Fak. 5 Verkehrs- und Maschinensysteme

1269 Items

Recent Submissions
Leveraging Circular Economy through a Methodology for Smart Service Systems Engineering

Halstenberg, Friedrich A. ; Lindow, Kai ; Stark, Rainer (2019-06-27)

Product Service Systems (PSS) and Smart Services are powerful means for deploying Circular Economy (CE) goals in industrial practices, through dematerialization, extension of product lifetime and efficiency increase by digitization. Within this article, approaches from PSS design, Smart Service design and Model-based Systems Engineering (MBSE) are combined to form a Methodology for Smart Servic...

Dealing with Nap-Core Sandwich Composites: How to Predict the Effect of Symmetry

Ha, Giap ; Zehn, Manfred ; Marinković, Dragan ; Fragassa, Cristiano (2019-03-15)

The behavior of nap-core sandwiches was investigated with a special focus on the effect of symmetry in nap cores. A nap-core is, in general terms, a 3D-formed hollow structure made of knitted textile impregnated by a thermosetting resin. The molding process determines if the nap-core is double-sided (symmetric) or single-sided. The sandwich with nap-core owns various remarkable properties of a ...

Numerical Simulation on the Origin of Solidification Cracking in Laser Welded Thick-Walled Structures

Bakir, Nasim ; Artinov, Antoni ; Gumenyuk, Andrey ; Bachmann, Marcel ; Rethmeier, Michael (2018-06-01)

One of the main factors affecting the use of lasers in the industry for welding thick structures is the process accompanying solidification cracks. These cracks mostly occurring along the welding direction in the welding center, and strongly affect the safety of the welded components. In the present study, to obtain a better understanding of the relation between the weld pool geometry, the stre...

Is Tribology Approaching Its Golden Age? Grand Challenges in Engineering Education and Tribological Research

Popov, Valentin L. (2018-11-19)

In spite of its obvious importance, the subject of tribology has relatively low visibility in the engineering community and among the general public. The author's hypothesis is that this problem is at least partly due to the poor “availability” of tribology. In other words, there are practically no simple methods or concepts having high predictive power for tribological problem-solving. That si...

Improvement of Filler Wire Dilution Using External Oscillating Magnetic Field at Full Penetration Hybrid Laser-Arc Welding of Thick Materials

Üstündağ, Ömer ; Avilov, Vjaceslav ; Gumenyuk, Andrey ; Rethmeier, Michael (2019-05-23)

Hybrid laser-arc welding offers many advantages, such as deep penetration, good gap bridge-ability, and low distortion due to reduced heat input. The filler wire which is supplied to the process is used to influence the microstructure and mechanical properties of the weld seam. A typical problem in deep penetration high-power laser beam welding with filler wire and hybrid laser-arc welding is a...

An Accurate Finite Element Method for the Numerical Solution of Isothermal and Incompressible Flow of Viscous Fluid

Abali, Bilen Emek (2019-01-08)

Despite its numerical challenges, finite element method is used to compute viscous fluid flow. A consensus on the cause of numerical problems has been reached; however, general algorithms—allowing a robust and accurate simulation for any process—are still missing. Either a very high computational cost is necessary for a direct numerical solution (DNS) or some limiting procedure is used by addin...

Boehmite Nanofillers in Epoxy Oligosiloxane Resins: Influencing the Curing Process by Complex Physical and Chemical Interactions

Topolniak, Ievgeniia ; Hodoroaba, Vasile-Dan ; Pfeifer, Dietmar ; Braun, Ulrike ; Sturm, Heinz (2019-05-09)

In this work, a novel boehmite (BA)-embedded organic/inorganic nanocomposite coating based on cycloaliphatic epoxy oligosiloxane (CEOS) resin was fabricated applying UV-induced cationic polymerization. The main changes of the material behavior caused by the nanofiller were investigated with regard to its photocuring kinetics, thermal stability, and glass transition. The role of the particle sur...

Short- and Long-Range Mechanical and Chemical Interphases Caused by Interaction of Boehmite (γ-AlOOH) with Anhydride-Cured Epoxy Resins

Ghasem Zadeh Khorasani, Media ; Elert, Anna-Maria ; Hodoroaba, Vasile-Dan ; Agudo Jácome, Leonardo ; Altmann, Korinna ; Silbernagl, Dorothee ; Sturm, Heinz (2019-06-04)

Understanding the interaction between boehmite and epoxy and the formation of their interphases with different mechanical and chemical structures is crucial to predict and optimize the properties of epoxy-boehmite nanocomposites. Probing the interfacial properties with atomic force microscopy (AFM)-based methods, especially particle-matrix long-range interactions, is challenging. This is due to...

Identifizierung leistungsrelevanter Merkmale der Teamkommunikation in der Domäne Flugsicherung

Papenfuß, Anne (2019)

Die Arbeit von Teams ist ein Einflussfaktor auf die Leistungsfähigkeit des Luftverkehrssystems. In dieser Arbeit wird ein Ansatz zur Analyse der Teamkommunikation vorgestellt, um Teamarbeit und den Einfluss neuartiger Flugführungskonzepte in High-Fidelity-Simulationen zu erfassen. Hierzu wurde der Einfluss der situativen Faktoren Kommunikationsmedium und Erfahrung auf das Kommunikationsverhalte...

Entwicklung und Validierung eines Diagnostikverfahrens zur Analyse von Lichtbogenfluktuationen beim Gleichstromplasmaspritzen

Thomas, Georg (2019)

Das Gleichstromplasmaspritzen (DC-Plasmaspritzen) mittels Plasmageneratoren in Einkathoden-Einanoden-Anordnung (F4/F6/MC60) ist gekennzeichnet durch eine permanente Instabilität des für die Plasmagenerierung genutzten Gleichstromlichtbogens, hervorgerufen durch dessen axiale und radiale Bewegungen. Dies äußert sich in massiven Fluktuationen der Lichtbogenspannung sowie der Plasmafreistrahlgeome...

Introducing a multivariate model for predicting driving performance: The role of driving anger and personal characteristics

Roidl, Ernst ; Siebert, Felix Wilhelm ; Oehl, Michael ; Höger, Rainer (2013-08-15)

Introduction: Maladaptive driving is an important source of self-inflicted accidents and this driving style could include high speeds, speeding violations, and poor lateral control of the vehicle. The literature suggests that certain groups of drivers, such as novice drivers, males, highly motivated drivers, and those who frequently experience anger in traffic, tend to exhibit more maladaptive ...

The influence of time headway on subjective driver states in adaptive cruise control

Siebert, Felix Wilhelm ; Oehl, Michael ; Pfister, Hans-Rüdiger (2014-06-04)

There is no agreement on the relation between driving parameters and drivers’ subjective states. A linear as well as a threshold relationship for different subjective variables and driving parameters has been put forward. In this study we investigate the relationship between time headway and the ratings of risk, task difficulty, effort, and comfort. Knowledge about this interrelation may advanc...

The exact determination of subjective risk and comfort thresholds in car following

Siebert, Felix Wilhelm ; Oehl, Michael ; Bersch, Florian ; Pfister, Hans-Rüdiger (2017-02-04)

In this study the location of vehicle to vehicle distance thresholds for self-reported subjective risk and comfort was researched. Participants were presented with ascending and descending time headway sequences in a driving simulator. This so called method of limits of ascending and descending stimuli (Gouy, Diels, Reed, Stevens, & Burnett, 2012) was refined to efficiently determine individual...

How speed and visibility influence preferred headway distances in highly automated driving

Siebert, Felix Wilhelm ; Wallis, Fares Lian (2019-07-06)

While the introduction of highly automated vehicles promises lower accident numbers, a main requirement for wide use of these vehicles will be the acceptance by drivers. In this study a crucial variable for the acceptance of highly automated vehicles, the vehicle to vehicle distance expressed in time headway, was researched in a driving simulator. Research has shown that time headway distances,...

Patterns of motorcycle helmet use – a naturalistic observation study in Myanmar

Siebert, Felix Wilhelm ; Albers, Deike ; Naing, U Aung ; Perego, Paolo ; Santikarn, Chamaiparn (2019-01-11)

Developing countries are subject to increased motorization, particularly in the number of motorcycles. As helmet use is critical to the safety of motorcycle riders, the goal of this study was to identify observable patterns of helmet use, which allow a more accurate assessment of helmet use in developing countries. In a video based observation study, 124,784 motorcycle riders were observed at s...

Investigation on Dynamic Response of Rubber in Frictional Contact

Nakano, Ken ; Kawaguchi, Kai ; Takeshima, Kazuho ; Shiraishi, Yu ; Forsbach, Fabian ; Benad, Justus ; Popov, Mikhail ; Popov, Valentin L. (2019-03-26)

In the present work, we analyze a device for measuring the dynamic response of rubber in sliding contact. The principle of the device is to measure excited oscillations of a mechanical system with a sliding contact between a rubber roller and a rigid surface. Depending on the contact properties, varying oscillation amplitudes are measured. The goal is to determine dynamic response properties of...

Survey of Finite Element Method-Based Real-Time Simulations

Marinković, Dragan ; Zehn, Manfred (2019-07-10)

The finite element method (FEM) has deservedly gained the reputation of the most powerful, highly efficient, and versatile numerical method in the field of structural analysis. Though typical application of FE programs implies the so-called “off-line” computations, the rapid pace of hardware development over the past couple of decades was the major impetus for numerous researchers to consider t...

Untersuchung elektrokortikaler Reaktionen auf die Exposition mit Ultraschall

Lindau, Alexander ; Weisskircher, Stephan ; Weinzierl, Stefan ; Gramann, Klaus (2016)

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Analyzing Temporal and Spatial Characteristics of Crop Parameters Using Sentinel-1 Backscatter Data

Harfenmeister, Katharina ; Spengler, Daniel ; Weltzien, Cornelia (2019-07-02)

The knowledge about heterogeneity on agricultural fields is essential for a sustainable and effective field management. This study investigates the performance of Synthetic Aperture Radar (SAR) data of the Sentinel-1 satellites to detect variability between and within agricultural fields in two test sites in Germany. For this purpose, the temporal profiles of the SAR backscatter in VH and VV po...

Enhanced Core-Mantle Coupling Due to Stratification at the Top of the Core

Glane, Sebastian ; Buffett, Bruce (2018-10-30)

Fluctuations in the length of day (LOD) over periods of several decades are commonly attributed to exchanges of angular momentum between the mantle and the core. However, the forces that enable this exchange are less certain. Suggestions include the influence of pressure on boundary topography, electromagnetic forces associated with conducting material in the boundary region and gravitational f...