TY - CONF A1 - Kalinka, Gerhard T1 - Optische Beobachtungen der Faser-Matrix-Trennung im Pull-out-Versuch N2 - Der Vortrag behandelt Rissentstehung und Ausbreitung an Faser-Matrix-Interfaces, untersucht mit dem optischen Mikroskop. T2 - Composites United, CU-Arbeitsgruppe/n Faser-Matrix-Haftung & Matrices CY - Online meeting DA - 02.12.2021 KW - Faser KW - Matrix KW - Pull-out KW - Interface PY - 2021 AN - OPUS4-53968 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhandarov, S. A1 - Mäder, E. A1 - Kalinka, Gerhard A1 - Scheffler, C. A1 - Poitzsch, C. A1 - Fliescher, S. T1 - Investigation of interfacial strength parameters in polymer matrix composites: Compatibility and reproducibility N2 - Effects of various geometrical and physical factors, as well as the method of data reduction (analysis of experimental forceedisplacement curves) on the values of local interfacial strength parameters (local IFSS, td, and critical energy release rate, Gic) determined by means of a single fiber pull-out test are discussed. Experimental results of our pull-out tests on several fiberepolymer matrix systems showed that td and Gic weakly depended on geometrical factors. However, the pull-out test appeared to be sensitive to the conditions of specimen formation and testing, such as changing the nature of the contacting surfaces (fiber sizing) and the fiber pull-out rate. Of several methods of td and Gic Determination from a forceedisplacement curve, the most reliable and reproducible one is the approach based on the values of the maximum force recorded in a pull-out test and the interfacial frictional force immediately after fiber debonding. KW - Interface KW - Interfacial shear strength KW - Pull-out composite materials KW - Polymer matrix composites KW - Critical energy release rate KW - Geometrical factors PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-460918 SN - 2542-5048 VL - 1 IS - 1 SP - 82 EP - 92 PB - Elsevier CY - Amsterdam AN - OPUS4-46091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Kalinka, Gerhard T1 - Local failure processes in fiber reinforced polymers N2 - The breakage of a fiber and its effect on the strain energy is studied in a model composite, this is, a single fiber embedded in a dogbone specimen. The fracture process is recorded by an acoustic emission device, the crack patterns are monitored under a microscope. A finite element analysis is performed in order to estimate the energy released by different failure scenarios. The abilities and limitations of the acoustic emission analysis in characterizing different failure types in fiber reinforced composites are evaluated. T2 - ICCM17 - 17th International conference on composite materials CY - Edinburgh, UK DA - 2009-07-27 KW - Fiber KW - Interface KW - Composite material KW - Failure KW - Acoustic emission KW - Fracture mechanics KW - Energy release rate KW - Finite element analysis PY - 2009 IS - D7:8 SP - 1 EP - 10 CY - Edinburgh, UK AN - OPUS4-21295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Juntaro, J. A1 - Pommet, M. A1 - Kalinka, Gerhard A1 - Mantalaris, A. A1 - Shaffer, M.S.P. A1 - Bismarck, A. T1 - Creating Hierarchical Structures in Renewable Composites by Attaching Bacterial Cellulose onto Sisal Fibers KW - Nanotubes KW - Cellulose KW - Polymer KW - Interface KW - Hierarchical Structures PY - 2008 U6 - https://doi.org/10.1002/adma.200703176 SN - 0935-9648 SN - 1521-4095 VL - 20 IS - 16 SP - 3122 EP - 3126 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Qian, Hui A1 - Bismarck, A. A1 - Greenhalgh, E.S. A1 - Kalinka, Gerhard A1 - Shaffer, M.S.P. T1 - Hierarchical composites reinforced with carbon nanotube grafted fibers: The potential assessed at the single fiber level N2 - The feasibility of reinforcing conventional carbon fiber composites by grafting carbon nanotubes (CNTs) onto the fiber surface has been investigated. Carbon nanotubes were grown on carbon fibers using the chemical vapor deposition (CVD) method. Iron was selected as the catalyst and predeposited using the incipient wetness technique before the growth reaction. The morphology of the products was characterized using scanning electron microscopy (SEM), which showed evidence of a uniform coating of CNTs on the fiber surface. Contact angle measurements on individual fibers, before and after the CNT growth, demonstrated a change in wettability that can be linked to a change of the polarity of the modified surface. Model composites based on CNT-grafted carbon fibers/epoxy were fabricated in order to examine apparent interfacial shear strength (IFSS). A dramatic improvement in IFSS over carbon fiber/epoxy composites was observed in the single fiber pull-out tests, but no significant change was shown in the push-out tests. The different IFSS results were provisionally attributed to a change of failure mechanism between the two types of tests, supported by fractographic analysis. KW - Composites KW - Nano tubes KW - Grafting KW - Interface PY - 2008 U6 - https://doi.org/10.1021/cm702782j SN - 0897-4756 SN - 1520-5002 VL - 20 IS - 5 SP - 1862 EP - 1869 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34568 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ho, K.K.C. A1 - Lamoriniere, S. A1 - Kalinka, Gerhard A1 - Schulz, Eckhard A1 - Bismarck, A. T1 - Interfacial behavior between atmospheric-plasma-fluorinated carbon fibers and poly(vinylidene fluoride) N2 - Atmospheric-plasma fluorination was used to introduce fluorine functionalities onto the surface of carbon fibers without affecting their bulk properties. The interfacial adhesion between atmospheric-plasma-fluorinated carbon fibers and poly(vinylidene fluoride) (PVDF) was studied by means of direct wetting measurements and single fiber pullout tests. Measured contact angles of PVDF melt droplets on modified carbon fibers show that short exposure times of carbon fibers to atmospheric-plasma fluorination (corresponding to a degree of surface fluorination of F/C = 0.01 (1.1%)) leads to improved wettability of the fibers by PVDF melts. The apparent interfacial shear strength as a measure of practical adhesion, determined by the single-fiber pullout test, increases by 65% under optimal treatment conditions. The improved practical adhesion is not due to the formation of transcrystalline regions around the fibers or a change of the bulk matrix crystallinity or to an increased surface roughness; it seems to be due to the compatibilization of the interface caused of the atmospheric-plasma fluorination of the carbon fibers. KW - Carbon fibers KW - Fluorination KW - Contact angle KW - Interface KW - Adhesion KW - Surface area KW - Fiber properties PY - 2007 U6 - https://doi.org/10.1016/j.jcis.2007.04.076 SN - 0021-9797 SN - 1095-7103 VL - 313 IS - 2 SP - 476 EP - 484 PB - Elsevier CY - Orlando, Fla. AN - OPUS4-16026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Munz, Martin A1 - Chung, Jae Un A1 - Kalinka, Gerhard ED - Possart, W. T1 - Mapping Epoxy Interphases T2 - 7th European Conference on Adhesion ; 7th EURADH CY - Freiberg, Germany DA - 2004-09-01 KW - Interface KW - Interphase KW - Epoxy KW - Copper (Cu) KW - Polyvinylpyrrolidone (PVP) KW - AFM/SFM KW - DSI KW - EDX/EDS KW - Stiffness KW - Modulus KW - Interdiffusion PY - 2005 SN - 3-527-31263-3 VL - 7 SP - 103 EP - 123 PB - Wiley-VCH CY - Weinheim AN - OPUS4-10894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kalinka, Gerhard A1 - Leistner, André A1 - Hampe, Andreas T1 - Characterisation of the fibre/matrix interface in reinforced polymers by the push-in technique N2 - The push-in test is the only micromechanical test method that is not restricted to artificial fibre/matrix arrangements, but allows the in situ characterisation of interfaces in composites fabricated and stressed under realistic conditions. However, with the application of this method to reinforced polymers some problems arise both in the mathematical model for evaluating test data and in the practical performance of the test. Because in some cases the deformation of the relatively compliant polymeric matrices cannot be neglected, an extension of the existing model is required. For this purpose, the elastic energy of the material around the debonded part of the fibre is estimated and included in the energy-balance analysis. Because of the small diameter of the fibres usually used for reinforcing polymers, a test apparatus was designed which ensures a high positioning accuracy in the xy plane as well as in the z direction. In order to minimise thermal and mechanical influences, the microscope for fibre selection and the force sensor/indenter are directly connected together and the apparatus is designed to be stiff in all components. A solid-state bending joint guarantees very precise control of the axial movement. Three examples of the application of this easy-to-handle and low-cost test apparatus are presented briefly in the paper: assess fibre/matrix combinations, measures to improve the interfacial adhesion and the influence of water on the interface. KW - Interface KW - Test method KW - Characterisation KW - Indentation KW - Push-in PY - 1997 SN - 0266-3538 VL - 57 IS - 8 SP - 845 EP - 851 PB - Elsevier CY - Barking AN - OPUS4-12011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Eckhard A1 - Kalinka, Gerhard A1 - Auersch, W. T1 - Effect of Transcrystallization in Carbon Fiber Reinforced Poly(p/phenylene sulfide) Composites on the Interfacial Shear Strength Investigated with the Single Fiber Pull-Out Test N2 - The effect of transcrystallinity in carbon fiber reinforced poly(p-phenylene sulfide (PPS) composites on the apparent shear strength was investigated with the single fiber pull-out test. Transcrystalline zones around the reinforcing fibers do not seem to improve the adhesion level significantly. Neighbor fibers hinder the formation of the transcrystalline zone and a ductile fracture behavior can be observed. However, the apparent strength level is slightly higher for composites containing such reinforcing neighbor fibers compared with single fiber composite samples. During annealing a brittle interface can be formed in the multifiber composite yielding a higher level of the apparent shear strength. KW - Thermoplaste KW - Kristallisation KW - Transkristallisation KW - Interface KW - Verbundwerkstoffe KW - Pull-out KW - Haftung KW - Adhäsion KW - Reibung PY - 1996 U6 - https://doi.org/10.1080/00222349608220393 SN - 0022-2348 SN - 1525-609X VL - 35 IS - 3-4 SP - 527 EP - 546 PB - Dekker Chemistry CY - New York, NY AN - OPUS4-11987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hampe, Andreas A1 - Kalinka, Gerhard A1 - Meretz, S. A1 - Schulz, Eckhard T1 - An advanced equipment for single-fibre pull-out test designed to monitor the fracture process KW - Verbundwerkstoffe KW - Thermoplaste KW - Adhäsion KW - Reibung KW - Haftung KW - Interface KW - Schubfestigkeit KW - Scherfestigkeit KW - Messmethode PY - 1995 SN - 0010-4361 VL - 26 IS - 1 SP - 40 EP - 46 PB - Butterworth-Heinemann CY - Guildford, Surrey AN - OPUS4-11988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Eckhard A1 - Kalinka, Gerhard A1 - Meretz, S. A1 - Hampe, Andreas T1 - Pull-out of Single Fibres KW - Verstärkungsfaser KW - Verbundwerkstoffe KW - Interface KW - Adhäsion KW - Reibung KW - Haftung KW - Thermoplast PY - 1994 SN - 0945-0084 VL - 84 IS - 5 SP - 25 EP - 26 PB - Hanser CY - München AN - OPUS4-11989 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Eckhard A1 - Kalinka, Gerhard A1 - Meretz, S. A1 - Hampe, Andreas T1 - Einzelfaserauszug - Eine Methode zum Bestimmen der Grenzflächenfestigkeit KW - Verstärkungsfaser KW - Verbundwerkstoffe KW - Interface KW - Adhäsion KW - Reibung KW - Haftung KW - Thermoplast PY - 1994 SN - 0023-5563 VL - 84 IS - 5 SP - 608 EP - 610 PB - Hanser CY - München AN - OPUS4-11994 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -