Wyniki wyszukiwania - BazTech

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Drive System Parameters Influence on Run-Up Process of the Drilling Rig Pumping Unit

Kovalchuk Roman, Molkov Yuriy, Lenkovskiy Taras, Grytsenko Oleksandr, Krasinskyi Volodymyr, Garbacz Tomasz

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 4

199--206

EN

A mathematical model of dynamic processes in pumping unit of a drilling rig with friction clutch, taking into account variable moment of inertia of slider-crank mechanism links and random number of pistons of the pump, was developed. Joint integration of differential equations of motion of pumping unit parts was carried out with numerical methods. The calculations performed considered the torque moment of friction in the clutch and equations of electromagnetic processes in asynchronous motor. The results of research of run-up processes of pumping unit were presented. The influence of parameters of friction clutch on the performance of pumping unit was established.

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Prof. Eugeniusz Kamiński (1923-1995)

Kamiński J., Pokorski J.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2015

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z. 4/104

5--7

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Modelowanie i symulacja numeryczna drgań młota udarowego RG-1

Klasztorny M., Niezgoda T., Gieleta R., Talarek P.

Biuletyn Wojskowej Akademii Technicznej

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2010

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Vol. 59, nr 4

313-334

PL

Przedmiotem modelowania i symulacji jest oryginalny młot udarowy sprężynowy o nazwie RG -1, zaprojektowany i wykonany w Katedrze Mechaniki i Informatyki Stosowanej Wydziału Mechanicznego Wojskowej Akademii Technicznej w Warszawie [1]. Opracowano nieliniowy dyskretny model dynamiczny układu młot-badany element energochłonny-wibroizolacja-fundament-podłoże i wyznaczono wartości parametrów tego modelu. Sformułowano nieliniowe równania ruchu układu w niejawnej postaci i opracowano algorytm numerycznego całkowania tych równań. Opracowano program komputerowy KESHA v2 do symulacji numerycznej drgań układu. Przeprowadzono wstępne badania numeryczne energochłonności elementów kompozytowych cylindrycznych. W celu redukcji drgań wywołanych pracą młota, urządzenie posadowiono na żelbetowym fundamencie blokowym za pośrednictwem wibroizolacji GERB, którą stanowi układ czterech wibroizolatorów sprężynowych z tłumikami wiskotycznymi, typu KV-452-247 03. Badany młot udarowy należy do klasy młotów o średnich prędkościach uderzenia i średniej energii uderzenia (vu = 2,5-11 m/s; Eu = 0,1-6,0 kJ).

EN

The study presents modelling and numerical simulation of the RG -1 spring stroke hammer, using the multi-body dynamics approach. The device has been designed and erected at the Laboratory of Strength of Materials of the Department of Mechanics and Applied Computer Science of Military University of Technology, Poland. The study develops a nonlinear discrete dynamic model of the hammer-examined specimen-vibroisolation-foundation-subsoil system as well as determines the values of the system parameters. A nonlinear matrix equation of motion of the system has been formulated partly in the implicit form, taking into consideration subsequent/simultaneous stages of the dynamic process, i.e., rapid release of the ram catch, expansion of the mainsprings, impact of the ram onto the examined specimen, shock absorption by the elastomeric pads, reduction of the forced vibrations by GERB vibroisolators, propagation of the vibrations in the subsoil, free damped vibrations of the system. An implicit algorithm for numerical integration of equations of motion, based on Newmark's average acceleration method, has been formulated. The problem has been reflected by a computer programme written in Pascal. The study presents numerical simulations reflecting dynamic tests of energy-absorbing composite cylindrical specimens. The ram fixed to the moving traverse is able to induce progressive failure up to the specimen length minus 15 mm. A distance of 15 mm is reserved for gathering the material of the destroyed part of the specimen. If this distance is achieved, the moving traverse strikes onto the elastomeric pads fixed to the cantilevers. All possible breakings away are taken into consideration in the matrix equation of motion. In order to reduce vibrations, induced by rapid releasing of the ram catch and by the main impact, the device has been connected to RC block foundation with four viscoelastic KV-452-247 03 GERB vibroisolation units. The fundamental natural frequency of the system is close to f1 = 3.4 Hz. The exemplary time histories of vibrations of select subsystems, corresponding to the initial shortening of the mainsprings equal to s = 75 mm and 150 mm, number of bobs n = 0, and the carbon/epoxy specimen CE-1, are shown in Figs. 10 and 11. The multi-body dynamic model of the device, the dynamic equation of motion, the computer algorithms and the computer programme constitute an effective tool for predicting energy absorption of composite specimens and for assessment of vibration isolation effectiveness. The GERB vibroisolation has appeared to be very effective. The investigated device belongs to the hammers class of the medium impact velocities (vu = 2.5-11 m/s) and the medium impact energy (Eu = 0.1-6.0 kJ).

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Modelling of Relations Between Liquid and Tank Truck's Constructions in Dynamic Conditions Using FEM

Osiński J., Sowiński D.

Machine Dynamics Problems

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2007

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Vol. 31, No. 4

80-98

EN

Tank trucks are the particular group of vehicle to transport fuel and other dangerous materials. Because of their specific role on the roads they have to be safe, reliable and economic. Designing these type of construction one concentrates on the economic factors. In consequence these type of constructions tends to minimize its masses and maximise load-carrying ability. To gain these goals most of modern tank trucks have self-load-carrying ability construction. To design proper construction of cistern the mechanics of deformable structures, membrane theory, stability and optimisation have to be known. The complexity of the matters has been taking into consideration in many references so far. One of the publication worth to look through is "Strength end optimisation of sheet metal tanks" (Magnucki, 1998). It is only polish version. The author assumes the science achievements in this field until 1998. The examples enhanced in the book show the scale of complication of this subject. Strict mathematic solution could be used only for really simplified cases of tanks. The article describes the new method of modelling influences of liquid on tank truck's elements in dynamic condition with FEM. The method makes allowance for modelling viscosity and compressibility of liquid and filling the chambers up to different levels. Most of the cisterns for fuel are designed to transport a few types of liquid (fuel, oil etc.). To enable the modelling of this kind of situation every chambers could be filled by different liquid's models. The results of investigations could develop up-to-date method of cistern's analysing. It'll be change into dynamic direction. It is a subject of doctor' thesis which has been written in Institute of Machine Design Fundamentals (Warsaw University of Technology). The hyperelastic material has been used to define properties of liquid. The models of tanks are modelled as typical shell construction (shell elements 3 or 4 nodes). The liquid's volume was modelled as 8 or 6 nodes solid elements with properties of hyperelastic material.

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Tłumienie drgań w nieliniowym układzie napędowym

Skup Z.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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1999

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z. 52 [174]

215-220

EN

The considerations consern the steady-state of a non-linear discrete of a three-degree-of-freedom power transmission system. The system vibrates under harmonic excitation. The tested system contains a multiple-disc friction clutch; structural friction and a nonlinear viscotic damping occurs. A non-uniform pressure distribution between the friction discs is taken into account. The influence of the external load amplitude, unit pressures, non-linear viscotic damping and geometric parameters, amplitude-frequency characteristic were analysed. The equations of motion of the tested power transmission system were solved by the slowly varying parameters method and numerical method.

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Efekty dynamiczne jako podstawowe kryterium projektowania wałów maszynowych

Dąbrowski Z.

Przegląd Mechaniczny

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1999

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nr 17-18

14-18

PL

Przedyskutowano tezę o konieczności wszechstronnej analizy dynamicznej w procesie projektowania wałów maszynowych przy złożonych małych współczynnikach bezpieczeństwa, zaproponowano sposób postępowania i kryteria wyboru różnych modeli dynamicznych.

EN

In this paper the problem of dynamic analysis of rotating system is considered. Author propose using the dynamic analysis as the first step in macine shafts designe process. Same examples of mathematical models are discused.