Robert Zalewski

The Active Magnetorheological Support as an Element of Damping of Vibrations Transferred from the Ground to Large-Scale Structure Supports

The active support of a large-scale structure, made up of two elements was designed and manufactured. The first of them - piezoelectric actuator, enables the simulations of vibrations transferred from the ground to the structure. In order to minimize vibrations transmitted through the ground to the construction, the second element of the active support - a system based on magnetorheological dampers was used. The active support enables the simulations of vibrations from the ground using a piezoelectric stack controlled in a reverse feedback loop. Control signals of the feedback loop are: the volume of deformation and vibrations in the selected structures node.

Modeling of Complex Properties of Vacuum Packed Particles Using Evolutionary Algorithms

A conglomerate, composed of granular materials encapsulated in a tight, flexible envelope, and submitted to an internal underpressure, changes its properties in the function of the vacuum range. The underpressure level, controlled by a vacuum pump, enables controlling the behavior of such a medium. This particular ability could be useful in some specific applications.

Designing Process of the Drone’s Passive Safety System

In this paper the authors would like to introduce a new air-bag’s prototype suitable for protecting valuable objects mounted on the drones. The experimental research results are presented for typical air-bag’s textile material. Laboratory tests were a base for the material’s model calibration process. The numerical simulations for proposed air-bag’s prototype were carried out in the LS-Dyna environment. Proposed solution seems to be a reasonable device for prevent the drone’s equipment from unexpected accidents.

Gamota-Filisko Model for Vacuum Packed Particles

In this paper authors would like to introduce a new controllable structure, in some aspects similar to MR fluids, which is composed on the basis of granular material. Loose material is initially placed in a deformable hermetic encapsulation (basically made of soft polymer), equipped in a special valve. In the next step, an internal pressure is pumped out of the structure and so called “underpressure” is generated.

Modelling of Innovative Controllable Structures Made of Granular Materials

The viscoplastic behavior of ”innovative” structure is considered. Investigated structures are created on the basis of vacuum packed particles. Partial vacuum generated inside a hermetic sleeve filled with loose granular material transforms the system from semi-liquid to semi-solid state. Such phenomenon, known as a ”jamming mechanism”, is strongly nonlinear in considered structures. Special granular structures have recently found interesting engineering and biomedical applications such as vacuum mattresses, orthopedic orthesis, universal robotic grippers and flexible endoscopes. To capture a response of the specially designed granular sample to external loading, a Bodner-Partom viscoplastic constitutive model has been chosen. The identification procedure is based on experimental compression tests realized at various strain rates and underpressure levels.