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Tytuł:
Necessary wind tunnel tests conditions of proper two- and three-dimensional measurements
Autorzy:
Krzysiak, A.
Powiązania:
https://bibliotekanauki.pl/articles/243813.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
applied aerodynamics
test reliability
aerodynamic measurements
Opis:
In this article, the conditions to be met by a two- and three dimensional wind tunnel tests in order to ensure their correctness are presented. First of all, they relate to the flow similarity between the real and wind tunnel conditions. This similarity enforces a wind tunnel calibration, a proper design and manufacturing of the tested models, a proper research, as well as processing of obtained test data including the usage of the wind tunnel corrections. In this work, the majority of these conditions were presented but in particular, the influence of the wind tunnel corrections on the tested models aerodynamic characteristics is consider. The two-dimensional airfoil studies and three-dimensional aircraft model balance investigation were performed in two low speed wind tunnels of a different sizes of theirs test section. The wind tunnel tests were performed in two Institute of Aviation low speed wind tunnels, namely in the wind tunnel T-1 (of the 1.5 m diameter test section) and in the wind tunnel T-3 (of the 5 m diameter test section), at the same undisturbed velocity, V∞ = 40 m/s. The comparison of the lift coefficient characteristic obtained in two different wind tunnels using the same two and three-dimensional models and same measurement techniques enabled to discuss the problem of necessity of the wind tunnel corrections usage.
Źródło:
Journal of KONES; 2018, 25, 3; 315-322
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wind tunnel tests of the Tu-154M aircraft aerodynamic characteristics
Autorzy:
Krzysiak, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/245216.pdf
Data publikacji:
2019
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
applied aerodynamics
test reliability
aerodynamic measurements
Opis:
Determination of possible manoeuvres to be performed by the aircraft requires knowledge of its aerodynamic characteristics including, in particular, characteristics of the aircraft at configuration with deflected control surfaces. In this article, the wind tunnel tests results of the model of passenger Tu-154M aircraft manufactured at the scale 1:40 are presented. The model was designed and manufactured by the Military University of Technology based on the Tu154M aircraft geometry obtained by full-scale object scanning. The model mapped all aircraft control surfaces, along with the gaps between these surfaces and the main wing part. During the tests all the model’s control surface like, flaps, ailerons, spoilers, slots, rudder, elevator and tail plane were deflected at the same deflection angles range as they are used in the full scale aircraft. The aerodynamic characteristics of the tested Tu-154M aircraft model were measured by the 6-component internal balance. Based on the obtained measurements the aircraft model aerodynamic coefficients were calculated. In the article the basic aerodynamic characteristics of the tested Tu-154M aircraft model i.e. lift, drag coefficients as well as pitching, yawing and rolling moment coefficients versus model angles of attack and sideslip angles were presented. The tests were performed in the Institute of Aviation low speed wind tunnels T-1 of the 1.5 m diameter test section at the undisturbed velocity, V∞ = 40 m/s
Źródło:
Journal of KONES; 2019, 26, 3; 113-120
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of pressure in front of shock wave : assessment of methodology influence on the measurement results on the basis of experiments with the shock tube
Autorzy:
Perkowski, W.
Irzycki, A.
Kawalec, M.
Łukasik, B.
Snopkiewicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/242676.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
shock wave
shock tube
pressure measurements
Opis:
The experiments, described in the article, are related to research of a rotating detonation that has been conducted in the Institute of Aviation in Warsaw since 2009, under the OPIE project: “Turbine engine with detonation combustion chamber”. Measurements of the shock wave parameters, are among the most difficult in the art. This is due to high speed of the wave transition, and above all, a very small thickness of the shock wave. For the purposes of the mentioned project, a methodology for measuring pressure on the rotating detonation wave was developed. It included the type of sensors, their location and their protection from heat and flames. In order to determine the capabilities, limitations and accuracy of the method that was used, a series of experiments were planned and carried out. They enabled the assessment of the impact, on the measurement of pressure in the shock wave, of the following factors: the location of the sensor (frontal and lateral) relative to the shock wave front, protrusion or retraction of the sensor in its housing, the covering of the sensor with a protective layer (such as a high temperature silicon). This paper presents the results of the experiments that were carried out with use of a small shock tube of a simple design. The high-pressure part of the tube (so-called “driver”) was charged with the compressed nitrogen gas. The membrane was designed to be torn by pressure and pressure magnitude of the shock wave were measured by a “twin pair” of the Kistler 603B type piezoelectric sensors, one of which was always the reference sensor.
Źródło:
Journal of KONES; 2013, 20, 4; 333-340
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Initiation of rotating detonation in experimental combustion chamber : practical realization
Autorzy:
Kawalec, M.
Perkowski, W.
Irzycki, A.
Snopkiewicz, K.
Wróblewski, W.
Bilar, A.
Łukasik, B.
Powiązania:
https://bibliotekanauki.pl/articles/246536.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
engines
shock wave
shock tube
pressure measurements
Opis:
Since 2009 in the Institute of Aviation, Warsaw a project that aim is to develop combustion chamber with rotating detonation for turbine engine has been carried out. Desired fuel is aviation kerosene (Jet-A) detonated in air. One of the most important problems to be solved was the initiation of rotating detonation in combustible mixture, which requires the fulfilment of several conditions: 1) good mixing of combustible mixture components, 2) properly fast flow of combustible mixture in the cylinder-shaped channel, 3) the appropriate height of the flow channel, associated with detonation cell size for the combustible mixture, 4) use of a source of detonation initiation with an appropriate energy and power for a given combustible mixture. There were considered and tested, in practice several different types of initiators: a) spark electric discharge in air, b) plasma electric discharge (the so-called "exploding wire"), c) micro-explosive charges, d) blank ammunition, e) gas initiator (with detonation of acetylene-oxygen stoichiometric mixture induced by spark electric discharge). The paper summarizes the theoretical energy parameters of several types of initiators, and the results of their comparative research on the test bench. In the course of these researches, the pressures of the shock wave generated by the initiators and recorded by a fast pressure sensor located at a distance from the initiator were compared.
Źródło:
Journal of KONES; 2013, 20, 4; 163-168
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-ray stress measurements in the institute of aviation possibilities and examples
Autorzy:
Gadalińska, E.
Malicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/242492.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
X-ray diffraction
residual stress measurements
fatigue
Opis:
From the point of view of the airplane construction, its fatigue lifetime and exploitation process, the stress states and levels are of crucial importance. The most appropriate experimental methods to determine stress values are diffraction methods with different radiation type employed. These methods allow the determination of the elastic lattice deformation and distortion (effectively the stress state) from the displacement and broadening of the diffraction peak. Diffraction methods are widely known as the experimental methods for determining not only the stress values but also the elastic properties of polycrystalline materials (also of all alloys types used in the aerospace industry). The advantages of diffraction experiments result from their non-destructive character and the possibility to obtain absolute values of stresses in different phases of each type of crystal material (the measurements are performed selectively only for crystallites contributing to the measured diffraction peak, i.e. for the grains having lattice orientations for which the Bragg condition is fulfilled). In the frame of this work, the laboratory possibilities of the Institute of Aviation in this area are presented as well as the exemplary results of stress measurements performed there.
Źródło:
Journal of KONES; 2018, 25, 3; 159-166
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aerodynamic measurements micro air vehicle
Autorzy:
Zyluk, A.
Sibilski, K.
Kowalski, M.
Wiśniowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/243837.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
construction of micro air vehicles
aerodynamic measurements
Opis:
In present times, constructions of micro air vehicles arouse more and more interest researchers and manufacturers. Air turbulence is perceived as a major problem for Micro Air Vehicles (MAV) in outdoor applications. According to the literature, short duration vertical gusts may have velocity comparable to MAV airspeed, so brief periods of flight at very large angles of attack have to be considered. In these circumstances, it seems reasonable to apply the design with as high stall angle of attack as possible. In particular, the flow has to be attached to control surfaces to perform effective control in order to damp air turbulence effect. Therefore, an aircraft configuration was developed with cranked delta wing and propeller located inside the wing contour. To prove the value of the concept, wind tunnel experiment was undertaken. The prototype demonstrated ability to fly controllably at extremely high angles of attack. Moreover we present few disadvantages of these construction for example it was very sensitive to the motor settings, since every rpm change required immediate airplane trimming to maintain straight path of flight. This drawback can be eliminated by application of counter-rotating propeller. The status of the program is presented in the paper, including the most recent results, as well as currently undertaken experiments and plans for the nearest future.
Źródło:
Journal of KONES; 2015, 22, 4; 343-353
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of car vehicle class on volatile organic compounds (VOCs) concentration in microatmosphere of car cabin
Autorzy:
Janicka, A. B.
Reksa, M.
Sobianowska-Turek, A.
Powiązania:
https://bibliotekanauki.pl/articles/247600.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
volatile hydrocarbons
indoor measurements
car vehicle cabin
Opis:
The inner atmosphere of a car vehicle became one of the most important environments of human life. Many elements inside of a car cabin are potential sources ofvolatile organic compounds (VOC's) which hazardous effect on human health is proved. To estimate quality of indoor air of a car the qualitative analysis of hydrocarbons is very important considering the fact that some substances (i.e. benzene, acetone and xylene isomers) despite low concentration level characterize toxic and carcinogenic properties. A significant impact on VOC's concentration has vehicle cabin eąuipment and quality of applied materials. The internal sources of the pollution are elements of cabin equipment (textiles, foams, plastic materials), solvents in glues, paints, lacąuers and car cosmetics. The external sources of the pollution are pollutants emitted to environment in gas phase by mobile or static sources. This paper presents the results of the research which aim was qualitative and quantitative analysis of VOC's concentration inside of various classes of car vehicle cabins. The research was done in Emission Research Laboratory of the Division of Motor vehicles and Internal Combustion Engines. The analysis was done according to European standard (EN ISO 16017-1: 2006) on gas chromatograph (Varian 450 GC) eąuipped in capillary column and flame-ionization detector (FID). Keywords: Volatile hydrocarbons, indoor measurements, car vehicle cabin.
Źródło:
Journal of KONES; 2010, 17, 4; 207-212
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geometrical structure for endoprosthesis surface lubrication and wear prognosis
Autorzy:
Wierzcholski, K.
Powiązania:
https://bibliotekanauki.pl/articles/242452.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
endoprosthesis
surface
measurements
gap height
wear
random prognosis
Opis:
It can be stated that over the last ten years in the European Union, the number of bone fractures caused by osteoarthritis has increased twofold. More than 100,000 hip or knee joints in total were implanted in Germany during one year. Within ten years, 5% of them have failed by aseptic loosening. The non-invasive determination of friction forces and control of their values during lubrication of cartilage cells on the superficial layer of human joint surfaces before implantation has a significant but not sufficient impact on the observation of the early abrasive wear of the cartilage joint and development of osteoporosis. From this fact was drawn the inspiration for the performed investigations related to the endoprosthesis surface parameters because knowledge of the roughness of prosthesis surfaces and friction forces and their control methods permits provision of a necessary standard deviation of the gap height and finally information about the implantation possibility. This article has been prepared based on the objective of European Project UE Grant IRSES,612593, 2013-2016 to represent the methodology and goal of the idea described in and make a wider discussion possible on this subject for further developments during the realization. To the research methods and materials used in this article realization belong: Rank Taylor Hobson-Talyscan 150 Apparatus implemented by Talymap Expert and Microsoft Excel Computer Program connected with the Mathcad 15 Professional Program and a new semi-analytical methods of probabilistic and statistic prognosis applied for theory of hydrodynamic lubrication of the curvilinear orthogonal surface and coordinates extended to the friction and wear problems of the endoprosthesis surfaces during the exploitation.
Źródło:
Journal of KONES; 2017, 24, 4; 335-341
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measuring instruments used at the research and accuracy of defining the efficiency of drive systems
Autorzy:
Skorek, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/246257.pdf
Data publikacji:
2019
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
energy efficiency
accuracy
measurements
measurement results
measuring instruments
Opis:
The aim of the article is to look at the possibility of accurately determining the energy efficiency of drive systems thanks to the use of high quality sensors and measuring instruments. The types of measuring instruments used on the test stand are presented. The results of experimentally determined efficiencies and simulationally determined efficiencies of two hydrostatic systems with throttling control were compared, which are fed with a constant capacity pump. The choice of the analysed systems is not accidental. There is still a view in the literature about limited possibilities of energy systems with proportional control. The research stand was very carefully designed and made. The applied measuring instruments were characterized by high accuracy of measurements. The issues related to the determination of energy losses and energy efficiency of the engine or drive system, which should be determined as dependent on the physical quantities independent of these losses, were also discussed. For laboratory verification, measurement methods were developed, the test stand was adapted and automated. It consists of tested system and loaded system. The measurements during the tests were saved on the computer disk. In order to be able to compare the efficiency of the overall system with the efficiency obtained on the basis of the simulation, coefficients ki determining the energy losses of individual elements of the system were calculated. The research showed a large convergence of the mathematical description of energy losses in the elements of the system and the efficiency of the system with reality. The mathematical model enables accurate simulation determination of the energy efficiency of the system at each point of its field of operation, i.e. at each speed and load of the controlled hydraulic motor. The range of motor speed and load variation can also be accurately determined simulationally.
Źródło:
Journal of KONES; 2019, 26, 2; 129-135
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of engine pistons form point of view of thermal shocks
Autorzy:
Sieminska, B.
Slawinski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/246075.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
piston engines
piston composite alloys
thermal shocks
temperature measurements
Opis:
Experimental test results of thermal shocks for heavy duty pistons of combustion engines are presented in the paper. The range and the level of thermal loads were diverse and dependent from working engine conditions as well as the temperature ranges were adapted for real conditions in which pistons of the combustion engine work. temperature measurement results on crown and skirt of a piston during an engine operating under different conditions are presented in the paper. Measured temperature differences during engine operating were greatest in areas, where appeared greatest piston temperatures. Researches of thermal shocks were realized on the special testing device. The device this is automatic, controlled a computer, makes possible the realization of the cycle of research of thermal shocks in the necessary range of the temperature. Test results showed that in following cycles of thermal shocks took place stable changes ofdimensions ofthe piston too. Mainfactors effecting on the resistance of piston materials on thermal shocks are presented in the paper, at this essential parameters influent on the resistance of materials on thermal shocks are coefficients of thermal expansion and Young's modules. In particular thermal shock resistance of the different piston alloys, dependence of dimensional thermal tensions versus the undimensional heat flux, Basic parameters of the composite material AK12 +20%Al2O3 and standard, values of heat conductivity coefficient the and temperature on the composite piston surface, values of stresses due with the temperature field in piston, values strains in the composite piston due the temperature field, the example of the influence of the number of thermal shocks on the deformation of the piston sample are presented in the paper.
Źródło:
Journal of KONES; 2010, 17, 1; 411-420
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nanoparticle research on four gasoline cars
Autorzy:
Czerwinski, J.
Comte, P.
Mayer, A.
Powiązania:
https://bibliotekanauki.pl/articles/247977.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
gasoline cars
combustion engine
nanoparticles measurements (NP)
NP fluctuation
Opis:
The invisible nanoparticles (NP) from combustion processes penetrate easily into the human body through the respiratory and olfactory ways and carry numerous harmful health effects potentials. NP count concentrations are limited in EU for Diesel passenger cars since 2013 and for gasoline cars with direct injection (GDI) since 2014. The limit for GDI was temporary extended to 6 x 1012 #/km. Nuclei of metals as well as organics are suspected to significantly contribute especially to the ultrafine particle size fractions, and thus to the particle number concentration. In the present paper, some results of investigations of nanoparticles from four gasoline cars – an older one with MPI and three never with DI – are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. The results show that the older vehicle with MPI emits high particle count concentrations. The size distributions of this vehicle are decisively bimodal with high numbers in nuclei mode. The emissions of the newer vehicles with DI show sometimes no typical uniform shape of particle size distributions and are at lower level, than for the older vehicle. There is no visible nuclei mode and the ultrafine particle concentrations below 10 nm are insignificant. Some of the newer, low-emitting vehicles show at constant speed operation a periodical fluctuation of the NPemissions. Increased NP-emissions at cold start were confirmed.
Źródło:
Journal of KONES; 2014, 21, 1; 49-57
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical measurement of aircraft engine turbine blades
Autorzy:
Budzik, G.
Kubiak, K.
Rokicki, P.
Dziubek, T.
Nowotnik, A.
Matysiak, H.
Cygan, R.
Tutak, M.
Boś, P.
Powiązania:
https://bibliotekanauki.pl/articles/247470.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
aircraft engines turbine blades
optical measurements
coordinate measuring technique
Opis:
Manufacturing of aircraft engine turbine blades requires control of blade geometric parameters at different stages of technological process. Acceleration and automation of measurement process can affect the duration of the finished item production. Modern technologies for measurement of aircraft engine turbine blades are based on numerical machines - measurement process is based on processing of numerical data obtained by measurement using coordinate measuring machines. The paper presents the opportunity of automation of aircraft engine turbine blades measurements using scanner ATOS II Triple Scan with blue light source technology. Coordinate measuring technique allows to specify full methodology for designation of complex dimensions of physical objects and transform them into a computer program space of coordinate measuring devices. Presented paper includes capabilities of device used in the study to improve the measurement process in the technological and economical aspects. Another issue described in the paper is impact of measurement performance in automatic mode on the quality of performance – the numerical model of surface, from the standpoint of accuracy and number of collected data points in time. The paper includes an analysis of conditions related to the measurement works, such as the process of preparing the model, measurement equipment and data processing capacity. As the result methodology for automated scanning measurements of aircraft engine turbine blades will be presented.
Źródło:
Journal of KONES; 2013, 20, 2; 21-26
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of dimensional accuracy of blade of aircraft engine using a coordinate measuring machine
Autorzy:
Budzik, G
Kubiak, Krzysztof
Zaborniak, M.
Przeszłowski, Ł.
Dziubek, T.
Cygan, M.
Tutak, M.
Matysiak, H
Powiązania:
https://bibliotekanauki.pl/articles/244267.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
aircraft engines turbine blades
optical measurements
coordinate measuring technique
Opis:
Technological process of aircraft engine turbine blades requires control of blade geometric parameters. Innovation technologies for measurement of aircraft engine turbine blades are based on coordinate numerical machines – measurement process is based on processing of numerical data obtained by measurement using coordinate measuring machines. The paper presents the opportunity of analysis of dimensional accuracy of aircraft engine turbine blades measurements using coordinate measuring machine (CMM). Coordinate measuring machine allows specifying full methodology for designation of complex dimensions of physical objects (blade of aircraft engine) and transforming them into a computer program space of coordinate measuring devices. Presented paper includes capabilities of device used in the study to improve the measurement process and blades geometry analysis in the technological and economical aspects. Another issue described in the paper is impact of measurement performance in automatic mode on the quality of performance – the numerical model of geometry, from the standpoint of accuracy and number of collected data points in time. Measurements using a coordinate measuring machine are among the most accurate methods of measuring. The paper includes an analysis of conditions related to the measurement works, such as the process of preparing the model, measurement equipment and data processing capacity. As the result, methodology of (CMM) measurements of aircraft engine turbine blades will be presented.
Źródło:
Journal of KONES; 2014, 21, 2; 33-37
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An assessment of trailer suspension dynamic behavior via vibration measurements
Autorzy:
Hunicz, J.
Koszałka, G.
Golec, M.
Taratuta, L.
Powiązania:
https://bibliotekanauki.pl/articles/241829.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
road transport
exceptional transport
semi-trailer
vibration measurements
suspension dynamics
Opis:
A dynamic response of a semi-trailer suspension to a real road profile under two different loads was investigated in this study. The trailer was a low loader for transporting heavy and large loads which configuration could be adjusted to the current needs. During the described investigation the vehicle was composed of: detachable gooseneck, maximally extended low bed and 5 hydraulically steered axles comprised 2-axle and 3-axle assemblies. The experiments were performed for unloaded and loaded with 60 tons trailer, that was equal to maximum trailer pay load. Acceleration measurements at unsprung and sprung parts of the vehicle were applied. As a test surface a railway track crossing was chosen. Acceleration time series were analysed by the means of power spectral density. The isolation of free vibration and forced vibration frequencies and effectiveness of suspension damping over wide frequency range was done. Two characteristic signal bands were identified. In the frequency range up to 10 Hz vehicle vibration energy decreased for the load increase for both, sprung and unsprung parts. In contrast, in the range between 10 and 25 Hz at higher load increase of vibration energy was noticed, however only at unsprung mass. Data analysis revealed complexity of vehicle vertical acceleration as a response to the road profile. Nevertheless, it allowed for estimation of the trailer dynamic loads under real road conditions.
Źródło:
Journal of KONES; 2012, 19, 4; 333-338
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Harmonical and modal analysis to determine the anisotropic properties of aviation composite materials
Autorzy:
Acopyan, A.
Axenov, V.
Shevtsov, V.
Soloviev, A.
Tamarkina, E.
Powiązania:
https://bibliotekanauki.pl/articles/243138.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
polymeric composite
elastic module
acoustic measurements
eigenmodes
finite element method
Opis:
The value of all composite elastic modules has the crucial influence on dynamic behaviour of aviation load-bearing structures. Numerous experimental techniques and standards are used to characterize the elastic properties of polymeric composite materials. Among this is the large group of static tests, acoustic methods based on longitudinal, lateral or shear surface sound wave speed measurements and also on vibrating surfaces amplitude measurements. However, preparation specimens for static test with shape required by standards not always possible from already manufactured piece. Again the designated dynamic experiment introduces difficulties of investigated specimen acoustic isolating, impossibility of some required wave type excitation and performing of displacements field measurement with guaranteed precision. In this study an acoustic method is developed using the measure of all specimen's eigenfrequencies in a certain frequency range. Small rectangular composite specimen is excited by glued piezoelectric actuator and response is measured by piezoelectric sensor. Preliminary performed finite-element (FE) analyses serve to think the vibration natural modes of linked mechanical system - specimen and piezoelectric element. In this FE analyse the rough estimations of all elastic constants obtained from other independents (as a rule static) experiments were used. Further the amelioration of initial elastic modules was performed. Thereby the target nonlinear functional dependent on all quest modules was minimized by genetic and (or) Levenberg-Marquardt algorithm.
Źródło:
Journal of KONES; 2007, 14, 3; 11-18
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 23

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