Pub Date : 2015-01-01DOI: 10.7494/MECH.2015.34.2.29
K. Dziedziech
System Identification is an important and often complex process in many areas of engineering. This process is not easy when parameters of the analysed system vary with time. In such cases classical methods fail to identify parameters properly. The work demonstrated in this paper deals with identification of natural frequencies of time-variant systems. The paper presents the application of the Time-Variant Frequency Response Function for this analysis. Calculation procedure requires division of output spectrum by input spectrum which often leads to division by close to zero values, and that leads to infinite (or undefined) values of resulting transfer function. Additional processing is required for interpretation. The major focus and challenge relate to ridge extraction of the above time-frequency characteristics. The methods presented in the paper are illustrated using experimental multi-degree-of-freedom system. The results show that the proposed method captures correctly the dynamics of the analysed time-variant systems.
{"title":"TIME-VARIANT FREQUENCY RESPONSE FUNCTION FOR ANALYSIS OF TIME-VARYING MECHANICAL SYSTEMS","authors":"K. Dziedziech","doi":"10.7494/MECH.2015.34.2.29","DOIUrl":"https://doi.org/10.7494/MECH.2015.34.2.29","url":null,"abstract":"System Identification is an important and often complex process in many areas of engineering. This process is not easy when parameters of the analysed system vary with time. In such cases classical methods fail to identify parameters properly. The work demonstrated in this paper deals with identification of natural frequencies of time-variant systems. The paper presents the application of the Time-Variant Frequency Response Function for this analysis. Calculation procedure requires division of output spectrum by input spectrum which often leads to division by close to zero values, and that leads to infinite (or undefined) values of resulting transfer function. Additional processing is required for interpretation. The major focus and challenge relate to ridge extraction of the above time-frequency characteristics. The methods presented in the paper are illustrated using experimental multi-degree-of-freedom system. The results show that the proposed method captures correctly the dynamics of the analysed time-variant systems.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"34 1","pages":"29"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78773286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.4.83
J. Bryła, A. Martowicz
The objective of this paper is to show a designing process for actuators that utilizes shape-memory materials. Analytical studies are carried out to design a dot actuator to be used in an electronic Braille display. Shape-memory materials are a relatively new group of smart materials that exhibit the transformation of their internal structures in solid state phases resulting from external mechanical or thermal excitation. This unique property shows up as three phenomena: one- and two-way memory effects as well as superelasticity, which all significantly influence the change of both the material properties and geometry. Hence, shape-memory materials are used as actuators effectively controlled by the above-mentioned types of excitation. The work presents the design guidelines for a proposed technical solution as well as the phenomenon utilized in the elaborated model of the actuator. The authors derived the mathematical descriptions for the proposed design configuration and an example of the calculations is shown. Moreover, the characteristics of the elaborated configuration are also discussed, taking into account the range of application areas.
{"title":"SHAPE-MEMORY MATERIALS AS CONTROL ELEMENTS USED IN DOT BRAILLE ACTUATOR","authors":"J. Bryła, A. Martowicz","doi":"10.7494/MECH.2014.33.4.83","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.4.83","url":null,"abstract":"The objective of this paper is to show a designing process for actuators that utilizes shape-memory materials. Analytical studies are carried out to design a dot actuator to be used in an electronic Braille display. Shape-memory materials are a relatively new group of smart materials that exhibit the transformation of their internal structures in solid state phases resulting from external mechanical or thermal excitation. This unique property shows up as three phenomena: one- and two-way memory effects as well as superelasticity, which all significantly influence the change of both the material properties and geometry. Hence, shape-memory materials are used as actuators effectively controlled by the above-mentioned types of excitation. The work presents the design guidelines for a proposed technical solution as well as the phenomenon utilized in the elaborated model of the actuator. The authors derived the mathematical descriptions for the proposed design configuration and an example of the calculations is shown. Moreover, the characteristics of the elaborated configuration are also discussed, taking into account the range of application areas.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"51 1","pages":"83"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76655098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.1.5
Bogusław Ładecki, F. Matachowski
The long period and conditions of operation are the cause of various types of severe damage to cranes used in the steelworks industry. Among the more dangerous and difficult to eliminate crane damage types, there is excess durable deflection of its supports from vertical axis. The object of the study is the semi-portal grab bridge-crane with steel lattice structure, for which deflection of a fixed support was detected that several times exceeded permissible values. For this crane, rectification was performed aimed at bringing fixed supports to the vertical line by stabilisation of the corrected location of the bearing structure of the crane using additional angle braces. The analysis of periodical geodetic measurements of the crane structure showed insufficient effect of the rectification, whereas loss of stability of some rods in the fixed support was detected. The study involved the FEM strength analysis of the crane, which revealed that the applied rectification method caused redistribution of forces in the rods of the fixed support, resulting in the loss of stability of some rods of the support, thus questioning the effectiveness of the rectification method applied.
{"title":"Problems with rectification of hoist supports on the example of a semi-portal bridge-crane with a lattice structure","authors":"Bogusław Ładecki, F. Matachowski","doi":"10.7494/MECH.2014.33.1.5","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.1.5","url":null,"abstract":"The long period and conditions of operation are the cause of various types of severe damage to cranes used in the steelworks industry. Among the more dangerous and difficult to eliminate crane damage types, there is excess durable deflection of its supports from vertical axis. The object of the study is the semi-portal grab bridge-crane with steel lattice structure, for which deflection of a fixed support was detected that several times exceeded permissible values. For this crane, rectification was performed aimed at bringing fixed supports to the vertical line by stabilisation of the corrected location of the bearing structure of the crane using additional angle braces. The analysis of periodical geodetic measurements of the crane structure showed insufficient effect of the rectification, whereas loss of stability of some rods in the fixed support was detected. The study involved the FEM strength analysis of the crane, which revealed that the applied rectification method caused redistribution of forces in the rods of the fixed support, resulting in the loss of stability of some rods of the support, thus questioning the effectiveness of the rectification method applied.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"2003 44","pages":"5"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72620250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.1.26
S. Weyna
A large variety of CFD/CAA hybrid approaches are commonly used today for aero-acoustic engineering applications using equations and the coupling between source and acoustic propagation region. The coupling is usually made using Lighthill’s acoustic analogies and Kirhchoff’s acoustic boundary conditions. This paper intends to give answer how the size and shape of the source may be influence on the accuracy of the different coupling methods and their sensitivity. In this way, some experimental investigation was made using sound intensity measurement technique to the graphic presentation of the spatial distribution of the acoustic power flow over various geometrical shapes of structures located in a three-dimensional space. The results of these studies contribute to the theory of sound and general knowledge about the physics of flow acoustic phenomena, especially in the near acoustic field. As a result of research, the visualization analysis of the sound intensity flux in 3D space is shown as flow wave reactions on the presence of obstacles with different shapes. The results of vectors flow fields around a rectangular and circular plate, over the cavity and inside a ducts are show. The visualization of acoustic power flow in real-life acoustic fields can explain many particular energetic acoustic effects like scattering, vortex flow in shielding area, etc., concerning areas where it is difficult to make numerical analysis.
{"title":"OVERVIEW OF THE EXPERIMENTAL DETERMINATION OF ACOUSTIC FLOW ON THE BASIS OF SOUND INTENSITY MEASUREMENTS","authors":"S. Weyna","doi":"10.7494/MECH.2014.33.1.26","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.1.26","url":null,"abstract":"A large variety of CFD/CAA hybrid approaches are commonly used today for aero-acoustic engineering applications using equations and the coupling between source and acoustic propagation region. The coupling is usually made using Lighthill’s acoustic analogies and Kirhchoff’s acoustic boundary conditions. This paper intends to give answer how the size and shape of the source may be influence on the accuracy of the different coupling methods and their sensitivity. In this way, some experimental investigation was made using sound intensity measurement technique to the graphic presentation of the spatial distribution of the acoustic power flow over various geometrical shapes of structures located in a three-dimensional space. The results of these studies contribute to the theory of sound and general knowledge about the physics of flow acoustic phenomena, especially in the near acoustic field. As a result of research, the visualization analysis of the sound intensity flux in 3D space is shown as flow wave reactions on the presence of obstacles with different shapes. The results of vectors flow fields around a rectangular and circular plate, over the cavity and inside a ducts are show. The visualization of acoustic power flow in real-life acoustic fields can explain many particular energetic acoustic effects like scattering, vortex flow in shielding area, etc., concerning areas where it is difficult to make numerical analysis.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"13 1","pages":"26"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77448407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.1.10
K. Mendrok
In recent years one can observe an increasing interest of the researchers, both from academia and industry, in the development of systems for the monitoring of health structures.. The main fields of application for these systems are rotating machinery, aircrafts and other means of group transport and civil engineering structures. Many of the latter, contain truss elements in its structure. That is why detection and possible localization of the fault in such a structures is crucial for the safety of its operation. In this paper the application of modal filtration to damage detection and localization in the truss structures is presented. The results of numerical simulation an laboratory experiment are shown.
{"title":"DAMAGE LOCALIZATION AND MONITORING OF LOAD CHANGES IN TRUSS STRUCTURES","authors":"K. Mendrok","doi":"10.7494/MECH.2014.33.1.10","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.1.10","url":null,"abstract":"In recent years one can observe an increasing interest of the researchers, both from academia and industry, in the development of systems for the monitoring of health structures.. The main fields of application for these systems are rotating machinery, aircrafts and other means of group transport and civil engineering structures. Many of the latter, contain truss elements in its structure. That is why detection and possible localization of the fault in such a structures is crucial for the safety of its operation. In this paper the application of modal filtration to damage detection and localization in the truss structures is presented. The results of numerical simulation an laboratory experiment are shown.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"104 1","pages":"10"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75606606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.3.75
Daniel Tokarczyk, M. Pluta, J. Wiciak
The article is about use of automatic mechanism able to play an instrument in research about play repeatability. Repeatability in this case refers to the time delays between played notes in the sequences. Subject will be discussed based on a guitar playing robot. During the research with the use of guitar playing robots, some conclusions were made that confirm, that human is unable to play twice sound sequences maintaining high repeatability . It is also proven, that use of robotic musical instrument (RMI) helps to obtain play repeatability of the sound sequences much higher than the one obtained by the human musician.
{"title":"Guitar playing robot, a tool assisting instrumental research","authors":"Daniel Tokarczyk, M. Pluta, J. Wiciak","doi":"10.7494/MECH.2014.33.3.75","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.3.75","url":null,"abstract":"The article is about use of automatic mechanism able to play an instrument in research about play repeatability. Repeatability in this case refers to the time delays between played notes in the sequences. Subject will be discussed based on a guitar playing robot. During the research with the use of guitar playing robots, some conclusions were made that confirm, that human is unable to play twice sound sequences maintaining high repeatability . It is also proven, that use of robotic musical instrument (RMI) helps to obtain play repeatability of the sound sequences much higher than the one obtained by the human musician.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"14 1","pages":"75"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73027888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.2.43
Ł. Jastrzębski
The paper summarises the results of laboratory testing of a vibration reduction system with energy harvesting capability, implemented in an 2 DOF mechanical application. The vibration reduction system comprises a commercially available RD-1005-3 type magnetorheological (MR) damper and an electromagnetic energy transducer (EPE) executing the reciprocating motion. The aim of the experiment was to compare the performance of the vibration reduction with two types of power conditioning systems and that in which the MR damper coil is fed directly with energy generated by EPE. Frequency characteristics are provided showing the plots of transmissibility coefficients, MR damper force, voltage generated by EPE, current intensity in the MR damper control coil, supplied electric power and mechanical power dissipated by the damper.
{"title":"CONDITIONING ELECTRONICS IN A SELF-POWERED VIBRATION REDUCTION SYSTEM: EXPERIMENTAL TESTING","authors":"Ł. Jastrzębski","doi":"10.7494/MECH.2014.33.2.43","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.2.43","url":null,"abstract":"The paper summarises the results of laboratory testing of a vibration reduction system with energy harvesting capability, implemented in an 2 DOF mechanical application. The vibration reduction system comprises a commercially available RD-1005-3 type magnetorheological (MR) damper and an electromagnetic energy transducer (EPE) executing the reciprocating motion. The aim of the experiment was to compare the performance of the vibration reduction with two types of power conditioning systems and that in which the MR damper coil is fed directly with energy generated by EPE. Frequency characteristics are provided showing the plots of transmissibility coefficients, MR damper force, voltage generated by EPE, current intensity in the MR damper control coil, supplied electric power and mechanical power dissipated by the damper.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"26 1","pages":"43"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82102774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.2.51
J. Korta, A. Mlyniec, P. Zdziebko, T. Uhl
The paper covers the subject of FE modeling of adhesive joints, which is gaining more and more attention in the contemporary industry, especially in the aerospace and automotive sectors. This technique of creating structural connections possesses many advantages over mechanical or welding methods and it seems that it will be exploited extensively in the future mechanical design. Ability of joining dissimilar materials, decreased minimum member cross-section size and corrosion inertness can be considered as its most important features. However, in the era of virtual prototyping, it is necessary to conduct reliable computer assisted analyses of these type of joints. It is because most of the contemporary structures are developed as numerical models first, and only the final product is prototyped physically, to validate the simulation results. The aim of this paper is to demonstrate how to elaborate a reliable and accurate adhesive joint models, using a cohesive zone modeling (CZM) method. The major profitable consequence of using the CZM technique is that it introduces into the model relatively small number of spatial degrees of freedom, and therefore, allows for short computational times.
{"title":"FINITE ELEMENT ANALASIS OF ADHESIVE BONDS USING THE COHESIVE ZONE MODELING METHOD","authors":"J. Korta, A. Mlyniec, P. Zdziebko, T. Uhl","doi":"10.7494/MECH.2014.33.2.51","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.2.51","url":null,"abstract":"The paper covers the subject of FE modeling of adhesive joints, which is gaining more and more attention in the contemporary industry, especially in the aerospace and automotive sectors. This technique of creating structural connections possesses many advantages over mechanical or welding methods and it seems that it will be exploited extensively in the future mechanical design. Ability of joining dissimilar materials, decreased minimum member cross-section size and corrosion inertness can be considered as its most important features. However, in the era of virtual prototyping, it is necessary to conduct reliable computer assisted analyses of these type of joints. It is because most of the contemporary structures are developed as numerical models first, and only the final product is prototyped physically, to validate the simulation results. The aim of this paper is to demonstrate how to elaborate a reliable and accurate adhesive joint models, using a cohesive zone modeling (CZM) method. The major profitable consequence of using the CZM technique is that it introduces into the model relatively small number of spatial degrees of freedom, and therefore, allows for short computational times.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"438 1","pages":"51"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78153597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.1.37
S. Wolny, Bogusław Ładecki, F. Matachowski
Designing of modern box pallets with folding walls, which are used for example to transport tires, requires fulfilment of a number of performance requirements. Such pallets, adapted to be moved by forklifts, are stored or transported without loading with walls folded, and during operation they are put together in the piles of a few pieces and braced by the transport belts. Difficult operating conditions are related to necessity to provide resistance of construction of a pallet or their pile on: bending, piling, stability, hitting in case of a free-fall, lifting by forklift, as well as the resistance to horizontal strokes by both edges and legs. In order to meet the above mentioned requirements, it is necessary to implement the relevant tensile FEM analyses, which are then reviewed by the relevant experimental testing. The paper discuss the requirements specified by standards for designing of the above mentioned pallets and presents FEM results in the process of pallets’ designing.
{"title":"DESIGNING FOLDING WALL BOX PALLETS","authors":"S. Wolny, Bogusław Ładecki, F. Matachowski","doi":"10.7494/MECH.2014.33.1.37","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.1.37","url":null,"abstract":"Designing of modern box pallets with folding walls, which are used for example to transport tires, requires fulfilment of a number of performance requirements. Such pallets, adapted to be moved by forklifts, are stored or transported without loading with walls folded, and during operation they are put together in the piles of a few pieces and braced by the transport belts. Difficult operating conditions are related to necessity to provide resistance of construction of a pallet or their pile on: bending, piling, stability, hitting in case of a free-fall, lifting by forklift, as well as the resistance to horizontal strokes by both edges and legs. In order to meet the above mentioned requirements, it is necessary to implement the relevant tensile FEM analyses, which are then reviewed by the relevant experimental testing. The paper discuss the requirements specified by standards for designing of the above mentioned pallets and presents FEM results in the process of pallets’ designing.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"54 1","pages":"37"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80174300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7494/MECH.2014.33.1.17
W. Rdzanek, W. Rdzanek
This study focuses on the sound radiation of a vibrating flat annular plate. The rigorous theoretical considerations deal with sometime-harmonic and axisymmetric vibrations. Three different boundary configurations are considered, i.e. one of the plate’s edges is simply supported and the other one is clamped or also is simply supported. The active and reactive self-impedance of the system are presented in their Hankel’s representations, valid within the whole frequency spectrum. The expressions obtained are transformed to their elementary forms, valid for the high frequencies. Low fluid loading and low internal friction of the plate are assumed. The obtained results are illustrated with sample plots in the domain of acoustic wavenumber. Elementary formulae presented can be useful for further theoretical analysis of the total sound power radiated by an excited flat plate in an acoustic fluid as well as for efficient engineering computations.
{"title":"ASYMPTOTIC FORMULAE FOR THE ACOUSTIC SELF-IMPEDANCE OF SIMPLY-SUPPORTED AND SIMPLY SUPPORTED-CLAMPED ANNULAR PLATES","authors":"W. Rdzanek, W. Rdzanek","doi":"10.7494/MECH.2014.33.1.17","DOIUrl":"https://doi.org/10.7494/MECH.2014.33.1.17","url":null,"abstract":"This study focuses on the sound radiation of a vibrating flat annular plate. The rigorous theoretical considerations deal with sometime-harmonic and axisymmetric vibrations. Three different boundary configurations are considered, i.e. one of the plate’s edges is simply supported and the other one is clamped or also is simply supported. The active and reactive self-impedance of the system are presented in their Hankel’s representations, valid within the whole frequency spectrum. The expressions obtained are transformed to their elementary forms, valid for the high frequencies. Low fluid loading and low internal friction of the plate are assumed. The obtained results are illustrated with sample plots in the domain of acoustic wavenumber. Elementary formulae presented can be useful for further theoretical analysis of the total sound power radiated by an excited flat plate in an acoustic fluid as well as for efficient engineering computations.","PeriodicalId":38333,"journal":{"name":"International Journal of Mechanics and Control","volume":"94 4 1","pages":"17"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83457782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}