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Total Focusing in the Virtual Wave Domain: 3D Defect Reconstruction Using Spatially Structured Laser Heating
No full textClassical active thermographic testing of industrial goods has mostly been limited to generating 2D defect maps. While for surface or near-surface defect detection, this is a desired result, for deeply buried defects, a 3D reconstruction of the defect geometry is coveted. This general trend can also be well observed in widely used NDT methods (radiography, ultrasonic testing), where the progression from 2D to 3D reconstruction methods has already made profound progress (CT, UT phased array transducers). Achieving a fully 3D defect reconstruction in active thermographic testing suffers from the diffusive nature of thermal processes. One possible solution to deal with thermal diffusion is the application of the virtual-wave concept, which, by solving an inverse problem, allows the diffusiveness to be extracted from the thermographic data in the post-processing stage. What is left follows propagating-wave physics, enabling the usage of well-known algorithms from ultrasonic testing. In this work, we present our progress in the 3D reconstruction of deeply buried defects using spatially structured laser heating in conjunction with applying the well-known total focusing method (TFM) in the virtual-wave domain
Examples for controlling safety in hydrogen systems
No full textFirst, BAM and its hydrogen competence centre H2Safety@BAM were briefly introduced.
This was followed by three examples of BAM's approaches to meeting the challenges of the hydrogen ramp-up. Afterwards, four examples were presented that show how safety can be better managed in factories.
In the final part, the approaches and successes to date in bilateral cooperation within the framework of the BMBF bridge project ‘H2 Safety Collaboration’ were presented and the possibilities for establishing contact and further cooperation were highlighted
Welding Process Data Management - openBIS workflows and lab integration
No full textArc welding processes are an important manufacturing technology applied to a wide range of critical materials and components such as offshore constructions, pressure vessels and additive manufacturing. Data management for experimental arc welding research faces the challenge of constantly changing experimental setups, incorporating a wide range of custom sensor integrations. Measurements include timeseries process and temperature recordings, 3D-geometry data and video recordings of the process from a sub-millisecond scale to multiple hour-long experiments. In addition, various manual pre-processing steps of the workpieces need to be considered to track the complete manufacturing process and its analysis – from raw materials to final dataset and publication.
As a unified RDM system, the BAM Data Store offers the capability to incorporate all steps – albeit not without its own challenges.
The talk gives an overview of the different workflows and processing steps along the welding experiments together with their integration into the BAM Data Store. Current solutions and ongoing integration work is explained and discussed. This includes the direct integration and upload of automated processing steps into the Data Store from different machines and sensors using custom Python APIs.
Ultimately the complete processing chain across multiple internal steps should be represented in the Data Store
Interfaces Under the Isotopic Lens: Rethinking Degradation in Lithium-Ion Batteries
No full textThis work investigates Li isotope fractionation in Li-ion batteries, questioning whether there is a correlation between chenges in isotopic distribution and battery capacity loss (cell degradation). The results point to Li-isotope distribution as a new benchmark for electrode/electrolyte interfaces investigation, which can potentialy provide information about the interface formation mechanism
Stand der Normung in den Bereichen Explosivstoffe und Pyrotechnik
No full textDer Vortrag gibt einen Überblick über die Aktivitäten in den Normungsgremien des CEN/TC 212 Pyrotechnics und CEN/TC 321 Civil Explosives. Es werden die aktuellen Themen, Herausforderungen und ein Blick in die Zukunft vorgestellt
Digital LabHub: Inkubator für die Digitale Transformation der Laborbranche
No full textIn den Praxiswerkstätten für Prüf- und Kalibrierlabore, einem Dialogprozess mit der Laborbranche, der von BAM, DAkkS und dem Verband unabhängiger Prüflabore gestaltet wurde, wurde der Bedarf der Labore nach einem Zentralen Informations- und Netzwerkangebot zum Thema digitale Transformation im Labor als zentral identifiziert. Der Vortrag präsentiert die daraufhin gestartete Initiative des Digital Labhub. Als Zusammenschluss zentraler Akteure zu Themen der digitalen Transformation im Labor, treiben die Akteur*innen gemeinsam die Gestaltung eines vernetzten, standardisierten und interoperablen digitalen Labor-Ökosystems voran. Der Vortrag gibt Einblick in die Initiative
Hollow Specimen Method for Tests in High-Pressure Hydrogen Gas: The Role of Strain-Rate and Surface Quality
No full textThe hollow specimen technique is a simple and economical technique that has the potential to make materials qualification with pressurised gaseous hydrogen widely accessible to academia and industry.
This contribution focuses on the results obtained from assessing the influence of the specimen production and its response to hydrogen effects. Depending on the production method, different roughness and residual stresses can be expected on the inner hole surface of the specimens. This is relevant because an increase in stress concentration sites, e.g. notches, has been found to be associated with increased severity of hydrogen effects. The presence of strain-induced martensite caused by mechanical stress may also be detrimental and accelerate the embrittlement. To assess this influence, the inner hole of the hollow specimens was manufactured in two different ways: 1) only drilling; 2) EDM followed by honing.
A representative steel widely used in hydrogen technologies was assessed, X5CrNi18-10 (AISI 304). Roughness measurements, and electron back-scatter diffraction (EBSD) analysis have been performed previous to mechanical testing to infer on the effect of the different production methods on the surface of the inner hole. Next, the specimens were mechanically tested via slow strain rate tensile tests in argon and in hydrogen, both at 150 bar and room temperature. Here, a strain-rate sensibility analysis was performed to investigate the influence of strain-rate on hydrogen degradation
About the Toxicity of Polymerization Catalysts and Polymer Additives Based on Tin(II) Salts and Tin(IV) Compounds
No full textThis article reviews and discusses information on the toxicity of numerous tin-based catalysts used in academic research and industrial production for the synthesis of various polymers, such as polyesters, polyurethanes, and polysiloxanes. Tin(IV) compounds used as additives and as PVC stabilizers are also considered. Emphasis is put on the differentiation between tin(II) salts on the one hand and tin(IV) compounds on the other hand. In the first chapter, historical facts about human contact with stannous ions are discussed, along with toxicity studies of canned foods and beverages. In the second part, toxicity tests based on cell cultures and medical applications of tin(II)-containing films or implants are described. The third part focuses on alkyl and aryl tin(IV) compounds
Euro-MIC COST Action CA20130 Closing Workshop & Conference
No full textEnsuring the safety of offshore wind structures (OWS) is critical to guaranteeing their long-term performance and supporting reliable green energy supply. Microbiologically influenced corrosion (MIC) presents a significant challenge, particularly for monopiles in seabed environments. This study investigates the behavior of microorganisms and their impact on the corrosion process of carbon steel within monopiles. To simulate MIC at the sediment/water interface, an in-house experimental column was developed and inoculated with sediment and water samples from the North Sea. The system was operated under varying flow rates to replicate seabed movement conditions. Multiple molecular microbiological methods, surface analysis techniques, and other approaches were employed to assess the effects of different treatments. This study provides insights into MIC mechanisms in offshore environments and supports the development of strategies to monitor MIC in OWS infrastructur
Unveiling aluminum diethyl phosphinate dual identity: Transfer from epoxy resins to glass fiber-reinforced composites
No full textThis study examines the transfer of the flame-retardant aluminum diethyl phosphinate (AlPi) from epoxy resins to composites and the impact of AlPi on fire behavior and fire stability. Further, the effects of different particle sizes and the addition of zinc hydroxy stannate (ZHS) and inorganic silicate (InSi) are investigated. The research provides a detailed analysis of the fire behavior, fire stability, pyrolysis, flame-retardant modes of action, and flame retardancy index. Interestingly, the particle sizes did not significantly affect the flammability, fire behavior, or fire stability in the systems investigated. AlPi acts primarily in the gas phase, releasing phosphorus that yields flame inhibition. Adding glass fibers (GFs) to the epoxy resin boosts the flame retardancy in the condensed phase, reducing the heat release rate (HRR), total heat release (THR), and peak heat release rate (PHRR) by about 60%. This improvement is largely due to replacing fuel and forming a protective layer during burning. Despite the differences between thermoset and composite, the study demonstrates an effective transfer of flame-retardant properties from epoxy resins to fiber-reinforced composites, significantly enhancing the flame retardancy performance in both material systems