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- Active thermography (14)
- Concrete (11)
- Non-destructive testing (10)
- Thermography (10)
- Radar (8)
- CFRP (7)
- GFRP (6)
- Infrared thermography (6)
- Data fusion (5)
- Process monitoring (5)
- Additive Manufacturing (4)
- Additive manufacturing (4)
- Civil engineering (4)
- Flash excitation (4)
- Flash thermography (4)
- NDT (4)
- Numerical simulation (4)
- Additive manufacturing (AM) (3)
- Delamination (3)
- Historic masonry (3)
- Impulse thermography (3)
- Impulse-thermography (3)
- Mechanochemistry (3)
- Selective laser melting (SLM) (3)
- Ultrasonic (3)
- Voids (3)
- Analytical model (2)
- Artificial weathering (2)
- CFK (2)
- Crack sizing (2)
- Cultural heritage (2)
- D. Thermal analysis (2)
- Emissivity (2)
- Energy sensor (2)
- FFT (2)
- Flash lamp (2)
- Flat bottom holes (2)
- Honeycombing (2)
- Impact-echo (2)
- Insects (2)
- LMD (2)
- Laser powder bed fusion (L-PBF) (2)
- Metal (2)
- Plants (2)
- Polymers (2)
- Pulse phase thermography (2)
- Pulse thermography (2)
- Pulsed thermography (2)
- Railway (2)
- Round robin test (2)
- SAFT (2)
- Semitransparent (2)
- Ultrasonics (2)
- 2D model (1)
- 3D Druck (1)
- 3D laser scanner (1)
- 3D printing (1)
- A. Laminates (1)
- AISI 316L (1)
- Absorption coefficient (1)
- Active and passive thermography (1)
- Additive Fertigung (1)
- Additive Manufacturing (AM) (1)
- Aktive Thermografie (1)
- Automotive industry (1)
- B. Defects (1)
- B. Delamination (1)
- B. Thermal properties (1)
- Bridges (1)
- Building façade (1)
- CFRP-laminates (1)
- Calorimetric principle (1)
- Carbon fiber reinforced polymer (1)
- Characterisation (1)
- Compaction faults (1)
- Composites (1)
- Computed Tomography (1)
- Computed tomography (1)
- Computed tomography (CT) (1)
- Concrete structures (1)
- Conversion efficiency (1)
- Copper (1)
- Crack detection (1)
- D. Non-destructive testing (1)
- D. Radiography (1)
- Data reconstruction (1)
- Defect detection (1)
- Defects (1)
- Defekte (1)
- Delaminations (1)
- Destructive and non-destructive tests (1)
- Direct energy deposition (1)
- Emisssivity (1)
- Energy dissipation (1)
- Environment (1)
- Ettringite (1)
- Evidence theory (1)
- FEM (1)
- FEM modeling (1)
- Fatigue (1)
- Fibre reinforced composites (1)
- Finite differences (1)
- Flash (1)
- Flash lamps (1)
- Heterogeneous (1)
- Historical structure (1)
- IR thermography (1)
- IR thermometry (1)
- Image registration (1)
- Impact (1)
- Impact behaviour (1)
- Impact damage (1)
- Impact echo (1)
- Impulse (1)
- In situ (1)
- In situ monitoring (1)
- In situ studies (1)
- In-situ Process Monitoring (1)
- In-situ monitoring (1)
- Infrared (1)
- Infrared imaging (1)
- Infrastructure (1)
- Inspection (1)
- Inverse Probleme (1)
- Inverse problems (1)
- Kohlenstofffaserverstärkter Kunststoff (1)
- Lack-of-fusion (1)
- Laminates (1)
- Laser Metal Deposition (1)
- Laser Powder Bed Fusion (1)
- Laser Powder Bed Fusion (L-PBF) (1)
- Laser Pulver Auftragsschweißen (1)
- Laser beam melting (LBM) (1)
- Laser excitation (1)
- Laser heating (1)
- Laser metal deposition (1)
- Laser scanner (1)
- Laser thermography (1)
- Laser-induced breakdown spectroscopy (LIBS) (1)
- Laser-thermography (1)
- Lock-in (1)
- Lock-in Thermografie (1)
- Lock-in Thermography (1)
- Lock-in excitation (1)
- Lock-in thermography (1)
- Lockin (1)
- MWIR (1)
- Material properties (1)
- Materials Characterization (1)
- Metals (1)
- Microwave transmission (MBV) (1)
- Milling (1)
- Monitoring (1)
- Multi-parameter POD (1)
- Multispectral thermography (1)
- NIR (1)
- Non-Destructive testing (1)
- Non-destructive Materials (1)
- Non-destructive Testing (1)
- Nondestructive testing (1)
- Nondestructive tests (1)
- Notches (1)
- Numerical modelling (1)
- On-site inspection (1)
- On-site investigation (1)
- Online Monitoring (1)
- Opaque materials (1)
- Open surface cracks (1)
- Optical Tomography (1)
- Optical tomography (1)
- Passive thermography (1)
- Performance demonstration (1)
- Phase measurement (1)
- Phototropism (1)
- Pixel level (1)
- Pores (1)
- Process development (1)
- Pulse phase thermography (PPT) (1)
- Quantification (1)
- Quantitative analysis (1)
- Raman spectroscopy (1)
- Reconstruction (1)
- Reinforcement (1)
- Rekonstruktion (1)
- Residual Stress (1)
- Roll contact fatigue (1)
- SWIR (1)
- SWIR camera (1)
- Safety (1)
- Salt efflorescence (1)
- Selective Laser Melting (SLM) (1)
- Semi-transparent composite (1)
- Signal-to-noise ratio (1)
- Signal-to-noise-ratio (1)
- Simulation (1)
- Soft matter (1)
- Solar excitation (1)
- Solar heating (1)
- Solder joint (1)
- Spectral-induced polarization (SIP) (1)
- Spot welding (1)
- Standardisation (1)
- Standardisierung (1)
- Steel fibres (1)
- Structural and material characterization (1)
- Structural health monitoring (1)
- Structures (1)
- Surface braking cracks (1)
- Surface properties (1)
- TES (1)
- Temperature emissivity separation (1)
- Tendon duct (1)
- Tensile loading (1)
- Thermal analysis (1)
- Thermal diffusivity (1)
- Thermal imaging (1)
- Thermal properties (1)
- Thermal testing (1)
- Thermische Diffusivität (1)
- Thermografie (1)
- Thermometry (1)
- UV/VIS spectroscopy (1)
- Ultraschall (1)
- Ultrasound (1)
- Validation of methods (1)
- Wall thickness (1)
- Water damage (1)
- X-ray computed tomography (XCT) (1)
- X-ray diffraction (1)
- XRD (1)
- Zerstörungsfreie Prüfung (1)
- aluminum (1)
- computed tomography (1)
- flash thermography (1)
- infrared Thermography (1)
- optical excitation (1)
- pores (1)
- standardization (1)
- ultrasonic excitation (1)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (21)
- 8.0 Abteilungsleitung und andere (20)
- 9 Komponentensicherheit (9)
- 8.5 Röntgenbildgebung (6)
- 9.3 Schweißtechnische Fertigungsverfahren (6)
- 9.6 Additive Fertigung metallischer Komponenten (3)
- 6 Materialchemie (2)
- 6.3 Strukturanalytik (2)
- 7 Bauwerkssicherheit (2)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (2)
Non-destructive testing (NDT) of concrete structures is performed using pulse-echo methods. According to the type of the applied waves it can be classified as acoustic (Impact-Echo, Ultrasonics) and electromagnetic methods (Radar). The results are visualised through different imaging processes. This work is performed in the frame of a research project promoted by Deutsche Forschungsgemeinschaft (FOR384). The objective of data fusion is to use the complementary information of the different methods. Radar can detect metallic reflectors in concrete (metallic ducts and concrete reinforcement) very well. This method is not able to locate defects behind these reflectors (injecting defects, defects behind close concrete reinforcement), because the electromagnetic waves are completely reflected at metals. The acoustic methods are able to compensate this deficit i.e. Acoustic waves can penetrate through metal. But acoustic waves in the ultrasonic range are completely reflected by air layers. Air layers have smaller influence on radar propagation, so that both methods complement each other. In order to be able to combine the NDT-data from several methods records at the same volume, the different data setsmodes of signals must be adapted. The ultrasonic and radar data have to be reconstructed with programs based on the Synthetic Aperture Focusing Technique (SAFT) before data fusion. Subsequently, a conversion of the data into a uniform format has to be carried out. This is a prerequisite in order to keep the data exchange between the project partners as simple as possible. After the data sets are imported and transferred into a common reference system, they can be processed with operations according to the purpose of the investigation. Results, which have been achieved in concrete test specimen with radar and ultrasonics, will be presented and will show the feasibility of the data fusion method.
Within the scope of a DIN INS project, a flash thermography round robin test that evaluates reliability, comparability, and efficiency of different testing situations was organized. The results give information about the detectability of defects, e.g. depending on their size and depth, the evaluation methods and the materials used. Besides, the influences of equipment and parameters used by the participants on the results were analysed. All of the quantitative results as well as the feedback given by the participants will be presented in a DIN committee in order to contribute to a flash thermography standard.
False colour infrared (IR) thermography was performed on a sunny summer day in the Berlin Botanic Garden. The main interest focused on blossoms of different size, colours and shapes: disk-, bowl- and funnel-like anatomy demonstrating various modes of light absorption and heating-up during the day. Some of the flowers were phototropic or even solar tracking. Blossom temperatures ranged from 18.0 to 33.3 °C (mean 26.3 ± 2.5 °C, S.D., n = 37) at 21 °C air temperature. Several thermograms showed honey- and bumblebees also. In some cases the results are compared with those of a contact-free IR thermometry. One winter- and one late-spring-flowering plant are included in the overview.
Additively manufactured test specimens made of polyamide 12 (PA 12) by Laser Sintering (LS) as well as of acrylnitril-butadien-styrol (ABS) by Fused Layer Modeling (FLM), were tested with active thermography. For this, two different excitation methods (flash and impulse excitation) were used and compared, regarding the suitability for the detection of constructed and imprinted defects. To increase the quality of the thermograms, data processing methods like thermal signal reconstruction (TSR) and Fourier-Transformation were applied. Furthermore, the long-term stability of the probes towards environmental stress, like UV-radiation, heat, water contact and frost is being investigated in the presented project with artificial weathering tests.
Additively manufactured test specimens made of polyamide 12 (PA 12) by Laser Sintering as well as of acrylonitrile butadiene styrene (ABS) by Fused Layer Modelling, were characterised with active thermography directly after manufacturing and after artificial weathering. For this, two different excitation methods (flash and pulse heating) were used and compared, regarding their suitability for the detection of constructed and imprinted defects inside the test specimens. To increase the quality of the thermograms, data processing methods like thermal signal reconstruction (TSR) and Fourier Transformation after TSR were applied. To further investigate the long-term stability of the additively manufactured test specimens towards environmental stress, like UV radiation, heat, humidity, water contact and frost with active thermography, an artificial weathering test over 2000 hours (~3 months) was applied to the specimens. The monitoring of the changes in the optical properties of the weathered plastics was supplemented by spectral reflectance and UV/VIS spectroscopy.
Additive manufacturing (AM) techniques have risen to prominence in many industrial sectors. This rapid success of AM is due to the freeform design, which offers enormous possibilities to the engineer, and to the reduction of waste material, which has both environmental and economic advantages. Even safety-critical parts are now being produced using AM. This enthusiastic penetration of AM in our daily life is not yet paralleled by a thorough characterization and understanding of the microstructure of materials and of the internal stresses of parts. The same holds for the understanding of the formation of defects during manufacturing. While simulation efforts are sprouting and some experimental techniques for on-line monitoring are available, still little is known about the propagation of defects throughout the life of a component (from powder to operando/service conditions). This Issue was aimed at collecting contributions about the advanced characterization of AM materials and components (especially at large-scale experimental facilities such as Synchrotron and Neutron sources), as well as efforts to liaise on-line process monitoring to the final product, and even to the component during operation. The goal was to give an overview of advances in the understanding of the impacts of microstructure and defects on component performance and life at several length scales of both defects and parts.
Pulse thermography (PT) has proven to be a valuable non-destructive testing method to identify and quantify defects in fiber-reinforced polymers. To perform a quantitative defect characterization, the heat diffusion within the material as well as the material parameters must be known. The heterogeneous material structure of glass fiber-reinforced polymers (GFRP) as well as the semitransparency of the material for optical excitation sources of PT is still challenging. For homogeneous semitransparent materials, 1D analytical models describing the temperature distribution are available.
Here, we present an analytical approach to model PT for laterally inhomogeneous semitransparent materials.We show the validity of the model by considering different configurations of the optical heating source, the IR camera, and the differently coated GFRP sample. The model considers the lateral inhomogeneity of the semitransparency by an additional absorption coefficient. It includes additional effects such as thermal losses at the samples surfaces, multilayer systems with thermal contact resistance, and a finite duration of the heating pulse. By using a sufficient complexity of the analytical model, similar values of the material parameters were found for all six investigated configurations by numerical fitting.
Impulse-thermography is an active method for quantitative investigations of the near surface region of various structures. It has recently been applied and optimised to applications in civil engineering. By using either an internal or external heat source, parts of the structure under investigation are heated up and the transient heat flux is observed by recording the temperature change at the surface as a function of time. This method is very well suited for the detection of voids and honeycombing in concrete, up to concrete covers of 10 cm as well as for the location of delaminations in multi-layered systems (e.g. plaster on concrete, CFRP-laminates on concrete, asphalt on concrete). Also safety relevant defects like voids in tendon ducts and cracks in concrete could be recognised.