Open Access
Refine
Document Type
- Article (132)
- Conference Proceeding (72)
- Report (4)
- Doctoral Thesis (3)
Language
- English (211) (remove)
Is part of the Bibliography
- yes (211) (remove)
Keywords
- virtual reality (9)
- Business Process Management Systems (4)
- Fuzzy Logic (4)
- visualization (4)
- Assignment Automation (2)
- Augmented Reality (2)
- Business Process Modeling Notation (2)
- Git (2)
- Systems Modeling Language (SysML) (2)
- artificial neural networks (2)
- machine learning (2)
- software configuration management (2)
- software design pattern detection (2)
- software engineering (2)
- systems engineering (2)
- systems modeling (2)
- version control systems (2)
- Business Process Modelling (1)
- Re- source Assignment Automation (1)
- Resource Allocation Algorithms (1)
- Resource Assignment Automation (1)
- Rule Engines (1)
- Staff Assignment Algorithms (1)
- augmented virtuality (1)
- business process management (1)
- business process mining (1)
- code coverage (1)
- data pipelines (1)
- data stream processing (1)
- event stream processing (1)
- event-driven architecture (1)
- graph analysis (1)
- graph embeddings (1)
- integrated development environments (1)
- mixed reality (1)
- process analysis (1)
- process mining (1)
- requirements traceability (1)
- rule-based expert system (1)
- software requirements traceability (1)
- software test coverage (1)
- software test traceability (1)
- software testing (1)
- software verification and validation (1)
Institute
- Wirtschaftswissenschaften (71)
- Maschinenbau und Werkstofftechnik (55)
- Elektronik und Informatik (34)
- Optik und Mechatronik (34)
- Chemie (9)
- Maschinenbau/Fertigungstechnik (1)
- Mechatronik (1)
Adoption of artificial intelligence technologies in German SMEs — Results from an empirical study
(2021)
Forming complex parts out of high and ultra-high strength aluminium alloys has proved to be more challenging in comparison to the currently used deep drawing steels. Nevertheless, aluminium alloys show a limited formability in contrast with, for example, deep drawing steels. Novel processes like Warm-forming, W-Temper or Hotforming, offer the potential to produce light and highly integrated one-piece components from such aluminium alloys at elevated temperatures. When considering aluminium alloys of the 7000 group, which can reach strength values (UTS) of about 600 MPa, crash components such as side impact bars would offer a suitable field of application.
Forming at elevated temperatures, in particular with the Hotforming process, offers high potential in the production of complex structural components on the one hand and in the use of existing press hardening equipment on the other. To date, the material behaviour of aluminium alloys in the 7000 group, applied in such processes and in the later final state after forming, is not sufficiently known.
Therefore, in this study, systematic investigations on the formability and the final strength during and after forming at elevated temperature of the EN AW-7075 aluminium wrought alloy from different suppliers are conducted. In general, material- and damage/ failure models were created and implemented into simulation in order to make predictions. Characterisation of the plastic material properties on the basis of various tensile specimens as shear-, notched-, tensile- and Erichsen tests are carried out to adapt the complex material- and failure models such as Barlat YLD2000 and GISSMO to the experimental values using a parameter optimisation. These were made for the material conditions during forming, i.e. after solution heat treatment, the final condition after artificial ageing at 180°C for 20 minutes, which corresponds to the cathodic dip coating, and the T6 condition, which is the highest strength condition.
To evaluate a suitable friction coefficient for high temperature forming processes, anti-friction agents are screened, and the potential applicability evaluated by strip-drawing tests. Thereby, using an analytical relationship, friction coefficients are determined at room temperature and 180°C, which are used as corresponding friction model for the finite element forming simulation.
Crash simulations using the nonlinear finite element method (FEM) of side impact protection beams are used to demonstrate the weight saving potential of high and ultra-high strength aluminium alloys compared to a beam made of press hardened steel. A weight saving of about 20 % could be achieved with the same crash performance. This can be significantly increased to around 30 % - 40 % by using local reinforcements such as CFRP or GFRP (carbon/ glass fibre reinforced plastic) patch. For this reason, a novel process was developed which is based on the conventional Hotforming process with an integrated thermal direct joining step called “Extended Hotforming”.
Subsequently, a heatable forming tool for the production of a serial like sheet metal side impact beam was developed to validate the finite element simulation and to demonstrate the potential of the forming processes at elevated temperatures for aluminium sheet metal components.
Application of a robotic THz imaging system for sub-surface analysis of ancient human remains
(2019)
We used a robotic-based THz imaging system to investigate the sub-surface structure of an artificially mummified ancient Egyptian human left hand. The results obtained are compared to the results of a conventional CT and a micro-CT scan. Using such a robotic THz system promises new insights into the sub-surface structure of human remains. The depth resolution of the THz images exceeds the resolution of a conventional CT scan and is comparable with a micro-CT scan. The advantage of THz measurements over micro-CT scans is the fact that even comparatively large samples, like complete bodies, can be scanned. These would not fit into a conventional micro-CT scanner.