Wyniki wyszukiwania - BazTech

1

Robust switched controller design for linear continuous-time systems

Ilka A., Veselý P.

Archives of Control Sciences

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2015

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Vol. 25, no. 4

401--416

EN

In this paper we study a novel approach to the design of a robust switched controller for continuous-time systems described by a novel robust plant model using quadratic stability and multi parameter dependent quadratic stability approaches. In the proposed design procedure with an output feedback a novel quadratic cost function is proposed which allows to obtain different performance dependence on the working points. Finally a numerical examples are investigated.

2

Assessment with indentation techniques of the local mechanical behavior of joints in polymer parts

Lach R, Hutař P, Veselý P, Nezbedová E, Knésl Z, Koch T, Bierögel C, Grellmann W

Polimery

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2013

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T. 58, nr 11-12

900--905

EN

The paper summarizes our investigations performed with micro- and nanoindentation techniques and results presented in literature, concerning local mechanical behavior of welded joints [polyamide 6, polypropylene, polyethylene (high density and crosslinked polyethylene), poly(vinyl chloride)] and weld lines (polypropylene, polycarbonate, polystyrene) of amorphous and semicrystalline polymers. For amorphous polymers, minimum of hardness and indentation modulus in the joint are found or no change in the properties were stated, whereas for semicrystalline polymers, hardness and indentation modulus mostly pass through a maximum in the weld line, the welded joint or the heat-affected zones.

PL

W pracy podsumowano wyniki badań wykonanych metodą wciskania wgłębnika w zakresie mikro i nano oraz wyniki przedstawione w literaturze, dotyczące lokalnych właściwości złączy spawanych [poliamidu 6, polipropylenu, polietylenu (dużej gęstości i usieciowanego), poli(chlorku winylu)] i linii spoiny polimerów amorficznych i semikrystalicznych (polipropylenu, poliwęglanu, polistyrenu). W przypadku polimerów amorficznych wykazano w złączu minimum twardości i modułu sprężystości przy wciskaniu wgłębnika lub stwierdzono brak zmian tych właściwości. W przypadku polimerów semikrystalicznych twardość i moduł sprężystości osiągają maksimum w linii spoiny, złączu spawanym lub w strefach wpływu ciepła.

3

Analiza wpływu nierównomierności podziałki ostrzy pił tarczowych na wielkość zapylenia emitowanego podczas cięcia drewna

Kopecký Z., Veselý P., Mičánek J., Mazal P., Rousek M., Kowalski M.

Mechanik

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2012

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R. 85, nr 8-9CD (SOS)

521--528

4

The efect of particle filler in PPH Matrix on thoughness behaviour

Veselý P., Nezbedová E., Fiedler L., Vlach B.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2007

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Vol. 321, z. 89

47-47

EN

The use of commodity polymers in many technical applications is limited due to its material behavior - thermal stability, barrier properties, toughness or mechanical strength. That is the reason why to modify the basic polymer with fillers, reinforcement at different macroscale, microscale as well as nanoscale level. All the physical and chemical properties can be modified by way of fillers. The goal is find the way how to enhance the toughness of this system by keeping its stiffness.[l,2,3,] The first step is to modify relevant parameters of the matrix at molecular as well as super molecular level (adding a and p nucleation agent). Effect of particles on the properties and behavior of system strongly depends on its size, shape, surface coating and distribution. Mechanisms of toughening (creation of shear bands) can starts after releasing the stress concentration on the interface. [4,5,6] The system PP matrix filled with rigid submicroscopic particles of CaCC>3 was confrontate with system PP/kaolin, PP/ talc. Tensile test was applied to estimate the tensile properties. The fracture mechanics approach was chosen to describe the toughness of the system. Particularly, the J-R curve procedure was used. The results were reviewed with microscopy observation.