A finite element method for simulation of lens-less line focus acoustic microscopy is proposed in this paper to nondestructively evaluate the leaky surface wave (LSW) velocity. The defocusing measurement model is established, in which the geometrical focusing radius will be 20 mm. The piezoelectric polyvinylidene fluoride film is selected as the active element. The excitation is a standard black Harris wavelet signal with a centre frequency of 5 MHz. Simulations of measurements on typical bulk materials (Al) are carried out. Then, the time-resolved wave signal series are acquired when the defocusing distance varies continuously. The LSW velocity will be easily determined by the examination of the slope of the LSW’s arrival time versus the defocusing position. The LSWs’ propagating path will be analyzed geometrically in time-domain. Meanwhile, the LSWs’ velocities are also extracted by applying the specially developed digital signal processing algorithm to the defocusing experimental data, which is called V (f, z) analysis method based on two-dimensional fast Fourier transform. Finally, the relationship between the time-resolved method and the V (f, z) technique is discussed, in which the interpretation of the formation of surface waves and the description of its analysing methods will be given.
{"title":"Finite Element Modeling and Wave Propagation Analysis for Lens-Less Line Focus Acoustic Microscopy","authors":"Guorong Song, Qin Dengqian, Lyu Yan, Guangfu Hong, Xu Yuyang, Wu Bin, He Cunfu","doi":"10.20855/IJAV.2017.22.4498","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4498","url":null,"abstract":"A finite element method for simulation of lens-less line focus acoustic microscopy is proposed in this paper to nondestructively evaluate the leaky surface wave (LSW) velocity. The defocusing measurement model is established, in which the geometrical focusing radius will be 20 mm. The piezoelectric polyvinylidene fluoride film is selected as the active element. The excitation is a standard black Harris wavelet signal with a centre frequency of 5 MHz. Simulations of measurements on typical bulk materials (Al) are carried out. Then, the time-resolved wave signal series are acquired when the defocusing distance varies continuously. The LSW velocity will be easily determined by the examination of the slope of the LSW’s arrival time versus the defocusing position. The LSWs’ propagating path will be analyzed geometrically in time-domain. Meanwhile, the LSWs’ velocities are also extracted by applying the specially developed digital signal processing algorithm to the defocusing experimental data, which is called V (f, z) analysis method based on two-dimensional fast Fourier transform. Finally, the relationship between the time-resolved method and the V (f, z) technique is discussed, in which the interpretation of the formation of surface waves and the description of its analysing methods will be given.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45923242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4486
F. Masurkar, Nitesh P. Yelve
The present research focuses on localizing structural damages in an aluminium and a woven fabric composite laminate. Finite Element (FE) and experimental simulation studies are carried out on specimens of these plates with and without damages, and the response data are collected at various sensor locations. Piezoelectric wafer (PW) transducers are used for actuation and reception of Lamb wave. The group velocity dispersion curves obtained through the experiment and simulation are compared with those obtained analytically to ensure effective actuation and sensing of Lamb wave. A Continuous Wavelet Transform (CWT) is used for receiving the arrival times of the wave reflected from the damages to the sensor locations. After acquiring arrival time data, the geodesic algorithm is employed to locate the damage in the specimens. The geodesic algorithm used is a two-step strategy initially using the Pythagorean Theorem to find the discrete geodesics in the structure, using mesh information and followed by locating the intersections of these geodesics to get the damage locations. Herein, the geodesic algorithm is shown to be effective in detecting several damages in a plate, both experimentally and through FE simulation.
{"title":"Lamb Wave Based Experimental and Finite Element Simulation Studies for Damage Detection in an Aluminium and a Composite Plate using Geodesic Algorithm","authors":"F. Masurkar, Nitesh P. Yelve","doi":"10.20855/IJAV.2017.22.4486","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4486","url":null,"abstract":"The present research focuses on localizing structural damages in an aluminium and a woven fabric composite laminate. Finite Element (FE) and experimental simulation studies are carried out on specimens of these plates with and without damages, and the response data are collected at various sensor locations. Piezoelectric wafer (PW) transducers are used for actuation and reception of Lamb wave. The group velocity dispersion curves obtained through the experiment and simulation are compared with those obtained analytically to ensure effective actuation and sensing of Lamb wave. A Continuous Wavelet Transform (CWT) is used for receiving the arrival times of the wave reflected from the damages to the sensor locations. After acquiring arrival time data, the geodesic algorithm is employed to locate the damage in the specimens. The geodesic algorithm used is a two-step strategy initially using the Pythagorean Theorem to find the discrete geodesics in the structure, using mesh information and followed by locating the intersections of these geodesics to get the damage locations. Herein, the geodesic algorithm is shown to be effective in detecting several damages in a plate, both experimentally and through FE simulation.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43374270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4493
Chen Luqi, Wu Xiaohong, Sun Qing, Xu Xiaomin
The hysteresis characteristic in macro fibre composite (MFC) actuator is intimately related to their application in vibration control system. In this paper, the electromechanical hysteresis property of MFC actuator is studied. First, experimental study on the electromechanical behaviours under different voltages and frequencies is carried out, and the hysteretic property of MFC actuator is investigated. A digital signal processing (DSP) system is used to control input voltage and a digital image correlation (DIC) system as noncontact setup is used to obtain the output strain of the MFC actuator in the experiment. The experimental results indicate that the relationship of the voltage and strain displays hysteresis with nonlocal memory. Second, the Preisach model is used to describe hysteresis characteristic of the MFC actuator. In order to improve the accuracy of the model, the modifications are made, in which the experimental data under the quasi-static frequency range and the congruency property are used to establish the modified Preisach model. Finally, the hysteresis characteristics of the MFC actuator predicted from the proposed model are compared with those obtained from the classical Preisach model. The results indicate that the proposed model gives better accuracy than the classical Preisach model, and it is suggested that the present study on the hysteresis model of the MFC actuator can be used in the active vibration control.
{"title":"Experimental study on the electromechanical hysteresis property of macro fiber composite actuator","authors":"Chen Luqi, Wu Xiaohong, Sun Qing, Xu Xiaomin","doi":"10.20855/IJAV.2017.22.4493","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4493","url":null,"abstract":"The hysteresis characteristic in macro fibre composite (MFC) actuator is intimately related to their application in vibration control system. In this paper, the electromechanical hysteresis property of MFC actuator is studied. First, experimental study on the electromechanical behaviours under different voltages and frequencies is carried out, and the hysteretic property of MFC actuator is investigated. A digital signal processing (DSP) system is used to control input voltage and a digital image correlation (DIC) system as noncontact setup is used to obtain the output strain of the MFC actuator in the experiment. The experimental results indicate that the relationship of the voltage and strain displays hysteresis with nonlocal memory. Second, the Preisach model is used to describe hysteresis characteristic of the MFC actuator. In order to improve the accuracy of the model, the modifications are made, in which the experimental data under the quasi-static frequency range and the congruency property are used to establish the modified Preisach model. Finally, the hysteresis characteristics of the MFC actuator predicted from the proposed model are compared with those obtained from the classical Preisach model. The results indicate that the proposed model gives better accuracy than the classical Preisach model, and it is suggested that the present study on the hysteresis model of the MFC actuator can be used in the active vibration control.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48353278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4501
C. He, Peng Deng, Yan Lu, Xiucheng Liu, Zenghua Liu, J. Jiao, Bin Wu
A quantitative characterization method is introduced for estimating surface crack depth using Rayleigh waves in pitch-catch mode by electromagnetic acoustic transducers (EMATs). The method employs the experimentally determined reflection and transmission coefficients of Rayleigh waves scattered at a surface crack, which will be compared to the reference curves obtained from two-dimensional finite element method (FEM) simulations based on variable crack depth. Three EMAT couples with different centre frequencies were employed to extend the measuring range, and to implement the quantitative characterization of crack depth. The reference curves and measurement results were verified to be repeatable with great accuracy, which shows a maximum error of 17% with crack depth ranging from 0.2–3.0 mm.
{"title":"Estimation of Surface Crack Depth using Rayleigh Waves by Electromagnetic Acoustic Transducers","authors":"C. He, Peng Deng, Yan Lu, Xiucheng Liu, Zenghua Liu, J. Jiao, Bin Wu","doi":"10.20855/IJAV.2017.22.4501","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4501","url":null,"abstract":"A quantitative characterization method is introduced for estimating surface crack depth using Rayleigh waves in pitch-catch mode by electromagnetic acoustic transducers (EMATs). The method employs the experimentally determined reflection and transmission coefficients of Rayleigh waves scattered at a surface crack, which will be compared to the reference curves obtained from two-dimensional finite element method (FEM) simulations based on variable crack depth. Three EMAT couples with different centre frequencies were employed to extend the measuring range, and to implement the quantitative characterization of crack depth. The reference curves and measurement results were verified to be repeatable with great accuracy, which shows a maximum error of 17% with crack depth ranging from 0.2–3.0 mm.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49299253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4494
M. S. Azam, V. Ranjan, B. Kumar
In this paper, free vibration analysis of rhombic plate with pre-existing central crack has been done using the finite element method. The Mindlin theory of plate has been used in the process of investigation. The following six boundary conditions at the edges of the plate have been considered. They are simply supported at all edges (SSSS), clamped at all edges (CCCC), free at all edges (FFFF), clamped-simply supported (CSSC), clamped-free (CFFC), and clamped-free-simply supported (CSFS). Effects of crack length on natural frequencies of rhombic plate with different skew angles i.e. 15◦, 30◦, 45◦, 60◦ have been studied. It is observed that percentage drop in fundamental frequency due to presence of central crack in the rhombic plate increases with an increase in skew angle for CCCC, SSSS, and CSSC edge conditions at a given crack ratio (non-dimensional crack length). Under the CFFC, CSFS, and FFFF edge conditions, percentage drop in natural frequency of rhombic plate is very small for crack ratio of 0.2 at different skew angles. In case of the CFFC edge condition of the rhombic plate, percentage drop in fundamental frequency is within 0.7% at all skew angles and with all crack ratios considered. Some of the results obtained by the present method have been compared with the published results. Most of the results obtained are novel for rhombic crack plate.
{"title":"Free Vibration Analysis of Rhombic Plate with Central Crack","authors":"M. S. Azam, V. Ranjan, B. Kumar","doi":"10.20855/IJAV.2017.22.4494","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4494","url":null,"abstract":"In this paper, free vibration analysis of rhombic plate with pre-existing central crack has been done using the finite element method. The Mindlin theory of plate has been used in the process of investigation. The following six boundary conditions at the edges of the plate have been considered. They are simply supported at all edges (SSSS), clamped at all edges (CCCC), free at all edges (FFFF), clamped-simply supported (CSSC), clamped-free (CFFC), and clamped-free-simply supported (CSFS). Effects of crack length on natural frequencies of rhombic plate with different skew angles i.e. 15◦, 30◦, 45◦, 60◦ have been studied. It is observed that percentage drop in fundamental frequency due to presence of central crack in the rhombic plate increases with an increase in skew angle for CCCC, SSSS, and CSSC edge conditions at a given crack ratio (non-dimensional crack length). Under the CFFC, CSFS, and FFFF edge conditions, percentage drop in natural frequency of rhombic plate is very small for crack ratio of 0.2 at different skew angles. In case of the CFFC edge condition of the rhombic plate, percentage drop in fundamental frequency is within 0.7% at all skew angles and with all crack ratios considered. Some of the results obtained by the present method have been compared with the published results. Most of the results obtained are novel for rhombic crack plate.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42078036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4489
Wu Xiaohong, Zhao Jianhua, Z. Ling, Sun Qing
The problem of placing sensors plays a significant role in the domains of structural health monitoring (SHM) applications and parameter estimation in structural dynamics. In this paper, the particle swarm optimisation (PSO) algorithm is introduced firstly and utilised to place sensors optimally on a truss structure for the purpose of modal identification. Then, two different types of fitness functions are constructed as to be the optimal criteria, which are based on modal assurance criterion (MAC) and maximising measures of the observability gramian matrix, respectively. The former one is mainly used to distinguish between two sets of mode shapes with the aim of maximising the off-diagonal elements in MAC matrix, and the latter one ensures proper observability of the structure. Finally, a truss structure model is considered as an example to demonstrate the efficiency and validity of the proposed method. Numerical results show that the two approaches using the PSO algorithm can find the optimal location of sensors successfully and identify the modal frequencies of the truss structure accurately by acceleration FRF method.
{"title":"Optimal Sensor Placement for a Truss Structure Using Particle Swarm Optimisation Algorithm","authors":"Wu Xiaohong, Zhao Jianhua, Z. Ling, Sun Qing","doi":"10.20855/IJAV.2017.22.4489","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4489","url":null,"abstract":"The problem of placing sensors plays a significant role in the domains of structural health monitoring (SHM) applications and parameter estimation in structural dynamics. In this paper, the particle swarm optimisation (PSO) algorithm is introduced firstly and utilised to place sensors optimally on a truss structure for the purpose of modal identification. Then, two different types of fitness functions are constructed as to be the optimal criteria, which are based on modal assurance criterion (MAC) and maximising measures of the observability gramian matrix, respectively. The former one is mainly used to distinguish between two sets of mode shapes with the aim of maximising the off-diagonal elements in MAC matrix, and the latter one ensures proper observability of the structure. Finally, a truss structure model is considered as an example to demonstrate the efficiency and validity of the proposed method. Numerical results show that the two approaches using the PSO algorithm can find the optimal location of sensors successfully and identify the modal frequencies of the truss structure accurately by acceleration FRF method.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48786770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/ijav.2017.22.4488
Mojtaba Eftekhar, S. Kamyab, M. Eftekhari, M. Hosseini
A fault diagnosis procedure based on r2PSO algorithm—a newly developed version of particle swarm optimization (PSO)—is presented for detecting crack depth and location in a functionally graded material (FGM) cantilever beam. The governing equation and boundary conditions are obtained by using the extended Hamilton’s principle, and the characteristic equation is obtained as a function of position ratio and depth ratio of crack. Identification of the crack is formulated as an optimization problem. The r2PSO algorithm is used to find the optimal solution of the cost function, which is based on the summation of the absolute value of the characteristic equation for three natural frequencies. The position ratio and depth ratio of crack are computed by algorithm, when three natural frequencies of FGM beam are entered to algorithm as inputs. The obtained results confirm the applicability and efficiency of r2PSO to calculate the parameters of crack with high accuracy and suitable convergence rate.
{"title":"Application of R2PSO Algorithm in Crack Detection of Functionally Graded Beams","authors":"Mojtaba Eftekhar, S. Kamyab, M. Eftekhari, M. Hosseini","doi":"10.20855/ijav.2017.22.4488","DOIUrl":"https://doi.org/10.20855/ijav.2017.22.4488","url":null,"abstract":"A fault diagnosis procedure based on r2PSO algorithm—a newly developed version of particle swarm optimization (PSO)—is presented for detecting crack depth and location in a functionally graded material (FGM) cantilever beam. The governing equation and boundary conditions are obtained by using the extended Hamilton’s principle, and the characteristic equation is obtained as a function of position ratio and depth ratio of crack. Identification of the crack is formulated as an optimization problem. The r2PSO algorithm is used to find the optimal solution of the cost function, which is based on the summation of the absolute value of the characteristic equation for three natural frequencies. The position ratio and depth ratio of crack are computed by algorithm, when three natural frequencies of FGM beam are entered to algorithm as inputs. The obtained results confirm the applicability and efficiency of r2PSO to calculate the parameters of crack with high accuracy and suitable convergence rate.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44178634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4500
Chong Wang, Jie Mao, Tao Leng, Ze Zhuang, Xiaomin Wang
Total focusing method (TFM) has improved resolution and accuracy over traditional ultrasonic phased array technology. In this paper, an advanced parallel architecture in field programmable gate arrays is suggested to significantly accelerate the imaging efficiency of TFM. Several techniques are investigated, including the real-time concurrent calculation for time of flight, parallel generation of multiple pixels, and the Hilbert transform to the pixels array. This architecture achieves the real-time computation of the flight times for each pixel and the concurrent generation of double pixels for TFM imaging. Compared to conventional methods, the efficiency of TFM imaging is greatly accelerated and the impact from the increase of element and pixel number is also effectively reduced. Simulation data was used to verify the architecture, and experiment results confirmed that the efficiency was only related to the pulse repeated frequency and element number, which reaches to the physical limitation of TFM inspection. This approach also shows that high efficiency is maintained when pixel number increases, and a strict real-time imaging can be achieved in this architecture. As a result, an effective way for the fast inspection with TFM is provided.
{"title":"Efficient Acceleration for Total Focusing Method Based on Advanced Parallel Computing in FPGA","authors":"Chong Wang, Jie Mao, Tao Leng, Ze Zhuang, Xiaomin Wang","doi":"10.20855/IJAV.2017.22.4500","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4500","url":null,"abstract":"Total focusing method (TFM) has improved resolution and accuracy over traditional ultrasonic phased array technology. In this paper, an advanced parallel architecture in field programmable gate arrays is suggested to significantly accelerate the imaging efficiency of TFM. Several techniques are investigated, including the real-time concurrent calculation for time of flight, parallel generation of multiple pixels, and the Hilbert transform to the pixels array. This architecture achieves the real-time computation of the flight times for each pixel and the concurrent generation of double pixels for TFM imaging. Compared to conventional methods, the efficiency of TFM imaging is greatly accelerated and the impact from the increase of element and pixel number is also effectively reduced. Simulation data was used to verify the architecture, and experiment results confirmed that the efficiency was only related to the pulse repeated frequency and element number, which reaches to the physical limitation of TFM inspection. This approach also shows that high efficiency is maintained when pixel number increases, and a strict real-time imaging can be achieved in this architecture. As a result, an effective way for the fast inspection with TFM is provided.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47888336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4491
M. Azadi, E. Azadi, S. Fazelzadeh
In this paper, a satellite with two flexible appendages and a central hub is considered. The piezoelectric layers are attached to both side of the appendages and used as actuators. The governing equations of motion are derived based on Lagrange method. Using Rayleigh-Ritz technique ordinary differential equations of motion are obtained. A robust inverse dynamic control is applied to the system to not only control the three axes manoeuvre of the satellite but also suppress the vibrations of the flexible appendages. Finally, the system is simulated and simulation results show good performance of this controller.
{"title":"Robust Inverse Dynamic Control of a Maneuvering Smart Flexible Satellite with Piezoelectric Layers","authors":"M. Azadi, E. Azadi, S. Fazelzadeh","doi":"10.20855/IJAV.2017.22.4491","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4491","url":null,"abstract":"In this paper, a satellite with two flexible appendages and a central hub is considered. The piezoelectric layers are attached to both side of the appendages and used as actuators. The governing equations of motion are derived based on Lagrange method. Using Rayleigh-Ritz technique ordinary differential equations of motion are obtained. A robust inverse dynamic control is applied to the system to not only control the three axes manoeuvre of the satellite but also suppress the vibrations of the flexible appendages. Finally, the system is simulated and simulation results show good performance of this controller.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44153939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-01DOI: 10.20855/IJAV.2017.22.4499
Wang Feng, Xu Xing, Fang Zong-de
To analyse the power transmission process of herringbone gear train system supported by rolling element bearings more accurately, meshing stiffness calculation method is firstly developed through tooth load contact analysis. The model of mesh impact force and the approach to calculate the equivalent friction torque coefficient in mixed elastohydrodynamic lubrication state are sequentially derived. The twelve-degree-of-freedom herringbone gear vibration model is finally established. Upon the consideration of different supporting ways between pinion and gear shaft, dynamic loads on support bearings are calculated separately. Based on rolling element bearing dynamic model and internal load distribution on bearings, comprehensive analysis of the vibration transmission process in meshing gear pair, rolling element bearings, and internal walls of gearbox bearing holes is conducted. Under the real dynamic load boundary condition, harmonic response and transient response of gearbox are obtained correspondingly. To evaluate the proposed model approach, a rolling element bearings support herringbone gear system is adopted to do real closed power flow vibration test. Simulation and experimental results show that the theoretical analysis in this paper is scientific and reasonable to calculate the dynamic load transfer process, and the maximum relative deviation between the theoretical results and the experimental data is less than 15%.
{"title":"New Method with Experimental Validation for Power Transmission Process Analysis on Herringbone Gear Train System","authors":"Wang Feng, Xu Xing, Fang Zong-de","doi":"10.20855/IJAV.2017.22.4499","DOIUrl":"https://doi.org/10.20855/IJAV.2017.22.4499","url":null,"abstract":"To analyse the power transmission process of herringbone gear train system supported by rolling element bearings more accurately, meshing stiffness calculation method is firstly developed through tooth load contact analysis. The model of mesh impact force and the approach to calculate the equivalent friction torque coefficient in mixed elastohydrodynamic lubrication state are sequentially derived. The twelve-degree-of-freedom herringbone gear vibration model is finally established. Upon the consideration of different supporting ways between pinion and gear shaft, dynamic loads on support bearings are calculated separately. Based on rolling element bearing dynamic model and internal load distribution on bearings, comprehensive analysis of the vibration transmission process in meshing gear pair, rolling element bearings, and internal walls of gearbox bearing holes is conducted. Under the real dynamic load boundary condition, harmonic response and transient response of gearbox are obtained correspondingly. To evaluate the proposed model approach, a rolling element bearings support herringbone gear system is adopted to do real closed power flow vibration test. Simulation and experimental results show that the theoretical analysis in this paper is scientific and reasonable to calculate the dynamic load transfer process, and the maximum relative deviation between the theoretical results and the experimental data is less than 15%.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42873141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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