5 Werkstofftechnik
Filtern
Dokumenttyp
- Vortrag (52)
- Zeitschriftenartikel (39)
- Posterpräsentation (15)
- Beitrag zu einem Tagungsband (14)
- Dissertation (4)
- Beitrag zu einem Sammelband (2)
- Forschungsdatensatz (2)
- Sonstiges (1)
Sprache
- Englisch (97)
- Deutsch (31)
- Mehrsprachig (1)
Schlagworte
- Fatigue (15)
- Glass fiber reinforced polymers (9)
- Composite (6)
- Environmental stress cracking (6)
- Full Notch Creep Test (6)
- Sandwich (6)
- Wind turbine blades (6)
- Diesel (5)
- High-density polyethylene (5)
- Mikroplastik (5)
- Polymer matrix composites (5)
- Betriebsfestigkeit (4)
- Environmental Stress Cracking (4)
- Environmental stress cracking (ESC) (4)
- Fracture (4)
- Full-Notch Creep Test (FNCT) (4)
- Microplastics (4)
- Non-destructive testing (4)
- PE-HD (4)
- Polymer (4)
- Scarf repairs (4)
- TED-GC-MS (4)
- Thermomechanics (4)
- X-ray refraction (4)
- Biodiesel (3)
- CFK (3)
- Carbon Fiber Reinforced Plastics (3)
- Carbon fibres (3)
- Composites (3)
- Crack Propagation (3)
- Crack evolution (3)
- Degradation (3)
- Diffraction Enhanced Imaging (3)
- Ermüdung (3)
- Fracture surface analysis (3)
- GFRP (3)
- In situ tensile test (3)
- Infrarotspektroskopie (3)
- Interfacial strength (3)
- Lightweight materials (3)
- Luftultraschall (3)
- Mechanical properties (3)
- Polyethylene (3)
- Pulveraktivkohle (3)
- Rotor blade (3)
- Röntgenrefraktion (3)
- Self-healing (3)
- Temperature (3)
- Thermogravimetrie (3)
- UV-irradiation (3)
- Wind energy (3)
- Wind turbine blade shells (3)
- Windenergie (3)
- Air-coupled ultrasonic testing (2)
- Airborne ultrasonic testing (2)
- Analysis (2)
- Belebtschlamm (2)
- Crack propagation analysis (2)
- Crop protection products (2)
- Cross linking (2)
- Cure process (2)
- Damage (2)
- Dynamic mechanical analysis (DMA) (2)
- Environmental Stress Cracking (ESC) (2)
- Erneuerbare Energien (2)
- Faser-Kunststoff-Verbunde (2)
- Faserkunststoffverbunde (2)
- Fatigue of sandwich shell structures (2)
- Ferroelectret (2)
- Ferroelektret (2)
- Fiber reinforced polymer (2)
- Fracture Surface Analysis (2)
- Full notch creep test (FNCT) (2)
- GFK (2)
- Interface (2)
- Interfacial shear strength (2)
- Kavitation (2)
- Laminography (2)
- Laser scanning microscopy (LSM) (2)
- Long-term storage (2)
- Mikrostruktur (2)
- Photon counting detector (2)
- Polyethylen (2)
- Polyethylen hoher Dichte (2)
- Polyethylene, PE-HD (2)
- Polymer Matrix Composites (2)
- Push-out Test (2)
- Recycling (2)
- Residual stresses (2)
- Rissentwicklung (2)
- Rotorblattschalen (2)
- Röntgen-Refraktion (2)
- Röntgenbeugung (2)
- Schädigung (2)
- Slow crack growth (SCG) (2)
- Sorption (2)
- Spannungsriss (2)
- Synchrotronstrahlung (2)
- Thermoanalyse (2)
- Thermogravimetry (2)
- Thermomechanik (2)
- Thermoset polymers (2)
- Wandler (2)
- Wind turbine (2)
- X-ray laminography (2)
- Abwasser (1)
- Advanced wastewater treatment (1)
- Alterung (1)
- Alumina (1)
- Analyse (1)
- Analytik (1)
- BTEX (1)
- Bacterial attachment (1)
- Bilanzierung (1)
- Biopolymer (1)
- Boden (1)
- Brittle / ductile fracture behavior (1)
- Brittle fracture (1)
- Bruchflächenanalyse (1)
- Bruchflächenauswertung (1)
- C. lap-shear (1)
- CFRP (1)
- Carbon Fibers (1)
- Carbon Fibre (1)
- Carbon fibre-reinforced-plastics (1)
- Carbon nanotubes (1)
- Cavitation (1)
- Cellulose (1)
- Ceramic spring (1)
- Ceramic springs (1)
- Certification Standard 22 (1)
- Chemometrics (1)
- Chemometrie (1)
- Chromatography (1)
- Coating (1)
- Composite recycling (1)
- Composite structures (1)
- Composite testing (1)
- Cooling rate (1)
- Crack growth (1)
- Crack opening displacement (1)
- Crack propagation (1)
- Craze–crack mechanism (1)
- Creep (1)
- Critical energy release rate (1)
- Crop protection formulations (1)
- Cryogenic (1)
- Crystal Texture (1)
- D. aging (1)
- D. creep D. viscoelasticity (1)
- Damage evolution (1)
- Damage mechanisms (1)
- Data Management (1)
- Data Structures (1)
- Debonding (1)
- Deformation behavior (1)
- Degradation signatures (1)
- Dentine (1)
- Desorption (1)
- Diesel Fuel (1)
- Digitalisierung (1)
- Distributed fiber optic sensing (1)
- Distributed fiber optic sensors (1)
- Distributed fibre optic sensors (1)
- Dual-energy (1)
- EASA (1)
- Elastic properties (1)
- Electric conductivity (1)
- Enamel (1)
- Epoxidharz (1)
- Epoxy (1)
- Epoxy Resin (1)
- Epoxy resin (1)
- FNCT (1)
- Failure mechanisms (1)
- Faser (1)
- Faser-Kunststoff-Verbund (1)
- Faserverstärkte Kunstoffe (1)
- Fatigue Life Evaluation (1)
- Fatigue Testing (1)
- Fatigue of sandwich structures (1)
- Fiber reinforced polymers (1)
- Fiber-matrix interface (1)
- Fiber/matrix bond (1)
- Fibre reinforced plastic (1)
- Fibre/matrix bond (1)
- Fibre/matrix bonding (1)
- Force-distance diagram (1)
- Four-point bending test (1)
- Fourier transform infrared spectroscopy (1)
- Fracture behavior (1)
- Fracture surface (1)
- Fracture surfaces (1)
- Fracture toughness (1)
- Fuel sorption (1)
- Full Notch Creep Test (FNCT) (1)
- Full notch creep test (1)
- Full-Notch Creep Test (1)
- Full-notch creep test (1)
- GC-MS (1)
- General Aviation (1)
- Geometrical factors (1)
- Glas fibre reinforced polymer (1)
- Glasfaserverstärkter Kunststoff (1)
- Glass Fibres (1)
- Glass capillaries (1)
- Glass fiber reinforced polymer (1)
- Glass fiber-epoxy composites (1)
- Glass fibre (1)
- Glass fibre reinforced plastics (1)
- HDPE Soprption (1)
- HDPE Sorption (1)
- High density polyethylene (1)
- High-density polyethylene (PE-HD) (1)
- High-temperature properties (1)
- Hydrogel (1)
- Hydrogen storage (1)
- Hydrothermal Ageging (1)
- Hygrothermal (1)
- Imaging (1)
- Imaging techniques (1)
- Indentation hardness (1)
- Initial attachment (1)
- Interface Strength (1)
- Interfacial Strength (1)
- Intermediate scale (1)
- Internal Surfaces (1)
- Interphase (1)
- Joints/joining (1)
- Keywords: Poly(ether ether ketone) (1)
- Klebung (1)
- Knowledge Representation (1)
- Komponentenprüfung (1)
- Kurzfaser-verstärkte Thermoplaste (1)
- Laminographie (1)
- Laser Scanning Microscopy (LSM) (1)
- Laserscanningmikroskopie (LSM) (1)
- Light curing (1)
- Lightweighting (1)
- Linear elastic fracture mechanics (1)
- Long-term calculation (1)
- Lösungsmittel (1)
- Manufacturing (1)
- Masterschädigungslinie (1)
- Material degradation (1)
- Material failure (1)
- Materialmodell (1)
- Materialwissenschaft (1)
- Matrix (1)
- Matrix residual stress (1)
- Mechanical and thermal testing (1)
- Mechanical deformation (1)
- Microstructural orientation (1)
- NDT (1)
- Nahinfrarotspektroskopie (1)
- Natural (1)
- Near Infrared Spectroscopy (1)
- New standards (1)
- Nondestructive testing (1)
- Normung (1)
- Oberflächenaktive wässrige Medien (1)
- Ontology (1)
- Optical backscatter reflectometry (1)
- Optical criterion (1)
- Optical criterion of brittleness (1)
- Optical fibre (1)
- Orientation-dependent microstructure (1)
- PA6.6 (1)
- PE-HD Sorption (1)
- PLS-DA (1)
- PPA (1)
- Packaging (1)
- Permeability (1)
- Phase transformation (1)
- Photocleavable organosilanes (1)
- Photopolymer composites (1)
- Phytolith (1)
- Plasma nanocoatings (1)
- Plasticity (1)
- Polymer Matrix Composite (1)
- Polymer analysis/characterization (1)
- Polymer composite (1)
- Polymer-matrix composites (PMC) (1)
- Polymerwissenschaften (1)
- Polymer–matrix composites (1)
- Polyolefins (1)
- Polypropylene (1)
- Polystyrene (1)
- Powdered activated carbon (1)
- Pull-out (1)
- Pull-out composite materials (1)
- Pultruded fiber rods (1)
- Renewable ernergy (1)
- Repair of sandwich shell structures (1)
- Repair patch (1)
- Rohrprobekörper (1)
- Rotorblatt (1)
- Rotorblätter (1)
- Sailplane Development Panel (1)
- Sandwich structures (1)
- Sandwichstruktur (1)
- Scanning Electron Microscopy (SEM) (1)
- Scanning acoustic microscopy (SAM) (1)
- Scarf joint (1)
- Scarf joint repair (1)
- Scarf joint repairs (1)
- Schalenprüfstand (1)
- Semantic Web Technologies (1)
- Sewage treatment plant (1)
- Short-beam strength (1)
- Single fiber pull-out test (1)
- Slow Crack Growth (SCG) (1)
- Slow crack growth (1)
- Smart materials (1)
- Soil (1)
- Soil sample (1)
- Spar cap design (1)
- Stress intensity factor (1)
- Structural composites (1)
- Structural health monitoring (1)
- Structural health monitoring (SHM) (1)
- Support vector machines (1)
- Surface modification (1)
- Surface treatments (1)
- Swept wavelength interferometry (1)
- Swept wavelength interferometry (SWI) (1)
- Synthesis (1)
- TED (1)
- Test Improvement (1)
- Thermal cycling (1)
- Thermal degradation (1)
- Thermal desorption mass spectrometry (1)
- Thermische Analyse (1)
- Thermo mechanical fatigue (1)
- Thermo-mechanical-loading (1)
- Thermo-mechanics (1)
- Thermoanalysis (1)
- Thermographie (1)
- Thermoplastic (1)
- Thermoplastic matrix (1)
- Thermoplastic prepreg (1)
- Thermoset composition (1)
- Thermosetting resin (1)
- Tooth wear (1)
- Transducers (1)
- Umgebungsbedingter Spannungsriss (1)
- Unidirectional composites (1)
- Verbundwerkstoffe (1)
- Very high cycle fatigue (1)
- Viscoelastic model (1)
- Volatiles from thermosets (1)
- WAXS (1)
- Waste water (1)
- Water Diffusion (1)
- Werkstoffdaten (1)
- Werkstoffprüfung (1)
- Wind turbine blade shell structures (1)
- Windkraft (1)
- Work of adhesion (1)
- X-ray computed tomography (CT) (1)
- X-ray refractography (1)
- ZfP (1)
- Zirconia (1)
- Zug-Druck-Schubprüfung (1)
- multi scale testing (1)
- thermomechanische Beanspruchung (1)
Organisationseinheit der BAM
- 5.3 Polymere Verbundwerkstoffe (129) (entfernen)
Paper des Monats
- ja (1)
Eingeladener Vortrag
- nein (52)
3D structural investigations are described by X-ray laminography studies of sandwich shell segments, made of a PVC foam core, covered by non-crimp fabric glass fibre composite lay-ups processed by vacuum assisted resin infusion of epoxy. The specific scope of this study is to image transversal flaws within the foam core (joints) and of single ply overlaps. Test flaws were purposely implemented in order to simulate typical failure under cyclic load. In a dedicated test rig for shell structures, the flaw evolution/propagation is monitored by thermography and optical 3D inspection of deformation. Due to the unfavourable preconditions for classical computed tomography as of large aspect ratio, the samples were investigated by coplanar translational laminography. Its limited range of observation angles of ± 45°, results in anisotropic artefacts about the normal to the sample surface, but the typical flaws are well visualized in the as-prepared state, in a state of early damage, and in the repaired state.
Um den sicheren Betrieb von Windkraftanlagen zu gewährleisten, werden Rotorblätter nach der Fertigung und nach Reparatur mit verschiedenen zerstörungsfreien Verfahren auf Schaden untersucht. Bei der Fertigung von Blattschalen, die in einer Sandwich-Schalenbauweise gefertigt werden, entstehen Imperfektionen, die unter Belastung zu großen Rissen führen können. Zur Prüfung von Blattschalen wird unter anderem Ultraschallprüfung in Kontakttechnik eingesetzt. Um den Wartungsaufwand von Ultraschallanlagen zu reduzieren und um manche Kompositstrukturen vor Koppelmittel zu schützen, wird die Anwendung von Luftultraschall erforscht. Insbesondere große Fortschritte gibt es im Bereich der Entwicklung neuer Wandler.
In diesem Beitrag berichten wir über die Luftultraschallprüfung von Schalen für Rotorblätter. Es wurden typische Sandwichschalenstrukturen hergestellt und mit einem eigenentwickelten Schalenprüfstand unter simulierter Betriebsbeanspruchung belastet. Die in den Schalenprüfkörpern entstandenen Schäden wurden außerhalb des Prüfstandes mit Luftultraschall in Durchschallung untersucht. Es wurden fokussierende Wandler auf Basis von Ferroelektreten entwickelt und für diese Prüfungen eingesetzt. Mit zusätzlicher elektrischer Vorspannung konnte die Empfindlichkeit der Empfänger deutlich erhöht werden. Die nach dem Lastwechsel entstandenen Schäden in den Rotorblattschalen waren eindeutig zu detektieren.
Um den sicheren Betrieb von Windkraftanlagen zu gewährleisten, werden Rotorblätter nach der Fertigung und nach Reparatur mit verschiedenen zerstörungsfreien Verfahren auf Schaden untersucht. Bei der Fertigung von Blattschalen, die in einer Sandwich-Schalenbauweise gefertigt werden, entstehen Imperfektionen, die unter Belastung zu großen Rissen führen können. Zur Prüfung von Blattschalen wird unter anderem Ultraschallprüfung in Kontakttechnik eingesetzt. Um den Wartungsaufwand von Ultraschallanlagen zu reduzieren und um manche Kompositstrukturen vor Koppelmittel zu schützen, wird die Anwendung von Luftultraschall erforscht. Insbesondere große Fortschritte gibt es im Bereich der Entwicklung neuer Wandler.
In diesem Beitrag berichten wir über die Luftultraschallprüfung von Schalen für Rotorblätter. Es wurden typische Sandwichschalenstrukturen hergestellt und mit einem eigenentwickelten Schalenprüfstand unter simulierter Betriebsbeanspruchung belastet. Die in den Schalenprüfkörpern entstandenen Schäden wurden außerhalb des Prüfstandes mit Luftultraschall in Durchschallung untersucht. Es wurden fokussierende Wandler auf Basis von Ferroelektreten entwickelt und für diese Prüfungen eingesetzt. Mit zusätzlicher elektrischer Vorspannung konnte die Empfindlichkeit der Empfänger deutlich erhöht werden. Die nach dem Lastwechsel entstandenen Schäden in den Rotorblattschalen waren eindeutig zu detektieren.
3D structural investigations are described by X-ray laminography studies of sandwich shell segments, made of a PVC foam core, covered by non-crimp fabric glass fibre composite lay-ups processed by vacuum assisted resin infusion of epoxy. The specific scope of this study is to image transversal flaws within the foam core (joints) and of single ply overlaps. Test flaws were purposely implemented in order to simulate typical failure under cyclic load. In a dedicated test rig for shell structures, the flaw evolution/propagation is monitored by thermography and optical 3D inspection of deformation. Due to the unfavourable preconditions for classical computed tomography as of large aspect ratio, the samples were investigated by coplanar translational laminography. Its limited range of observation angles of ± 45°, results in anisotropic artefacts about the normal to the sample surface, but the typical flaws are well visualized in the as-prepared state, in a state of early damage, and in the repaired state.
Motivation:
> Zunehmender Einsatz von Pulveraktivkohle (PAK) zur
Spurenstoffelimination in kommunalen Kläranlagen
> Bisher keine analytische Methode zur Quantifizierung von PAK in
Belebungsbecken, bzw. in Gegenwart von Belebtschlamm
> Anwendung der Thermogravimetrischen Analyse (TGA) zur
Feststoffcharakterisierung auf Umweltfragestellungen
Ergebnisse:
> Quantifizierung von PAK in Belebtschlamm ist möglich und kann
über unterschiedliche zweistufige TGA-Methoden erfolgen
> Zersetzungsgasanalyse zeigt veränderte und verzögerte
Freisetzung aliphatischer Produkte des Belebtschlamms
Advanced wastewater treatment with powdered activated carbon (PAC) leads to a spread of PAC into different purification stages of wastewater treatment plants (WWTP) due to recirculation and filter back-wash. Currently, no methods for quantification of PAC in activated sludge are available. In this study, PAC containing activated sludge from four WWTP were examined by two-step thermogravimetric analysis (TGA) with heating up to 600°C in N2 and subsequently in synthetic air. Direct quantification of PAC according to temperature specific weight losses was possible for one WWTP. Quantification by combining specific mass losses was found to be an alternative direct method, with a detection limit of 1.2% PAC in dry sample mass.
Additionally, evolved gas analysis (EGA) by infrared-spectroscopy (FTIR) during TGA revealed interaction mechanisms between PAC and activated sludge. Aliphatic compounds from activated sludge were identified as major substances influenced by PAC. In derivative thermogravimetry (DTG), a typical double peak at approximately 300°C was found to be related to carbonylic species with increased evolution of acetic acid in aged activated sludge. TGA and EGA are promising tools to understand, control and optimise the application of PAC in advanced wastewater treatment.
The presence, fate and effects of microplastics (MP) in terrestrial systems are largely unknown. The few existing studies investigated either agricultural or industrial sites. Several techniques were used for analysis, primarly spectroscopic methods such as FTIR or Raman. Sample pretreatments like density separations are common to reduce matrix. A lack of harmonised and standardised sampling instructions for microplastic investigations in the terrestrial area was identified as particular critical, because different studies are barely comparable.
The aim of the project is to develop a proposal for a harmonized procedure for sampling, sample preparation and the detection of microplastics in terrestrial matrices for total content determination. By detecting specific degradation products the thermal extraction desorption gas chromatography mass spectrometry (TED-GC-MS) allows a direct determination of mass content of MP in environmental samples.
As the well-known damage mechanisms slow crack growth (SCG) and environmental stress cracking (ESC) are the major causes for possible failure of polyolefin-based materials, especially for PE-HD, they are highly relevant and need to be considered thoroughly. Furthermore, due to slight but perceptible differences in damaging effect, a differentiation between SCG and ESC is expedient. SCG appears in “inert” or “neutral” media without a decisive influence of the surrounding medium whereas ESC occurs in “active” media, which influence the failure behavior and time to failure crucially.
To characterize the inherent resistance of the material against those damage mechanisms, the well-established Full-Notch Creep Test (FNCT) is used. In this study, the FNCT – usually applied according to ISO 16770 [3] using a few universal model liquid media and mainly for pipe materials – is extended by investigations with appropriate parameters of selected relevant PE-HD container materials also in real media, such as the topical fuels diesel and biodiesel. The investigations were performed using a novel FNCT-device with 12 individual sub-stations, each equipped with individual electronic stress and temperature control and continuous online monitoring of the specimen elongation.
Especially, mechanical stress and temperature were varied systematically during FNCT and time to failure values, time-dependent elongation data as well as detailed fracture surface analysis by laser scanning microscopy (LSM) were combined for the first time (Fig. 1). Particularly, the fracture surface analysis provides a sound basis to characterize failure behavior, mainly regarding the balance between brittle crack propagation and ductile deformation. Therefore, fracture surface analysis is an essential tool for a decent assessment of SCG and ESC by FNCT measurements.