@article{9991, abstract = {{Abstract:Since fine powders tend strongly to adhesion and agglomeration, their processing withconventional methods is difficult or impossible. Typically, in order to enable the handling of finepowders, chemicals are added to increase the flowability and reduce adhesion. This contributionshows that instead of additives also vibrations can be used to increase the flowability, to reduceadhesion and cohesion, and thus to enable or improve processes such as precision dosing, mixing,and transport of very fine powders. The methods for manipulating powder properties are describedin detail and prototypes for experimental studies are presented. It is shown that the handling of finepowders can be improved by using low-frequency, high-frequency or a combination of low- andhigh-frequency vibration.}}, author = {{Dunst, Paul and Bornmann, Peter and Hemsel, Tobias and Sextro, Walter}}, journal = {{Actuators 2018, 7(2).}}, keywords = {{powder handling, flowability, dosing, transport, mixing, dispersion, piezoelectricactuators, vibrations}}, pages = {{1--11}}, title = {{{Vibration-Assisted Handling of Dry Fine Powders}}}, doi = {{10.3390/act7020018}}, year = {{2018}}, } @inproceedings{9889, abstract = {{A measurement method is presented that combines the advantages of the multisine measurement technique with a prediction method for peak bending behavior. This combination allows the analysis of the dynamic behavior of mechanical structures at distinctly reduced measurement durations and has the advantage of reducing high excitation impacts on the structure under test.}}, author = {{Sprock, Christian and Sextro, Walter}}, booktitle = {{Instrumentation and Measurement Technology Conference (I2MTC) Proceedings, 2014 IEEE International}}, keywords = {{bending, dynamic testing, measurement, structural engineering, vibrations, measurement durations, mechanical structures, multisine measurement technique, nonlinear peak bending behavior, prediction method, time-efficient dynamic analysis, Heuristic algorithms, Nonlinear systems, Oscillators, Time measurement, Time-frequency analysis, Vibrations}}, pages = {{320--324}}, title = {{{Time-efficient dynamic analysis of structures exhibiting nonlinear peak bending}}}, doi = {{10.1109/I2MTC.2014.6860760}}, year = {{2014}}, } @inproceedings{9519, abstract = {{Several positioning tasks demand translatory drive instead of rotary motion. To achieve drives that are capable e.g. to drive the sunroof of a car or to lift a car's window, multiple miniaturized motors can be combined. But in this case many other questions arise: the electromechanical behavior of the individual motors differs slightly, the motor characteristics are strongly dependent on the driving parameters and the driven load, many applications need some extra power for special cases like overcoming higher forces periodically. Thus, the bundle of motors has to act well organized and controlled to get an optimized drive that is not oversized and costly.}}, author = {{Hemsel, Tobias and Mracek, Maik and Wallaschek, Jörg and Vasiljev, Piotr}}, booktitle = {{Ultrasonics Symposium, 2004 IEEE}}, issn = {{1051-0117}}, keywords = {{drives, electromechanical effects, linear motors, ultrasonic motors, car sunroof, car window, electromechanical behavior, high power ultrasonic linear motors, multiple miniaturized motors, positioning tasks, translatory drive, Costs, Electromagnetic forces, Frequency, Laboratories, Manufacturing, Mechatronics, Micromotors, Ultrasonic imaging, Vibrations, Voltage}}, number = {{Vol.2}}, pages = {{1161--1164}}, title = {{{A novel approach for high power ultrasonic linear motors}}}, doi = {{10.1109/ULTSYM.2004.1417988}}, volume = {{2}}, year = {{2004}}, } @inproceedings{8926, abstract = {{Piezoelectric transformers are well known since the publication of some patent applications at the end of the 1950s. But until today their only business use lies in the field of backlighting systems for LCDs. Due to key features as light-weight, flatness, high step-up at low volume and high efficiency piezoelectric transformers should be usable in a much broader range of applications. This contribution returns to mind their operating principle, shows how to model and to develop such devices as well as give some aspects for development trends that will lead to further applications.}}, author = {{Hemsel, Tobias and Littmann, Walter and Wallaschek, Jörg}}, booktitle = {{Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE}}, issn = {{1051-0117}}, keywords = {{piezoelectric devices, reviews, transformers, backlighting systems, flatness, high efficiency piezoelectric transformers, high step-up, light-weight, low volume, operating principle, piezoelectric transformers, Circuits, Costs, Electromagnetic devices, Electromagnetic fields, Mechanical energy, Piezoelectric materials, Power electronics, Switching frequency, Transformers, Vibrations}}, number = {{vol.1}}, pages = {{645--648}}, title = {{{Piezoelectric transformers - state of the art and development trends}}}, doi = {{10.1109/ULTSYM.2002.1193485}}, volume = {{1}}, year = {{2002}}, } @inproceedings{8915, abstract = {{Ultrasonic linear motors have now been investigated for several years. Their key features are high thrust forces related to their volume and good position-accuracy. This contribution consists of two main parts. In the first part we describe the state-of-the-art of linear piezoelectric motors. Characteristics like no-load velocity, maximum thrust force and other technical properties of commercially available devices will be reported as well as those of prototypes. In the second part we report an ongoing research and development project aiming at a linear piezoelectric motor, which is capable of surpassing some of the shortcomings of other piezoelectric motors}}, author = {{Hemsel, Tobias and Wallaschek, Jörg}}, booktitle = {{Ultrasonics Symposium, 2000 IEEE}}, issn = {{1051-0117}}, keywords = {{linear motors, ultrasonic motors, linear piezoelectric motor, maximum thrust force, no-load velocity, ultrasonic linear motor, Electromagnetic devices, Electromagnetic fields, Frequency, Friction, Gears, Materials science and technology, Piezoelectric materials, Research and development, Vibrations, Wheels}}, pages = {{663--666 vol.1}}, title = {{{State of the art and development trends of ultrasonic linear motors}}}, doi = {{10.1109/ULTSYM.2000.922635}}, volume = {{1}}, year = {{2000}}, }