Compositional materials with controllable vibration damping parameters

The paper proposes laminated sandwich-elements containing electrorheological composite as a structural element, which enable designing novel thin-wall structures with a locally varying rigidity and vibrostability for aerospace engineering, ship-building, high-speed devices in mechanical engineering (machine tools, robots), in transport means (controlled springs), in instrument fabrication, et

Research of ultrasonic sensing and mixing elements for control of magnetorheological fluids stability

Using of magnetorheological fluids (MRF) can reduce energy costs and weight and increase the devices speed and lifetime. In order to fully use all the qualities of MRF properties one must from time to time mix them and measure their properties. These systems are still being designed and tested in the laboratories. There are many structures with rheological fluid, but in many devices fluids are sealed and mechanical mixing and direct measurement of fluid properties are not possible. Effective stability control system for the rheological fluids, which supports homogeneity of the fluid, is described. (Е-mail: [email protected]

Investigation of the piezoelectric thimble tactile device operating modes

A multifunctional device to transfer graphical or text information for blind or visually impaired is presented. The prototype using tactile perception has been designed where information displayed on the screen of electronic device (mobile phone, PC) is transferred by oscillating needle, touching the fingertip. Having the aim to define optimal parameters of the fingertip excitation by needle, the computational analysis of different excitation modes has been carried out. A 3D solid computational finite element model of the skin segment, comprising four main fingertip skin layers (stratum corneum, epidermis, dermis and hypodermis) was built by using ANSYS Workbench FEA software. Harmonic analysis of its stress–strain state under excitation with different frequency (up to 10000 Hz) and harmonic force (0.01 N), acting outer stratum corneum layer in normal direction at one, two or three points has been performed. The influence of the mode of dynamic loading of skin was evaluated (in terms of the tactile signal level) on the basis of the normal and shear elastic strain in dermis, where mechanoreceptors are placed. It is shown that the tactile perception of information, delivered by three vibrating pins, may be influenced by configuration of excitation points (their number and phase of loading) and the frequency of excitation

Analytical research of damping efficiency and heat generation of magnetorheological damper

International audienceMagnetorheological (MR) dampers are currently used in various areas, such as: human prosthetics,seismic protection, active suspensions, safety systems, amongst other. This paper deals with theproper design of a MR damper in the innovative field for vibration control. A methodology forcalculation some principal characteristics of the damper such as: electromagnet’s magnetic fieldvalue, emitted heat and damping force is presented. The methodology is based on analyticcalculations of the characteristics and finite element method analysis. The obtained theoreticalresults were confirmed by performed experimental tests, thanks to a specially designed and realisedMR damper. Two main geometrical characteristics of the damper, namely: piston thickness andelectromagnet width were optimally chosen, thus allowing to reach maximum damping force

Analytical research of damping efficiency and heat generation of magnetorheological damper

International audienceMagnetorheological (MR) dampers are currently used in various areas, such as: human prosthetics,seismic protection, active suspensions, safety systems, amongst other. This paper deals with theproper design of a MR damper in the innovative field for vibration control. A methodology forcalculation some principal characteristics of the damper such as: electromagnet’s magnetic fieldvalue, emitted heat and damping force is presented. The methodology is based on analyticcalculations of the characteristics and finite element method analysis. The obtained theoreticalresults were confirmed by performed experimental tests, thanks to a specially designed and realisedMR damper. Two main geometrical characteristics of the damper, namely: piston thickness andelectromagnet width were optimally chosen, thus allowing to reach maximum damping force