TY - GEN A1 - Bohse, Jürgen A1 - Krietsch, Torsten A1 - Chen, J. H. A1 - Brunner, A. J. ED - Williams, J. G. ED - Pavan, A. T1 - Acoustic emission analysis and micro-mechanical interpretation of mode I fracture toughness tests on composite materials N2 - Mode I fracture toughness tests on Double Cantilever Beam specimens from carbon-fibre and glassfibre reinforced polymer-matrix composites were monitored with Acoustic Emission (AE) and loaddisplacement traces and delamination lengths were recorded. AE characterized the kinetics of delamination propagation. The progress of AE activity and AE intensity with load and AE source location plots are used to determine the delamination onset on the microscopic and macroscopic scale. Energy dissipating processes initiated in the damage zone near the delamination tip. Low Interface adhesion results in lower debonding stresses and larger damage zones compared with composites with good adhesion. Time-dependent linear location of AE sources yields the average length of the damage zone and the average speed of delamination propagation. Parameter analysis has been used empirically for identifying AE source mechanisms. A new Classification Software for transient AE waveforms permits identification of the source mechanism of individual AE signals. A micro-mechanical fracture model based on the AE results describes the contributions of microscopic matrix and Interface mechanisms to the interlaminar fracture energy. T2 - 2nd ESIS TC4 Conference on Fracture of Polymers, Composites, and Adhesives CY - Les Diablerets, Switzerland DA - 13.09.1999 KW - Mode I KW - DCB test KW - Acoustic emission analysis KW - Polymer composites KW - Damage zone KW - Micro-mechanisms KW - Interface adhesion KW - Micro-mechanical fracture model KW - Interlaminar fracture energy PY - 2000 SN - 0-08-043710-9 SN - 1566-1369 N1 - Serientitel: ESIS publication – Series title: ESIS publication IS - 27 SP - 15 EP - 26 PB - Elsevier CY - Amsterdam AN - OPUS4-4153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bohse, Jürgen T1 - Acoustic emission characteristics of micro-failure processes in polymer blends and composites N2 - Acoustic emission (AE) characteristics of micro-failure processes in HDPE/PP blends with and without compatibilizer, single-fibre composites (glass/epoxy, carbon/epoxy, glass/polycarbonate) and unidirectionally reinforced multi-fibre composites (glass/polypropylene) were studied. For blends, the number and the elastic fracture energy release of micro-failure processes are theoretically approximated and correlated with the number of AE signals and the AE energy. A qualitative correlation of the mechanical energy released from fibre/matrix debonding and fibre-fracture processes in single-fibre pull-out experiments with the measured AE energy is demonstrated. For the single-fibre fragmentation of glass fibres and carbon fibres, a quantitative approximation of the AE amplitudes at locations of the fragmentation sources is achieved. A new method for the selection of single transient acoustic emissions and the classification of failure mechanisms in composites is introduced. Selected emissions are classified into matrix cracking, fibre breakage and interface processes (fibre/matrix debonding or fibre pull-out) from their total power in defined frequency intervals of the spectral power density. A fracture-mechanics investigation of the delamination behaviour of unidirectional composites accompanied by AE examinations is discussed. The extension of the damage zone around the crack tip is quantified by the location of AE events and compared with the theoretically approximated dimensions. The size of the damage zone is used for theoretical calculations of the mechanical energy release from micro-failure processes. A correlation of the AE energy-release rates with the mechanical energy-release rates from participated failure mechanisms like matrix cacking, fibre/matrix debonding and fibre breakage is presented. KW - Polymer blends KW - Polymer-matrix composites KW - Fracture toughness KW - Delamination KW - Acoustic emission PY - 2000 U6 - https://doi.org/10.1016/S0266-3538(00)00060-9 SN - 0266-3538 VL - 60 SP - 1213 EP - 1226 PB - Elsevier CY - Barking AN - OPUS4-4155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bohse, Jürgen A1 - Chen, J.H. T1 - Acousitc Emission Examination of Mode I, Mode II and Mixed-Mode I/II Interlaminar Fracture of Unidirectional Fiber-Reinforced Polymers PY - 2001 SN - 0730-0050 VL - 19 SP - 1 EP - 10 PB - Acoustic Emission Group CY - Los Angeles, Calif. AN - OPUS4-4157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bohse, Jürgen T1 - Acoustic Emission of Micro-Failure Processes in Polymer Blends and Composites T2 - PPS 2001 Regional Meeting CY - Antalya, Turkey DA - 2001-10-22 PY - 2001 AN - OPUS4-7488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brunner, A. J. A1 - Bohse, Jürgen T1 - Acoustic emission standards and guidelines 2002 - a comparative assessment and perspectives N2 - A comparative analysis of selected standards and guidelines on Acoustic Emission testing published by international and national organisations yields an assessment of the current status of standardisation. Areas where existing documents do not yet exist or appear unsatifactory for some reason are identified and formulated as perspectives for further work. In the future, structural integrity assessment with Acoustic Emission methods is expected to gain in importance. PY - 2002 UR - http://www.ndt.net/article/v07n09/21/21.htm SN - 1435-4934 VL - 7 IS - 9 SP - 1 EP - 10 PB - NDT.net CY - Kirchwald AN - OPUS4-1792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bohse, Jürgen T1 - Damage Analysis of polymer Matrix Composites by Acoustic Emission Testing T2 - 26th European Conference on Acoustic Emission Testing (EWGAE 2004) CY - Berlin, Germany DA - 2004-09-15 PY - 2004 AN - OPUS4-3503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bohse, Jürgen T1 - Acoustic emission examination of polymer-matrix composites PY - 2004 SN - 0730-0050 VL - 22 SP - 208 EP - 223 PB - Acoustic Emission Group CY - Los Angeles, Calif. AN - OPUS4-6944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bohse, Jürgen A1 - Mair, Georg T1 - Acoustic Emission Testing of Composite Cylinders - Test Experience at BAM T2 - EIGA WG2 Meeting CY - Brussels, Belgium DA - 2005-12-14 PY - 2005 AN - OPUS4-11364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bohse, Jürgen A1 - Mair, Georg A1 - Novak, Pavel ED - Pullin, R. ED - Holford, M. T1 - Acoustic emission testing of high-pressure composite cylinders T2 - 27th European Conference on Acoustic Emission Testing (EWGAE 2006) CY - Cardiff, Wales, UK DA - 2006-09-20 KW - Composite calinders KW - Pressure equipment KW - Damage analysis PY - 2006 SN - 0-87849-420-0 N1 - Serientitel: Advances materials research – Series title: Advances materials research IS - 13-14 SP - 267 EP - 272 PB - Trans Tech Publ. CY - Zürich AN - OPUS4-13865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bohse, Jürgen T1 - Acoustic emission for non-destructive evaluation of composites T2 - Structural Composites Conference, Applications in Corrosion Prevention, Transportation, Defense and Infrastructure CY - Birmingham, AL, USA DA - 2006-02-08 PY - 2006 SP - 1 EP - 30(?) PB - American Composites Manufactures Association (ACMA) CY - Birmingham, USA AN - OPUS4-13904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -