TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure of fiber reinforced composites under multiaxial stresses on microscale N2 - The failure of composites is initiated by imperfections on microscale. The interface between fiber and matrix is a key parameter concerning failure initiation. In order to get an improved understanding of local failure processes a fracture mechanical analysis of interfacial failure in a composite ply under transverse stresses is performed. The mixed mode energy release rate is calculated. In addition the failure of interfaces under cyclic loading is studied on a single fiber model. The quasistatic debonding process is compared with the interfacial failure under fatigue loading. It is shown that the tan delta can be used as an indicator for the damage propagation. T2 - ICMFF11 CY - Sevilla, Spain DA - 01. 06. 2016 KW - Composites KW - Failure KW - Energy release rate PY - 2016 AN - OPUS4-36746 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Influence of loading rate and loading time on mechanical behaviour of epoxy resins N2 - Epoxy resins are frequently used for advanced fiber reinforced composites applications. Even though the fibers are dominating strength and stiffness of the composites, specifically when loaded in fiber direction, the failure usually initiates in the matrix near or directly at the interface. Especially in plies loaded transverse to the fiber direction, the mechanical behaviour is highly influenced by the mechanical properties of the epoxy matrix. Accordingly the mechanical properties of the matrix are of great importance. T2 - 10th International conference on the mechanics of time dependent materials (MTDM) CY - Paris, France DA - 17. 06. 2016 KW - Viscoelasticity KW - Epoxy resin KW - Loading rate KW - Relaxation KW - Residual strain PY - 2016 AN - OPUS4-36407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure of fiber reinforced composites – role of the matrix behaviour and the interface strength N2 - Failure of fiber reinforced composites initiates at microdefects in the matrix or at the interface. The interface strength is calculated from the stress field directly before crack initiation by nonlinear finite element simulations. Large deformations and plastic material behaviour are taken into account. Microscopical inspections of the fibers after failure show only small regions with adhering matrix material. This indicates that the interface strength is below the matrix strength. T2 - 2nd International Conference on Mechanics of Composites CY - Porto, Portugal DA - 12.07.2016 KW - composites KW - fracture mechanics KW - nonlinear material behaviour PY - 2016 AN - OPUS4-36905 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - The influence of local defects and nonlinear matrix behaviour on the failure process of fiber reinforced composites N2 - The aim of the paper is to analyse the failure process taking place on microscale in fiber reinforced composites. The failure is initiated at microscopical defects presumingly in the interface. The circumferential propagation of interface cracks starting at microdefects in unidirectional plies under transverse loading is studied using a representative volume element. First a linear elastic fracture mechanical analysis of interface cracks in a carbon fiber reinforced epoxy resin is performed by calculating the mixed mode energy release rate using the virtual crack closure method. The influence of the fiber spacing is studied by varying the fiber volume fraction. The total energy release rate rapidly grows after crack initiation indicating an unstable crack propagation. The first phase is dominated by mode I. The mode II energy release rate starts slightly delayed but surpasses the mode I part after a short crack length. By increasing the fiber volume fraction the maximum of the energy release rate shifts to smaller crack angles. T2 - ECCM17 CY - Munich, Germany DA - 27.06.2016 KW - fracture mechanics KW - interface crack KW - plasticity PY - 2016 AN - OPUS4-36906 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - The influence of local defects and nonlinear matrix behaviour on the failure process of fiber reinforced composites N2 - The premise for the development of improved failure criteria for fiber reinforced composites is the understanding of the failure processes on microscale. On microscale the local behaviour of the matrix polymer is crucial. It significantly differs from that found in macroscopic measurements. The present study is focused on the plastic material behaviour of a standard epoxy resin. Local plastic strains are measured in tensile test by using digital image correlation. A multilinear plastic law is implemented by the experimental data. The stress field arising in an idealised representative volume element of a unidirectional ply is analysed by finite element calculations. The change of the stress and strain field due to plastic deformation according to the multilinear plastic law is shown. The change leads to a shift of the critical locations where failure is likely to initiate. In addition, the failure type changes from stress based to strain based failure. The dominant role of the shear strains is shown. T2 - ECCM17 CY - Munich, Germany DA - 27.06.2016 KW - failure mechanisms KW - plasticity KW - micromechanics KW - interfacial stresses KW - local deformation PY - 2016 SN - ISBN 978-3-00-053387-7 SP - 1 EP - 8 CY - München AN - OPUS4-37863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure of fiber reinforced composites under multiaxial stresses on microscale N2 - The failure of composites is initiated by imperfections on microscale. The interface between fiber and matrix is a key parameter concerning failure initiation. In order to get an improved understanding of local failure processes a fracture mechanical analysis of interfacial failure in a composite ply under transverse stresses is performed. The mixed mode energy release rate is calculated. In addition the failure of interfaces under cyclic loading is studied on a single fiber model. The quasistatic debonding process is compared with the interfacial failure under fatigue loading. It is shown that the tan delta can be used as an indicator for the damage propagation. T2 - ICMFF11 CY - Sevilla, Spain DA - 01.06.2016 KW - failure mechanics KW - failure mechanisms KW - multiaxial loading KW - micromechanics PY - 2016 SP - 1 EP - 8 AN - OPUS4-37864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Fracture on microscale of fiber reinforced composites N2 - Failure of composite materials is initiated by fracture processes on microscale, especially by interfacial debonding. Failure processes taking place on microscale are studied by single fiber experiments. This is, single fibers embedded in tensile specimen are loaded under various off-axis angles. Starting at microdefects interface cracks propagate circumferentially as well as longitudinally, depending on the loading angle. In addition, finite element simulations of interfacial crack propagation around single fibers as well as fibers embedded in a hexagonal composite are shown based on linear elastic fracture mechanics. The course of the energy release rate is given in dependence of the fiber volume fraction. T2 - Seminar CY - Imperial College, London, UK DA - 12.10.2016 KW - Composites KW - Fracture surfaces KW - Micromechanics KW - Epoxy resin PY - 2016 AN - OPUS4-37853 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 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure on microscale of epoxy resin and composites - limits of continuum mechanical analysis on micro- and nanoscale N2 - The problems of the limits of continuum mechanics are shown on some examples. The fiber-matrix debonding and subsequent crack propagation in fiber reinforced composites is studied. While Finite Element Analyses predict clear crack surfaces, either following the interface or bridging to the neighbouring fiber forming planes, the actual surfaces are very cliffy. Due to the much larger fracture surfaces and the completely different stress states on the cliffy fracture surfaces the continuum mechanical prediction is far from the actual local behaviour. The phenomenon of local high stresses which re much higher than the macroscopically measured strength of the material is also encountered in general fracture mechanics. The scale dependency of materials is shown on indentation tests conducted on different scales. From a continuum mechanical point of view it makes no difference if the indentation test is performed on a nano-, micro- or macroscale, because it is a matter of self-similarity. However, in nano- or microindentation tests on a pure polymer using e.g. a Berkovic indentor, the extremely high stress concentrations arising at the indentor tip are domination more or less the whole region around the indentor. In case of a macroscopical test, this zone covers only a small part of the material loaded by the indentor. Accordingly, the results of the different test cannot be scaled up. T2 - Second International Symposium on Directions in Damage and Durability of Composite Materials CY - Venedig, Italy DA - 18.06.2016 KW - continuum mechanics KW - fracture mechanics KW - epoxy resin KW - plasticity KW - large deformations PY - 2016 AN - OPUS4-37857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus ED - Thomson, Ole T1 - Characterisation of failure processes of composite plies under transverse loading N2 - For the design of laminates the knowledge of the failure behaviour of plies under multiaxial stresses is a necessary precondition. The strength of plies under multiaxial stresses commonly is determined by standard off-axis tests using fixed clamps. By varying the off axis angle the ratio of shear to normal stresses can be prescribed. However, by preventing the rotation a complex stress field develops which strongly varies with the off axis angle as well. While these effects are not crucial when determining the elastic material parameters since the stress state in the center of the specimen is not far from the ideal uniaxial stress state they have a great influence on the failure behaviour. T2 - ICCM20 CY - Copenhagen, Danmark DA - 19. 07. 2015 KW - debonding KW - composites KW - failure process KW - fracture mechanics KW - energy release rate PY - 2015 UR - www.iccm-central.org/Proceedings/ICCM20proceedings/ VL - 2015 SP - Paper No. 3314-4 page 01 EP - Paper No. 3314-4 page 09 AN - OPUS4-36414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure modes of unidirectional fiber reinforced materials under off-axis loading T2 - ICCS18 - 18th International Conference on Composite Structures CY - Lissabon, Portugal DA - 2015-06-15 PY - 2015 AN - OPUS4-33445 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Characterisation of failure processes of composite plies under transverse loading T2 - ICCM 20 - 20th International Conference on Composite Materials CY - Copenhagen, Denmark DA - 2015-07-19 PY - 2015 AN - OPUS4-34182 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Viscoelastic behaviour and fracture of epoxy resins under mixed mode loading T2 - Thermosets 2015 CY - Berlin, Germany DA - 2015-09-16 PY - 2015 AN - OPUS4-34183 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure processes of fiber reinforced composites under off-axis loading T2 - ICM 12 - 12th International Conference on the Mechanical Behavior of Materials CY - Karlsruhe, Germany DA - 2015-05-10 PY - 2015 AN - OPUS4-33183 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Verfahren zur Messung der Adhäsion zwischen Faser und Matrix - Einfluss der Faserbeschlichtung T2 - Rotorblätter von Windkraftanlagen - 7th Technical Conference CY - Essen, Deutschland DA - 2015-06-23 PY - 2015 AN - OPUS4-33478 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Fracture Processes in Composites under Off-Axis Loading T2 - 28. Workshop Composite Forschung in der Mechanik CY - Paderborn, Deutschland DA - 2015-12-09 PY - 2015 AN - OPUS4-35300 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - MATERIALS NONLINEARITY AND FAILURE ON MICROSCALE T2 - Composite Damage Workshop CY - Vicenza, Italy DA - 2015-09-09 PY - 2015 AN - OPUS4-34452 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - FAILURE MECHANISMS IN FIBER REINFORCED PLASTICS ON MICROSCALE T2 - EUROMAT 2015 CY - Warsaw, Poland DA - 2015-09-21 PY - 2015 AN - OPUS4-34453 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Limits of continuum mechanics in analysing failure processes in fiber reinforced composites on microscale T2 - Composite Damage Workshop VI CY - Gerona, Spain DA - 2014-09-08 PY - 2014 AN - OPUS4-31346 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Limits in the determination of mechanical properties of composites by off-axis tests T2 - European SAMPE Conference CY - Paris, France DA - 2014-03-10 PY - 2014 AN - OPUS4-30337 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Limits in the determination of mechanical properties of composites by off-axis tests N2 - Off-axis tests are widely used for the determination of the anisotropic mechanical properties of composite materials, this is, the longitudinal E-modulus and the strength. The mechanical properties are evaluated from the test data under idealising assumptions such as homogeneity of the material as well as a homogeneous stress distribution. In real off-axis tests, however, significant deviations from the idealising assumptions are present. The reduction of the accuracy of the results strongly depends on the off-axis angle. In this paper a series of off-axis tests is analysed. The stresses on potential failure plane are calculated by finite element analyses. By varying the geometrical parameters it is shown how small deviations from the ideal case influence the measured elastic constants and the strength. Especially at low off-axis angles the mechanical properties strongly vary with the angle. In addition, fracture surfaces for different shear/normal stress combinations are studied and typical phenomena are identified. T2 - SEICO 14 - SAMPE Europe 35th International conference and forum CY - Paris, France DA - 10.03.2014 KW - Off-axis test KW - Composites KW - Strength KW - E-modulus PY - 2014 SN - 978-90-821727-0-6 IS - Session 5B SP - 293 EP - 300 AN - OPUS4-30376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Fracture mechanics on microscale of composite plies under transverse loading T2 - ECCM 16 - 16th European Conference on Composite Materials CY - Seville, Spain DA - 2014-06-22 PY - 2014 AN - OPUS4-31012 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Interface cracks on microscale in composites T2 - ECF20 - 20th European Conference on Fracture CY - Trondheim, Norway DA - 2014-06-30 PY - 2014 AN - OPUS4-31017 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Limits of the continuum mechanical treatment of problems on micro- and nanoscale. T2 - COMPO 2014 CY - Rehovot, Israel DA - 2014-04-28 PY - 2014 AN - OPUS4-30639 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Khater, Mohamed Essam A1 - Elabshihy, Karim T1 - Identification of material properties of epoxy resins by micro- and nanoindentation tests T2 - GUC Workshop Materials Research and Industry CY - Berlin, Germany DA - 2014-05-13 PY - 2014 AN - OPUS4-30663 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Fracture of fiber reinforced materials under off-axis loading N2 - The failure behaviour of unidirectional plies tested under off-axis loading is studied. The stress distribution occurring in standard off-axis tests is briefly discussed. The different failure modes, this is, pure fiber breakage, pure inter fiber failure as well as a superposition of both is analysed based on test data and fracture patterns. The large difference of the failure load depending on the failure mode at small off-axis angles is studied by comparison of a short and a long 3° off-axis angle specimen. T2 - APCF/SIF-2014 - Asian-Pacific conference on fracture and strength / International conference on structural integrity and failure - Recent advances in structural integrity analysis CY - Sydney, Australia DA - 09.12.2014 KW - Debonding KW - Off-axis strength KW - Fracture mechanics KW - Composite materials PY - 2014 SN - 978-0-08-100203-2 SN - 978-0-08-100225-4 SP - 351 EP - 355 PB - Elsevier AN - OPUS4-32324 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 - TY - CONF A1 - Marotzke, Christian T1 - Fracture mechanical analysis of fiber-matrix debonding in fiber reinforced materials T2 - IMP Workshop Composites@IMP CY - Villeurbanne, France DA - 2014-03-27 PY - 2014 AN - OPUS4-30470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Fracture mechanics on microscale of composite plies under transverse loading N2 - The energy release rate delivered during the debonding of a fiber inside a composite ply is analysed using a representative volume element. Two different fiber volume fractions are studied by a linear elastic fracture mechanical analysis by using the finite element method. The dependency of the mixed mode energy release rate on the length of the crack increment is analysed. It is shown that the same general behaviour found in case of a straight Interface crack is valid also for circular cracks. As a result the discrimination of the energy release rate into mode I and mode II portions is questionable. T2 - ECCM16 - 16th European conference on composite materials CY - Seville, Spain DA - 22.06.2014 KW - Composite KW - Interface crack KW - Energy release rate KW - Mode mixity PY - 2014 SN - 978-84-616-9798-4 SP - 0472-1 EP - 0472-8 AN - OPUS4-31133 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Micromechanics of First Ply Failure in Composite Laminates T2 - 17th International Conference on Composite Structures (ICCS17) CY - Oporto, Portugal DA - 2013-06-17 PY - 2013 AN - OPUS4-28676 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Fracture mechanics of fiber-matrix interfaces in composites under transverse loading T2 - International Conference on Fracture and Damage Mechanics (FDM) CY - Alghero, Italy DA - 2013-09-17 PY - 2013 AN - OPUS4-29121 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Fracture mechanics of composite plies on microscale N2 - The determination of the strength and the failure behaviour of fiber reinforced composites is a complex task. This is mainly due to the anisotropy and the inhomogeneiety of the material on the microscale. The strength or the fracture toughness of the interface between fiber and matrix is the key factor controlling the failure process on microscale, especially under loads transverse to the fiber axes. The ultimate failure of a laminate is a complex process consisting of a large number of different subprocesses. Due to its highly dynamic nature on one hand and the microscopical scale on the other it is not possible to observe the ultimate failure directly or even to analyse it theoretically. However, long before ultimate failure occurs a large number of elementary failure processes take place in a rather static manner or at least at low crack Propagation speed. T2 - ICCM19 - 19th International conference on composite materials CY - Montreal, Canada DA - 28.07.2013 KW - Fracture mechanics KW - Laminate KW - Interface KW - Debonding KW - Energy release rate PY - 2013 SP - 5354 EP - 5363 AN - OPUS4-28913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Fracture mechanics of composite plies on microscale T2 - International Conference on Composite Materials - ICCM19 CY - Montreal, Canada DA - 2013-07-29 PY - 2013 AN - OPUS4-28876 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure of epoxy resins and composites under multiaxial loads N2 - The failure of laminates is originated in plies loaded transverse to the fiber direction, e.g. in the 90° ply of a cross ply laminate. The initiation of failure is due to the debonding of individual fibers At some point the interface crack kinks into the matrix and propagates towards the inter-face of the neighbouring fiber. The cracks then continue propagating through the full ply. The interface failure obviously is the dominating process of the failure of plies in high fiber volume fraction composites. Several authors investigated the interfacial crack propagation on model systems. First, Varna and Paris studied the debonding process on a single fiber embedded in pure matrix under transverse ten-sion by fracture mechanical analyses. Correa and Paris performed experimental as well as numerical studies by calculating the mixed mode energy release rate under different loading conditions. These analyses were extended to fibers surrounded by a composite material by the present authors. Among others, Comninou as well as Sun and Jih have shown that the separation into a mode I and mode II energy release rate is not universal but the mixed mode ratio depends on the length of the crack increment. Comninou developed a solution of an interface crack between dissimilar media which reveals the even a small contact zone is found near the crack tip. As a result, the mode I part of the energy release rate vanishes because no opening of the crack takes place. The contact zone, however, is extremely small. If these mathematical phenomena, however, are relevant for physical problems is not verified. T2 - Thermosets 2013 - 3rd International conference on thermosets CY - Berlin, Germany DA - 18.09.2013 KW - Fracture mechanics KW - Laminate KW - Interface KW - Debonding KW - Energy release rate PY - 2013 SN - 978-3-00-043394-8 SP - 83 EP - 86 AN - OPUS4-29164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Failure of Epoxy Resins and Composites under Multiaxial Loads T2 - Thermosets 2013 CY - Berlin, Germany DA - 2013-09-19 PY - 2013 AN - OPUS4-29137 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus ED - Milazzo, A. ED - Aliabadi, M. H. T1 - Fracture mechanics of fiber-matrix interfaces in composites under transverse loading T2 - FDM 2013 - 12th International conference on fracture and damage mechanics CY - Sardinia, Italy DA - 2013-09-17 KW - Fracture mechanics KW - Laminate KW - Interface KW - Debonding KW - Energy release rate PY - 2013 SN - 978-3-03785-830-1 SN - 1013-9826 SN - 1662-9809 SN - 1662-9795 SP - 433 EP - 436 PB - Trans Tech Publications AN - OPUS4-29142 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 T2 - 12th SAMPE SEICO Conference CY - Paris, France DA - 2012-03-26 PY - 2012 AN - OPUS4-25699 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Interfacial failure in composites under off-axis loading T2 - MCM 2012 Conference CY - Riga, Latvia DA - 2012-05-29 PY - 2012 AN - OPUS4-25957 LA - deu 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 circumferential propagation of an interface crack in a hexagonal fiber array is studied. The analysis 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 closes. 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 - 2012-03-26 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 T2 - 15th European Conference on Composite Materials (ECCM15) CY - Venice, Italy DA - 2012-06-25 PY - 2012 AN - OPUS4-26127 LA - deu 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 - 2012-06-24 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 T1 - Influence of the Interface on the Failure of Composites under Off-Axis Loading T2 - Interface 21, Kyoto Institute of Technology CY - Kyoto, Japan DA - 2012-08-06 PY - 2012 AN - OPUS4-26471 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Failure criterion based on adhesion for composites under transverse loading T2 - Thermosets 2011 Conference CY - Berlin, Germany DA - 2011-09-21 PY - 2011 AN - OPUS4-24384 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Interfacial Failure in Composites under Transverse Loading T2 - 15th Meeting on Composites Materials and Structures CY - Haifa, Israel DA - 2011-11-15 PY - 2011 AN - OPUS4-24808 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Failure Criteria for Fiber Reinforced Materials based on the Interface Strength T2 - ICM11 - International Conference on the Mechanical Behaviour of Materials CY - Como, Italy DA - 2011-06-05 PY - 2011 AN - OPUS4-23806 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Failure criterion based on adhesion for composites under transverse loading N2 - The failure of laminates usually is initiated by the failure of the plies with the maximum transverse stresses. The failure of those plies generally reduces the load carrying capability of the laminate, even though they carry only a small part of the external load. The analysis of failure under off-axis stresses accordingly is essential for the prediction of the strength of laminates. This is taken into account in the "mechanisms based failure criteria" e.g. by Puck. Most of these inter fiber failure criteria are not based on the micromechanics of the failure process but on prescribed stress interaction functions. The failure of plies under transverse loading obviously is governed by the bond strength between fiber and matrix fiber. The interfacial debonding was studied e.g. by Paris et al. and Corea et al.. The bond strength between fiber and matrix usually is measured by using micromechanical tests e.g. pull-out, push-out or fragmentation tests. Stress analyses as well as fracture mechanical analyses show that the interfacial failure over a large range is dominated by shear stresses (Kim and Mai, Pisanova et al, Marotzke and Qiao). The stress distribution arising in those experiments however differs from the stresses acting in a lamina under transverse loading. In transverse failure of a lamina, radial stresses as well as shear stresses are dominating the failure process of the interface. In addition longitudinal shear stresses are present. Experimental work concerning off-axis loading of single fibers was done e.g. by Tandon and Kim and by Ogihara and Koyanagi. They studied the influence of the fiber alignment by using a specimen in form of a cruciform with skew wings. T2 - Thermosets 2011 - From monomers to components - 2nd international conference on thermosets CY - Berlin, Germany DA - 21.09.2011 KW - Composites KW - Strength KW - Adhesion KW - Fracture mechanics PY - 2011 SN - 978-3-8396-0312-3 SP - 86 EP - 88 PB - Fraunhofer Verlag CY - Berlin AN - OPUS4-26451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Adhäsion zwischen Faser und Matrix - Schlüssel zu leistungsfähigen Verbundwerkstoffen T2 - DVS - 50 Jahre Kleb-, Gießharz und Laminiertechnik, BAM CY - Berlin, Germany DA - 2011-01-21 PY - 2011 AN - OPUS4-23073 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Basan, Ricardo T1 - Micromechanics Based Failure Analysis of Laminates under Off-axis Loading T2 - ICCM-18 - International Conference on Composite Materials CY - Jeju, South Korea DA - 2011-08-21 PY - 2011 AN - OPUS4-24195 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Strength of Composite Structural Parts - Role of Fiber/Matrix Interface T2 - SAMPE-SEICO Conference CY - Paris, France DA - 2011-03-28 PY - 2011 AN - OPUS4-23462 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Strength of composite structural parts - role of the fiber/matrix interface N2 - The strength of laminates distinctly depends on the transverse strength of the laminas. The transverse failure is dominated by the adhesion between fiber and matrix. Usual strength criteria however do not take into account the adhesive strength explicitly. The determination of the interface strength is performed on the micromechanical scale using single fiber specimens. The fibers are loaded under off-axis loading while the debonding is monitored under a microscope. The stresses acting in the Interface are calculated by finite element analyses. It is found that for off-axial angles up to 35° interfacial debonding is the dominant failure mode while fiber breakage takes place at lower angles. The occurrence of fiber breakage and debonding under off-axis loading shows that the restriction to two potential failure planes - perpendicular or parallel to the fibers - as applied in common failure criteria has to be put in question. T2 - SEICO 11 - SAMPE Europe - 32nd International technical conference CY - Paris, France DA - 28.03.2011 KW - Composites KW - Strength KW - Adhesion PY - 2011 SN - 978-3-9523565-3-1 IS - Session 3B SP - 250 EP - 257 AN - OPUS4-23680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Basan, Ricardo T1 - Micromecanics based failure analysis of laminates under off-axis loading N2 - The debonding of a fiber in a glass fiber / epoxy composite under transverse loading is studied. The stress field in the interface as well as the energy release rate are analysed for two fiber volume fractions. The circumferential propagation of an Interface crack starting at the center of a fiber which is located within a hexagonal fiber array is studied. The analysis is performed by a finite element Simulation under plane stress conditions. Two fiber volume fractions are considered, this is 30% and 70%. The stress distribution before and during crack propagation is calculated for different stages of the crack. The crack opens by dominating tensile stresses in the first phase while it closes when propagating along the interface. The total energy release rate as well as the mode I and mode II parts are calculated. In the first phase the crack is driven by an increasing mode I energy release rate, indicating an unstable crack propagation. Then the mode II energy release rate increases rapidly and dominates the debonding process while the mode I part decreases and finally vanishes. Subsequently also the mode II part decreases, indicating stable crack propagation. In the last phase the crack becomes unstable again due to a strongly increasing mode I energy release rate. During the debonding process a remarkable change the mode ratio takes place. The main features of the debonding process are similar for low and high fiber volume fraction. In case of the high fiber content, however, the mode I part is more pronounced and the maximum of the total energy release rate is shifted to lower crack angles. T2 - ICCM 18 - 18th International conference on composite materials CY - Jeju Island, Korea DA - 21.08.2011 KW - Composite Materials KW - Interface Crack KW - Failure Analysis KW - Adhesion PY - 2011 IS - T35-3-IF2032 SP - 1 EP - 6 AN - OPUS4-24252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Influence of the interface on the strength of fiber reinforced polymers N2 - The debonding of fibers under mixed-mode loading is studied on model composites containing fibers with different orientations with respect to the loading direction. The spacing of the fibers is large, accordingly no significant fiber interaction takes place. For any fiber orientation, interfacial debonding occurs, even though at different load levels. Only for the low off-axis angle, additional fiber fracture is found. Using a rectangular specimen, the interface crack starts at the edges propagating into the center at low speed. In the first phase, only the central part of the interface debonds. After the whole fiber is debonded, the crack propagates in circumferential direction. The superimposition of fiber breakage and debonding shows that the restriction of two potential failure planes - perpendicular or parallel to the fibers - has to be put in question. T2 - 14th European conference on composite materials CY - Budapest, Hungary DA - 2010-06-07 KW - Strength KW - Composites KW - Crack propagation PY - 2010 IS - Paper 708-ECCM14 SP - 1 EP - 10 AN - OPUS4-21278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Influence of the interface on the strength of fiber reinforced polymers T2 - 14th European Conference on Composite Materials, ECCM 14 CY - Budapest, Hungary DA - 2010-07-07 PY - 2010 AN - OPUS4-21264 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - The interface strength - key to physically based failure criterion for composites T2 - IIMM 2010 Conference, Interfaces and Interphases in Multicomponent Materials CY - Sheffield, England DA - 2010-09-01 PY - 2010 AN - OPUS4-21879 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Bohse, Jürgen A1 - Kalinka, Gerhard T1 - Local failure processes in fiber reinforced polymers T2 - International Conference on Composite Materials (ICCM17) CY - Edinburgh, Scotland DA - 2009-07-27 PY - 2009 AN - OPUS4-18372 LA - deu 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 - CONF A1 - Marotzke, Christian A1 - Kalinka, Gerhard T1 - Interface Faser-Matrix - welche Rolle spielt das Interface bei der Festigkeit von Faserverbundwerkstoffen T2 - 15. Nationales SAMPE Symposium, BAM CY - Berlin, Germany DA - 2009-02-18 PY - 2009 AN - OPUS4-19016 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Kalinka, Gerhard T1 - Failure Processes in Fiber Reinforced Polymers T2 - Thermosets 2009 CY - Berlin, Germany DA - 2009-09-30 PY - 2009 AN - OPUS4-20057 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Festigkeit von Faserverbundwerkstoffen - vom Interface zum Werkstoff T2 - Kolloquium der Fraunhofer-Einrichtung für Polymermaterialien und Composite PYCO und Brandenburgische Technische Universität Cottbus Lehrstuhl Polymermaterialien CY - Teltow, Germany DA - 2008-12-09 PY - 2008 AN - OPUS4-18371 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Kalinka, Gerhard T1 - Microscopical failure processes in fiber reinforced polymers - Mechanical aspects of the adhesion between fiber and matrix T2 - 11th International Conference on Mechanics and Technology of Composite Materials CY - Sofia, Bulgaria DA - 2006-10-02 PY - 2006 AN - OPUS4-13239 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Kalinka, Gerhard ED - Zachariev, G. T1 - Microscopical Failure Processes in Fiber Reinforced Polymers - Mechanical Aspects of the Adhesion between Fiber and Matrix T2 - 11th International Conference on Mechanics and Technology of Composite Materials CY - Sofia, Bulgaria DA - 2006-10-02 KW - Composite materials KW - Failure process KW - Adhesion PY - 2006 SP - 37 EP - 42 PB - Bulgarian Academy of Sciences CY - Sofia AN - OPUS4-14027 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Trappe, Volker T1 - Mikrorissbildung als Sonde für die Beanspruchungsgeschichte von Faserverbundwerkstoffen T2 - Composite Forschung in der Mechanik CY - Paderborn, Germany DA - 2004-12-14 PY - 2004 AN - OPUS4-5883 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Characterization of the interface strength and polymer composites T2 - 7th International Conference on Interfacial Phenomena in Composite Materials - IPCM 2001 CY - Arcachon, France DA - 2001-09-11 PY - 2001 AN - OPUS4-5949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Rissphänomene in Modell Composites T2 - 14. Workshop "Composite Forschung in der Mechanik" CY - Paderborn, Germany DA - 2001-12-03 PY - 2001 AN - OPUS4-5950 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Analysis of fiber, matrix and interface fracture in composites and fragmentation tests T2 - 9th ECCM ; 9th [European Conference on Composite Materials] CY - Brighton, England, UK DA - 2000-06-04 KW - Interface crack KW - Energy release rate KW - Fracture mechanics KW - Debonding KW - Thermal stresses KW - Friction KW - Finite element method KW - FEM PY - 2000 N1 - Serientitel: CF / IOM Communications Ltd – Series title: CF / IOM Communications Ltd IS - 11 SP - 1 EP - 10(?) PB - IOM Communications CY - London AN - OPUS4-6808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Bruchmechanische Analyse des Grenzflächenversagens bei Einzelfaser Pull-out und Fragmentation Tests T2 - DVM-Tagung Bruchvorgänge CY - Berlin, Germany DA - 2000-02-22 PY - 2000 AN - OPUS4-5945 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Analysis of fiber, matrix and interface fracture in composites and fragmentation tests T2 - ECCM 9 Conference CY - Brighton, England DA - 2000-06-04 PY - 2000 AN - OPUS4-5946 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Hampe, Andreas A1 - Rudolph, Hans-Volker A1 - Ivers, Heinz T1 - Detektion von Schädigungen in Faserverbundwerkstoffen mittels Röntgenrefraktion T2 - Tagung: Compositeforschung in der Mechanik CY - Paderborn, Germany DA - 2000-12-04 PY - 2000 AN - OPUS4-5947 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Hampe, Andreas T1 - Fiber, matrix and interface fracture in composites T2 - Gordon Research Conference on Composites CY - Ventura, CA, USA DA - 2000-01-09 PY - 2000 AN - OPUS4-5948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marotzke, Christian A1 - Hampe, Andreas A1 - Qiao, Linan T1 - Influence of the Interface Strenght on Local Failure Processes in Fiber Reinforced Composites T2 - 12th International Conference on Composite Materials ; 12th ICCM Europe CY - Paris, France DA - 1999-07-05 KW - Interface crack KW - Energy release rate KW - Fracture mechanics KW - Debonding KW - Thermal stresses KW - Friction KW - Finite element method KW - FEM PY - 1999 SN - 2-9514526-2-4 IS - 423 CY - Paris AN - OPUS4-6809 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Hampe, Andreas A1 - Qiao, Linan T1 - Fracture mechanical analysis of failure in micromechanical tests T2 - IPCM '99 Conference CY - Berlin, Germany DA - 1999-09-08 PY - 1999 AN - OPUS4-5941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Bruchmechanische Analyse mikromechanischer Tests - numerische Modellierung und Experimente T2 - Seminar am IPF CY - Dresden, Germany DA - 1999-03-29 PY - 1999 AN - OPUS4-5942 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Elementare Versagensprozesse in Faserverbundwerkstoffen T2 - Workshop: Composite Forschung in der Mechanik CY - Paderborn, Germany DA - 1999-11-29 PY - 1999 AN - OPUS4-5943 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Hampe, Andreas A1 - Qiao, Linan T1 - Influence of the interface strength on local failure process in fiber reinforced composites T2 - ICCM-12 Conference CY - Paris, France DA - 1999-07-05 PY - 1999 AN - OPUS4-5944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marotzke, Christian A1 - Qiao, Linan ED - Visconti, I. T1 - Fracture Mechanical Analysis of Fragmentation Pull-Out Tests T2 - 8th European Conference on Composite Materials (ECCM-8) CY - Naples, Italy DA - 1998-06-03 PY - 1998 SN - 1-85573-377-3 VL - 4 SP - 443 EP - 450 PB - Woodhead Publishing Ltd CY - Cambridge AN - OPUS4-6807 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Analyse von Grenzflächenrissen in Faserverbundwerkstoffen T2 - 30. Tagung des DVM-Arbeitskreises Bruchvorgänge CY - Dresden, Deutschland DA - 1998-02-17 PY - 1998 SN - 0943-3473 IS - 230 SP - 459 EP - 468 PB - DVM CY - Berlin AN - OPUS4-6376 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Measurement and theoretical analysis of the interfacial toughness by micromechanical experiments, Part II T2 - Gordon Research Conference on Composites CY - Ventura, CA, USA DA - 1998-01-04 PY - 1998 AN - OPUS4-5934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Analyse von Grenzflächenrissen in Faserverbundwerkstoffen T2 - DVM-AK Bruchvorgänge CY - Dresden, Germany DA - 1998-02-18 PY - 1998 AN - OPUS4-5935 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Fracture mechanical analysis of fragmentation and pull-out tests T2 - Proceedings of ECCM-8 CY - Naples, Italy DA - 1998-06-03 PY - 1998 AN - OPUS4-5936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Ausbreitung von Mikrorissen in Faserverbundwerkstoffen T2 - Composite Forschung in der Mechanik 11 CY - Paderborn, Germany DA - 1998-12-08 PY - 1998 AN - OPUS4-5937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hampe, Andreas A1 - Marotzke, Christian T1 - The Energy Release Rate of the Fiber/Polymer Matrix Interface: Measurement and Theoretical Analysis PY - 1997 SN - 0731-6844 SN - 1530-7964 VL - 16 IS - 4 SP - 341 EP - 352 PB - Technomic Publ. Co. CY - Westport, Conn. AN - OPUS4-6827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marotzke, Christian A1 - Hampe, Andreas ED - Scott, M. T1 - Fracture Mechanical Analysis of Pull-out and Fragmentation Tests T2 - 11th International Conference on Composite Materials CY - Gold Coast, Queensland, Australia DA - 1997-07-14 PY - 1997 SN - 1-85573-350-1 SP - V863 EP - V872 PB - Woodhead CY - Cambridge AN - OPUS4-6828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marotzke, Christian ED - Rossmanith, H.-P. T1 - Analysis of singularities and interfacial crack propagation in micromechanical tests T2 - 1st International Conference on Damage and Failure of Interfaces (DFI 1) CY - Vienna, Austria DA - 1997-09-22 PY - 1997 SN - 90-5410-899-1 SP - 365 EP - 372 PB - Balkema CY - Rotterdam AN - OPUS4-6829 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Interfacial Crack Propagation arising in Single-Fiber Pull-Out Tests PY - 1997 SN - 0266-3538 VL - 57 SP - 887 EP - 897 PB - Elsevier CY - Barking AN - OPUS4-6830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Hampe, Andreas T1 - Fracture Mechanical Analysis of Pull-Out and Fragmentation Tests T2 - ICCM-11 - 11th International Conference on Composite Materials CY - Gold Coast, Australia DA - 1997-07-14 PY - 1997 AN - OPUS4-5923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Energy Release Rate in Pull-out and Fragmentation Tests T2 - IPCM '97 CY - Eger, Hungary DA - 1997-09-01 PY - 1997 AN - OPUS4-5924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Analysis of singularities and interfacial crack propagation in micromechanical tests T2 - DFI-1 CY - Vienna, Austria DA - 1997-09-22 PY - 1997 AN - OPUS4-5925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Rissausbreitung in Faser-Matrix-Grenzflächen T2 - DVM AG (Mixed-Mode Probleme) CY - Zittau, Germany DA - 1997-11-21 PY - 1997 AN - OPUS4-5926 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Singularities and Interface Cracks in Micromechanical Tests T2 - 10. Workshop Composite Forschung in der Mechanik CY - Paderborn, Germany DA - 1997-12-09 PY - 1997 AN - OPUS4-5927 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 - GEN A1 - Marotzke, Christian A1 - Qiao, Linan ED - Bader, M. T1 - Determination of the interfacial toughness using micromechanical tests T2 - 7th European Conference on Composite Materials (ECCM-7) CY - London, England, UK DA - 1996-05-14 PY - 1996 SN - 1-85573-304-8 SP - 17 EP - 22 PB - Woodhead Publishing Ltd CY - Cambridge AN - OPUS4-6826 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Determination of the interfacial toughness using micromechanical tests T2 - ECCM-7, Seventh European Conference on Composite Materials CY - London, England DA - 1996-05-14 PY - 1996 AN - OPUS4-5918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Qiao, Linan T1 - Interfacial crack propagation with friction arising in single fiber pull-out tests T2 - ICCI-VI - The Sixth International Conference on Composite Interfaces CY - Tel Aviv, Israel DA - 1996-05-05 PY - 1996 AN - OPUS4-5919 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Vergleich der Energiefreisetzungsrate bei mikromechanischen Versuchen T2 - Composite Forschung in der Mechanik CY - Paderborn, Germany DA - 1996-12-03 PY - 1996 AN - OPUS4-5920 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hampe, Andreas A1 - Marotzke, Christian T1 - The fracture toughness of the glass fibre/polymer matrix interface: measurement and theoretical analysis T2 - The fracture toughness of the glass fibre/polymer matrix interface: measurement and theoretical analysis CY - Guildford, England, UK DA - 1995-03-27 PY - 1995 CY - Guildfort AN - OPUS4-6823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hampe, Andreas A1 - Marotzke, Christian T1 - The energy release rate of the fiber/polymer matrix interface: measurement and theoretical analysis PY - 1995 SP - 326 EP - 335 PB - Technomic Publ. CY - Lancaster AN - OPUS4-6824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marotzke, Christian A1 - Hampe, Andreas T1 - Micromechanics of the interface in polymer composites capabilities and limitations of the common test methods T2 - 10th International Conference on Composite Materials CY - Quebec, Canada DA - 1995-05-08 PY - 1995 SN - 1-566-76313-4 VL - 6 SP - 517 EP - 524 PB - Technomic Publ. CY - Lancaster, Pa. AN - OPUS4-6825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Hampe, Andreas T1 - Micromechanics of the interface in polymer composites-capabilities and limitations of the common test methods T2 - ICCM10 CY - Whistler, Canada DA - 1995-08-12 PY - 1995 AN - OPUS4-5912 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian T1 - Theoretical analysis of the fracture process arising in single fiber pull-out tests T2 - IPCM4 CY - Eindhoven, Netherlands DA - 1995-09-11 PY - 1995 AN - OPUS4-5913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -