TY - JOUR AU - Lenz, Peter AU - Mahnken, Rolf ID - 52218 JF - International Journal of Solids and Structures KW - Applied Mathematics KW - Mechanical Engineering KW - Mechanics of Materials KW - Condensed Matter Physics KW - General Materials Science KW - Modeling and Simulation SN - 0020-7683 TI - Multiscale simulation of polymer curing of composites combined mean-field homogenisation methods at large strains VL - 290 ER - TY - JOUR AB - The success of engineering complex technical systems is determined by meeting customer requirements and institutional regulations. One example relevant to the automobile industry is the United Nations Economic Commission of Europe (UN ECE), which specifies the homologation of automobile series and requires proof of traceability. The required traceability can be achieved by modeling system artifacts and their relations in a consistent, seamless model—an effect-chain model. Currently, no in-depth methodology exists to support engineers in developing certification-compliant effect-chain models. For this purpose, a new methodology for certification-compliant effect-chain modeling was developed, which includes extensions of an existing method, suitable models, and tools to support engineers in the modeling process. For evaluation purposes, applicability is proven based on the experience of more than 300 workshops at an automotive OEM and an automotive supplier. The following case example is chosen to demonstrate applicability: the development of a window lifter that has to meet the demands of UN ECE Regulations R156 and R21. Results indicate multiple benefits in supporting engineers with the certification-compliant modeling of effect chains. Three benefits are goal-oriented modeling to reduce the necessary modeling capacity, increasing model quality by applying information quality criteria, and the potential to reduce costs through automatable effect-chain analyses for technical changes. Further, companies in the automotive and other industries will benefit from increased modeling capabilities that can be used for architecture modeling and to comply with other regulations such as ASPICE or ISO 26262. AU - Gräßler, Iris AU - Wiechel, Dominik AU - Koch, Anna-Sophie AU - Sturm, Tim AU - Markfelder, Thomas ID - 44382 IS - 3 JF - Systems KW - Information Systems and Management KW - Computer Networks and Communications KW - Modeling and Simulation KW - Control and Systems Engineering KW - Software SN - 2079-8954 TI - Methodology for Certification-Compliant Effect-Chain Modeling VL - 11 ER - TY - CONF AB - The development of autonomous vehicles and their introduction in urban traffic offer many opportunities for traffic improvements. In this paper, an approach for a future traffic control system for mixed autonomy traffic environments is presented. Furthermore, a simulation framework based on the city of Paderborn is introduced to enable the development and examination of such a system. This encompasses multiple elements including the road network itself, traffic lights, sensors as well as methods to analyse the topology of the network. Furthermore, a procedure for traffic demand generation and routing is presented based on statistical data of the city and traffic data obtained by measurements. The resulting model can receive and apply the generated control inputs and in turn generates simulated sensor data for the control system based on the current system state. AU - Link, Christopher AU - Malena, Kevin AU - Gausemeier, Sandra AU - Trächtler, Ansgar ID - 44390 KW - Traffic Simulation KW - Traffic Control KW - Car2X KW - Mixed Autonomy KW - Autonomous Vehicles KW - SUMO KW - Sensor Simulation KW - Traffic Demand Generation KW - Routing KW - Traffic Lights KW - Graph Analysis KW - Traffic Observer SN - 978-989-758-652-1 T2 - Proceedings of the 9th International Conference on Vehicle Technology and Intelligent Transport Systems TI - Simulation Environment for Traffic Control Systems Targeting Mixed Autonomy Traffic Scenarios ER - TY - JOUR AU - Andreiev, Anatolii AU - Hoyer, Kay-Peter AU - Hengsbach, Florian AU - Haase, Michael AU - Tasche, Lennart AU - Duschik, Kristina AU - Schaper, Mirko ID - 44078 JF - Journal of Materials Processing Technology KW - Industrial and Manufacturing Engineering KW - Metals and Alloys KW - Computer Science Applications KW - Modeling and Simulation KW - Ceramics and Composites SN - 0924-0136 TI - Powder bed fusion of soft-magnetic iron-based alloys with high silicon content VL - 317 ER - TY - JOUR AB - The introduction of Systems Engineering is an approach for dealing with the increasing complexity of products and their associated product development. Several introduction strategies are available in the literature; nevertheless, the introduction of Systems Engineering into practice still poses a great challenge to companies. Many companies have already gained experience in the introduction of Systems Engineering. Therefore, as part of the SE4OWL research project, the need to conduct a study including expert interviews and to collect the experiences of experts was identified. A total of 78 hypotheses were identified from 13 expert interviews concerning the lessons learned. Using exclusion criteria, 52 hypotheses were validated in a subsequent quantitative survey with 112 participants. Of these 52 hypotheses, 40 could be confirmed based on the survey results. Only four hypotheses were rejected, and eight could neither be confirmed nor rejected. Through this research, guidance is provided to companies to leverage best practices for the introduction of their own Systems Engineering and to avoid the poor practices of other companies. AU - Wilke, Daria AU - Grothe, Robin AU - Bretz, Lukas AU - Anacker, Harald AU - Dumitrescu, Roman ID - 47800 IS - 3 JF - Systems KW - Information Systems and Management KW - Computer Networks and Communications KW - Modeling and Simulation KW - Control and Systems Engineering KW - Software SN - 2079-8954 TI - Lessons Learned from the Introduction of Systems Engineering VL - 11 ER - TY - JOUR AB - Abstract Sandwich packings represent new separation column internals, with a potential to intensify mass transfer. They comprise two conventional structured packings with different specific geometrical surface areas. In this work, the complex fluid dynamics in sandwich packings is modeled using a novel approach based on a one-dimensional, steady momentum balance of the liquid and gas phases. The interactions between the three present phases (gas, liquid, and solid) are considered by closures incorporated into the momentum balance. The formulation of these closures is derived from two fluid-dynamic analogies for the film and froth flow patterns. The adjustable parameters in the closures are regressed for the film flow using dry pressure drop measurements and liquid hold-up data in trickle flow conditions. For the froth flow, the tuning parameters are fitted to overall pressure drop measurements and local liquid hold-up data acquired from ultra-fast X-ray tomography (UFXCT). The model predicts liquid hold-up and pressure drop data with an average relative deviation of 16.4 % and 19 %, respectively. Compared to previous fluid dynamic models for sandwich packings, the number of adjustable parameters could be reduced while maintaining comparable accuracy. AU - Franke, Patrick AU - Shabanilemraski, Iman AU - Schubert, Markus AU - Hampel, Uwe AU - Kenig, Eugeny Y. ID - 48580 JF - Chemical Product and Process Modeling KW - Modeling and Simulation KW - General Chemical Engineering SN - 1934-2659 TI - A new approach to model the fluid dynamics in sandwich packings ER - TY - JOUR AU - Lenz, Peter AU - Kreutzheide, Phil AU - Mahnken, Rolf ID - 48673 JF - Computers & Structures KW - Computer Science Applications KW - Mechanical Engineering KW - General Materials Science KW - Modeling and Simulation KW - Civil and Structural Engineering SN - 0045-7949 TI - Multiphase elasto-plastic mean-field homogenisation and its consistent linearisation VL - 290 ER - TY - GEN AB - Iron oxide nanoparticles are very interesting for many applications in different industrial sectors. A promising process to manufacture these nanoparticles is flame spray pyrolysis (FSP). A lack of understanding of the individual sub-processes in FSP makes it challenging to tailor nanoparticle properties. This work provides insights into the formation of iron oxide nanoparticles in a turbulent spray flame using Large Eddy Simulations (LES), which are based on a comprehensive model, including customized submodels. Highlights are the adaption of a turbulent combustion model and a bivariate hybrid method of moments for modeling nanoparticle dynamics. The work focuses on the SpraySyn burner, which is a standardized laboratory burner and was operated with a precursor-solvent mixture of ethanol and iron(III) nitrate nonahydrate. For studying the relevance of precursor chemistry, LES using an evaporation-limited precursor chemistry model is compared with a model that includes detailed iron chemistry. A further novelty is the inclusion of adsorption in the simulation, which defines a third model for comparison. Sufficient validation is achieved for the undoped LES using experimental data from the literature. A strong impact of the detailed iron chemistry and adsorption is found on the precursor consumption and the aggregate and primary particle formation. Comparing the particle diameters with experimental measurements from the literature and data generated for this work is found unsuitable to asses the precursor chemistry model and revealed an urgent need for future experimental and numerical research. This work serves as a step forward in realizing a reliable model. ED - Fröde, Fabian ED - Grenga, Temistocle ED - Pitsch, Heinz ED - Dupont, Sophie ED - Kneer, Reinhold ED - Tischendorf, Ricardo ED - Massopo, Orlando ED - Schmid, Hans-Joachim ID - 51136 KW - Flame spray pyrolysis KW - Iron oxide formation KW - Large eddy simulation KW - Method of moments KW - SpraySyn T2 - Applications in Energy and Combustion Science TI - Large eddy simulation of iron oxide formation in a laboratory spray flame ER - TY - JOUR AB - In virtual reality (VR), participants may not always have hands, bodies, eyes, or even voices—using VR helmets and two controllers, participants control an avatar through virtual worlds that do not necessarily obey familiar laws of physics; moreover, the avatar’s bodily characteristics may not neatly match our bodies in the physical world. Despite these limitations and specificities, humans get things done through collaboration and the creative use of the environment. While multiuser interactive VR is attracting greater numbers of participants, there are currently few attempts to analyze the in situ interaction systematically. This paper proposes a video-analytic detail-oriented methodological framework for studying virtual reality interaction. Using multimodal conversation analysis, the paper investigates a nonverbal, embodied, two-person interaction: two players in a survival game strive to gesturally resolve a misunderstanding regarding an in-game mechanic—however, both of their microphones are turned off for the duration of play. The players’ inability to resort to complex language to resolve this issue results in a dense sequence of back-and-forth activity involving gestures, object manipulation, gaze, and body work. Most crucially, timing and modified repetitions of previously produced actions turn out to be the key to overcome both technical and communicative challenges. The paper analyzes these action sequences, demonstrates how they generate intended outcomes, and proposes a vocabulary to speak about these types of interaction more generally. The findings demonstrate the viability of multimodal analysis of VR interaction, shed light on unique challenges of analyzing interaction in virtual reality, and generate broader methodological insights about the study of nonverbal action. AU - Klowait, Nils ID - 43437 JF - Human Behavior and Emerging Technologies KW - Human-Computer Interaction KW - General Social Sciences KW - Social Psychology KW - Virtual Reality : Multimodality KW - Nonverbal Interaction KW - Search Sequence KW - Gesture KW - Co-Operative Action KW - Goodwin KW - Ethnomethodology SN - 2578-1863 TI - On the Multimodal Resolution of a Search Sequence in Virtual Reality VL - 2023 ER - TY - CONF AB - Recent reinforcement learning approaches for continuous control in wireless mobile networks have shown impressive results. But due to the lack of open and compatible simulators, authors typically create their own simulation environments for training and evaluation. This is cumbersome and time-consuming for authors and limits reproducibility and comparability, ultimately impeding progress in the field. To this end, we propose mobile-env, a simple and open platform for training, evaluating, and comparing reinforcement learning and conventional approaches for continuous control in mobile wireless networks. mobile-env is lightweight and implements the common OpenAI Gym interface and additional wrappers, which allows connecting virtually any single-agent or multi-agent reinforcement learning framework to the environment. While mobile-env provides sensible default values and can be used out of the box, it also has many configuration options and is easy to extend. We therefore believe mobile-env to be a valuable platform for driving meaningful progress in autonomous coordination of wireless mobile networks. AU - Schneider, Stefan Balthasar AU - Werner, Stefan AU - Khalili, Ramin AU - Hecker, Artur AU - Karl, Holger ID - 30236 KW - wireless mobile networks KW - network management KW - continuous control KW - cognitive networks KW - autonomous coordination KW - reinforcement learning KW - gym environment KW - simulation KW - open source T2 - IEEE/IFIP Network Operations and Management Symposium (NOMS) TI - mobile-env: An Open Platform for Reinforcement Learning in Wireless Mobile Networks ER - TY - JOUR AB - Distributed, software-intensive systems (e.g., in the automotive sector) must fulfill communication requirements under hard real-time constraints. The requirements have to be documented and validated carefully using a systematic requirements engineering (RE) approach, for example, by applying scenario-based requirements notations. The resources of the execution platforms and their properties (e.g., CPU frequency or bus throughput) induce effects on the timing behavior, which may lead to violations of the real-time requirements. Nowadays, the platform properties and their induced timing effects are verified against the real-time requirements by means of timing analysis techniques mostly implemented in commercial-off-the-shelf tools. However, such timing analyses are conducted in late development phases since they rely on artifacts produced during these phases (e.g., the platform-specific code). In order to enable early timing analyses already during RE, we extend a scenario-based requirements notation with allocation means to platform models and define operational semantics for the purpose of simulation-based, platform-aware timing analyses. We illustrate and evaluate the approach with an automotive software-intensive system. AU - Holtmann, Jörg AU - Deantoni, Julien AU - Fockel, Markus ID - 31071 JF - Software and Systems Modeling KW - Modeling and Simulation KW - Software SN - 1619-1366 TI - Early timing analysis based on scenario requirements and platform models ER - TY - CONF AB - In this work, methods will be evaluated to numerically calculate the passive electrical parameters of planar coils. These parameters can then be used to optimize inductive applications such as wireless power transmission. The focus here will be on inductive localization, which uses high-frequency magnetic fields and the resulting induced voltage to provide localization through the coupling parameter mutual inductance. To achieve localization with high accuracy and best possible operation (resonance, signal strength, etc.), the coil parameters need to be well known. For this reason, some numerical methods for the calculation of these quantities are presented and validated. In addition, the physical effects are thereby considered in more detail, allowing the localization procedure to be better optimized compared to simulative black-box methods. The goal should be a dedicated simulation platform for planar coils to be able to develop training data for neural networks and to test and optimize localization algorithms. AU - Lange, Sven AU - Hedayat, Christian AU - Kuhn, Harald AU - Hilleringmann, Ulrich ID - 33508 KW - Simulation Environment KW - Inductive Localization KW - Coil Parameters KW - Inductive Applications KW - Near-Field T2 - 2022 Smart Systems Integration (SSI) TI - Modeling and Characterization of a 3D Environment for the Design of an Inductively Based Locating Method by Coil Couplings ER - TY - CONF AU - Bernemann, Sören Antonius AU - Maćkowiak, Jan AU - Maćkowiak, Jerzy AU - Bertling, René AU - Lutters, Nicole AU - Kenig, Eugeny ID - 33522 KW - CFD KW - simulation KW - agricultural waste KW - multiphase TI - Development of an innovative separation unit for nitrogen recovery from agricultural waste ER - TY - CHAP AB - Predicting the durability of components subjected to mechanical load under environmental conditions leading to corrosion is one of the most challenging tasks in mechanical engineering. The demand for precise predictions increases with the desire of lightweight design in transportation due to environmental protection. Corrosion with its manifold of mechanisms often occurs together with the production of hydrogen by electrochemical reactions. Hydrogen embrittlement is one of the most feared damage mechanisms for metal constructions often leading to early and unexpected failure. Until now, predictions are mostly based on costly experiments. Hence, a rational predictive model based on the fundamentals of electrochemistry and damage mechanics has to be developed in order to reduce the costs. In this work, a first model approach based on classical continuum damage mechanics is presented to couple both, the damage induced by the mechanical stress and the hydrogen embrittlement. An elaborated two-scale model based on the selfconsistent theory is applied to describe the mechanical damage due to fatigue. The electrochemical kinetics are elucidated through the Langmuir adsorption isotherm and the diffusion equation to consider the impact of hydrogen embrittlement on the fatigue. The modeling of the mechanism of hydrogen embrittlement defines the progress of damage accumulation due to the electrochemistry. The durability results like the S-N diagram show the influence of hydrogen embrittlement by varying, e.g. the fatigue frequency or the stress ratio. AU - Shi, Yuhao AU - Harzheim, Sven AU - Hofmann, Martin AU - Wallmersperger, Thomas ID - 34209 KW - Hydrogen embrittlement KW - Fatigue KW - Continuum damage mechanics KW - Numerical simulation KW - Multi-field problem SN - 1869-8433 T2 - Material Modeling and Structural Mechanics TI - A Damage Model for Corrosion Fatigue Due to Hydrogen Embrittlement ER - TY - JOUR AU - Protte, Marius AU - Fahr, Rene AU - Quevedo, Daniel E. ID - 35586 IS - 6 JF - IEEE Control Systems KW - Electrical and Electronic Engineering KW - Modeling and Simulation KW - Control and Systems Engineering KW - Electrical and Electronic Engineering KW - Modeling and Simulation KW - Control and Systems Engineering SN - 1066-033X TI - Behavioral Economics for Human-in-the-Loop Control Systems Design: Overconfidence and the Hot Hand Fallacy VL - 40 ER - TY - JOUR AB - An initial-boundary value problem for a coupled chemotaxis-Navier–Stokes model with porous medium type diffusion is considered. Previous related literature has provided profound knowledge in cases when the system is augmented with no-flux/no-flux/no-slip boundary conditions for the density of cells, the chemical concentration and the fluid velocity field, respectively; in particular, available qualitative results strongly indicate that only trivial solution behavior can be expected on large time scales. In line with refined modeling approaches to oxygen evolution near fluid-air interfaces, this study now focuses on situations involving a fixed chemoattractant concentration on the boundary. Despite an apparent loss of mathematically favorable energy structures thereby induced, by means of an alternative variational approach a basic theory of global existence is developed in a natural framework of weak solvability. Beyond this, some additional qualitative information on the large time behavior of these solutions is derived by identifying a certain global relaxation property. Specifically, a second result asserts, within a suitable topological setting, the existence of a bounded set which eventually absorbs each individual of the obtained trajectories, and the diameter of which is bounded only by the physically relevant quantities of total population size and prescribed boundary concentration of the chemical signal. AU - Black, Tobias AU - Winkler, Michael ID - 34676 IS - 01 JF - Mathematical Models and Methods in Applied Sciences KW - Applied Mathematics KW - Modeling and Simulation SN - 0218-2025 TI - Global weak solutions and absorbing sets in a chemotaxis-Navier–Stokes system with prescribed signal concentration on the boundary VL - 32 ER - TY - JOUR AB - In timing chain drives, the chain is the critical component regarding the wear. Relative movements take place at the chain joint between pin and bush, which lead to wear of the chain joint due to friction and so to chain elongation. The chain joint is generally lubricated with oils, through which elastohydrodynamic processes can occur in the gap between the pin and the bush of the chain joint. A simulation model is developed here to examine these elastohydrodynamic processes considering a mass conserving cavitation model, the Newtonian flow behaviour of the lubricant and the structuring of the bush surface, whereby the real form of the bush is considered. MBS simulations are used to obtain realistic loads on the chain joint. AU - Simo Kamga, Lionel AU - Meffert, Dominik AU - Magyar, Balázs AU - Oehler, Manuel AU - Sauer, Bernd ID - 34434 JF - Tribology International KW - EHL-simulation KW - Cavitation KW - Chain drives KW - Chain joint KW - Micro-structuring SN - 0301-679X TI - Simulative investigation of the influence of surface texturing on the elastohydrodynamic lubrication in chain joints VL - 171 ER - TY - JOUR AU - Hein, Maxwell AU - Lopes Dias, Nelson Filipe AU - Kokalj, David AU - Stangier, Dominic AU - Hoyer, Kay-Peter AU - Tillmann, Wolfgang AU - Schaper, Mirko ID - 41496 JF - International Journal of Fatigue KW - Industrial and Manufacturing Engineering KW - Mechanical Engineering KW - Mechanics of Materials KW - General Materials Science KW - Modeling and Simulation SN - 0142-1123 TI - On the influence of physical vapor deposited thin coatings on the low-cycle fatigue behavior of additively processed Ti-6Al-7Nb alloy VL - 166 ER - TY - JOUR AU - Hein, Maxwell AU - Lopes Dias, Nelson Filipe AU - Kokalj, David AU - Stangier, Dominic AU - Hoyer, Kay-Peter AU - Tillmann, Wolfgang AU - Schaper, Mirko ID - 41490 JF - International Journal of Fatigue KW - Industrial and Manufacturing Engineering KW - Mechanical Engineering KW - Mechanics of Materials KW - General Materials Science KW - Modeling and Simulation SN - 0142-1123 TI - On the influence of physical vapor deposited thin coatings on the low-cycle fatigue behavior of additively processed Ti-6Al-7Nb alloy VL - 166 ER - TY - JOUR AB - We introduce a new phase field model for tumor growth where viscoelastic effects are taken into account. The model is derived from basic thermodynamical principles and consists of a convected Cahn–Hilliard equation with source terms for the tumor cells and a convected reaction–diffusion equation with boundary supply for the nutrient. Chemotactic terms, which are essential for the invasive behavior of tumors, are taken into account. The model is completed by a viscoelastic system consisting of the Navier–Stokes equation for the hydrodynamic quantities, and a general constitutive equation with stress relaxation for the left Cauchy–Green tensor associated with the elastic part of the total mechanical response of the viscoelastic material. For a specific choice of the elastic energy density and with an additional dissipative term accounting for stress diffusion, we prove existence of global-in-time weak solutions of the viscoelastic model for tumor growth in two space dimensions [Formula: see text] by the passage to the limit in a fully-discrete finite element scheme where a CFL condition, i.e. [Formula: see text], is required. Moreover, in arbitrary dimensions [Formula: see text], we show stability and existence of solutions for the fully-discrete finite element scheme, where positive definiteness of the discrete Cauchy–Green tensor is proved with a regularization technique that was first introduced by Barrett and Boyaval [Existence and approximation of a (regularized) Oldroyd-B model, Math. Models Methods Appl. Sci. 21 (2011) 1783–1837]. After that, we improve the regularity results in arbitrary dimensions [Formula: see text] and in two dimensions [Formula: see text], where a CFL condition is required. Then, in two dimensions [Formula: see text], we pass to the limit in the discretization parameters and show that subsequences of discrete solutions converge to a global-in-time weak solution. Finally, we present numerical results in two dimensions [Formula: see text]. AU - Garcke, Harald AU - Kovács, Balázs AU - Trautwein, Dennis ID - 45970 IS - 13 JF - Mathematical Models and Methods in Applied Sciences KW - Applied Mathematics KW - Modeling and Simulation SN - 0218-2025 TI - Viscoelastic Cahn–Hilliard models for tumor growth VL - 32 ER -