Advances in Mechanisms Design : Proceedings of TMM 2012

The International Conference on the Theory of Machines and Mechanisms is organized every four years, under the auspices of the International Federation for the Promotion of Mechanism and Machine Science (IFToMM) and the Czech Society for Mechanics. This eleventh edition of the conference took place at the Technical University of Liberec, Czech Republic, 4-6 September 2012. This volume offers an international selection of the most important new results and developments, in 73 papers, grouped in seven different parts, representing a well-balanced overview, and spanning the general theory of machines and mechanisms, through analysis and synthesis of planar and spatial mechanisms, dynamics of machines and mechanisms, linkages and cams, computational mechanics, rotor dynamics, biomechanics, mechatronics, vibration and noise in machines, optimization of mechanisms and machines, control and monitoring systems of machines, accuracy and reliability of machines and mechanisms, robots and manipulators to the mechanisms of textile machines

Advances in Mechanisms DesignProceedings of TMM 2012 /

XXIV, 560 p.online resource

Magnetic accumulation of kinetic energy from a reciprocating mechanical system for a dynamic behaviour improvement

This paper presents a magnetic means of accumulating kinetic energy from a traversing rod (TR) used to guide yarn during winding processes on rotor spinning machines. A passive magnetic system for accumulating kinetic energy at the reversal points of reciprocating motion is introduced, and its unique repulsive magnetic force is described in relation to the specific traversing-motion characteristic. The magnetic damping force phenomenon and preconditions for its application in the machine are also defined and discussed. We also show magnetic field optimisation by means of pole-piece geometry modification to obtain a magnetic force characteristic that closely approximates the required motion characteristic. Thus, the efficiency of kinetic-energy accumulation at the reversal points of the reciprocating motion of the TR is increased. The utilisation of an eddy-current effect on the accumulator body to apply the magnetic-damping phenomenon for vibration reduction is also described. The results of this work demonstrate the promise of the system using modern rare-earth compound-based magnets applicable not only to the studied traversing system but also to various mechanical devices as a non-contact means of reducing deformation and vibration. The developed and experimentally verified mathematical models presented here represent a useful tool for further optimisation of specific applications in the field of mechanics. (C) 2019 Elsevier Ltd. All rights reserved

Fabrication of dual-functional composite yarns with a nanofibrous envelope using high throughput AC needleless and collectorless electrospinning

Abstract Nanotechnologies allow the production of yarns containing nanofibres for use in composites, membranes and biomedical materials. Composite yarns with a conventional thread core for mechanical strength and a nanofibrous envelope for functionality, e.g. biological, catalytic, have many advantages. Until now, the production of such yarns has been technologically difficult. Here, we show an approach to composite yarn production whereby a plume of nanofibers generated by high throughput AC needleless and collectorless electrospinning is wound around a classic thread. In the resulting yarn, nanofibres can form up to 80% of its weight. Our yarn production speed was 10 m/min; testing showed this can be increased to 60 m/min. After the yarn was embedded into knitwear, scanning electron microscope images revealed an intact nanofibrous envelope of the composite yarn. Our results indicate that this production method could lead to the widespread production and use of composite nanofibrous yarns on an industrial scale

Simulating asteroid impacts and meteor events by high-power lasers : from the laboratory to spaceborne missions

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