Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Erscheinungsjahr
Dokumenttyp
- Beitrag zu einem Tagungsband (530) (entfernen)
Sprache
- Englisch (530) (entfernen)
Schlagworte
- Corrosion (30)
- Laser beam welding (20)
- Wear (19)
- Additive manufacturing (18)
- Friction (16)
- Additive Manufacturing (13)
- Niobium carbide (13)
- Fatigue (12)
- Hydrogen (12)
- Steel (12)
Organisationseinheit der BAM
- 9 Komponentensicherheit (108)
- 7 Bauwerkssicherheit (69)
- 5 Werkstofftechnik (45)
- 9.3 Schweißtechnische Fertigungsverfahren (45)
- 8 Zerstörungsfreie Prüfung (40)
- 7.6 Korrosion und Korrosionsschutz (29)
- 5.1 Mikrostruktur Design und Degradation (24)
- 9.5 Tribologie und Verschleißschutz (24)
- 7.1 Baustoffe (22)
- 6 Materialchemie (19)
- 8.0 Abteilungsleitung und andere (19)
- 9.4 Integrität von Schweißverbindungen (19)
- 9.6 Additive Fertigung metallischer Komponenten (15)
- 3 Gefahrgutumschließungen; Energiespeicher (13)
- 4 Material und Umwelt (13)
- 7.4 Baustofftechnologie (13)
- 5.2 Metallische Hochtemperaturwerkstoffe (11)
- 9.2 Versuchsanlagen und Prüftechnik (9)
- 6.2 Material- und Oberflächentechnologien (8)
- 8.4 Akustische und elektromagnetische Verfahren (8)
- 8.5 Röntgenbildgebung (8)
- 9.0 Abteilungsleitung und andere (8)
- 2 Prozess- und Anlagensicherheit (7)
- 3.4 Sicherheit von Lagerbehältern (7)
- 5.3 Polymere Verbundwerkstoffe (6)
- 1 Analytische Chemie; Referenzmaterialien (5)
- 4.2 Material-Mikrobiom Wechselwirkungen (5)
- 6.6 Physik und chemische Analytik der Polymere (5)
- 1.2 Biophotonik (4)
- 4.1 Biologische Materialschädigung und Referenzorganismen (4)
- 5.5 Materialmodellierung (4)
- 6.1 Oberflächen- und Dünnschichtanalyse (4)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (4)
- 4.5 Kunst- und Kulturgutanalyse (3)
- 5.4 Multimateriale Fertigungsprozesse (3)
- 7.2 Ingenieurbau (3)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (3)
- 7.7 Modellierung und Simulation (3)
- 8.6 Faseroptische Sensorik (3)
- 2.1 Sicherheit von Energieträgern (2)
- 2.2 Prozesssimulation (2)
- 3.0 Abteilungsleitung und andere (2)
- 3.2 Gefahrguttanks und Unfallmechanik (2)
- 5.0 Abteilungsleitung und andere (2)
- 6.5 Synthese und Streuverfahren nanostrukturierter Materialien (2)
- 7.0 Abteilungsleitung und andere (2)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (2)
- 1.4 Prozessanalytik (1)
- 2.0 Abteilungsleitung und andere (1)
- 2.4 Prüfung und Bewertung von Explosivstoffen/Pyrotechnik (1)
- 2.5 Konformitätsbewertung Explosivstoffe/Pyrotechnik (1)
- 3.1 Sicherheit von Gefahrgutverpackungen und Batterien (1)
- 3.5 Sicherheit von Gasspeichern (1)
- 4.3 Schadstofftransfer und Umwelttechnologien (1)
- 5.6 Glas (1)
- 6.3 Strukturanalytik (1)
- 7.3 Brandingenieurwesen (1)
- 8.3 Thermografische Verfahren (1)
Even after autoclaving for 2 weeks in the temperature range of 120 to 200 °C, CEM I paste with a water-to-cement ratio of 0.5 still contains some low-crystalline C-S-H. The conversion of low-crystalline C-S-H to crystalline is faster with increasing temperature. The observed low-crystalline and crystalline C-S-H phases (reinhardbraunsite, jaffeite) indicate that the sampleshave not reached equilibrium yet under these experimental conditions. However, there is a good agreement between experiment and thermodynamic modelling for the other solids indicating that the used datasets are suitable for this application.
The European Commission has identified Advanced Manufacturing and Advanced Materials as two of six Key Enabling Technologies (KETs). It is considered that Metrology is a key enabler for the advancement of these KETs. Consequently, EURAMET, the association of metrology institutes in Europe, has strengthened the role of Metrology for these KETs by enabling the creation of a European Metrology Network (EMN) for Advanced Manufacturing. The EMN is comprised of National Metrology Institutes (NMIs) and Designated Institutes (DIs) from across Europe and was formally established in October 2021. The aim of the EMN is to provide a high-level coordination of European metrology activities for the Advanced Manufacturing community.
The EMN itself is organized in three sections representing the major stages of the manufacturing chain: 1) Advanced Materials, 2) Smart Manufacturing Systems, and 3) Manufactured Components & Products. The EMN for Advanced Manufacturing is engaging with stakeholders in the field of Advanced Manufacturing (large companies & SMEs, industry organisations, existing networks, and academia), as well as the wider Metrology community, including Technical Committees, to provide input for the Strategic Research Agenda (SRA) on Metrology for Advanced Manufacturing.
This contribution will give an overview about the first version of the SRA prepared by the EMN for Advanced Manufacturing
Degradation and damage analysis of composite pressure vessels via experimental modal analysis
(2023)
For mobile gas storage systems, the application of type IV pressure vessels is state of the art. Type IV tanks consist of an inner polymer liner fully wrapped with fibre-reinforced plastic (FRP). Because of the complex fabric of the FRP as well as a difficulty estimable interaction behaviour between the single components under load, there are still no satisfying non-destructive testing methods to assess the current state of failure nor to estimate the level of degradation accurately and economically. At BAM division 3.5, analysing the ageing process of mobile composite pressure vessels is a major task to ensure safe usage over the whole lifetime. In this context, key aspects of our ongoing research activities are the invention of new test procedures and the development of accurate lifetime prediction models. In order to determine the level of degradation or damage, one meaningful non-destructive approach is to analyse the structural dynamic behaviour via an experimental modal analysis (EMA). Over the last few years, different types and sizes of composite pressure vessels have been tested in several research projects. The presented paper gives an insight into how to extract and interpret modal parameters and how to fit them to the results of residual strength tests.
Structural build-up describes the stability and early-age strength development of fresh mortar used in 3D printing. lt is influenced by several factors, i.e. the composition of the print able material, the printing regime, and the ambient conditions. The existing modelling approaches for structural build-up usually define the model parameters for a specific material composition with out considering the influence of the ambient conditions. The goal of this contribution is to explicitly include the temperature dependency in the modelling approach. Temperature changes have signifi cant impact on the structural build-up process: an increase of the temperature leads to a faster dissol ution of cement phases and accelerates hydration. The proposed extended model includes temperature dependency using the Arrhenius theory. The new model parameters are successfully calibrated based on Viskomat measurement data using Bayesian inference. Furthermore, a higher impact of the temperature in the re-flocculation as in the structuration stage is observed.
In recent years, the use of simulation-based digital twins for monitoring and assessment of complex mechanical systems has greatly expanded. Their potential to increase the information obtained from limited data makes them an invaluable tool for a broad range of real-world applications. Nonetheless, there usually exists a discrepancy between the predicted response and the measurements of the system once built. One of the main contributors to this difference in addition to miscalibrated model parameters is the model error. Quantifying this socalled model bias (as well as proper values for the model parameters) is critical for the reliable performance of digital twins. Model bias identification is ultimately an inverse problem where information from measurements is used to update the original model. Bayesian formulations can tackle this task. Including the model bias as a parameter to be inferred enables the use of a Bayesian framework to obtain a probability distribution that represents the uncertainty between the measurements and the model. Simultaneously, this procedure can be combined with a classic parameter updating scheme to account for the trainable parameters in the original model.
This study evaluates the effectiveness of different model bias identification approaches based on Bayesian inference methods. This includes more classical approaches such as direct parameter estimation using MCMC in a Bayesian setup, as well as more recent proposals such as stat-FEM or orthogonal Gaussian Processes. Their potential use in digital twins, generalization capabilities, and computational cost is extensively analyzed.
In this study, we present an enhanced deep learning framework for the prediction of porosity based on thermographic in-situ monitoring data of laser powder bed fusion processes. The manufacturing of two cuboid specimens from Haynes 282 (Ni-based alloy) powder was monitored by a short-wave infrared camera. We use thermogram feature data and x-ray computed tomography data to train a convolutional neural network classifier. The classifier is used to perform a multi-class prediction of the spatially resolved porosity level in small sub-volumes of the specimen bulk.
Safety-critical applications of products manufactured by laser powder bed fusion (PBF-LB/M) are still limited to date. This is mainly due to a lack of knowledge regarding the complex relationship between process, structure, and resulting properties. The assurance of homogeneity of the microstructure and homogeneity of the occurrence and distribution of defects within complexly shaped geometries is still challenging. Unexpected and unpredicted local inhomogeneities may cause catastrophic failures. The identification of material specific and machine specific process parameter windows for production of fully dense simple laboratory specimens is state of the art. However, the incorporation of changing thermal conditions that a complexly shaped component can be faced with during the manufacturing process is often neglected at the stage of a process window determination. This study demonstrates the tremendous effect of changing part temperatures on the defect occurrence for the broadly used stainless steel alloy AISI 316L. Process intrinsic variations of the surface temperature are caused by heat accumulation which was measured by use of a temperature adjusted mid-wavelength infrared (MWIR) camera. Heat accumulation was triggered by simple yet effective temporal and geometrical restrictions of heat dissipation. This was realized by a variation of inter layer times and reduced cross section areas of the specimens. Differences in surface temperature of up to 800 K were measured. A severe development of keyhole porosity resulted from these distinct intrinsic preheating temperatures, revealing a shift of the process window towards unstable melting conditions. The presented results may serve as a warning to not solely rely on process parameter optimization without considering the actual process conditions a real component is faced with during the manufacturing process. Additionally, it motivates the development of representative test specimens.
Since 2016 ISO Technical Committee (TC) 265 is working on standardization the whole CCS-process chain. Around 30 countries are working together to provide international guidelines. As ISO 27913 was the first standard finished within these activities it is already in the stage of first revision.
The objective of ISO 27913 is “to provide specific requirements and recommendations on certain aspects of safe and reliable design, construction and operation of pipelines intended for the large-scale transportation of CO2 that are not already covered in existing pipeline standards such as ISO 13623, ASME B31.8, EN 1594, AS 2885 or other standards. Existing pipeline standards cover many of the issues related to the design and construction of CO2 pipelines; however, there are some CO2 specific issues that are not adequately covered in these standards. The purpose of this document is to cover these issues consistently. Hence, this document is not a standalone standard, but is written to be a supplement to other existing pipeline standards for natural gas or liquids for both onshore and offshore pipelines.”
This contribution shall provide information on the content, the current stage of the revision process, encourage to contribute to this standard and make listeners aware to consider the influence of ISO standard on documents currently in draft.
This research deals with the development of the Vickers hardness knowledge graph, mapping the example dataset in them, and exporting the data-mapped knowledge graph as a machine-readable Resource Description Framework (RDF). Modeling the knowledge graph according to the standardized test procedure and using the appropriate upper-level ontologies were taken into consideration to develop the highly standardized, incorporable, and industrial applicable models. Furthermore, the Ontopanel approach was utilized for mapping the real experimental data in the developed knowledge graphs and the resulting RDF files were successfully evaluated through the SPARQL queries.
Early detection of fatigue cracks and accurate measurements of the crack growth play an important role in the maintenance and repair strategies of steel structures exposed to cyclic loads during their service life. Observation of welded connections is especially of high relevance due to their higher susceptibility to fatigue damage. The aim of this contribution was to monitor fatigue crack growth in thick welded specimens during fatigue tests as holistically as possible, by implementing multiple NDT methods simultaneously in order to record the crack initiation and propagation until the final fracture. In addition to well-known methods such as strain gauges, thermography, and ultrasound, the crack luminescence method developed at the Bundesanstalt für Materialforschung und -prüfung (BAM), which makes cracks on the surface particularly visible, was also used. For data acquisition, a first data fusion concept was developed and applied in order to synchronize the data of the different methods and to evaluate them to a large extent automatically. The resulting database can ultimately also be used to access, view, and analyze the experimental data for various NDT methods. During the conducted fatigue tests, the simultaneous measurements of the same cracking process enabled a comprehensive comparison of the methods, highlighting their individual strengths and limitations. More importantly, they showed how a synergetic combination of different NDT methods can be beneficial for implementation in large-scale fatigue testing but also in monitoring and inspection programs of in-service structures - such as the support structures of offshore wind turbines.