Modellierung und experimentelle Untersuchung von materialintegrierten Sensoren

The thesis is divided in a theoretical and an experimental part. In the theoretical part investigations on the foreign body effect of a sensor in a material in terms of mechanical, thermal and thermo-mechanical loads are done. The second part is based on experiments on the foreign body effect to prove the results of the first part. Therefore temperature and force sensors are integrated in epoxy resin, aluminum and steel

Investigations into packaging technology for membrane-based thermal flow sensors

A new packaging method to mount a membrane-based thermal flow sensor, flush with the surface, is presented. Therefore, a specific design for the housing is shown, which is also adaptable to other conditions. It has been experimentally shown that it is important to mount the sensor flush with the surface. In addition, the experimental results are discussed. If a membrane-based thermal flow sensor is not mounted flush with the surface, vortices can occur (depending on velocity and fluid properties) or the reduction in the channel cross section plus a decrease in sensitivity have to be taken into account

Nonlocal damage based failure models, extraction of crack opening and transition to fracture

International audienceDamage models are capable to represent initiation and somehow crack propagation in a continuum framework. Thus crack openings are not explicitly described. However for concrete structures durability analysis, crack opening through transfer properties is a key issue. Therefore, in this contribution we present a new approach that is able from a continuum modelling to locate a crack from internal variable field and then to estimate crack opening along its path. Results compared to experimental measures for a three point bending test are in a good agreement with an error lower than 10% for widely opened crack (40μm)

Kleintektonische Unregelmaessigkeiten im Zusammenhang mit Gas-Kohlen-Ausbruechen

SIGLETIB: DR 6752 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Modeling and experimental study of material integrated sensors

The thesis is divided in a theoretical and an experimental part. In the theoretical part investigations on the foreign body effect of a sensor in a material in terms of mechanical, thermal and thermo-mechanical loads are done. The second part is based on experiments on the foreign body effect to prove the results of the first part. Therefore temperature and force sensors are integrated in epoxy resin, aluminum and steel

Virtualize A Piece Of Evidence Or Mount Its Partition With Linux

Abstract In a computer forensic investigation, there is always a divergence between the time required to visualize data from evidence and the times when investigators need the data to evaluate it. On the one hand, the processing time that is required for the analysis of existing and deleted data, and on the other hand, the time that elapses to make potentially existing data visible. Data, which the investigator needs immediately because it can be crucial for solving the case. The motivation for this master thesis is to shorten the time it takes to invest until the first sight- ing of data. More and more often, offenders try to disguise their illegal activities on data carriers with new methods and acquired expertise. Therefore, it is important for the investigator to be able to ac- cess hidden or deleted data. This in turn, depending on the amount of data and complexity, often entails immense processing time. The first step of the forensic-process is to create a forensic clone of a disk image and store it in a file. A clone meaning a copy of the evidence data. With this copy further forensic investigations are then made. In special cases, such as terrorism or hostage-taking means, it applies in a very short reaction time, to being able to access data from the evidence without changing the evidence itself (e.g., changing timestamps). With the results of the forensic investigation, follow-up measures can then be recognized and initiated. These follow-up measures are required to take place immedi- ately. Under certain circumstances, indications of further assassination, accomplices or escape routes can be obtained from this data. This would prevent the possibility of imminent actions, thus save lives and/or arrest the perpetrators which in turn prevent further acts. That would not be possible without an immediate inspection of the data. Now, following the well-tried method, a lot of time would be lost until the first data could be used from the evidence. To produce this result, Information Technology (IT) specialists (forensic scientists) are needed to process this data and make it available to the investigator in an appropriate manner so that the investigator is able to use the data in the ongoing investigation. This takes a lot of time. Time and knowledge are the limits of this method, currently. The aim of this master thesis is to study whether an investigator without the special IT know- how can work out the required data and everything in the shortest possible time. Two ways would be conceivable, on the one hand with standard Linux programs to mount par- titions from the evidence (hard disk or image), on the other hand with standard Linux programs to virtualize the evidence as ”Virtual Machine”, in a new way. Now the detailed results would be available in a much shorter time even without an IT specialist. If the investigator is able to view the data of the evidence, he can review the possible data contents of the applications (e-mail, chats, internet protocol, own documents and recently used documents, etc.). He does not need any particular knowledge of the structure of the used file system, the can simply start the applications and watch the results as if he were operating the physical PC. It may then be very important to use this data in the ongoing investigation and deduce further follow-up

Printed Sensors for Material Integrated Sensing: Functionalization of Semi-Finished Parts

A new and innovative approach is presented to integrate sensors in materials and set up “smart materials”. Semi-finished parts are functionalized by printed sensors and printed interconnects. These functionalized parts are then further processed to components. This is a new and simple approach to integrate sensors in a material. Two examples of printed sensors and the process of integration are presented. One is a printed sensor on carbon weaves, integrated in carbon fiber reinforced plastic. The other one is a sensor structure printed on an aluminum sheet and integrated during high pressure die casting. Besides the benefits of this technological approach, challenges are focused in the paper as well

Modellierung und numerische Simulation von Rissfortschritt in spröden und quasi-spröden Materialien auf Basis der Extended Finite Element Method\textit {Extended Finite Element Method}

Die vorliegende Arbeit widmet sich der Modellierung von Rissen und der numerischen Simulation von Rissfortschritt auf der Basis der Extended Finite Element Method (X-FEM). Neben quasi- spröden Materialien - wie zum Beispiel zementgebundenen Werkstoffen - werden auch spröde Materialien - wie zum Beispiel Glas oder Keramik - betrachtet. Die Extended Finite Element Method bietet die Möglichkeit diskrete Risse und Rissfortschritt unabhängig vom verwendeten Finite Elemente Netz zu simulieren. Im Rahmen diskreter Rissmodelle ist die Formulierung eines geeigneten Rissfortschritts- und Rissrichtungskriteriums von entscheidender Bedeutung. Daher bildet die Entwicklung eines globalen Energiekriteriums zur Bestimmung der Rissfortschrittsrichtung und der Rissfortschrittslänge einen zentralen Punkt dieser Arbeit. Die Leistungsfähigkeit des entwickelten Modells wird anhand repräsentativer Beispiele und durch den Vergleich der Ergebnisse mit experimentellen Untersuchungen demonstriert