Weimar – a Personal Tribute. - Ilmenau : Universitätsverlag Ilmenau, 2023. - 1 Online-Ressource ([XII], 376 Seiten). - (Berichte aus dem Institut für Maschinen- und Gerätekonstruktion (IMGK) ; Band 39)
Weimar is a relatively small town in the centre of Germany. Around 1552 it became the capital of the small Herzogtum Sachsen-Weimar (Principality Saxony-Weimar), from 1741 until 1918 the capital of the (still relatively small) Principality – since 1815 Grand Principality – (Groß-) Herzogtum Sachsen-Weimar-Eisenach (Saxony-Weimar-Eisenach). After World War I all monarchic structures in Germany were abandoned, the democratic Free State of Thuringia was founded in 1920, and Weimar became its capital until 1950. - Despite its moderate size, Weimar managed to gain a cultural profile that extended and still extends far beyond the borders of the (Grand-) Principality, even beyond Germany. The foundations were laid in the 18th and early 19th century, connected to writers and pilosophers like Christoph Martin Wieland, Johann Wolfgang von Goethe, Johann Gottfried von Herder, and Friedrich von Schiller who all lived and worked in Weimar. In the late 19th and early 20th century more writers, musicians and artists contributed to Weimar’s reputation, e.g. Franz Liszt, Richard Strauss, Hugo von Hofmannsthal, Harry Graf Kessler, Henry van de Velde, Edvard Munch, Walter Gropius, Paul Klee, Oskar Schlemmer, Wassily Kandinsky, Lyonel Feininger. - In politics, Weimar played ambiguous roles between a comparatively liberal (Grand) Principality, the birth place of the first democratic state in Germany (Weimar Republic), turning “brown” (National-Socialist) from the late 1920s, Communist after World War II, democratic again after the German re-unification in 1990. - Weimar is a very special, even intriguing place. This book tries to convey its aura by telling its story from the early beginnings in the 16th century until today, with a main focus on the last three centuries – embedded into pan-German, even pan-European developments.
Systematic optimisation process for an eBike drive unit in a highly variable environment. - In: Proceedings of the Design Society, ISSN 2732-527X, Bd. 3 (2023), S. 3305-3314
Drive units of eBikes are used in every type of bicycle and for different riding scenarios and riders. Due to the different riders and bike types, an enormous variety of influencing parameters and load spectra must be considered during the design process. Therefore, in this paper, a systematic approach for the optimization of the drive unit is presented, which adopts and combines several approaches from design theory. The focus is on efficient modeling and simulation of the relevant parameters and load spectra to minimize uncertainties in the design process. Based on a system analysis, dimension-reduced parameter spaces are formed for the simulation of the system, meta-models are integrated into the simulation model and the results of the simulation are transferred into a data-based surrogate model to cover the parameter space in an efficient way with a minimum number of time consuming FE simulations. Furthermore, a coordinate-based evaluation method is presented for the FE model in order to form the input for the surrogate model, reduces the amount of data, and to allows a geometry- and mesh-independent evaluation to compare different models.
Perspectives on robust design - an overview of challenges and research areas across industry fields. - In: Proceedings of the Design Society, ISSN 2732-527X, Bd. 3 (2023), S. 2885-2894
Robust Design offers a coherent and widely appreciated approach for the parametric exploration of the design space by means of simulation or experimentation, which is well-established in the quality-by design domain. From the perspective of design research, however, this only addresses a relatively narrow part of the design process and is not fully integrated with other design decisions such as concept exploration, the suitable configuration of system elements, or the design of interfaces. Particularly in light of the growing importance of developing technologically advanced and “smart” systems, it seems that a new methodical perspective on Robust Design is needed. Against this background, this paper consolidates knowledge and insights from different research fields and industry sectors. On this basis, new angles to the discussion on product robustness in different domains are explored in order to suggests directions for action and new research areas, both with respect to a methodical RD approach as well as the question of systematic research procedures.
Model-based systems engineering using security design patterns in the context of ISO/SAE 21434. - In: Proceedings of the Design Society, ISSN 2732-527X, Bd. 3 (2023), S. 2675-2684
The development of modern vehicles is complex, especially regarding compliance with security and safety. ISO/SAE 21434 considers security and safety along the entire product life cycle. According to the standard, a system architecture, a risk analysis, and the application of countermeasures are carried out in the early system design. Design patterns are solutions to known design problems. Security Design Patterns (SDP) describe countermeasures and are used to reduce risk. After our literature review, we did not find a suitable approach that presents SDPs that would be applicable in early system design. In this paper, we present 10 SDPs for early system design, which we evaluated during an 11-week student project with 28 teams. We present the results of the quantitative analysis and the evaluation of the feedback.
Systemic conception of the data acquisition of Digital Twin solutions for use case-oriented development and its application to a gearbox. - In: Systems, ISSN 2079-8954, Bd. 11 (2023), 5, 227, S. 1-17
Digital Twins are being used more and more frequently and provide information from the Real Twin for different applications. Measurements on the Real Twin are required to obtain information, which in many cases requires the installation of supplementary sensors. For their conception and design, it is particularly important that the measuring principles are selected purposefully and the appropriate sensors are integrated at the goal-oriented measuring positions without impairing the functions and other properties of the Real Twin by the integration of these sensors. In this article, a "Design for Digital Twin" approach is discussed for the systematic procedure and demonstrated using a multi-staged gearbox as a concrete example. The approach focuses on the mechanical and hardware side of the Real Twin. For the systematic conception and design of the Digital Twin solution, an understanding of the stakeholder demands and the expected use cases is necessary. Based on the stakeholder demands and use cases, the relevant product properties can be determined. Using the relevant properties, an iterative process of conception, design, and analysis takes place. The conception is carried out by means of target-oriented cause-effect analyses, taking into account systemic interrelations of the Real Twin components and systematics for the selection of measurement principles. Systemic considerations, combined with an effect graph, allow for the analysis and evaluation of disturbing factors.
Determination and characterization of the influences of the bike frame on eBike drive units as the basis for their design and optimization. - In: Neunte IFToMM D-A-CH Konferenz 2023, (2023), S. 1-7
In this paper, the influence of the bike frame on the loading of the eBike drive unit is determined. For this purpose, relevant load cases and boundary conditions are derived based on the existing norms for the individual consideration of the frame and the drive. In this context, external loads on the frame and the forces acting on the engine must be taken into account. The following simulative study shows that the bike frame has an enormous and load-dependent influence on the load situation of the frame interface and the stresses within the housing of the drive unit. In general, this influence can be explained by the stiffness of the frame construction. Altogether, these results show that the design of the eBike drive unit according to its current standard requirements is not sufficient to cover these enormous influences of the bike frame.
Model signatures for design and usage of simulation-capable model networks in MBSE. - In: Product Lifecycle Management, (2023), S. 155-164
Product development is characterised by numerous synthesis and analysis loops. Analysis provides information on the fulfillment of the required properties of the system under development. Analysis results therefore are an important basis for further synthesis steps. In the context of Model-Based Systems Engineering (MBSE), different types of simulation models play an important role. The overall system (product) can be broken down to system elements. For each system element a set of models has to be established, that provides the required degrees of fidelity, representations of system properties, flows, etc. reflecting the variety of modelling purposes. These models have to be integrated horizontally (same system level along the relevant flows of material, energy, and information) and vertically (aggregation from subsystem level to the overall system level, refinement in the opposite direction) to create a holistic model-based system representation. An important and challenging task is to identify and shape relevant subsystem models. In order to define an appropriate structure of these models, model developers may utilize criteria like selected properties of system elements and interrelations, their degree of detail or modelling assumptions. The relevant criteria have to be made transparent. For this purpose, the paper discusses the concept of model signatures that contain relevant meta information about each single model of all system elements, subsystems up to models of the overall system. This standardized meta information enables an identification and selection of those models and the decision on the necessary model integration. The concept is discussed on the basis of a roller bearing as an example out of an electro-mechanical drivetrain. A potential analysis provides information about the possible usage of the model signatures concept.
Model signatures for the integration of simulation models into system models. - In: Systems, ISSN 2079-8954, Bd. 10 (2022), 6, 199, S. 1-15
Model-based systems engineering (MBSE) is an auspicious approach to the virtual development of cyber-physical systems. The behavior of the system’s elements is thus represented by specialized simulation models that are integrated into the descriptive SysML-based system model. Although many simulation models have been developed in research for the common system elements for various purposes and fidelities, their integration remains a major challenge: the parameter interfaces of the simulation models must be coupled with each other and with the parameters of the system elements in such a way that they are correctly parameterized. So far, this coupling can only be carried out by model experts in a time-consuming and error-prone manner. Therefore, in this paper, we first propose a concept that structures the system element parameters for targeted use in validation and design cases. Second, we propose a model signature for simulation models that differentiates its parameters by input, internal, output, and model parameters and specifies them with spatial and temporal dimensions as well as admissible ranges, among others. Based on the two contributions, domain models can be validly and automatable coupled and used for the virtual development of system elements in model-based systems engineering.
Modeling of corner-filleted flexure hinges under various loads. - In: Mechanism and machine theory, Bd. 175 (2022), 104937, S. 1-11
Compliant mechanisms are widely applied in precision engineering, measurement technology and microtechnology, due to their potential for the reduction of mass and assembly effort through the integration of functions into fewer parts and an increasing motion repeatability through less backlash and wear, if designed appropriately. However, a challenge during the design process is the handling of the multitude of geometric parameters and the complex relations between loads, deformations and strains. Furthermore, some tasks such as the dimensioning by means of optimization or the modeling for a controller design require a high number of analysis calculations. From this arises the need for sufficient computational analysis models with low calculation time. Existing studies of analysis models are mostly based on selected load cases, which may limits their general validity. The scope of this article is the comparison of models for the analysis of corner-filleted flexure hinges under various loads, to determine their advantages, disadvantages and application fields. The underlying methods of the study can further be used to evaluate future models based on a broad selection of possible load cases.
A method for the support of the design for Digital Twin solution and its application on a gearbox system. - In: Proceedings of the Design Society, ISSN 2732-527X, Bd. 2 (2022), S. 1609-1618
The information from Real Twins are increasingly used to construct Digital Twins. Acquisition of information from the Real Twin or in other words performing measurements on the Real Twin may lead to effects in the working of Real Twin. For instance, the introduction of sensors may impair certain functions of a Real Twin. Therefore, it is important to analyse the effect of any change that is performed on the Real Twin for achieving the Digital Twin. In this paper, a method for Digital Twin solution is presented that address these aspects as well as its use is demonstrated by a case example.