Chemie und Prozesstechnik
Filtern
Erscheinungsjahr
- 2022 (36) (entfernen)
Dokumenttyp
- Beitrag zu einem Tagungsband (36) (entfernen)
Sprache
- Englisch (36) (entfernen)
Schlagworte
- Concrete (5)
- Non-destructive testing (4)
- LIBS (3)
- NDT (3)
- Ultrasound (3)
- Air-coupled ultrasound (2)
- Circular economy (2)
- Civil engineering (2)
- DLP (2)
- DMD (2)
- Dimensional metrology (2)
- Inspection (2)
- Internal defects (2)
- Material classification (2)
- Nondestructive testing (2)
- Open Guided Waves Platform (2)
- Recycling (2)
- Super resolution (2)
- Thermography (2)
- Ultrasonic Guided Waves (2)
- Acoustic damping (1)
- Additive manufacturing (1)
- Additive manufacturing of concrete (1)
- Aeroacoustics (1)
- Ait-coupled ultrasound (1)
- Algorithmic Differentiation (1)
- Artificial Neural Network (1)
- Atmospheric pressure discharges (1)
- Basic qualification (1)
- Bingham fluid (1)
- Bistable amplifier (1)
- Bridge (1)
- Building materials (1)
- CT (1)
- CT simulation, spherical step-wedge (1)
- Calibrated reference standards (1)
- Capillary conductivity (1)
- Cascade impactor (1)
- Certification (1)
- Chlorine (1)
- Competencies (1)
- Composites (1)
- Computed Tomography (1)
- Conformity assessment (1)
- Conformity assessment body (1)
- Conical hole sheet (1)
- Contact area (1)
- Corrosion (1)
- Crack depth (1)
- Curriculum (1)
- Damage evolution (1)
- Data fusion (1)
- Diffusion (1)
- Digital maturity (1)
- Digital transformation (1)
- Digitalization (1)
- Durability assessment (1)
- Epitaxially grown 4H-SiC layers (1)
- FMEA (1)
- Failure Modes and Effects Analysis (1)
- Fluidic oscillators (1)
- Fluidics (1)
- Frequency modulation (1)
- Geometrical misalignment (1)
- Geometry (1)
- Herculaneum (1)
- High-entropy alloy (1)
- Human Factors (1)
- Hydrogen (1)
- Image processing (1)
- Image-based models (1)
- Imaging ellipsometry (1)
- Indirect noise (1)
- Insulation material (1)
- Inverse Methods (1)
- Laboratory (1)
- Liner (1)
- Main-flow oriented vorticity-nozzle interaction (1)
- Material testing (1)
- Microplastics (1)
- Multi-geometry cuboid (1)
- Multiple principal element alloy (1)
- Muon tomography (1)
- NDT Reliability (1)
- NDT-CE (1)
- Nondestructive evaluation (1)
- Nuclear magnetic resonance (1)
- Performance assessment (1)
- Plasma acoustics (1)
- Pore-size distribution (1)
- Probability of Detection (1)
- Process monitoring (1)
- Python (1)
- Quadtree meshes (1)
- Quality infrastructure (1)
- Quantification (1)
- Radiographic XCT geometry determination (1)
- Radiographic simulation software (1)
- Reconstruction (1)
- SAFT (1)
- SBFEM (1)
- Scaled Boundary Finite Element Method (1)
- Simulation (1)
- Software (1)
- Structural Health Monitoring (1)
- Structural health monitoring (1)
- Synchrotron radiation (1)
- Task specific numerical measurement uncertainty (1)
- Tendon duct (1)
- Testing (1)
- Thermal desorption analysis (1)
- Thermal extraction (1)
- Transient analysis (1)
- Tungsten-Edge (1)
- Tunnel Inspection (1)
- UFP (1)
- Ultrasonic (1)
- Ultrasonics (1)
- University (1)
- Validation (1)
- Water samples (1)
- Wave defect interaction (1)
- White light interference microscopy (1)
- Wide bandgap compound semiconductor (1)
- X-ray refraction radiography (1)
- X-ray tomography (1)
- XCT machine geometry (1)
- XRF (1)
- Zero Massflow Liner (ZML) (1)
- ink (1)
- inspection (1)
- papyrus (1)
- traceability (1)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (30)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (10)
- 8.4 Akustische und elektromagnetische Verfahren (10)
- 8.0 Abteilungsleitung und andere (8)
- 8.5 Röntgenbildgebung (5)
- 4 Material und Umwelt (2)
- 6 Materialchemie (2)
- 7 Bauwerkssicherheit (2)
- 4.2 Material-Mikrobiom Wechselwirkungen (1)
- 4.5 Kunst- und Kulturgutanalyse (1)
This contribution presents a set of largely novel reference standards specially designed for testing different important physical effects and functionalities of radiography-based computed tomography (CT) simulation software. These standards were developed within the scope of the German cooperation project “CTSimU – Radiographic Computed Tomography Simulation for Measurement Uncertainty Evaluation” [1] and serve as tools for the basic qualification of the sufficient physical correctness and required features of simulation software of CT-based coordinate measurement systems (CMSs) via the analyses either of 2D projection images only or of full CT scans. The results serve as input to the German standardisation committee for the development of a new national VDI/VDE guideline in the series VDI/VDE 2630 dealing with the basic qualification aspect of CT simulation software and shall lay ground for the measurement uncertainty determination of dimensional measurements using CT.
An important focus of research in Industrial X-ray Computed Tomography (CT) is to determine the task-specific measurement uncertainty of CT measurements numerically by using simulations. For this, all relevant influence factors need to be identified and quantified. It is known, for example, that geometrical misalignments of the detector lead to measurement deviations if the reconstruction does not consider these misalignments. This contribution uses computer simulation of CT data to investigate the influence of geometrical misalignments of the detector on several measurands found in typical measurements tasks in the industry. A newly developed test specimen with a broad variety of features is used for this study. Angular and positional detector deviations are systematically introduced into the simulations and deliberately left uncompensated during the CT reconstruction. The resulting measurement deviations are shown and discussed.
Traceable determination of non-static XCT machine geometry: New developments and case studies
(2022)
It is fundamental to determine the machine geometry accurately for dimensional X-ray computed tomography (XCT) measurements. When performing high-accuracy scans, compensation of a non-static geometry, e.g. due to rotary axis errors or drift, might become necessary. Here we provide an overview of methods to determine and account for such deviations on a per projection basis. They include characterisation of stage error motions, in situ geometry measurements, numerical simulations, and reconstruction-based optimization relying on image quality metrics and will be discussed in terms of their metrological performance. Since a radiographic calibration is always required to provide an initial absolute geometry, this method will be presented as well. The improvements of the XCT geometry correction methods are presented by means of case studies. The methods can be applied individually or in combination and are intended to provide a toolbox for XCT geometry compensation.
A software toolbox is introduced that addresses several needs common to computed tomography (CT). Built for the WIPANO CTSimU project to serve as the reference implementation for its image processing and evaluation tasks, it provides a Python 3 interface that is adaptable to many conceivable applications. Foremost, the toolbox features a pipeline architecture for sequential 2D image processing tasks, such as flat field corrections and image binning, and enables the user to create their own processing modules. Beyond that, it provides means to measure line profiles and image quality assessment algorithms to calculate modulation transfer functions (MTF) or to determine the interpolated basic spatial resolution (iSRb) using a duplex wire image. It can also be used to calculate projection matrices for the reconstruction of scans with arbitrary industrial CT geometries and trajectories. The CTSimU project defined a framework of projection- and volume-based test scenarios for the qualification of radiographic simulation software towards its use in dimensional metrology. The toolbox implements the necessary evaluation routines and generates reports for all projection-based tests.
Alternative to conventional transmission-based radiography and computed tomography, X-ray refraction techniques are being increasingly used to detect damage in light materials. In fact, their range of application has been recently extended even to metals. The big advantage of X-ray refraction techniques is that they are able to detect nanometric defects, whose size would lie below the resolution of even state-of-the-art synchrotron-based X-ray computed tomography (SXCT). The superiority of synchrotron X-ray refraction radiography and tomography (SXRR and SXRCT) has been shown in the case of light materials, in particular composites. X-ray refraction techniques also yield a quantitifaction of the amount of damage (the so-called relative internal specific surface) and can well be compared with damage models. At the same time, it is impossible for SXRR and SXRCT to image single defects. We show that the combination of refraction- and transmission-based imaging techniques yields an impressive amount of additional information about the type and amount of defects in microstructured materials such as additively manufactured metals or metal matrix composites. We also show that the use of data fusion techniques allows the classification of defects in statistically significant representative volume elements.
Corrosion of concrete reinforcement is one of the major damage mechanisms affecting both the load-bearing capacity and the serviceability of re-inforced concrete structures significantly. When externally discernible damages are observed during visual inspections on the structure, the extent of the damage inside the concrete is often already significant. Corrosion caused by carbonation often leads to severe discoloration of the surface or even large-area spalling of the concrete cover. In contrast, chloride-induced corrosion is usually difficult to observe visually but can cause much more serious damage in less time. The effect occurs locally and can lead to weakening of the cross-section of the reinforce-ment. This, in turn, can cause sudden structural collapses without prior notice.
In the meanwhile, various non-destructive and minimally invasive testing methods are available to evaluate the resistance to penetration of corrosion-pro-moting pollutants and to detect active corrosion. In this paper, a bridge crossing the river Regen is used as a case-study to demonstrate how the information ob-tained applying different testing methods can be combined and evaluated in the context of structural reassessments. Both the results of the permeability testing and the electrical resistance measurement are considered, as well as active corro-sion areas are localized using the half-cell potential mapping combined with the concrete cover measurement with the eddy current method and ground penetrat-ing radar. The results are evaluated using drill cores and in addition laser-induced breakdown spectroscopy was applied to obtain information about possible chlo-ride ion transport into the concrete.