TY - JOUR A1 - Hampe, Andreas A1 - Marotzke, Christian T1 - Experimental Results of a Pull-Out Test Performed with Single- and Multi-Fiber Samples N2 - Widely-used methods for characterising the fibre/matrix interface in polymeric composites are the fragmentation test and the droplet test as a special kind of the single-fibre pull-out test. A severe disadvantage of these tests is that non-realistic model samples are investigated which contain only one fibre in the matrix. In order to obtain data about the effect of the different residual stress situations for fibres in such samples and in composites, pull-out tests of E-glass fibres in polystyrene and polycarbonate are performed using samples, where the investigated fibre is surrounded by 0 to 3 other near fibres. Neighbouring fibres can increase the pull-out forces by a factor of three and the interfacial toughness by a factor of four. This has to be taken into account, if the tests are performed not only for comparison reasons but for measuring interface properties. KW - Interface KW - Fiber pull-out KW - Residual stress KW - Fracture toughness KW - Friction PY - 2002 DO - https://doi.org/10.1080/00218460210381 SN - 0021-8464 SN - 1545-5823 VL - 78 IS - 2 SP - 167 EP - 187 PB - Gordon & Breach CY - New York, NY AN - OPUS4-1975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marotzke, Christian A1 - Qiao, Linan ED - Bader, M. T1 - Determination of the interfacial fracture toughness using micromechanical tests T2 - 7th European Conference on Composite Materials (ECCM-7) CY - London, England, UK DA - 1996-05-14 KW - Micromechanik KW - Grenzfläche KW - Bruch KW - Finite-Elemente-Methode PY - 1996 SN - 1-85573-304-8 VL - 2 SP - C609-1-C609-6 PB - Woodhead Publishing Ltd CY - Cambridge AN - OPUS4-655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Basan, Ricardo T1 - Fracture toughness of fiber reinforced composites under transverse loading N2 - The debonding of a fiber in a glass fiber / epoxy composite under transverse loading is analysed. The stress field in the interface as well as the energy release rate are analysed for various fiber volume fractions between 5% and 85%. The circumferen-tial propagation of an interface crack in a hexagonal fiber array is studied. The analy-sis is performed by a finite element simulation under plane stress conditions. The stress distribution during crack propagation is calculated for different crack phases. The crack starts under dominating mode I stresses. After propagating some 60° the mode II part reaches a maximum while the mode I part vanishes and the crack clos-es. The further crack propagation is driven by mode II stresses only. In addition, the stress transfer into the neighbouring fibers during debonding is studied. T2 - SAMPE Europe 33rd International conference SEICO 12 CY - Paris, France DA - 26.03.2012 KW - Composites KW - Fracture toughness KW - Interface PY - 2012 SN - 978-3-9523565-5-5 IS - Session 5B / Paper 13 SP - 309 EP - 314 AN - OPUS4-26070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure of composites under transverse loading - a fracture mechanical approach N2 - The failure of fiber reinforced composites under transverse loading is investigated on a representative volume element. The volume element is composed of a twelve fiber hexagonal array. The debonding of the central fiber is studied under transverse shear as well as under transverse compressive loading by calculating the mode I and mode II part of the energy release rate. The initiation of failure is assumed to take place at the location of maximum tensile or maximum shear stresses, respectively. In order to determine the failure initiation point, the stress field in the interface before crack initiation is calculated. T2 - ECCM15 - 15th European conference on composite materials CY - Venice, Italy DA - 24.06.2012 KW - Composites KW - Failure criteria KW - Fracture KW - Debonding KW - Fracture toughness KW - Interface PY - 2012 SN - 978-88-88785-33-2 SP - 1 EP - 7 AN - OPUS4-26450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Nonlinear time dependent behaviour of epoxy resins N2 - The nonlinear behaviour of epoxy resins is studied on standard tensile tests. A strain field measurement system is applied (Aramis) in order to monitor local strains. The residual strain is measured by recovering the specimens for up to 68 hours after unloading. The time span the specimen is exposed to load has a large influence on the creeping process and the residual strain after recovering. This is studied by comparison of instantaneous unloading with keeping the specimen under permanent load for thirty minutes. It is shown that moderate differences in the initial strain can lead to large differences in the creep behaviour as well as in the residual strain. T2 - 37th Risø International Symposium on Materials Science CY - Risø, DK DA - 05.09.2016 KW - composites KW - epoxy resin KW - viscoelasticity KW - plasticity PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-378552 DO - https://doi.org/10.1088/1757-899X/139/1/012035 SN - 1757-8981 VL - 139 SP - Article 012035, 1 EP - 8 PB - IOP Publishing CY - London AN - OPUS4-37855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prewitz, Marc A1 - Müller, Ralf A1 - Marotzke, Christian A1 - Holtappels, Kai T1 - Characterization of glass capillary storage modules considering permeability and mechanical stress via finite elements N2 - Glass capillaries are potential candidates for long term hydrogen storage under high pressure. Burst pressure strongly drops with surface damaging, a polymer coating is needed. The aim is to study stress distribution within single coated glass capillaries sealed to metal fittings T2 - 88. Glastechnische Tagung DGG – ACerS GOMD 2014 CY - Aachen, Germany DA - 25.05.2014 KW - Burst test KW - Hydrogen storage KW - Polymer coating PY - 2014 AN - OPUS4-35784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -