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 -