TY - CONF A1 - White, J. A1 - Wolf, Julia A1 - Shokouhi, Parisa A1 - Hurlebaus, S. A1 - Wimsatt, Andrew T1 - Nondestructive evaluation of concrete linings at Hanging Lake tunnel N2 - Tunnel lining evaluation is performed in the Hanging Lake Tunnel near Glenwood Springs, Colorado, using variations of four nondestructive evaluation (NDE) methods: air- and ground-coupled ground penetrating radar (GPR), ultrasonic echo (US echo), ultrasonic tomography (UST), and impact echo (IE). Potential regions of interest are identified using high-speed air-coupled GPR and visual inspection. A robotic frame with pneumatically-operated vacuum plates was used to automate the ground-coupled GPR, US echo, and IE tests, while the UST technique was used manually. This study shows that a particular combination of NDE techniques is a powerful tool for assessing the condition of tunnel linings and can detect potential anomalies such as delamination, depth of surface cracks, reinforcement depth and layout, and lining thickness. By mapping the phase shift of the ultrasonic pulses at detected interface, the potential bonding of layer interfaces and reinforcement is assessed. T2 - TRB 92nd Annual meeting CY - Washington, D.C., USA DA - 13.01.2013 KW - Nondestructive evaluation KW - Concrete KW - Ultrasonic KW - GPR KW - Impact echo PY - 2013 UR - http://trid.trb.org/view.aspx?id=1241994 SP - 1 EP - 16 AN - OPUS4-32027 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heideklang, René A1 - Shokouhi, Parisa T1 - Multi-sensor image fusion at signal level for improved near-surface crack detection N2 - This study aims at improving the detection of near-surface defects in magnetizable and conductive specimens by combining the measurements of eddy current, magnetic flux leakage and thermography testing. Different signal processing methods for data normalization are proposed to enable data fusion at the pixel level. These methods are applied to a test specimen which contains 10 variably-sized defects. We quantitatively evaluate the performances of a total of 29 detection methods with respect to false alarm reduction at a fixed level of true positive rate. We report that false positive rate could be reduced from 1.65% down to 0.28% by the best multi-sensor method compared to the best single-sensor performance on the smallest defect, when 50% found flaw pixels are required for successful detection. KW - Data fusion KW - Image processing KW - Surface flaw KW - Detection PY - 2015 DO - https://doi.org/10.1016/j.ndteint.2014.12.008 SN - 0963-8695 VL - 71 SP - 16 EP - 22 PB - Elsevier Ltd. AN - OPUS4-32577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - White, J. A1 - Hurlebaus, S. A1 - Shokouhi, Parisa A1 - Wimsatt, Andrew T1 - Use of ultrasonic tomography to detect structural impairment in tunnel linings - Validation study and field evaluation N2 - Tunnel inspection is a challenging problem because of high-volume traffic and routine operations in naturally aggressive environments. The need to keep tunnels open during inspection and minimize tunnel closures and user delays must be carefully balanced with the need to conduct in-depth lining inspections to ensure the safety of drivers. This paper describes the laboratory validation and field performance of a recently developed in-depth nondestructive testing technology for the detection of impairments in tunnel lining: linear array shear wave tomography, typically referred to as ultrasonic tomography (UST). Before this equipment is used in the field, the system is first evaluated through the use of laboratory specimens with artificial defects that mock common structural problems, such as air- and water-filled voids, delaminations, and other potential abnormalities. The device is also used to determine concrete thickness and reinforcement depth and spacing. The test results are discussed to determine the device's capabilities and limitations in locating defects in concrete structures. After the system is evaluated on the basis of its ability to detect these simulated defects, the system is taken to the field to inspect a public tunnel for natural structural defects. Potential regions of interest are first identified through high-speed air-coupled ground-penetrating radar (GPR) and visual inspection and subsequently inspected with UST. This paper shows that the combination of preliminary inspection procedures (GPR surveys and visual inspection) and an in-depth technique like UST is powerful for the assessment of the condition of tunnel linings and can detect potential anomalies, such as delamination, reinforcement depth and layout, and lining thickness. KW - Evaluierung KW - Tunneluntersuchung KW - Ultraschall-Tomografie KW - Validierung PY - 2014 DO - https://doi.org/10.3141/2407-03 SN - 0361-1981 VL - 2 IS - 2407 SP - 20 EP - 31 PB - National Research Council CY - Washington, DC AN - OPUS4-31520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heideklang, René A1 - Shokouhi, Parisa T1 - Application of data fusion in nondestructive testing (NDT) N2 - Applying contemporary data fusion techniques, the multi-modal nondestructive testing (NDT) data sets can be combined to obtain more reliable results. The reliability can be quantified in terms of the probability of detection of sought material defects. A concise review of the published studies on NDT data fusion is provided here and the key concepts and anticipated challenges are discussed. The detailed steps involved in the NDT fusion process are explained with reference to a case study. The presented data set includes the results of three different NDT techniques on a test specimen with built-in defects. Several pixel-level fusion algorithms were applied and their performances are quantitatively compared. T2 - FUSION 2013 - 16th International Conference on Information Fusion CY - Istanbul, Turkey DA - 09.07.2013 PY - 2013 SN - 978-605-86311-1-3 SP - 835 EP - 841 AN - OPUS4-30033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shokouhi, Parisa A1 - Wolf, Julia A1 - Wiggenhauser, Herbert T1 - Detection of delamination in concrete bridge decks by joint amplitude and phase analysis of ultrasonic array measurements N2 - The accuracy and precision of low-frequency (center frequency of approximately 55 kHz) ultrasonic testing for detection and characterization of delamination in concrete bridge decks were evaluated. A multiprobe ultrasonic testing system (with horizontally polarized shear-wave transducers) was used to detect built-in delamination defects of various size, depth, and severity (i.e., thickness) in a test specimen—a 6.1 m × 2.4 m × 216 mm (20 ft × 8 ft × 8.5 in.) reinforced concrete slab-built to simulate a concrete bridge deck. The collected data sets were reconstructed applying synthetic aperture focusing technique (SAFT). The reconstructed measurement results were then used to assess the condition of the concrete slab at individual points [point-by-point data collection and two-dimensional (2D) reconstruction] as well as along lines, where data were collected at smaller steps and reconstructed in a three-dimensional (3D) format. The local-phase information was also calculated, superimposed on the reconstructed images and used as complementary information in condition assessment. The precision and accuracy of condition assessments were evaluated. The results indicated that, using the multiprobe ultrasonic array, delamination defects as small as 30 cm² (1 ft²) could be reliably detected. Deep delaminations [i.e., those deeper than 150 mm (6 in.)] were directly detected and characterized, whereas shallow delaminations [shallower than 65 mm (2.5 in.)] were detected only indirectly. The precision of the measurements was demonstrated by comparing repeated measurements at several test points. Similar measurement results obtained on a delaminated portion of a real bridge deck support the conclusions of the validation study. KW - Concrete bridge deck KW - Bridge deck evaluation KW - Delamination KW - Nondestructive testing (NDT) KW - Ultrasonic testing PY - 2014 DO - https://doi.org/10.1061/(ASCE)BE.1943-5592.0000513 SN - 1084-0702 VL - 19 IS - 3 SP - 04013005-1 EP - 04013005-11 PB - Soc. CY - Reston, Va. AN - OPUS4-31261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heideklang, René A1 - Shokouhi, Parisa T1 - Quantitative multi-modal NDT data analysis N2 - A single NDT technique is often not adequate to provide assessments about the integrity of test objects with the required coverage or accuracy. In such situations, it is often resorted to multi-modal testing, where complementary and overlapping information from different NDT techniques are combined for a more comprehensive evaluation. Multimodal material and defect characterization is an interesting task which involves several diverse fields of research, including signal and image processing, statistics and data mining. The fusion of different modalities may improve quantitative nondestructive evaluation by effectively exploiting the augmented set of multi-sensor information about the material. It is the redundant information in particular, whose quantification is expected to lead to increased reliability and robustness of the inspection results. There are different systematic approaches to data fusion, each with its specific advantages and drawbacks. In our contribution, these will be discussed in the context of nondestructive materials testing. A practical study adopting a high-level scheme for the fusion of Eddy Current, GMR and Thermography measurements on a reference metallic specimen with built-in grooves will be presented. Results show that fusion is able to outperform the best single sensor regarding detection specificity, while retaining the same level of sensitivity. T2 - Quantitative nondestructive Evaluation conference 2013 (QNDE) CY - Baltimore, MD, USA DA - 2013-07-21 KW - Data fusion KW - Multi-sensor KW - Reliability PY - 2013 SP - 1 EP - 5(?) AN - OPUS4-30058 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Gucunski, N. A1 - Imani, A. A1 - Romero, F. A1 - Nazarian, S. A1 - Yuan, D. A1 - Wiggenhauser, Herbert A1 - Shokouhi, Parisa A1 - Taffe, Alexander A1 - Kutrubes, D. T1 - Nondestructive testing to identify concrete bridge deck deterioration N2 - This work was sponsored by the Federal Highway Administration in cooperation with the American Association of State Highway and Transportation Officials. It was conducted in the second Strategic Highway Research Program (SHRP 2), which is administered by the Transportation Research Board of the National Academies. The project was managed by Monica Starnes, Senior Program Officer for SHRP 2 Renewal. The research reported herein was performed by the Center for Advanced Infrastructure and Transportation (CAIT) at Rutgers University (RU); the Center for Transportation Infrastructure Systems (CTIS) at The University of Texas at El Paso (UTEP); the Federal Institute for Materials Research and Testing (BAM), Germany; and Radar Systems International, Inc. (RSI). Rutgers University was the coordinator and contractor for this project. Dr. Nenad Gucunski, professor and chair of Civil and Environmental Engineering and director of CAIT’s Infrastructure Condition Monitoring Program at RU, was the principal investigator. The other authors of this report are Dr. Soheil Nazarian, professor of Civil Engineering and director of CTIS at UTEP; Dr. Deren Yuan, research associate at CTIS at UTEP; Dr. Herbert Wiggenhauser, head of Non-Destructive Testing (NDT) in Civil Engineering at BAM; Dr. Alexander Taffe, leader of Combination and Automation of NDT of Buildings at BAM; Dr. Parisa Shokouhi, Alexander von Humboldt Research Fellow, hosted by BAM; and Doria Kutrubes, president of RSI. Arezoo Imani and Touraj Tayebi, graduate research assistants at RU, helped conduct the validation testing, data analysis, and web manual content preparation. Hoda Azari, a graduate research assistant, and Dr. Manuel Celaya, a research engineer at UTEP, assisted in the validation study as well. Hooman Parvardeh, research assistant at RU, helped build the reference database and develop the framework for the web manual, while Erica Erlanger, a research staff member at RU, edited the manuscript. Their contributions are gratefully acknowledged. The research team also gratefully acknowledges contributions of the participants from industry and academia in the validation testing. The participants include NDT Corporation; Germann Instruments; Olson Engineering; Dr. Ralf Arndt, National Research Council associate at FHWA Turner–Fairbank Highway Research Center; Ingegneria Dei Sistemi S.p.A. (IDS), Italy; 3D-RADAR, Norway; Dr. John Popovics, University of Illinois at Urbana-Champaign; Dr. Jinying Zhu, The University of Texas at Austin; Rutgers University—Center for Advanced Infrastructure and Transportation; and The University of Texas at El Paso—Center for Transportation Infrastructure Systems. The contributions of these participants were critical for the evaluation and grading of the performance of NDT technologies. PY - 2013 UR - http://onlinepubs.trb.org/onlinepubs/shrp2/SHRP2_S2-R06A-RR-1.pdf SN - 978-0-309-12933-6 SP - 1 EP - 96 PB - Transportation Research Board, Washington D.C. AN - OPUS4-34732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Shokouhi, Parisa A1 - Stähler, S. A1 - Nowak, Thomas Rudolf T1 - Detection of subtle changes in materials by Coda Wave interferometry T2 - 10th European conference on non-destructive testing CY - Moscow, Russia DA - 2010-06-07 KW - Cold wave interferometry KW - Beton KW - Concrete KW - Stress PY - 2010 IS - Paper 4.02.18 SP - 1 EP - 9 AN - OPUS4-21468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa A1 - Zoëga, Andreas A1 - Wiggenhauser, Herbert A1 - Fischer, G. T1 - Macro-effect of microcracks on sonic surface wave velocity in concrete under compression T2 - 89th TRB Annual Meeting CY - Washington, D.C., USA DA - 2010-01-10 KW - NDT KW - Microcracking KW - Sonic wave velocity KW - Concrete KW - Load KW - Stress PY - 2010 SP - 1 EP - 17 AN - OPUS4-20942 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa T1 - Nondestructive Evaluation of the State of Damage in Concrete under Uniaxial Compression T2 - QNDE- Review of Progress in Quantitative NDE CY - Kingston, RI, USA DA - 2009-07-26 PY - 2009 AN - OPUS4-21059 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa T1 - Macro-Effect of Microcracks on Sonic Surface Wave Velocity in Concrete under Compression T2 - Transportation Research Board TRB 2010, 89th Annual Meeting CY - Washington, D.C., USA DA - 2010-01-10 PY - 2010 AN - OPUS4-21060 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa A1 - Zoëga, Andreas A1 - Wiggenhauser, Herbert ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Nondestructive evaluation of damage in concrete under uniaxial compression N2 - Surface wave velocities over the sonic frequency range (<20 KHz) were measured on concrete specimens undergoing various cycles of loading and unloading. Acoustic Emission test (AE) was conducted simultaneously to monitor the microcracking activities. The sonic surface wave velocity was found to be highly stress-dependent. The observed changes in surface wavespeed are repeatable and follow a particular trend. By measuring the wave velocities in both loading and unloading phases, the effects of stress and stress-induced damages could be distinguished. The observed trend could be explained by a combination of acoustoelasticity and microcracking theories. T2 - 36th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Kingston, RI, USA DA - 2009-07-26 KW - Nondestructive testing (NDT) KW - Microcracking KW - Sonic wave velocity KW - Concrete KW - Load KW - Stress PY - 2010 UR - http://link.aip.org/link/?APCPCS/1211/1525/1 SN - 978-0-7354-0748-0 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings SP - 1525 EP - 1532 CY - Melville, NY AN - OPUS4-22642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zoëga, Andreas A1 - Shokouhi, Parisa A1 - Wiggenhauser, Herbert ED - Nagesh R. Iyer, ED - K. Balaji Rao, ED - N. Gopalakrishnan, ED - Bharatkumar, B. H. ED - V. Kalyanaraman, T1 - Propagation time of elastic surface waves on concrete specimens under uniaxial loads KW - Propagation time KW - Surface-wave KW - Concrete KW - Uniaxial loading KW - Laser vibrometer KW - Stress-dependency KW - Direction-dependency PY - 2009 SN - 0970-0137 VL - 36 IS - 1 SP - 11 EP - 15 CY - Madras AN - OPUS4-19462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Shokouhi, Parisa A1 - Gucunski, N. A1 - Wiggenhauser, Herbert T1 - Using Impact Echo for Nondestructive Detection of Delamination in Concrete Bridge Decks T2 - NDE Conference on Civil Engineering CY - St. Louis, Missouri, USA DA - 2006-08-14 KW - Zerstörungsfreie Prüfung im Bauwesen KW - Impact-Echo PY - 2006 SN - 1-57117-148-7 SP - 285 EP - 292 PB - ASTM CY - St. Louis AN - OPUS4-14367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa T1 - Using Impact-Echo for nondestructive detection of delamination in concrete bridge decks T2 - 2006 NDE Conference on Civil Engineering CY - St. Louis, MO, USA DA - 2006-08-14 PY - 2006 AN - OPUS4-14414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa T1 - Stress-dependency of sonic velocity in concrete under uniaxial load T2 - Transportation Research Board (TRB) 87th Annual Meeting, Session 568 CY - Washington, D.C., USA DA - 2008-01-13 PY - 2008 AN - OPUS4-16595 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa A1 - Feldmann, Rüdiger A1 - Wiggenhauser, Herbert T1 - Stress-Dependency of Sonic Velocity in Concrete under Unaxial Load KW - Design KW - Public Transportation and Ferries KW - Safety PY - 2008 IS - CD-ROM (Paper 08-1450 / Session 568) SP - 1 EP - 15 PB - TRB CY - Washington, DC AN - OPUS4-16650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shokouhi, Parisa A1 - Wöstmann, Jens A1 - Schneider, Gerhard A1 - Milmann, Boris A1 - Taffe, Alexander A1 - Wiggenhauser, Herbert T1 - Nondestructive detection of delamination in concrete slabs - multiple-method investigation N2 - The delamination of concrete slabs is the separation along a plane roughly parallel to, and generally near, the surface. Corrosion-induced delamination is a common problem in old concrete bridge decks. If undetected, delaminations could expand, reach the surface, and result in spalling. Early detection of delamination is necessary for planning timely repairs that prevent costly deck replacement projects. Most bridge owners rely on routine visual and traditional surveys of bridge deck conditions. These surveys are highly subjective and can locate only large shallow delaminated zones. Several nondestructive testing (NDT) techniques have recently been employed for bridge deck evaluation to obtain more objective and comprehensive assessment. The reliability of applicable methods needs to be established before a greater role for NDT in routine inspections can be encouraged. This paper presents a validation study aimed at evaluating the effectiveness of three NDT techniques, namely impact echo, ultrasound (US) echo, and US linear array, in detection of delamination. This study is unique because the subject test specimens were deteriorated bridge deck segments preserved from the demolition of a prestressed box girder bridge. The results of the tests conducted on one of the specimens are presented and discussed here: impact echo provided satisfactory overall assessment, but the individual results were often difficult to interpret; US echo detected deep delaminations but not shallow ones; and US linear array located the extent of deep delaminations and provided indications of shallow ones. KW - Delamination KW - Concrete KW - Ultrasonic testing KW - Impact echo KW - Scanning PY - 2011 DO - https://doi.org/10.3141/2251-11 SN - 0361-1981 VL - 2251 SP - 103 EP - 113 PB - National Research Council CY - Washington, DC AN - OPUS4-25552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolkoori, Sanjeevareddy A1 - Shokouhi, Parisa A1 - Höhne, Christian A1 - Rahman, Mehbub-Ur A1 - Kreutzbruck, Marc A1 - Prager, Jens T1 - A comparative study of ray tracing and CIVA simulation for ultrasonic examination of anisotropic inhomogeneous austenitic welds N2 - Ultrasonic examination of anisotropic inhomogeneous austenitic welds is challenging, because of the columnar grain structure of the weld leads to beam skewing and splitting. Modeling tools play an important role in understanding the ultrasound field propagation and optimization of experimental parameters during the ultrasonic testing of austenitic welds as well as the interpretation of the test results. In this contribution, an efficient theoretical model based on the ray tracing concepts is developed to calculate the ultrasonic fields in inhomogeneous austenitic welds quantitatively. The developed model determines the ultrasound fields by taking into account the directivity of the ray source, the inhomogenity of the weld as well as ray transmission coefficients. Directivity of the ray source in columnar grained austenitic materials (including layback orientation) is obtained in three dimensions based on Lamb's reciprocity theorem. Ray energy reflection and transmission coefficients at an interface between two general columnar grained austenitic materials are calculated in three dimensions. The ray tracing model predictions on inhomogeneous austenitic weld material are compared against those from CIVA, a commercial non-destructive modeling and simulation tool. The ultrasonic modeling tools in CIVA are based on semi-analytical solutions. For beam propagation simulation, a so-called 'pencil method' is used, which involves modeling the probe as a set of individual source points, each radiating 'a bundle' of diverging rays into the medium and integrating those elementary contributions. Inhomogenity in the weld region is approximated by mapping the grain orientations on weld macrograph. Simulation results for ultrasonic field profiles for an austenitic weld are shown to be in good agreement with the corresponding experimental results. T2 - 39th Annual review of progress in quantitative nondestructive evaluation CY - Denver, Colorado, USA DA - 15.07.2012 KW - Crystal microstructure KW - Ray tracing KW - Ultrasonic materials testing KW - Ultrasonic propagation KW - Ultrasonic reflection KW - Ultrasonic transmission KW - Welds PY - 2013 SN - 978-0-7354-1129-6 DO - https://doi.org/10.1063/1.4789158 SN - 0094-243X SN - 1551-7616 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1511 SP - 1043 EP - 1050 PB - AIP Publishing AN - OPUS4-27736 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa T1 - Using Ultrasonic Coda Wave Interferometry for Monitoring Stress-Induced Changes in Concrete T2 - Symposium on Engineering and Environmental Geophysics (SAGEEP) CY - Keystone, CO, USA DA - 2010-04-11 PY - 2010 AN - OPUS4-21164 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -