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Tytuł:
Passive-active noise control of an acoustic duct
Pasywno-aktywne metody kontroli hałasu w przewodzie akustycznym
Autorzy:
Tiseo, B.
Concilio, A.
Powiązania:
https://bibliotekanauki.pl/articles/281856.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
acoustic structural control
damping noise control
feedback
Opis:
In the recent years, noise control has become a significant factor in the design of automotive and aircraft industries. In general, methods of the passive noise control are practical and most effective at mid and high frequencies. On the other hand, active noise control techniques are more efficient at the low frequency range. Combined solutions seem to be the most appropriate key to cover the whole frequency range of frequencies. In the present study, a description of simulations for both feedback structural and acoustical structural control strategies are illustrated in order to maximize the damping within an acoustic duct by applying a passive foam layer bonded to an “active” surface.
W ostatnich latach problem sterowania poziomem hałasu stał się szczególnie znaczący w projektowaniu na potrzeby przemysłu samochodowego i lotniczego. Jako ogólną zasadę można przyjąć, że pasywne metody redukcji hałasu są efektywne dla średnich i wysokich częstości dźwięku, podczas gdy metody aktywne dobrze się sprawdzają dla częstości niskich. Rozwiązanie oparte na kombinacji tych metod stanowi naturalny i najbardziej skuteczny sposób ograniczania hałasu w całym przedziale częstości. W pracy przedstawiono opis strategii sterowania poziomem hałasu bazującym na strukturalnym i akustycznym sprzężeniu zwrotnym, celującym w maksymalizację tłumienia wewnątrz przewodu akustycznego, na którego „aktywną” powierzchnię naniesiono warstwę pasywnej pianki.
Źródło:
Journal of Theoretical and Applied Mechanics; 2011, 49, 4; 1135-1149
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sound Transmission Through a Thin Plate with Shaped Frequency Response
Autorzy:
Wrona, Stanislaw
Mazur, Krzysztof
Rzepecki, Jaroslaw
Chraponska, Anna
Pawelczyk, Marek
Powiązania:
https://bibliotekanauki.pl/articles/177996.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
structural control
frequency response shaping
vibrating plate
optimisation
modelling
Opis:
Thin plates, in the form of individual panels or whole device casings, often separate the noise source from its recipients. It would be very desirable if the panels could effectively block the sound transmission preventing noise from further propagation. This is especially challenging to achieve at low frequencies. A promising approach, intensively developed in the recent years, is to employ active control methods by adding sensors and actuators, and running a control algorithm. However, if the noise is narrow-band, an alternative passive solution originally developed by the authors can be applied. It is based on appropriately located passive elements which can be used to alter the frequency response of the vibrating structure thus improving its sound insulation properties. Such an approach is referred to as the frequency response shaping method. The purpose of this paper is to further develop this method and apply it to a device casing panel. The efficiency of the method is evaluated by simulation and real experiments. Appropriate cost functions and mathematical models are formulated and used to optimise the arrangement of passive elements mounted to the plate, enhancing its sound insulation properties at the given frequency range. The results are reported, and advantages and limits of the method are pointed out and discussed.
Źródło:
Archives of Acoustics; 2019, 44, 4; 731-738
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic behavior of steel frames with tuned mass dampers
Autorzy:
Jouneghani, K. T.
Hosseini, M.
Rohanimanesh, M. S.
Dehkordi, M. R.
Powiązania:
https://bibliotekanauki.pl/articles/103041.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
earthquake
Tuned Mass Dampers
vibration control
dynamic behaviour
steel frames
structural control
Opis:
In this paper, the application of tuned mass damper in improving the response of structures is considered. At first, three frames of 3, 9 and 20 stories are evaluated in which time history analysis is done according to El – Straw earthquake. The maximum reduction of among the three mentioned frames belongs to a 20-stories structure in which the rate of story displacement reduction is between 25 to 45%, and this indicates that by increasing the height of the structure, the performance of tuned mass damper improved. In the second part, the effect of semi-active tuned mass damper is studied on a 10-stories frame. Studies showed that using a tuned mass damper system with viscous damper with controller force decreases the average of maximum displacement of roof story down to 39.9 % and this amount of reduction is 22.8% for semi-active tuned mass damper. Finally, the performance of tuned Single and multiple mass Damper is evaluated on a 20-stories frame, and the results show that single and multiple dampers decrease structures ‘responses and the performance of tuned multiple dampers depends on the mass and frequency ratio and also concluded that the performance of tuned multiple mass dampers is reduced by transition to middle of the structure stories.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 2; 146-158
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of synthesis methods in position optimisation and selection of tuned mass damper (TMD) parameters for systems with many degrees of freedom
Autorzy:
Dymarek, Andrzej
Dzitowski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/1409049.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
structural control system
vibration
simple fractions
synthesis
rational functions
dynamic characteristics
Opis:
The paper formulates and formalises a method for selecting parameters of the tuned mass damper (TMD) for primary systems with many degrees of freedom. The method presented uses the properties of positive rational functions, in particular their decomposition, into simple fractions and continued fractions, which is used in the mixed method of synthesis of vibrating mechanical systems. In order to formulate a method of tuning a TMD, the paper discusses the basic properties of positive rational functions. The main assumptions of the mixed synthesis method is presented, based on which the general method of determining TMD parameters in the case of systems with many degrees of freedom was formulated. It has been shown that a tuned mass damper suppresses the desired resonance zone regardless of where the excitation force is applied. The advantages of the formulated method include the fact of reducing several forms of the object’s free vibration by attaching an additional system with the number of degrees of freedom corresponding to the number of resonant frequencies reduced. In addition, the tuned mass damper determined in the case of excitation force applied at a single point can be attached to any element of the inertial primary system without affecting the reduction conditions in this way. It results directly from the methodology formalised in the paper. As part of the paper, numerical calculations were performed regarding the tuning of the TMD to the first form of free vibration of a system with 3 degrees of freedom. The parameters determined were subjected to analysis and verification of the correctness of the calculations carried out. For the considered case of a system with 3 degrees of freedom together with a TMD, time responses of displacement, from each floor, were generated to excitation induced by a harmonic force equal to the first form of vibration of the basic system. In addition, in the case of the parameters obtained, the response of the inertial element system to which the TMD was attached to random white noise excitation was determined.
Źródło:
Archives of Control Sciences; 2021, 31, 1; 185-211
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The structural control of the Mroczna Cave development on the slopes of Mt Kornuty (the Flysch Carpathians, Beskid Niski Mts)
Autorzy:
Zatorski, M.
Powiązania:
https://bibliotekanauki.pl/articles/295108.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Geomorfologów Polskich
Tematy:
mass movements
flysch Carpathians
crevice-type cave
structural control
anisotropic rock massif
Opis:
The Mroczna Cave is one of the longest caves in the Beskid Niski Mts., located on the south-western slopes of Mt Kornuty, along the main scarp of the landslide. According to the geomechanical criterion, it is dilation cave, where extension has played a major role. Morphotectonic analysis indicates that the main gravitational movement was of a toppling nature but there were also rotation around the vertical axis as well as a backward rotation. The relatively large cave depth (15.5 m) and its shape (cross-section of its passages) indicate that it was formed along a new gravitational cutting surface of the rock massif, associated with joint sets.
Źródło:
Landform Analysis; 2014, 27; 55-65
1429-799X
Pojawia się w:
Landform Analysis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geological control on the Osława River meander at Duszatyn, Western Bieszczady Mountains, Polish Outer Carpathians
Autorzy:
Margielewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/191585.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
neotectonics
structural control
Quaternary alluvium
Osława River
Western Bieszczady Mountains
Polish Outer Carpathians
Opis:
At Duszatyn village (Western Bieszczady Mts.), the Osława River forms an unique meander loop which is not typical for the mountainous area. Detailed analysis has shown that this landform was created due to the evolution of two left-hand tributaries of the Osława River during the formation of its regressive water-gap. These processes were determined by mass movements which have strongly stimulated the fluvial system. The origin of the Osława River meander was largely controlled by lithological differences in rock resistance, orientation of the joint pattern, as well as the presence of bordering oblique and thrust faults which have had a bearing on the diversified neotectonic uplift of the area.
Źródło:
Annales Societatis Geologorum Poloniae; 2004, 74, No 3; 325-338
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active noise control with a single nonlinear control filter for a vibrating plate with multiple actuators
Autorzy:
Mazur, K.
Pawełczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/176906.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active noise-vibration control
active structural acoustic control
adaptive control
nonlinear control
Opis:
Vibrating plates can be used in Active Noise Control (ANC) applications as active barriers or as secondary sources replacing classical loudspeakers. The system with vibrating plates, especially when nonlinear MFC actuators are used, is nonlinear. The nonlinearity in the system reduces performance of classical feedforward ANC with linear control filters systems, because they cannot cope with harmonics generated by the nonlinearity. The performance of the ANC system can be improved by using nonlinear control filters, such as Artificial Neural Networks or Volterra filters. However, when multiple actuators are mounted on a single plate, which is a common practice to provide effective control of more vibration modes, each actuator should be driven by a dedicated nonlinear control filter. This significantly increases computational complexity of the control algorithm, because adaptation of nonlinear control filters is much more computationally demanding than adaptation of linear FIR filters. This paper presents an ANC system with multiple actuators, which are driven with a single nonlinear filter. To avoid destructive interference of vibrations generated by different actuators the control signal is filtered by appropriate separate linear filters. The control system is experimentally verified and obtained results are reported.
Źródło:
Archives of Acoustics; 2013, 38, 4; 537-545
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Weak compactness in the space of operator valued measures $M_ba(Σ,(X,Y))$ and its applications
Autorzy:
Ahmed, N.
Powiązania:
https://bibliotekanauki.pl/articles/729361.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
space of operator valued measures
weak compactness
semigroups of bounded linear operators
optimal structural control
Opis:
In this note we present necessary and sufficient conditions characterizing conditionally weakly compact sets in the space of (bounded linear) operator valued measures $M_{ba}(Σ,(X,Y))$. This generalizes a recent result of the author characterizing conditionally weakly compact subsets of the space of nuclear operator valued measures $M_{ba}(Σ,₁(X,Y))$. This result has interesting applications in optimization and control theory as illustrated by several examples.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2011, 31, 2; 231-247
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Internal Model Control for a Light-Weight Active Noise-Reducing Casing
Autorzy:
Mazur, K.
Pawełczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/177886.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active noise-vibration control
active structural acoustic control
active casing
Internal Model Control
Opis:
The active noise-reducing casing developed and promoted by the authors in recent publications have multiple advantages over other active noise control methods. When compared to classical solutions, it allows for obtaining global reduction of noise generated by a device enclosed in the casing. Moreover, the system does not require loudspeakers, and much smaller actuators attached to the casing walls are used instead. In turn, when compared to passive casings, the walls can be made thinner, lighter and with much better thermal transfer than sound-absorbing materials. For active noise control a feedforward structure is usually used. However, it requires an in-advance reference signal, which can be difficult to be acquired for some applications. Fortunately, usually the dominant noise components are due to rotational operations of the enclosed device parts, and thus they are tonal and multitonal. Therefore, it can be adequately predicted and the Internal Model Control structure can be used to benefit from algorithms well developed for feedforward systems. The authors have already tested that approach for a rigid casing, where interaction of the walls was significantly reduced. In this paper the idea is further explored and applied for a light-weight casing, more frequently met in practice, where each vibrating wall of the casing influences all the other walls. The system is verified in laboratory experiments.
Źródło:
Archives of Acoustics; 2016, 41, 2; 315-322
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hammerstein Nonlinear Active Noise Control with the Filtered-Error LMS Algorithm
Autorzy:
Mazur, K.
Pawełczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/176841.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active noise-vibration control
active structural acoustic control
adaptive algorithm
nonlinear system
Opis:
Active Noise Control (ANC) of noise transmitted through a vibrating plate causes many problems not observed in classical ANC using loudspeakers. They are mainly due to vibrations of a not ideally clamped plate and use of nonlinear actuators, like MFC patches. In case of noise transmission though a plate, nonlinerities exist in both primary and secondary paths. Existence of nonlinerities in the system may degrade performance of a linear feedforward control system usually used for ANC. The performance degradation is especially visible for simple deterministic noise, such as tonal noise, where very high reduction is expected. Linear feedforward systems in such cases are unable to cope with higher harmonics generated by the nonlinearities. Moreover, nonlinearities, if not properly tackled with, may cause divergence of an adaptive control system. In this paper a feedforward ANC system reducing sound transmitted through a vibrating plate is presented. The ANC system uses nonlinear control filters to suppress negative effects of nonlinearies in the system. Filtered-error LMS algorithm, found more suitable than usually used Filtered-reference LMS algorithm, is employed for updating parameters of the nonlinear filters. The control system is experimentally verified and obtained results are discussed.
Źródło:
Archives of Acoustics; 2013, 38, 2; 197-203
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Double Panel Structure for Active Control of Noise Transmission
Autorzy:
Morzyński, L.
Szczepański, G.
Powiązania:
https://bibliotekanauki.pl/articles/176968.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
noise
sound insulating enclosure
active structural acoustic control
virtual microphone
Opis:
Passive noise reduction means are commonly used to reduce noise in the industry but, unfortunately, their effectiveness is poor in the low frequency range. By applying active structural acoustic control to the enclosure walls significant improvement of the insulating properties in this frequency range can be achieved. In this paper a model of double panel structure with ASAC is presented. The structure consists of two aluminium plates separated by an air gap. Two inertial magnetoelectric actuators and two piezoceramic MFC sensors were used for controlling the structure. A multichannel FxLMS algorithm with virtual error microphone technique is used as a control algorithm. The signal of a virtual error microphone is extrapolated basing on signals from MFC sensors. Performance of this actively controlled structure for tonal signals at selected frequencies is presented in the article. During the study, a double panel structure was mounted on one wall of sound insulating enclosure located in an acoustic chamber. During the measurements local and global reduction of noise test signal was investigated.
Źródło:
Archives of Acoustics; 2018, 43, 4; 689-696
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active Noise-Vibration Control using the Filtered-Reference LMS Algorithm with Compensation of Vibrating Plate Temperature Variation
Autorzy:
Mazur, K.
Pawełczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/177469.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active noise-vibration control
active structural acoustic control
adaptive control
gain scheduling
temperature influence
Opis:
Vibrating plates have been recently used for a number of active noise control applications. They are resistant to difficult environmental conditions including dust, humidity, and even precipitation. However, their properties significantly depend on temperature. The plate temperature changes, caused by ambient temperature changes or plate heating due to internal friction, result in varying response of the plate, and may make it significantly different than response of a fixed model. Such mismatch may deteriorate performance of an active noise control system or even lead to divergence of a model-based adaptation algorithm. In this paper effects of vibrating plate temperature variation on a feedforward adaptive active noise reduction system with the multichannel Filtered-reference LMS algorithm are examined. For that purpose, a thin aluminum plate is excited with multiple Macro-Fiber Composite actuators. The plate temperature is forced by a set of Peltier cells, what allows for both cooling and heating the plate. The noise is generated at one side of the plate, and a major part of it is transmitted through the plate. The goal of the control system is to reduce sound pressure level at a specified area on the other side of the plate. To guarantee successful operation of the control system in face of plate temperature variation, a gain-scheduling scheme is proposed to support the Filteredreference LMS algorithm.
Źródło:
Archives of Acoustics; 2011, 36, 1; 65-76
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Feedforward Control of a Light-Weight Device Casing for Active Noise Reduction
Autorzy:
Wrona, S.
Pawelczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/177744.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active control
flexible structures
active noise control
active vibration control
active structural acoustic control
active casing
Opis:
It is possible to enhance acoustic isolation of the device from the environment by appropriately controlling vibration of a device casing. Sound insulation efficiency of this technique for a rigid casing was confirmed by the authors in previous publications. In this paper, a light-weight casing is investigated, where vibrational couplings between walls are much greater due to lack of a rigid frame. A laboratory setup is described in details. The influence of the cross-paths on successful global noise reduction is considered. Multiple vibration actuators are installed on each of the casing walls. An adaptive control strategy based on the Least Mean Square (LMS) algorithm is used to update control filter parameters. Obtained results are reported, discussed, and conclusions for future research are drawn.
Źródło:
Archives of Acoustics; 2016, 41, 3; 499-505
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Topological dual of $B_∞(I, ₁(X,Y))$ with application to stochastic systems on Hilbert space
Autorzy:
Ahmed, N.
Powiązania:
https://bibliotekanauki.pl/articles/729390.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
representation theory
topological dual
finitely additive operator-valued measures
polish space
Hilbert space
stochastic systems
structural control
uncertainty abatement
Opis:
In this paper, we prove that the topological dual of the Banach space of bounded measurable functions with values in the space of nuclear operators, furnished with the natural topology, is isometrically isomorphic to the space of finitely additive linear operator-valued measures having bounded variation in a Banach space containing the space of bounded linear operators. This is then applied to a stochastic structural control problem. An optimal operator-valued measure, considered as the structural control, is to be chosen so as to minimize fluctuation (volatility). Both existence of optimal policy and necessary conditions of optimality are presented including a conceptual algorithm.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2009, 29, 1; 67-90
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparing the efficiency of different structural skeleton for base isolated domes
Autorzy:
Casciati, Sara
Powiązania:
https://bibliotekanauki.pl/articles/27311406.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
base isolation
design requirements
dome
isolation device
passive structural control
wymagania projektowe
kopuła
urządzenie izolujące
izolacja sejsmiczna
kontrola strukturalna pasywna
Opis:
The structural concept of the dome dates back to the Pantheon in Rome. It is used as the cover of many churches and mosques all around the world. Light solutions, with a well-visible dome-shaped truss skeleton, are often preferred in modern architecture. Base isolation techniques can be adopted to mitigate the seismic effects. This paper aims to investigate the efficiency of different designs for the truss skeleton. To solve the problem, one has to assign the constraints, the materials and the geometry of the dome, its supporting structure and the isolation devices (number, locations, and type). The screening of the effects of different scheme assumptions on structural behaviour provides a better insight into the problem.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 3; art. no. e143555
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interaction between tectonics, plutonism and mineralization of the Duna Pb-Ba ore deposit regarding fluid inclusion study (Central Alborz, Iran)
Autorzy:
Sadeghi, Alireza
Asiabar, Saeid Hakimi
Nezafati, Nima
Ganji, Alireza
Mukherjee, Soumyajit
Powiązania:
https://bibliotekanauki.pl/articles/27323967.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Alborz
overprinting tectonics
plutonism
fluid inclusion
structural control
duna type ore deposit
Pb-Ba ore deposit
carbonate-hosted
Elburs
plutonizm
inkluzja fluidalna
sterowanie strukturalne
złoża rud
Opis:
This article discusses the impacts of overprinting of tectonic and plutonic events on the mineralization of the Duna Pb-Ba ore deposit, according to geologic settings and fluid inclusion studies. The Duna carbonate-hosted deposit contains a significant amount of Ag (18.9–264.3 ppm ), Cu (77–41600 ppm), Sb (32.7–11000 ppm), Sr (63.5–15100 ppm), and Fluid inclusions with 7.34–23.65 wt.% NaCl equivalent. The homogenization temperature of about 110–285°C, as well as the paragenesis of the minerals shows a difference compared with other Pb-Zn deposits such as the Irish-type and MVT. The ore mineralization in the Duna mine occurred as stratabound, open space-filling, and along the brecciated fault zones. The concordant (stratabound) type of mineralization, with salinity and homogenization temperature of 18.54 to 23.65 wt.% NaCl equivalent, and 113°C to 165°C respectively, is usually typical of MVT-ore deposits, which in this area evolved during the Early Cimmerian orogeny and was later interrupted by mineralization along younger brecciated fault zones with salinity and homogenization temperature of 7.34 to 23.65 wt.% NaCl equivalent, and 113°C to 285°C respectively. This discordant mineralization, which occurred along the faults, formed by the end of the Late Cretaceous and during the Cenozoic as a result of the intrusion of a plutonic mass, and is comparable to the Irish-type ore deposits.
Źródło:
Acta Geologica Polonica; 2023, 73, 2; 201--222
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal passive structural control under extreme earthquake excitations using a combined pendulum tuned mass damper
Autorzy:
Kamel, Abanoub G.
Basily, Remon M.
Powiązania:
https://bibliotekanauki.pl/articles/2175498.pdf
Data publikacji:
2021
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
passive structural control
earthquake excitations
offshore platform
Tuned Mass Damper
mathematical modelling
MATLAB©
pasywna kontrola konstrukcji
wzbudzenia trzęsień ziemi
platforma morska
wielokrotne strojone tłumiki masowe
modelowanie matematyczne
Opis:
Many engineering applications utilize passive Tuned Mass Dampers (TMDs) in several engineering applications because of their simplicity, readiness, and their ability in attenuating structural vibrations exposed to mild or extreme earthquake excitations. The main aim of this work is to find the optimum values of the system parameters after attaching a three degree of freedom Combined Pendulum Tuned Mass Damper (3-DOF CPTMD) to the main structure to investigate if the proposed solution will assist in reducing the amplitudę of the vibration. Three optimization search techniques are utilized, and the best optimum method is determined. Moreover, the structural system was modelled mathematically to get the governing motion equations, and the system was put into state-space format before being simulated using a homemade MATLAB© code. Additionally, it is found that the proposed 3-DOF CPTMD is very effective in dampening the structural vibrations under various earthquake excitations (including extreme conditions)
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2021, 20, 4; 51--64
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active Transient Sound Radiation Control from a Smart Piezocomposite Hollow Cylinder
Autorzy:
Hasheminejad, S. M.
Rabbani, V.
Powiązania:
https://bibliotekanauki.pl/articles/177572.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active structural acoustic control (ASAC) thick cylindrical shells
exact elasto-acoustic analysis
time-domain solution
intelligent system
sound field attenuation
Opis:
The linear 3D piezoelasticity theory along with active damping control (ADC) strategy are applied for non-stationary vibroacoustic response suppression of a doubly fluid-loaded functionally graded piezolaminated (FGPM) composite hollow cylinder of infinite length under general time-varying excitations. The control gain parameters are identified and tuned using Genetic Algorithm (GA) with a multi-objective performance index that constrains the key elasto-acoustic system parameters and control voltage. The uncontrolled and controlled time response histories due to a pair of equal and opposite impulsive external point loads are calculated by means of Durbin’s numerical inverse Laplace transform algorithm. Numerical simulations demonstrate the superior (good) performance of the GA-optimized distributed active damping control system in effective attenuation of sound pressure transients radiated into the internal (external) acoustic space for two basic control configurations. Also, some interesting features of the transient fluid-structure interaction control problem are illustrated via proper 2D time domain images and animations of the 3D sound field. Limiting cases are considered and accuracy of the formulation is established with the aid of a commercial finite element package as well as comparisons with the current literature.
Źródło:
Archives of Acoustics; 2015, 40, 3; 359-381
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strukturalne uwarunkowania rozwoju rzeźby Karpat zewnętrznych : nowe spojrzenie
Structural control on the Outer Carpathians relief : a new approach
Autorzy:
Jankowski, L.
Margielewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/2075092.pdf
Data publikacji:
2014
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
relief transformation
structural control
compressional-extensional stages
back thrusting
gravitational tectonics
faulting
chaotic complexes
Polish Outer Carpathians
rozwój tektoniczno-basenowy Karpat
rozwój rzeźby
uskoki
kompleksy chaotyczne
strukturalne uwarunkowania
Polskie Karpaty Zewnętrzne
Opis:
The article presents a new concept of structural control on the Outer Carpathians relief. The Carpathians’ relief development originated in the stage of sedimentary basin deposition (e.g., gravitational positioning of fragments of rock massif), as well as in the compressional stage of the orogen formation, and, finally, in the stage of secondary tectonic deformation, such as: strike-slip faulting, radial extension, and great extensional collapse of the Carpathian massifs. The difference in elevation between the Beskidy Mts. and Carpathian Foothills belt is caused by the structural position of these segments of rock massifs within an accretionary prism formed during the compressional stage. The tectonic elements formed during the earliest stage of compression (Magura, Dukla and southern Silesian units forming the High Beskid zone) attain the highest structural and elevation position, whereas the elements included as the last ones to the accretionary prism (Sub-Silesian and Skole units) take a lower topographic position, forming the foothills belt. A concept that gravitational collapse generated back-thrusts and tectonic exhumation of the Carpathian massifs allows us to explain seemingly considerable erosional unroofing of the Carpathian surface, estimated at several kilometres. Alternating position of elevated and lowered mountain ridges (Bieszczady–Beskid Niski–Beskid Wyspowy–Beskid Makowski Mts.) can be explained by their association with a major strike-slip fault. Chaotic complexes frequently occurring in the Carpathians are very important for the relief transformation and development of river network (controlled not only by dislocations, but also by chaotic complexes), as well as for the presence of erosional remnants (isolated hills representing blocks in matrix).
Źródło:
Przegląd Geologiczny; 2014, 62, 1; 29--35
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Feed-forward compensation for nonlinearity of vibrating plate as the sound source for active noise control
Kompensacja nieliniowości płyty drgającej jako źródła dźwięku dla systemów aktywnej redukcji hałasu
Autorzy:
Mazur, K.
Pawełczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/368955.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
aktywna redukcja hałasu
płyta drgająca
nieliniowe sterowanie
kompensacja
emisja dźwięku
adaptacja
ekwalizacja
active noise control
active structural acoustic control
vibrating plate
sound radiation
adaptation
feed-forward
equalization
nonlinear control
Opis:
Active Noise Control (ANC) systems are usually designed in the feed-forward structure with adaptive linear control filters. However, performance of such systems, when a vibrating plate is used as the secondary source, may be poor due to significant non-linearity of the plate response. The linear systems are then unable to cope with higher harmonics generated by the nonlinearity. One solution to this problem is to apply a nonlinear ANC algorithm. However, it adds additional complexity to this layer. It is particularly severe for multichannel systems, where the algorithms are complex by themselves, and making them nonlinear may significantly reduce their scalability. In this paper, another approach is proposed. Multiple actuators are mounted on a single plate, in order to effectively excite more vibration modes and generate a higher acoustic power, than in case of a single actuator. The response of the vibrating plate as the sound source is then linearized with a set of nonlinear finite impulse response filters, operating individually for each actuator. The Filtered-x LMS algorithm is adopted to update parameters of the nonlinear filters. The control system is experimentally verified and obtained results are reported.
Systemy aktywnej redukcji hałasu zwykle projektowane są w strukturze kompensacyjnej z adaptacyjnymi liniowymi filtrami sterującymi. Wówczas, w przypadku zastosowania płyty drgającej jako źródła dźwięku, skuteczność działania może być zmniejszona z powodu występujących nieliniowości w torze wtórnym. Liniowy układ kompensacji nie jest w stanie poradzić sobie z wyższymi harmonicznymi generowanymi przez nieliniowości. Jednym z rozwiązań jest zastosowanie nieliniowego algorytmu aktywnej redukcji hałasu. Zwiększa to jednak złożoność układu w tej warstwie sterowania. W przypadku wielokanałowych systemów aktywnej redukcji hałasu, które same w sobie są złożone, wprowadzenie nieliniowości w algorytmie znacząco zmniejsza skalowalność całego systemu. W niniejszym artykule zaproponowane jest inne podejście. Aby zapewnić efektywne pobudzenie większej liczby mod i uzyskanie większej mocy akustycznej jak w przypadku pojedynczego elementu wzbudzającego, zastosowano wiele elementów wykonawczych wzbudzających drgania. Odpowiedź płyty drgającej pełniącej rolę złożonego źródła dźwięku jest linearyzowana przez zbiór nieliniowych filtrów o skończonej odpowiedzi impulsowej działających niezależnie na poszczególne elementy wykonawcze. Do aktualizacji parametrów filtrów nieliniowych zastosowany jest algorytm Filtered-x LMS. Zaproponowany system sterowania został poddany weryfikacji eksperymentalnej, a uzyskane wyniki zostały zaprezentowane i skomentowane.
Źródło:
Mechanics and Control; 2011, 30, 3; 146-150
2083-6759
2300-7079
Pojawia się w:
Mechanics and Control
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dwupłytowa struktura aktywna do ograniczania transmisji hałasu przez obudowy i przegrody dźwiękoizolacyjne
Double-layered active structure for reducing noise transmission through sound insulating barriers
Autorzy:
Morzyński, L.
Krukowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/181117.pdf
Data publikacji:
2017
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
hałas
obudowa dźwiękoizolacyjna
akustyczno-strukturalna aktywna redukcja hałasu
mikrofon wirtualny
noise
sound insulation
sound insulation enclosure
active structural acoustic control
virtual microphone
Opis:
Obudowy dźwiękoizolacyjne są jednym i podstawowych środków technicznych, stosowanych powszechnie do ograniczania hałasu. Izolacyjność przegród pasywnych maleje jednak ze spadkiem częstotliwości dźwięku. Izolacyjność w zakresie niskich częstotliwości może być zwiększona poprzez zastosowanie aktywnych metod redukcji hałasu. W artykule przedstawiono budowę i zasadę działania dwupłytowej struktury aktywnej do ograniczania transmisji hałasu przez przegrody. Do sterowania przegrodą korzystano algorytm z ekstrapolacją sygnału błędu w oparciu o sygnały z przetworników drganiowych Przedstawiono wyniki badań struktury na stanowisku laboratoryjnym.
Sound insulating enclosures are a basic technical measure commonly used to reduce noise. Insulation of passive sound insulating barriers, however, decreases with a decrease in frequency. Insulation in the low frequency range can be increased by using active noise control methods. This article presents the structure and principle of operation of a double-layered active structure to limit the transmission of noise through barriers. An algorithm, which extrapolates the error microphone signal based on signals from the vibration transducers, is used for structure control. This article presents structure performance in laboratory conditions.
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2017, 10; 24-28
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active Transient Acousto-Structural Response Control of a Smart Cavity-Coupled Circular Plate System
Autorzy:
Hasheminejad, S. M.
Shakeri, R.
Powiązania:
https://bibliotekanauki.pl/articles/176771.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound radiation
structural-borne noise control
coupled multi-field problem
piezoelectric disc actuator
cylindrical enclosure
GA-tuned controller
Opis:
The transient vibroacoustic response suppression of a piezo-coupled sandwich circular plate backed by a rigid-walled cylindrical acoustic enclosure is investigated. Problem formulation is based on the linear acoustic wave theory, Kirchhoff thin plate model, fluid/structure compatibility relations, Rayleigh integra formula, and active damping control (ADC) strategy. Matlab’s Genetic Algorithm (GA) is utilized to identify and optimize the feedback controller gain parameter based on a multi-objective performance index function. Durbin’s numerical Laplace inversion scheme is then used to calculate the key acousto-structural response parameters due to a transverse impulsive shock force for selected cavity depths. Numerical simulations demonstrate satisfactory performance of adopted control methodology in effective suppression of panel displacement response and radiated external sound pressure for enclosures of shallow and moderate depths. Limiting cases are considered and accuracy of the proposed model is rigorously verified.
Źródło:
Archives of Acoustics; 2017, 42, 2; 273-286
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leaky partial updates to control a real device casing
Autorzy:
Bismor, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/24201999.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
structural active noise control
partial updates
leaky LMS
signal processing
strukturalna aktywna redukcja hałasu
aktualizacje częściowe
LMS z wyciekiem
przetwarzanie sygnałów
Opis:
Structural active noise control (ANC) is one of few solutions applicable when global noise reduction is required: control of a whole device casing allows to lower the acoustic energy emitted by this device. Unfortunately, structural ANC usually requires a large number of sensors and actuators, making the control system multichannel with large dimensionality. This in turn presents a huge computational power demands. There are several ways to lower this demand, the partial updates being one of them. The goal of this paper is to show applicability of the leaky partial update LMS algorithms in structural ANC of a washing machine casing. The transfer functions of the numerous device paths were identified using a real washing machine in the ANC laboratory. The identified transfer functions allowed to create a simulation system, where different algorithms could be easily tested. The results of the simulations confirm effectiveness of the proposed solution.
Źródło:
Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022304
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust control design of a smart building structure
Projektowanie sterowania odpornego w "inteligentnych" konstrukcjach budowlanych
Autorzy:
Marinova, D. G.
Stavroulakis, G. E.
Powiązania:
https://bibliotekanauki.pl/articles/280816.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
robust control
structural controI
applied optimization
uncertainty system
Opis:
This paper presents an application of a design method of robust H... optimal controI to a structural controI system. A dynamic model for a building structure under earthquake and wind excitations is considered. Structured uncertainties are introduced to reflect errors between the model and the reality. To obtain the best possible performance in the face of uncertainties, rob ust H... optimal controI for the active controI structure is used. Relevant numerical techniques, which have been implemented wit h the help of MATLAB routines, are applied to solve the formulated structural contral problem. By proper selection of the weight factor, the seismic response of the building structure can be reduced considerably. Numerical results show high robust performance of the proposed method.
Praca przedstawia aplikację metody projektowania optymalnego sterowania odpornego H... dla celów konstrukcyjnych. Rozważono dynamiczny model konstrukcji budowlanej poddanej obciążeniu trzęsieniem ziemi oraz wiatrem. Wprowadzono niepewność strukturalną do modelu, aby odzwierciedlić błędy wynikające z różnic między modelem i budynkiem rzeczywistym. Do uzyskania najlepszego działania układu sterowania w obecności założonego poziomu niepewności parametrów użyto w analizowanej aktywnej konstrukcji tzw. sterowania odpornego H... . W rozwiązywaniu problemu sterowania zastosowano symulacje numeryczne wspomagane gotowymi procedurami zaczerpniętymi ze środowiska MATLAB. Poprzez odpowiedni dobór współczynnika wagi uzyskano znaczący efekt redukcji wrażliwości sejsmicznej budynku. Wyniki badań pokazały wysoką odporność zaproponowanego układu sterowania.
Źródło:
Journal of Theoretical and Applied Mechanics; 2007, 45, 1; 73-90
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model based predictive control of guyed mast vibration
Predykcyjne sterowanie drganiami masztów z odciągami
Autorzy:
Błachowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/281574.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
structural vibrations
vibration control
guyed masts
wind fluctuations
Opis:
The purpose of this work is to present an algorithm for optimal vibration control of guyed masts and an example of its application to a numerical simulation. The objective of the proposed contral system is to minimize amplitudes of transverse vibrations of the top of a mast induced by wind pressure acting on the structure. Control forces are assumed to be physically realized through changes of tension in guy cables, supporting the mast. The only required measurements are velocities of guy cables at the anchor-points. On the basis of those, a complete state of deformation of the structure is obtained by using the Kalman filter. The Davenport spectral density function is adopted as a model of the stochastic action of the wind.
Celem pracy jest algorytm i jego przykładowe zastosowanie do symulacji numerycznej optymalnego sterowania drganiami masztów z odciągami. Zadaniem układu sterowania jest minimalizacja amplitud poprzecznych drgań wierzchołka masztu wywołanych oddziaływaniem wiatru. Realizacja sił sterowania odbywa się poprzez zmianę naciągu w odciągach masztu. Estymacja pełnego stanu deformacji konstrukcji na podstawie pomiaru jedynie prędkości w punktach zakotwienia odciągów uzyskana jest poprzez wykorzystanie filtru Kalmana. Do zamodelowania losowego oddziaływania wiatru użyto funkcję gęstości widmowej Davenporta.
Źródło:
Journal of Theoretical and Applied Mechanics; 2007, 45, 2; 405-423
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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