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Wyświetlanie 1-6 z 6
Tytuł:
Innovationality is the transfer process from the idea to commercialization
Autorzy:
Wiśniewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/243893.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ground vibration test
modal analysis
aircraft structure dynamics
Opis:
In today's world, innovationality is synonymous with modernity, development, good governance and strategic thinking. The country 's economy and whole of society should be innovative. The research and development process and the results of the work would be reviewed from the commercialization perspective. The all innovative projects should finish on thefree market, but majority of them end their lives at the research and development stage. The idea of spin-off corporations has to serve the subordination of the entire innovative project realization cycle to the vision of its commercialization. Innovative society and economy require implementation of both large and small innovations, created in large, medium and small R & D programs. In economically leading countries, the mega-programs play an important role in innovationality. small innovation programs are usually created by small research teams and individual inventors. For the balanced development of the country's economy, there is a needfor the variety, both small and large innovation programs. In the absence of an effective opportunity to realize one's own Polish mega-programs, it is worth to consider the mega-program named: ,,Provision of services on the International research market" as a Polish specialty. For 10 years the Warsaw's Institute of Aviation pursues this strategy. The Institute of Aviation employs about 800 specialists, which perform the advanced research of the new materials and designs for the new gas turbine engines and combustion systems.
Źródło:
Journal of KONES; 2010, 17, 1; 485-488
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of changes in some design parameters on the dynamic properties of aircraft
Autorzy:
Wiśniewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/243891.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ground vibration test
modal analysis
aircraft structure dynamics
Opis:
The aim of the study presented in the paper was to examine the impact of changes related to aircraft modernization, the dynamic properties of an aircraft on the basis of five cases studied experimentally. Which changes in the dynamics of an aircraft structure occurred as a result of modernization can be experimentally tested by resonance tests. For this purpose, resonance tests should be carried out before the aircraft modernization and after its completion. In order to mapping the conditions of free flight the objects were suspended flexibly. The electrodynamics actuators were used to induce vibrations, piezoelectric transducers were used for the measurement of vibrations. The size and phase of extortion forces and their application points were selected individually for each resonance in order to get the best separation of it. The first stage of the study was based on recordings the frequency - amplitude characteristics. The second stage of the study was the Identification of individual frequencies and mode shapes of each resonance, which was implemented by choosing the size and the proportion of mutual phase shifts between the extortion forces. In the selection the criteria based on minimizing the phase difference of vibrations measured at several points of the structure were used. The final stage of this study was to register the frequency and shapes mode of the tested resonance and the resonance generalized masses and damping coefficients.
Źródło:
Journal of KONES; 2010, 17, 1; 479-483
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of uncertainty analysis in structural dynamics
Autorzy:
Martowicz, A.
Pieczonka, Ł.
Uhl, T.
Powiązania:
https://bibliotekanauki.pl/articles/243305.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
structural dynamics
uncertainty analysis
eigen problem
finite element method
genetic algorithms
Opis:
The paper deals with the application of uncertainty analysis in structural dynamics. The usage of soft computing method, namely Genetic Algorithms (GA), is presented to show effective computational technique that allows for assessing the propagation of defmed uncertainties in modelled mechanical structure. Tested method is capable of finding variation of eigenfrequencies of Finite Element models and is based on scanning of interval global system matrices. During this process combination of values of input design parameters are found for which extremes of frequencies of vibration appear. FE model of windscreen, made available by Renault Technocentre, has been anafysed. Assumed uncertainties have taken. into account variability of material properties, geometrical characteristics and environmental conditions. Fuzzy theory together with alpha-cut strategy has been applied for modelling uncertain parameters. Sensitivity analysis has been performed to investigate the contribution effect introduced by each assumed input parameter to studied frequency of vibration. Obtained results have been presented and discussed within the context of referential results yielded from Monte Carlo simulation and GA used directly for the search of frequency extremes. Finally, observed time savings have been mentioned to justify the usage of tested computational method.
Źródło:
Journal of KONES; 2008, 15, 1; 153-167
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling and numerical analysis of the reinforced concrete viaduct under the Eurocity EC-114 train
Autorzy:
Szurgott, P.
Powiązania:
https://bibliotekanauki.pl/articles/246723.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
bridge - train interaction
moving train
reinforce concrete bridge
numerical analysis
dynamics
Opis:
The paper presents a methodology of finite element modelling and numerical simulation of symmetric vibrations of the reinforced concrete viaduct using advanced CAE systems. Two types of analysis were carried out - static analysis of the viaduct under dead load and dynamic analysis under a moving high speed train. The KNI 140070 viaduct of span length of 14.40 m with abutment zones was selected as a representative for the study. The serviced ballasted track was taken into consideration. The FE model of the track includes the main rails, fastening systems, sleepers and the ballast. The EuroCity EC 114, Polish high speed train, moving at 100-160 km/h was selected for the study. Components of the train FE model were considered as rigid bodies and were modelled using shell and beam elements. Cylindrical and revolute constrained joints were applied for kinematic connections and relations between relative components. Discrete springs and dampers were applied for modelling of the primary and the secondary suspension systems. The numerical analysis was performed using finite element code LS-DYNA. The stress distribution in selected components of the viaduct structure was presented as the results of the static analysis, whereas the selected time histories for displacements and stresses were shown as the results of the dynamic analysis. The results obtained from both analyses allowed to assess the actual displacement and stress states for the considered viaduct.
Źródło:
Journal of KONES; 2012, 19, 2; 515-524
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An application of order tracking procedure for diagnosis technical state of rotor system in shut - down process
Autorzy:
Grządziela, A.
Kluczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/242634.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
dynamics
vibration
gas turbines
rotor vibration
shut-down process
order analysis
Opis:
Vibration diagnostic tests of marine gas turbine engines are performed as a research of on-line and off-line types. On-line systems generally monitored one or two vibration symptoms, which asses the limited and/or the critical values of parameters and they, potentially, can warn and/or shutdown engines. Off-line Systems are usually used for vibration analysis during non-steady state of work. The paper presents a new method of vibration diagnostics of rotor bearing system of gas turbine systems. The study assumes implementation of characteristics of vibration signals during the shut-down process of the rotor. The shut-down process is non-stationary so the studies used the order tracking procedure. Identified orders constitute individual characteristics as a function of changes of the rotational speed and shut-down process time. These allow the observation of changes in the support rigidity of the rotor in the frequency domain and change the bearing resistance torque as a function of changing time of the shut-down process. The resulting characteristics are as reference fingerprints for each of the rotors. Changes in the characteristics of the primary evidence of the processes of wear. Changes in the stiffness of rotor supports make change the amplitude of orders and frequency of the resonance signals observed in the frequency domain - decreasing rotational speed. The bearing wear results in changes in the shut-down time between successive intervals of characteristic rotational speed and the total shut-down time.
Źródło:
Journal of KONES; 2013, 20, 1; 111-118
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of freeplay and friction in steering system on double lane change manoeuvre - modelling and simulation studies
Autorzy:
Więckowski, D.
Żardecki, D.
Powiązania:
https://bibliotekanauki.pl/articles/242049.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
vehicle dynamics
steering system
freeplay
friction
mathematical models
luz(...) and tar(...) projections
simulation studies
sensitivity analysis
optimization of maneuver
double lane change maneuver
Opis:
Modelling and simulation investigations of a car non-linear dynamics with regard to freeplay (backlash in steering gear) and friction (kinetic and static friction in king-pins) is always a challenge for researchers. Fortunately, by special luz(...) and tar(...) projections and their mathematical apparatus the elaborated models and simulation procedures of stick-slip phenomena in a steering system are managed in efficient forms (without any entangle constraints) even for optimization and sensitivity studies. Exactly, the presented studies deal with problems of sensitivity of optimized maneuvers for vehicle models considering freeplay / friction effects. Double lane change maneuvers (overtaking and avoiding) are discussed. A criterion function refers to several evaluations (precision of maneuver, calm steering, feeling of comfortable travel). The optimization of steering wheel angle signal is done on a reference model with "nominal" freeplay and friction parameters. Such input signal is applied to a "real" vehicle having "real" freeplay and friction parameters. The differences of output signals as well as differences between criterion function values are a subject of sensitivity analysis. The sensitivity of reference models on a variation of freeplay and friction parameters appears as important from theoretical as well as practical points of view. The paper takes up the problems of sensitivity analysis of steering system model applied for synthesis steering algorithms for a double lane change maneuver.
Źródło:
Journal of KONES; 2011, 18, 2; 483-492
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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