Fak. 5 Verkehrs- und Maschinensysteme

1223 Items

Recent Submissions
Methodische Entwicklung von nachhaltigen Innovationen in Start-Ups als Beitrag zur produktionstechnischen Wertschöpfung

Stock, Tim Erwin (2019)

Im heutigen Zeitalter des Anthropozäns stehen die Industrie-, Schwellen- und Entwicklungsländer vor vielfältigen Nachhaltigkeitsherausforderungen, die durch globale Trends im Handlungsfeld umweltbezogener, gesellschaftlicher und wirtschaftlicher Dimension menschlichen Wirkens hervorgerufen werden. Dazu zählen die steigende sozio-ökonomische Ungleichheit, der Klimawandel, die zunehmende Umweltbe...

Numerical study of the hydraulic excavator overturning stability during performing lifting operations

Mitrev, Rosen ; Marinković, Dragan (2019-05-02)

This article presents a numerical study of the stability of a hydraulic excavator during performing lifting operations. A planar dynamic model is developed with six degrees of freedom, which considers the base body elastic connection with the terrain, the front digging manipulator links, and the presence of the freely suspended payload. Differential equations describing the excavator dynamic be...

Should autonomous shared taxis replace buses? A simulation study

Leich, Gregor ; Bischoff, Joschka (2018)

The introduction of shared autonomous vehicles (SAV) will likely reduce operation cost per vehicle and might thereby allow to enhance conventional public transit systems with numerous small SAVs offering exible ridesharing-like feeder services. These demand-responsive services could replace conventional bus lines limited by their fixed routes and their fixed schedules. This simulation study exp...

Handbook of contact mechanics

Popov, Valentin L. ; Heß, Markus ; Willert, Emanuel (2019-04)

This open access book contains a structured collection of complete solutions of all significant axially symmetric contact problems. It provides solutions for classical profiles such as the sphere, cone or flat cylindrical punch as well as a multitude of other technically relevant shapes, e.g. the truncated cone, the worn sphere, rough profiles, hollow cylinders, etc. Normal, tangential and tors...

Microphone Array Benchmark b11: Rotating Point Sources

Herold, Gert (2017-07-28)

This benchmark case is part of a collection of synthetic and experimental array data sets compiled by the microphone array community for testing and comparing different microphone array methods. It consists of two simulated data sets featuring rotating point sources in a resting medium. Sound pressure time data are generated at 64 microphones, which are arranged evenly on a circle. The data are...

Mobility as a service and the transition to driverless systems

Bischoff, Joschka Felix (2019)

On-demand transport modes have developed over the last decades and are now often integrated into Mobility as a Service (MaaS) systems. Their current scope stretches from classical taxi and paratransit services to ride-hailing and ride-sharing and also includes free-floating car sharing systems. In the future, the ongoing trend towards a sharing-economy and improving autonomous driving capabilit...

Trust in highly automated driving

Stephan, Amelie (2019)

The automotive industry is on the verge of a new technology: self-driving vehicles. Such highly automated driving vehicles are more and more technically feasible, and corporations and research institutes all over the world are investing time and money to bring the once futuristic vision on the road. The technology is developed with the goal to release the driver from the manual task of controll...

Aktive Schwingungstilgung der horizontalen Schwingungen eines landwirtschaftlichen Spritzgestänges

Borchert, Anna-Gret (2019)

Die vorliegende Dissertation befasst sich mit der Optimierung des horizontalen Schwingungsverhaltens eines landwirtschaftlichen Spritzgestänges durch den Einsatz einer aktiven Schwingungstilgung.In Fahrtrichtung auftretende Gestängeschwingungen erzeugen Über- und Unterdosierungen beim Ausbringen von Pflanzenschutzmitteln oder Flüssigdünger. Daraus können ein inhomogener Pflanzenbewuchs und Ertr...

Untersuchung von PIO-Tendenzen bei plötzlichen Umschaltungen in der Flugdynamik

Schönfeld, Andrej (2019)

Bisher wurden Kopplungsphänomene des Gesamtsystems Pilot-Flugzeug (Piloteninduzierte Schwingungen, PIO) nach einer Umschaltung im Flugregelungssystem nur unzureichend systematisch untersucht. In den letzten Jahren traten jedoch einige Vorfälle in der zivilen Luftfahrt auf, die zeigten, dass schwere Vorfälle entstehen können, wenn Umschaltungen der Flugregelungsgesetze involviert sind. Die vorli...

Eine analytisch-numerische Betrachtung zu thermoelastischen Schwingungen von schnelldrehenden Rotoren beim Anstreifen an Bürstendichtungen

Fay, Robert (2019)

Bürstendichtungen brauchen gegenüber den im Turbomaschinenbau meist verwendeten Labyrinthdichtungen einen wesentlich geringeren axialen Bauraum bei gleichem Druckgefälle. Diesen zusätzlichen Bauraum kann der Entwickler nutzen, um seine Maschine zu optimieren - beispielsweise um die Eigenfrequenzen des Systems auf den Betriebsbereich anzupassen. Ein Risiko, welches sich aus dem Einsatz mit Bürst...

Numerical simulation and parametric investigation of the mechanical properties of fabric nap core sandwich

Ha, Giap Xuan (2019)

This research deals with the finite element (FE) simulation and the validation of FE models for a new type of sandwich-structured composite, the so-called nap-core sandwich. The nap-core is made of a two-dimensional knitted fabric impregnated with a thermosetting resin, which underwent deep drawing and curing processes to adopt a permanent three-dimensional shape. The nap-core can be considered...

Methodische Entwicklung einer modularen Lasersintermaschine zur Herstellung von bioresorbierbaren Implantatmatrizen

Kautz, Clemens Kolja (2019)

Eine aus dem Bereich der regenerativen Medizin stammende visionäre Anwendung der AM-Technologie ist die Fertigung von individuell angepassten Implantaten und Organen. Werden zur Herstellung von Implantatmatrizen, dem Gerüst zum Gewebeaufbau, bioresorbierbare Werkstoffe mittels Lasersintern verarbeitet, verbleibt das erzeugte Implantat nach der Transplantation im Körper des Patienten und wird do...

Adhesive Strength of Contacts of Rough Spheres

Li, Qiang ; Pohrt, Roman ; Popov, Valentin L. (2019-03-26)

The adhesive contact between a parabolic indenter with superimposed roughness and an elastic half space is studied in the JKR-limit (infinitely small range of action of adhesive forces) using the boundary element method with mesh-dependent detachment criterion suggested in 2015. Three types of superimposed roughness are considered: one- and two-dimensional waviness and randomly rough roughness....

Effects of Trust, Self-Confidence, and Feedback on the Use of Decision Automation

Wiczorek, Rebecca ; Meyer, Joachim (2019-03-12)

Operators often fail to rely sufficiently on alarm systems. This results in a joint human-machine (JHM) sensitivity below the one of the alarm system. The ‘confidence vs. trust hypothesis’ assumes the use of the system depends on the weighting of both values. In case of higher confidence, the task is performed manually, if trust is higher, the user relies on the system. Thus, insufficient relia...

Drug Delivery From Polymer-Based Nanopharmaceuticals—An Experimental Study Complemented by Simulations of Selected Diffusion Processes

Macha, Innocent J. ; Ben-Nissan, Besim ; Vilchevskaya, Elena N. ; Morozova, Anna S. ; Abali, Bilen Emek ; Müller, Wolfgang H. ; Rickert, Wilhelm (2019-03-08)

The success of medical therapy depends on the correct amount and the appropriate delivery of the required drugs for treatment. By using biodegradable polymers a drug delivery over a time span of weeks or even months is made possible. This opens up a variety of strategies for better medication. The drug is embedded in a biodegradable polymer (the “carrier”) and injected in a particular position ...

Agent-based modelling of air transport demand

Grether, Dominik ; Nagel, Kai (2013)

Constraints such as opening hours or passenger capacities influence travel options that can be offered by an airport and by the connecting airlines. If infrastructure, policy or technological measures modify transport options, then the benefits do not only depend on the technology, but also on possibly heterogeneous user preferences such as desired arrival times or on the availability of altern...

Mobiles Ganganalysesystem zur Bewertung der prothetischen Versorgung transfemoraler Amputationen

Thiele, Julius (2019)

Introduction: The loss of parts of the lower limbs means a severe change to anyone affected. With a prosthetic leg, mobility can be largely regained. Compared to the much more complex natural counterpart, even prostheses featuring modern microprocessor-based knee joint systems (MPK) have distinct limitations. Against this backdrop a reasonable selection of the prosthesis components and an accur...

Simulation and modeling of a Helmholtz resonator under grazing turbulent flow

Stein, Lewin (2019)

When gas flows along a surface containing a cavity or gap, this fluid-dynamical process is likely linked with acoustical effects. Primarily, in the transport and energy sector, the phenomenon occurs frequently: gas flows around land and air vehicles or streams inside duct systems and engines. A key challenge for these examples is either to prevent cavity noise before it arises or to reduce exis...

Network breakdown “at the edge of chaos” in multi-agent traffic simulations

Rieser, Marcel ; Nagel, Kai (2008)

Traffic is highly influenced by network structure and human behaviour. Small changes in the human behaviour can lead to huge changes in the load of a traffic network. Current transportation models do not, and most of them cannot, research such random behaviour but always calculate a steady state. In our multi-agent transport simulation, we frequently observe seemingly random "network breakdowns...

Preliminary Results of a Multiagent Traffic Simulation for Berlin

Beuck, Ulrike ; Nagel, Kai ; Rieser, Marcel ; Strippgen, David ; Balmer, Michael (2007)

This paper provides an introduction to multi-agent traffic simulation. Metropolitan regions can consist of several million inhabitants, implying the simulation of several million travelers, which represents a considerable computational challenge. We reports on our recent case study of a real-world Berlin scenario. The paper explains computational techniques necessary to achieve results. It turn...