture of PEEK-matrix composites, Composites. 17 (1986) 205-216. Cerca con Google

[69] H. Voss, J. Karger-Kocsis, Fatigue crack propagation in glass-fibre and glass-sphere filled PBT composites, Int. J. Fatigue. 10 (1988) 3-11. Cerca con Google

[70] J. Karger-Kocsis, K. Friedrich, Fatigue crack propagation in short and long fibre-reinforced injection-moulded PA 6.6 composites, Composites. 19 (1988) 105-114. Cerca con Google

[71] J. Karger-Kocsis, Effects of processing induced microstructure on the fatigue crack propagation of unfilled and short fibre-reinforced PA-6, Composites. 21 (1990) 243-254. Cerca con Google

[72] V. Bellenger, A. Tcharkhtchi, P. Castaing, Thermal and mechanical fatigue of a PA66/glass fibers composite material, Int. J. Fatigue. 28 (2006) 1348-1352. Cerca con Google

[73] A. Bernasconi, R.M. Kulin, Effect of frequency upon fatigue strength of a short glass fiber reinforced polyamide 6: A superposition method based on cyclic creep parameters, Polymer Composites. 30 (2009) 154-161. Cerca con Google

[74] M.G. Wyzgoski, G.E. Novak, Fatigue fracture of nylon polymers Part 1 Effect of frequency, Journal of Materials Science. 25 (1990) 4501-4510. Cerca con Google

[75] F. Berto, P. Lazzarin, A review of the volume-based strain energy density approach applied to V-notches and welded structures, Theor. Appl. Fract. Mech. 52 (2009) 183-194. Cerca con Google

[76] F. Berto, P. Lazzarin, Fatigue strength of structural components under multi-axial loading in terms of local energy density averaged on a control volume, Int. J. Fatigue. 33 (2011) 1055-1065. Cerca con Google

[77] P. Lazzarin, F. Berto, M. Eleices, J. Gomez, Brittle failures from U- and V-notches in mode I and mixed, I + II, mode: a synthesis based on the strain energy density averaged on finite-size volumes, Fatigue & Fracture of Engineering Materials & Structures. 32 (2009) 671-684. Cerca con Google

[78] C.M. Sonsino, Evaluating the fatigue behaviour of components with consideration of local stresses, Konstruktion. 45 (1993) 25-33. Cerca con Google

[79] M. Quaresimin, L. Susmel, R. Talreja, Fatigue behaviour and life assessment of composite laminates under multiaxial loadings, Int. J. Fatigue. 32 (2010) 2-16. Cerca con Google

[80] E. Moosbrugger, M. DeMonte, K. Jaschek, J. Fleckenstein, A. Büter, Multiaxial fatigue behaviour of a short-fibre reinforced polyamide - experiments and calculations, Materialwissenschaft und Werkstofftechnik. 42 (2011) 950-957. Cerca con Google

[81] M. De Monte, E. Moosbrugger, K. Jaschek, M. Quaresimin, Multiaxial fatigue behaviour of a short-fibre reinforced polyamide 6.6 in the presence of notches. ECCM - 13th European Conference on Composite Materials (2008). Cerca con Google

[82] B. Klimkeit, Y. Nadot, S. Castagnet, C. Nadot-Martin, C. Dumas, S. Bergamo, C.M. Sonsino, A. Büter, Multiaxial fatigue life assessment for reinforced polymers, Int. J. Fatigue. 33 (2011) 766-780. Cerca con Google

[83] B. Klimkeit, S. Castagnet, Y. Nadot, A.E. Habib, G. Benoit, S. Bergamo, C. Dumas, S. Achard, Fatigue damage mechanisms in short fiber reinforced PBT+PET GF30, Materials Science and Engineering: A. 528 (2011) 1577-1588. Cerca con Google

[84] M. De Monte, E. Moosbrugger, K. Jaschek, M. Quaresimin, Multiaxial fatigue of a short glass fibre reinforced polyamide 6.6 – Fatigue and fracture behaviour, Int. J. Fatigue. 32 (2010) 17-28. Cerca con Google

[85] H.K. Reimschuessel, Relationships on the effect of water on glass transition temperature and young's modulus of nylon 6, Journal of Polymer Science: Polymer Chemistry Edition. 16 (1978) 1229-1236. Cerca con Google

[86] J.L. Thomason, J.Z. Ali, The dimensional stability of glass–fibre reinforced polyamide 66 during hydrolysis conditioning, Composites Part A: Applied Science and Manufacturing. 40 (2009) 625-634. Cerca con Google

[87] J.L. Thomason, J.Z. Ali, J. Anderson, The thermo-mechanical performance of glass-fibre reinforced polyamide 66 during glycol–water hydrolysis conditioning, Composites Part A: Applied Science and Manufacturing. 41 (2010) 820-826. Cerca con Google

[88] J.L. Thomason, G. Porteus, Swelling of glass-fiber reinforced polyamide 66 during conditioning in water, ethylene glycol, and antifreeze mixture, Polymer Composites. 32 (2011) 639-647. Cerca con Google

[89] U.T. Kreibich, H. Batzer, Influence of water on thermal transitions in natural polymers and synthetic polyamides, Polymer Bulletin. 5 (1981) 585-590. Cerca con Google

[90] N. Jia, H.A. Fraenkel, V.A. Kagan, Effects of Moisture Conditioning Methods on Mechanical Properties of Injection Molded Nylon 6, Journal of Reinforced Plastics and Composites. 23 (2004) 729-737. Cerca con Google

[91] S. Barbouchi, V. Bellenger, A. Tcharkhtchi, P. Castaign, T. Jollivet, Effect of water on the fatigue behaviour of a PA66/glass fibers composite material, Journal of Materials Science. 42 (2007) 2181-2188. Cerca con Google

[92] N. Jia, V. Kagan, Mechanical Performance of Polyamides with Influence of Moisture and Temperature – Accurate Evaluation and Better Understanding, in: Plastics Failure: Analysis and Prevention, Plastic Design Library, New York, 2001, pp. 95-104. Cerca con Google

[93] D. Ferreño, I. Carrascal, E. Ruiz, J.A. Casado, Characterisation by means of a finite element model of the influence of moisture content on the mechanical and fracture properties of the polyamide 6 reinforced with short glass fibre, Polym. Test. 30 (2011) 420-428. Cerca con Google

[94] J. Karger-Kocsis, K. Friedrich, Skin-core morphology and humidity effects on the fatigue crack propagation of PA-6.6, Plastics and Rubber Processing and Applications. 12 (1989) 63-68. Cerca con Google

[95] S. Günzel, S. Hickmann, C. Wittemeyer, V. Trappe, Effects of Fiber Orientation and Moisture on the Crack Growth in Short Glass Fiber Reinforced Polyamide, Advanced Engineering Materials. 14 (2012) 867-872. Cerca con Google

[96] K. Noda, A. Takahara, T. Kajiyama, Fatigue failure mechanisms of short glass-fiber reinforced nylon 66 based on nonlinear dynamic viscoelastic measurement, Polymer. 42 (2001) 5803-5811. Cerca con Google

[97] R.W. Lang, J.A. Manson, Crack tip heating in short-fibre composites under fatigue loading conditions, Journal of Materials Science. 22 (1987) 3576-3580. Cerca con Google

[98] M. Pierantoni, M. De Monte, D. Papathanassiou, N. De Rossi, M. Quaresimin, Viscoelastic material behaviour of PBT-GF30 under thermo-mechanical cyclic loading, Procedia Engineering. 10 (2011) 2141-2146. Cerca con Google

[99] R. Talreja, Multi-scale modeling in damage mechanics of composite materials, Journal of Materials Science. 41 (2006) 6800-6812. Cerca con Google

[100] M. Quaresimin, P.A. Carraro, Damage initiation and evolution in glass/epoxy tubes subjected to combined tension–torsion fatigue loading, Int. J. Fatigue. 63 (2014) 25-35. Cerca con Google

[101] M. Quaresimin, P.A. Carraro, L.P. Mikkelsen, N. Lucato, L. Vivian, P. Brøndsted, B.F. Sørensen, J. Varna, R. Talreja, Damage evolution under cyclic multiaxial stress state: A comparative analysis between glass/epoxy laminates and tubes, Composites Part B: Engineering. 61 (2014) 282-290. Cerca con Google

[102] J.F. Mandell, F.J. McGarry, D.D. Huang, C.G. Li, Some effects of matrix and interface properties on the fatigue of short fiber-reinforced thermoplastics, Polymer Composites. 4 (1983) 32-39. Cerca con Google

[103] A.T. Dibenedetto, G. Salee, R. Hlavacek, A study of the fatigue behavior of fiber reinforced nylons, Polymer Engineering & Science. 15 (1975) 242-251. Cerca con Google

[104] J.W. Dally, D.H. Carrillo, Fatigue behavior of glass-fiber fortified thermoplastics, Polymer Engineering & Science. 9 (1969) 434-444. Cerca con Google

[105] R.W. Lang, J.A. Manson, R.W. Hertzberg, Mechanisms of fatigue fracture in short glass fibre-reinforced polymers, Journal of Materials Science. 22 (1987) 4015-4030. Cerca con Google

[106] J.F. Mandell, D.D. Huang, F.J. McGarry, Crack propagation Modes in Injection Molded Fiber Reinforced Thermoplastics, in: Short Fiber Reinforced Composite Materials, B.A. Sanders, Philadelphia, 1982, pp. 3-32. Cerca con Google

[107] R. Pyrz, J. Schjødt-Thomsen, Bridging the length-scale gap-short fibre composite material as an example, journal of Materials Science. 41 (2006) 6737-6750. Cerca con Google

[108] R.W. Hertzberg, J.A. Manson, Fatigue of engineering plastics, Academic Press, New York, 1980. Cerca con Google

[109] S. Mortazavian, A. Fatemi, Effects of fiber orientation and anisotropy on tensile strength and elastic modulus of short fiber reinforced polymer composites, Composites Part B: Engineering. 72 (2015) 116-129. Cerca con Google

[110] F. Cosmi, A. Bernasconi, Micro-CT investigation on fatigue damage evolution in short fibre reinforced polymers, Composites Sci. Technol. 79 (2013) 70-76. Cerca con Google

[111] A. Bernasconi, E. Conrado, P. Hine, An experimental investigation of the combined influence of notch size and fibre orientation on the fatigue strength of a short glass fibre reinforced polyamide 6, Polym. Test. 47 (2015) 12-21. Cerca con Google

[112] J.J. Horst, J.L. Spoormaker, Fatigue fracture mechanisms and fractography of short-glassfibre-reinforced polyamide 6, Journal of Materials Science. 32 (1997) 3641-3651. Cerca con Google

[113] J. Karger-Kocsis, K. Friedrich, Fracture behavior of injection-molded short and long glass fiber—polyamide 6.6 composites, Composites Sci. Technol. 32 (1988) 293-325. Cerca con Google

[114] R.W. Lang, Roughness-induced crack closure in short fibre-reinforced plastics, Journal of Materials Science Letters. 4 (1985) 1391-1396. Cerca con Google

[115] N. Sato, T. Kurauchi, S. Sato, O. Kamigaito, Microfailure behaviour of randomly dispersed short fibre reinforced thermoplastic composites obtained by direct SEM observation, Journal of Materials Science. 26 (1991) 3891-3898. Cerca con Google

[116] K. Friedrich, Microstructural efficiency and fracture toughness of short fiber/thermoplastic matrix composites, Composites Sci. Technol. 22 (1985) 43-74. Cerca con Google

[117] E. Belmonte, E. Moosbrugger, N. De Rossi, M. De Monte, M. Quaresimin, Life to crack initiation in notched specimens of unreinforced and short fiber reinforced polyamide under fatigue loading, to be submitted. Cerca con Google

[118] R.W. Lang, Roughness-induced crack closure in short fibre-reinforced plastics, Journal of Materials Science Letters. 4 (1985) 1391-1396. Cerca con Google

[119] H. Rolland, N. Saintier, G. Robert, Damage mechanisms into short glass fibre reinforced thermoplastic during in situ microtomographic tensile tests. 16th European Conference on Composite Materials, ECCM16 (2014). Cerca con Google

[120] S. Mortazavian, A. Fatemi, Fatigue behavior and modeling of short fiber reinforced polymer composites: A literature review, Int. J. Fatigue. 70 (2015) 297-321. Cerca con Google

[121] E. Belmonte, M. De Monte, C. Hoffmann, M. Quaresimin, Damage mechanisms in a short glass fiber reinforced polyamide under fatigue loading, to appear. Cerca con Google

[122] J.L. Thomason, The influence of fibre length, diameter and concentration on the impact performance of long glass-fibre reinforced polyamide 6,6, Composites Part A: Applied Science and Manufacturing. 40 (2009) 114-124. Cerca con Google

[123] G. Meneghetti, M. Quaresimin, Fatigue strength assessment of a short fiber composite based on the specific heat dissipation, Composites Part B: Engineering. 42 (2011) 217-225. Cerca con Google

[124] R.W. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials, 3rd ed., New York, 1989. Cerca con Google

[125] E. Belmonte, M. De Monte, C. Hoffmann, M. Quaresimin, Influence of fiber loading on the fatigue damage mechanisms in short glass fiber reinforced polyamide, to appear. Cerca con Google

[126] P.J. Hine, R.A. Duckett, P. Caton-Rose, P.D. Coates, Fibre orientation structures and their effect on crack resistance of injection moulded transverse ribbed plate, Plastics, Rubber and Composites. 33 (2004) 43-53. Cerca con Google

[127] B. Mlekusch, E.A. Lehner, W. Geymayer, Fibre orientation in short-fibre-reinforced thermoplastics I. Contrast enhancement for image analysis, Composites Sci. Technol. 59 (1999) 543-545. Cerca con Google

[128] C. Eberhardt, A. Clarke, Fibre-orientation measurements in short-glass-fibre composites. Part I: automated, high-angular-resolution measurement by confocal microscopy, Composites Sci. Technol. 61 (2001) 1389-1400. Cerca con Google

[129] A. Bernasconi, F. Cosmi, P.J. Hine, Analysis of fibre orientation distribution in short fibre reinforced polymers: A comparison between optical and tomographic methods, Composites Sci. Technol. 72 (2012) 2002-2008. Cerca con Google

[130] Abaqus Analysis User's Manual (Version 6.11), SIMULIA; 2011. Cerca con Google

[131] T. Riedel, Evaluation of 3D fiber orientation analysis based on x-ray computed tomography data. Proc. of Conference on Industrial Computed Tomography (2012). Cerca con Google

[132] Simpleware Ltd, exeter, United Kingdom. Cerca con Google

[133] M. Huang, Y. Li, X-ray tomography image-based reconstruction of microstructural finite element mesh models for heterogeneous materials, Computational Materials Science. 67 (2013) 63-72. Cerca con Google

[134] J.P. James, H.-. Choi, J.G. Pharoah, X-ray computed tomography reconstruction and analysis of polymer electrolyte membrane fuel cell porous transport layers, Int J Hydrogen Energy. 37 (2012) 18216-18230. Cerca con Google

[135] DIGIMAT, 2014, Software Platform for Nonlinear Multi-scale Modeling of Composite Materials and Structures, e-Xstream Engineering, Belgium and Luxembourg. Cerca con Google

[136] Autodesk, Inc., Moldflow 2014. Cerca con Google

[137] N. Despringre, Y. Chemisky, M.F. Arif, G. Robert, Multi-scale viscoelastic damage model of short glass fiber reinforced thermoplastics under fatigue loading. Proceeding of the 16th European Conference on Composite Materials (ECCM16) (22-26 June 2014). Cerca con Google

[138] E. Belmonte, T. Riedel, M. De Monte, M. Quaresimin, Local microstructure and stress distributions at the crack initiation site in a short glass fiber reinforced polyamide under fatigue loading, to appear. Cerca con Google

[139] V.N. Bulsara, R. Talreja, J. Qu, Damage initiation under transverse loading of unidirectional composites with arbitrarily distributed fibers, Composites Sci. Technol. 59 (1999) 673-682. Cerca con Google

Download statistics

Solo per lo Staff dell Archivio: Modifica questo record