In this work, the ratcheting-behavior of 9%Cr-1%Mo ferritic–martensitic steel is studied with uniaxial cyclic loading. To describe the ratcheting-behavior of this steel, a visco-plastic constitutive model with consideration of cyclic softening of Reduced Activation Ferritic Martensitic steels is further modified, based on the analysis of back stress.

The goal of this work is the introduction of efficient antenna structures on the basis of the requirement of different microwave imaging methods; i.e. quantitative and qualitative microwave imaging techniques. Several criteria are proposed for the evaluation of single element antenna structures for application in microwave imaging systems. The performance of the proposed antennas are evaluated in simulation and measurement scenarios.

Ein Ansatz zur Reproduktion reibungserregter Schwingungen in Schaltgetrieben im hörbaren Frequenzbereich wird präsentiert. Im Vordergrund stehen Folgelasten, die aus den Kontaktreaktionen in der Verzahnung und Reibung zwischen den Kupplungsscheiben resultieren. Zunächst wird ein MKS-Modell mit wenigen Freiheitsgraden vorgestellt, welches sukzessive erweitert wird. Neben der Stabilitätsuntersuchung des stationären Verhaltens werden dynamische Lösungen präsentiert und analysiert. An approach for the reproduction of friction induced vibrations in shift gearboxes in audible frequency range is presented. The research's core is given by follower forces, which arise out of the sliding clutch and gear contact. Firstly, a multi-body dynamic system with few degrees of freedom is presented, which is extended step-by-step. Besides the pure analysis of the stationary solution's stability, dynamic solutions are presented and discussed.

The present work deals with multi-field contact problems in the context of IGA. In particular, a thermomechanical as well as a fracture mechanical system is considered, where novel formulations are introduced for both. The corresponding discrete contact formulations are based on a variationally consistent mortar approach adapted for NURBS discretized and hierarchical refined surfaces. Finally, the capabilities of the proposed framework are demonstrated within numerous numerical examples.

The present work deals with the inverse dynamics simulation of underactuated multibody systems. In particular, the study focuses on solving trajectory tracking control problems of differentially flat underactuated systems. The use of servo constraints provides an approach to formulate trajectory tracking control problems of underacutated systems, which are also called underactuated servo constraint problems.

In diesem Buch erfolgt eine Betrachtung von kooperativen Regelkreisen in denen Mensch und Automation gemeinsam die Regelung eines Systems übernehmen. Es erfolgt eine formale Modellierung der Problemstellung aus der ein systematisches, kooperatives Regelkonzept abgeleitet wird. Kern ist die Lösung eines Differentialspiels auf einem gleitenden Horizont. Auf Basis dieses Konzepts werden zwei kooperative Fahrerassistenzsysteme entwickelt (Querführung und Längsführung). Cooperative control loops in which human and a technical automation system perform a control task in close cooperation are investigated. A control framework is proposed which is based on a formal description of the cooperative control problem. The main idea of the control algorithm is to solve a differential game on a sliding horizon. The concept has been applied to design two cooperative advanced driver-assistance systems. One for the longitudinal driving task, one for the lateral driving task.

Frühwarnsysteme dienen zur möglichst frühzeitigen Information über eine sich anbahnende oder auftretende Gefahr, um Personen und Organisationen die Möglichkeit zu geben entsprechend darauf reagieren zu können. Die Konzeption eines Frühwarnsystems stellt komplexe Herausforderungen an die Systemarchitekten, hierzu liefert die vorliegende Arbeit ein Rahmenwerk für die Architektur zukünftiger Frühwarnsysteme. Early warning systems are supposed to deliver information about an emerging threat in order to allow persons and organizations to react accordingly. The design of an early warning system presents complex challenges to the system architects. For this, the present work provides a framework for the architecture of future early warning systems. Particular attention is paid to solve various architectural problems by means of semantic technologies and the automation of workflows.

The grain microstructure and damage mechanisms at the grain level are the key factors that influence fatigue of metals at small scales. This is addressed in this work by establishing a new micro-mechanical model for prediction of multiaxial high cycle fatigue (HCF) at a length scale of 5-100μm. The HCF model considers elasto-plastic behavior of metals at the grain level and microstructural parameters, specifically the grain size and the grain orientation.

Efficient inbound networks in the European automotive industry rely on a set of different transport concepts including milk runs - understood as regularly scheduled pickup tours. The complexity of designing such a mixed network makes decision support necessary: In this book we provide definitions, mathematical models and a solution method for the Milk Run Design problem and introduce indicators assessing the performance of established milk runs in relation to alternative transport concepts.

The goal of this work is to provide building blocks for resource-aware robot architectures. The topic of these blocks are data-driven generation of context-sensitive resource models, prediction of future resource utilizations, and resource-aware computer vision and motion planning algorithms. The implementation of these algorithms is based on resource-aware concepts and methodologies originating from the Transregional Collaborative Research Center "Invasive Computing" (SFB/TR 89).