Wszystkie pola: vibration modelling - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Identification of main helicopters resonances by ground vibration test
Autorzy:: Wiśniowski, W.
Powiązania:: https://bibliotekanauki.pl/articles/242575.pdf
Data publikacji:: 2015
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: helicopter
resonance
modelling
ground vibration test
Opis:: Six resonances of the helicopter body standing on the airport apron and at least two resonances of the free helicopters the frequencies of which are within the range of basic loadings by the helicopter rotor is called (8+) model. It was proposed to identify (8+) model with the use of resonance tests. It was indicated that (8+) model allows for detuning the resonances from the frequency of working loads, tracing the process of moving through resonances as well as taking off and landing. The paper presents: example of a helicopter on a test rig and visible vibrations inductors; induction of resonance vibrations, induction of resonance vibrations with the forms of pitching, yawing, rolling; induction of resonance vibrations with the forms of pitching with opposite pylon yawing and tipping with opposite pylon yawing; model of helicopter resonances; the multiplication of the resonance amplitude for various velocities of moving through with visible growth of the resonance frequency and reduction of vibrations amplitude; change of the frequencies at the taking off and landing.
Źródło:: Journal of KONES; 2015, 22, 2; 287-291
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Comparative analysis of the calculation methods of the marine propeller’s blade thickness
Autorzy:: Murawski, L.
Powiązania:: https://bibliotekanauki.pl/articles/244269.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: marine propeller
strength
vibration
solid structure in fluid
FEM modelling methodology
Opis:: Strength of the propellers with the skewback greater than 25º has to be numerically analysed according to marine classification societies. The finite element method (FEM) is advised for that kind of calculations. Classical and typical propellers (skewback < 25º) may be designed on the base of empirical equations given by the societies. The minimal thickness of the propeller blade is determined by the equations. Each classification society has their own empirical formula. Sometimes, well-designed propeller for one society has not enough strength according to the other society. What is more, propellers designed according to the empirical formulas might be not optimal. Comparative analysis of the marine propeller’s blade strength has been described in the article. Calculations of the propeller’s blade thickness have been done by two international classification societies’ empirical formulas (ABS and DNV). The results have been compared with Finite Element Method calculations (NASTRAN program). The methodology of propeller static strength vibration analyses is presented. Numerical calculation methodology is based on solidstate mechanics with loadings determined by fluid mechanics calculations. Steady state and transient fluid flow of the propeller’s working conditions were taken into account. In order to determine the optimal modelling method of the propeller several different numerical models were compared, including free model of whole propeller and single blade with boundary conditions placed in the foot. The propeller optimization was the main target of the analyses. Propeller blade thickness might be reduced after FEM method analysis - the propeller mass saving can be achieved.
Źródło:: Journal of KONES; 2018, 25, 2; 253-260
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Agency of the suspension of the back idler on transport vibration of the tractor with triangular caterpillar contour
Autorzy:: Pobedin, A.
Varfolomeev, V.
Powiązania:: https://bibliotekanauki.pl/articles/244487.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: triangular caterpillar contour
suspension
back idler
modelling
Opis:: Recently leading producers of farm tractors even more often apply in running systems triangular caterpillar contour (TCC). In such running system one of the most problem knots is the back idler (BI) which is loaded by reaction from a caterpillar track and from weight of the casco having on this support. Thus the vertical component of reaction from a tension of a caterpillar track in addition loads with a tie-rod tangential force suspension bracket BI, thereby disturbing with a casco and reducing smoothness of a course of a tractor. Modelling and the analysis of dependence of affecting of vibration on a seat of the motor-man depending on applied type of a suspension bracket of a back idler are in-process executed. The analysis of parameters of smoothness of a course for the circuit design with triangular caterpillar contour and the offered suspension bracket of a back idler showed that in comparison with base configuration of a tractor of family VT On transport operations, at traffic on the soil road with the lifted tool, affectings on a seat of the operator decrease in 1,1-1,7 times in vertical and in 1.1-1.2 times in horizontal directions, at work with nominal loading, and also with Rkr=50 kN, on an eddish, provides minor alteration of smoothness of a course, the divergence of values of affecting on a seat of the operator, on the average, makes 12–19 %. In comparison with triangular caterpillar contour and "a classical" suspension bracket of a back idler, various displacement-yoke systems of a back idler, at work on transport operations, slightly influence a divergence of parameters of affecting on a seat of the operator which make 2.6 % and 4 % for vertical and horizontal affectings accordingly. At work with nominal loading on an eddish, affectings on a seat of the operator decrease in 1.7–2.7 times in vertical and in 1.4–1.8 times in horizontal directions and at work with draw-bar loading of Rkr=50 kN on an eddish, affectings on a seat of the operator decrease in 1.4–2.1 times in vertical and periodically increase on some speeds no more than by 30 % in a horizontal direction.
Źródło:: Journal of KONES; 2011, 18, 1; 447-452
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Modelling method of dynamic characteristics of marine thin-walled structure
Autorzy:: Doan, Do Van
Szeleziński, Adam
Murawski, Lech
Muc, Adam
Powiązania:: https://bibliotekanauki.pl/articles/245078.pdf
Data publikacji:: 2019
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: thin-walled structure
vibration
FEM
rectangular plate
Patran-Nastran software
Opis:: Thin-walled structures are very popular in industries, especially in the field of shipbuilding. There are many types of equipment and structures of ships, which are made up of thin-walled structures such as hull, deck and superstructure. Therefore, the analysis and understanding of the static and dynamic characteristics of a thin-walled structure are very important. In this article, we focus on vibration analysis of a typical thin-walled structurerectangular plate, a basic structure of the hull. Vibration analysis of a rectangular thin plate is conducted by two methods: numerical modelling method of the finite element on Patran-Nastran software platform and experimental method implemented in the laboratory of Gdynia Maritime University. Thin rectangular plate is fixed one end by four clamping plates and is modelled with finite elements and different meshing densities. The numerical model of thin rectangular plate is divided into four cases. Case 1, thin rectangular plate, and clamping plates are modelled with two-dimensional elements. Case 2, the rectangular thin plate is modelled with two-dimensional elements; the clamping plates are modelled with three-dimensional elements. Case 3, both the rectangular thin plate and clamping plates are modelled with three-dimensional elements. Case 4, the rectangular thin plate, and clamping plates are modelled with three-dimensional elements with larger mesh density to increase the accuracy of the calculation results. After that, the results of vibration analysis according to the numerical modelling method on Patran-Nastran software platform for these cases were compared with the measurement results. From there, assess the accuracy of analysis results of selected numerical model methods and the ability to widely apply this numerical model method to other marine structures
Źródło:: Journal of KONES; 2019, 26, 4; 39-46
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Methodology of selection of vibration isolators optimum characteristics for fastening additional equipment in vehicles
Metodyka doboru optymalnych charakterystyk wibroizolatorów do mocowania wyposażenia dodatkowego w pojazdach
Autorzy:: Borkowski, W.
Hryciów, Z.
Powiązania:: https://bibliotekanauki.pl/articles/244375.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
pojazdy
zawieszenie
modelowanie
optymalizacja
vehicles
suspension
modelling
optimization
Opis:: In the paper chosen questions relating to selection of rubber-metal vibration isolators, which are using to fastening additional equipment in vehicles are described. The problems connecting to selection of favourable solutions are introduced, particularly from comfort of drive point of view. In the paper the questions of vibration isolator's selection with optimum characteristic the special attention are dedicated. The possible to use method of optimization of spring and damping characteristic this type of elements is introduced. The object of investigations, its physical model and mathematical model is described. The task of optimization is formulated in frames which the criterion of optimization and objective function is passed, the set of design variables is specified as well as limitations put on these variables. The method of determinate the characteristic of elastic elements was passed as well as the general algorithm of program. In the paper the examples results of simulating investigations are put - the accelerations of vehicle and additional plate, the goal function and appointed optimum characteristic. Discrete model of vehicle, the influence of design variables on characteristic shape, the algorithm of program, the goal function, the optimal spring characteristic, vertical acceleration of vehicle body and additional plate are presented in the paper.
W pracy opisano wybrane zagadnienia dotyczące doboru wibroizolatorów gumowo-metalowych, służących do mocowania wyposażenia dodatkowego w pojazdach. Przedstawiono problemy związane z wyborem korzystnych rozwiązań z punktu poprawy komfortu jazdy. W pracy szczególną uwagę poświęcono zagadnieniom doboru wibroizolatorów o optymalnych charakterystykach. Przedstawiono możliwą do zastosowania metodę optymalizacji charakterystyk sprężysto-tłumiących tego typu elementów. Opisano obiekt badań, jego model fizyczny oraz model matematyczny. Sformułowano zadanie optymalizacji, w ramach którego podano kryteria optymalizacji, funkcję celu, sprecyzowano zbiór zmiennych decyzyjnych oraz podano ograniczenia nałożone na te zmienne. Podano także metodę wyznaczania charakterystyk elementów sprężystych oraz przedstawiono ogólny algorytm programu komputerowego. W pracy zamieszczono przykładowe wyniki badań symulacyjnych - przebiegi przyspieszeń nadwozia samochodu oraz dodatkowej płyty, funkcję celu oraz wyznaczoną charakterystykę optymalną. Model dyskretny pojazdu, wpływ zmiennych decyzyjnych na kształt charakterystyki, algorytm programu, funkcja celu, optymalna charakterystyka sprężystości, przyspieszenia pionowe nadwozia i dodatkowej płyty, model dyskretny pojazdu, wpływ zmiennych decyzyjnych na kształt charakterystyki są przedstawione w artykule.
Źródło:: Journal of KONES; 2007, 14, 4; 49-57
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Simulating researches of impact reaction of vehicle on subgrade in identification possibility aspect
Badania symulacyjne udarowego oddziaływania pojazdu na podłoże w aspekcie możliwości jego rozpoznawania
Autorzy:: Jackowski, J.
Hryciów, Z.
Powiązania:: https://bibliotekanauki.pl/articles/241607.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
pojazd kołowy
rozpoznanie
modelowanie
wheeled vehicle
identification
modelling
vibration
drgania
Opis:: In the paper chosen questions relating to the impact reaction of vehicle on subgrade caused by its movement over road unevenness were described. The problems of vehicles identification during armed conflicts and realizing tasks in frames of peacekeeping missions are introduced. The algorithm of vehicle identification process on the basis of subgrade vibrations caused by its movement was proposed. The model of analysed fragment of road surface worked out using the finite elements method (FEM) was described. The parameters characterizing separate layers of the road were passed. The method of construction loading by the pressure of wheels on road surface was passed as well as the general characteristics of analysed wheeled vehicles. The example results of simulating researches were put - the courses of accelerations and velocity of chosen point surface. The method of detection of number vehicle axles on the basis of ground vibration using time - frequency distribution was described. The basic dependences of Wagner -Ville distribution were passed as well. In the paper the examples results of identification of vehicles with differing mass and number of axels were put.
W pracy opisano wybrane zagadnienia dotyczące udarowego oddziaływania pojazdu na podłoże wywołane jego ruchem po nierównościach drogi. Przedstawiono problematykę zdalnego rozpoznania pojazdów w czasie konfliktów zbrojnych i realizacji zadań w ramach misji pokojowych. Zaproponowano algorytm procesu rozpoznawania pojazdu na podstawie drgań podłoża wywołanych jego ruchem. Opisano model analizowanego fragmentu nawierzchni drogi opracowany przy wykorzystaniu metody elementów skończonych (MES). Podano parametry charakteryzujące poszczególne warstwy drogi. Podano sposób obciążania konstrukcji siłami nacisku kół na nawierzchnię drogi, a także ogólną charakterystykę analizowanych pojazdów kołowych. Zamieszczono przykładowe wyniki badań symulacyjnych - przebiegi przyspieszeń i prędkości wybranego punktu nawierzchni. Opisano metodę detekcji liczby osi jezdnych samochodu na podstawie drgań gruntu wykorzystującą rozkłady czasowo-częstotliwościowe. Podano także podstawowe zależności rozkładu Wagnera-Ville'a. W pracy zamieszczono również przykładowe wyniki rozpoznania pojazdów różniących się masą oraz liczbą osi.
Źródło:: Journal of KONES; 2007, 14, 1; 219-226
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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