TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Bien, J. A1 - Kaminski, T. A1 - Bernardini, G. T1 - Multi-tool inspection and numerical analysis of an old masonry arch bridge JF - Structure & infrastructure engineering N2 - Complex special inspection of an old masonry arch bridge according to the Guideline on Inspection and Condition Assessment of Railway Bridges and numerical analysis of the structure are presented. The guideline summarises recommendations for the step-by-step investigation of railway bridges applying enhanced methods developed during the EU-funded project Sustainable Bridges. For the investigation of the arch barrel, the ballast parameters and the inner structure of the backfill behind the arch barrel a number of various advanced non-destructive and minor-destructive testing methods were applied. Deformation of the structure during load tests was measured using three independent measuring systems: laser vibrometer, LVDT and microwave radar. Results of calculations performed with 2D and 3D models based on FEM are compared with the field load tests. Sensitivity of the ultimate load of the structure to investigated parameters is studied in FE model. Some general conclusions according to methods of testing and modelling of masonry arch bridges are presented and discussed. KW - Masonry bridges KW - Non-destructive testing KW - Bridge inspection KW - Finite element method PY - 2010 DO - https://doi.org/10.1080/15732471003645666 SN - 1573-2479 SN - 1744-8980 IS - NSIE_A_465075 SP - 1 EP - 13 PB - Taylor & Francis CY - London AN - OPUS4-22838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hempel, M. A1 - Tomm, J.W. A1 - Ziegler, Mathias A1 - Elsaesser, T. A1 - Michel, N. A1 - Krakowski, M. T1 - Catastrophic optical damage at front and rear facets of diode lasers JF - Applied physics letters N2 - Single-pulse tests of the catastrophic optical damage (COD) are performed for three batches of diode lasers with different gain-regions. The tests involve in situ inspection of front, rear, and side of the devices by a thermocamera. Devices with an Al-containing gain-region show COD at the front facet, as expected for strong facet heating via surface recombination and reabsorption of laser light. In contrast, Al-free devices with low surface recombination rates tend to fail at the rear facet, pointing to a different heating scenario. The high carrier density at the rear facet favors heating and COD via Auger recombination processes. KW - Thermography KW - Catastrophic optical damage KW - High power diode lasers KW - Destructive testing KW - Non-destructive testing KW - Auger effect KW - Carrier density KW - Heating KW - Laser beam effects KW - Optical testing KW - Semiconductor lasers KW - Surface recombination PY - 2010 DO - https://doi.org/10.1063/1.3524235 SN - 0003-6951 SN - 1077-3118 VL - 97 IS - 23 SP - 231101-1 - 231101-3 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-22763 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thomas, Hans-Martin A1 - Dey, Anika A1 - Heyder, R. T1 - Eddy current test method for early detection of rolling contact fatigue (RCF) in rails JF - Insight N2 - The findings indicate that rolling contact fatigue with consecutive head checks develops preferentially in rail sections that have experienced operational work-hardening. Such hardening can be identified by instruments measuring the increased hardness values with respect to the base material. Eddy current testing was initially introduced with the aim to detect head checks and determine their damage depth. Because the material texture influences eddy current flow in the test objects very strongly, variations in hardness can easily be visualised using this method. Thus, in principle, it is possible to predict places where head checks will emerge later. This knowledge may be very helpful in improving our understanding of head check emergence under real conditions. This knowledge may also help in developing new and effective precautionary maintenance strategies. KW - Rails KW - Rolling contact fatigue KW - Head checks KW - Non-destructive testing KW - Eddy current technique PY - 2010 DO - https://doi.org/10.1784/insi.2010.52.7.361 SN - 0007-1137 VL - 52 IS - 7 SP - 361 EP - 365 PB - British Institute of Non-Destructive Testing CY - Northampton AN - OPUS4-21934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mantouvalou, I. A1 - Lange, K. A1 - Wolff, Timo A1 - Grötzsch, D. A1 - Lühl, Lars A1 - Haschke, M. A1 - Hahn, Oliver A1 - Kanngießer, B. T1 - A compact 3D micro X-ray fluorescence spectrometer with X-ray tube excitation for archaeometric applications JF - Journal of analytical atomic spectrometry N2 - In this work, the applicability of a new 3D micro X-ray fluorescence (3D Micro-XRF) laboratory spectrometer for the investigation of historical glass objects is demonstrated. The non-destructiveness of the technique and the possibility to measure three-dimensionally resolved fluorescence renders this technique into a suitable tool for the analysis of cultural heritage objects. Although absorption and resolution effects complicate qualitative analysis of the data, layered structures can be distinguished from homogeneous samples without the need for full quantification. Different manufacturing techniques were studied in this work with the help of hand-made reference samples. With the gained knowledge it could be shown for the investigated historical glass object, that black enamel as a stained glass contour colour was used in a cold painting. The object was not fired after the application of the black enamel, but instead the adhesion of the paint was solely provided through organic binding agents and the backing with metal foils. Thus, for the manufacturing of the object, a mixture of cold painting technique with a stained glass color was used. Quantitative measurements with a 3D Micro-XRF setup at the Berlin synchrotron BESSY II confirm the assumptions drawn on the basis of the qualitative investigation with the 3D Micro-XRF spectrometer with X-ray tube excitation. KW - 3D micro XRF KW - Archaeometry KW - Non-destructive testing KW - Cultural heritage PY - 2010 DO - https://doi.org/10.1039/b915912f SN - 0267-9477 SN - 1364-5544 VL - 25 SP - 554 EP - 561 PB - Royal Society of Chemistry CY - London AN - OPUS4-20878 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Wöstmann, Jens T1 - Complex resistivity and radar investigation of building material: First results of field scale measurements JF - Acta geophysica N2 - Moisture ingress is one of major damaging factors for masonry buildings. As the complex resistivity (CR) is sensitive to textural properties as well as to the pore fluid chemistry of wet porous media, its non-destructive application can provide helpful information for conservators. In a comprehensive laboratory study it has been shown that CR might even be able to distinguish between salt content and saturation degree in only one measurement. The combined use of electrical and electromagnetic measurement techniques in two field-scale flooding experiments has shown some unexpected differences. Possible reasons are discussed and it is shown that bringing together the information of both methods leads to a clearer picture. KW - Complex resistivity KW - Ground penetrating radar KW - Non-destructive testing KW - Masonry KW - Salt and moisture damage PY - 2010 DO - https://doi.org/10.2478/s11600-009-0019-4 SN - 1895-6572 SN - 1895-7455 VL - 58 IS - 1 SP - 96 EP - 113 PB - Springer CY - Warsaw AN - OPUS4-20575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -