The Experts below are selected from a list of 6462 Experts worldwide ranked by ideXlab platform
M Ganapathi - One of the best experts on this subject based on the ideXlab platform.
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nonlinear free Flexural Vibration of curvilinear fibre composite laminates using a higher order element
International Journal of Structural Stability and Dynamics, 2018Co-Authors: M Ganapathi, Anand Venkatachari, Mohamed Haboussi, Arun Tom MathewAbstract:In the present work, the nonlinear free Flexural Vibration of thick curvilinear fiber composite laminates is investigated using a higher-order shear flexible eight-noded quadrilateral element devel...
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a finite element study on the large amplitude Flexural Vibration characteristics of fgm plates under aerodynamic load
International Journal of Non-linear Mechanics, 2012Co-Authors: T Prakash, M K Singha, M GanapathiAbstract:Abstract The large amplitude Flexural Vibration characteristics of functionally graded material (FGM) plates are investigated here using a shear flexible finite element approach. Material properties of the plate are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of volume fractions of the constituents. The effective material properties are then evaluated based on the rule of mixture. The FGM plate is modeled using the first-order shear deformation theory based on exact neutral surface position and von Karman’s assumptions for large displacement. The third-order piston theory is employed to evaluate the aerodynamic pressure. The governing equations of motion are solved by harmonic balance method to study the Vibration amplitude of FGM plates under supersonic air flow. Thereafter, the non-linear equations of motion are solved using Newmark’s time integration technique to understand the Flexural Vibration behavior of FGM plates in time domain (simple harmonic or periodic or quasi-periodic). This work is new in the sense that it deals with the non-linear flutter characteristics of FGM plates under high supersonic airflow accounting for both the geometric and aerodynamic non-linearities. Some parametric study is conducted to understand the influence of these non-linearities on the flutter characteristics of FGM plates.
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large amplitude free Flexural Vibration of rings using finite element approach
International Journal of Non-linear Mechanics, 2003Co-Authors: B.p. Patel, M Ganapathi, D P Makhecha, P ShahAbstract:Here, the large amplitude free Flexural Vibrations of isotropic/laminated orthotropic rings are investigated, using a shear flexible curved beam element based on field consistency principle. A laminated refined beam theory is introduced for developing the element, which satisfies the interface transverse shear stress and displacement continuity, and has a vanishing shear stress on the inner and outer surfaces of the beam. The formulation includes in-plane and rotary inertia effects, and the non-linearity due to the finite deformation of the ring. The governing equations obtained using Lagrange's equations of motion are solved through the direct integration technique. Amplitude-frequency relationships evaluated from the dynamic response history are examined. Detailed numerical results are presented considering various parameters such as radius-to-thickness ratio, circumferential wave number and ovality for isotropic and laminated orthotropic rings. The nature and degree of the participation of various modes in non-linear asymmetric Vibration of oval ring brought out through the present study are useful for accurate modelling of the closed non-circular structures.
Haojiang Zhao - One of the best experts on this subject based on the ideXlab platform.
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Vibration band gaps in double vibrator pillared phononic crystal plate
Journal of Applied Physics, 2016Co-Authors: Haojiang Zhao, Hongwei Guo, Rongqiang Liu, Mingxing Gao, Zongquan DengAbstract:This paper proposes a double-vibrator three-component pillared phononic crystal plate and theoretically studies the properties of Vibration band gaps of this plate. The band structures and the displacement fields of the eigenmodes are calculated by the finite element method. Comparing the transmission power spectrums of the Vibrations in the plate, the Flexural Vibration gap is proved more useful than the longitudinal Vibration gap. The influence of the lattice constant, the height, and diameter of the pillars on the Flexural Vibration gaps are investigated. A supercell composed of the uni-vibrator and the double-vibrator unit cells is also investigated, and the analysis shows that the starting frequencies of the gaps in this supercell structure depend on the features of its pillars. This research can be used in the low frequency Vibration insulation of plate structures.
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Flexural Vibration band gaps in a double side phononic crystal plate
Journal of Applied Physics, 2015Co-Authors: Haojiang Zhao, Hongwei Guo, Zongquan Deng, Rongqiang LiuAbstract:Using the finite element method, we theoretically study the Vibration properties of a phononic crystal plate composed of a square array of composite cylindrical pillars on both sides of a thin homogeneous plate. The dispersion relations, the displacement fields of the eigenmodes, and the power transmission spectra are given to estimate the starting and cutoff frequency of the Flexural Vibration band gaps. We investigate the evolution of the Flexural Vibration band gaps in the double-side phononic crystal plate, with the height and diameter of the pillars on both sides arranged from a symmetrical distribution to an asymmetrical distribution. Numerical results show that the enlargement of the bandwidth of Flexural Vibration band gaps in both symmetrical and asymmetrical double-side phononic crystal plates depends strongly on the rise of the cutoff frequency of the gaps. The two pillars with an asymmetrical heights or diameters divide the first Flexural Vibration band gap into two gaps. These propagation properties of Flexural Vibration in the double-side plate can be utilized to design low-frequency Vibration insulation and band-pass filters.
Jing Qiu - One of the best experts on this subject based on the ideXlab platform.
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Flexural Vibration band gaps in timoshenko beams with locally resonant structures
Journal of Applied Physics, 2006Co-Authors: Yaozong Liu, Gang Wang, Honggang Zhao, Jing QiuAbstract:Flexural Vibration in Timoshenko beams with periodically attached local resonators is studied theoretically and experimentally. The existence of a low frequency Flexural Vibration gap is indicated by the complex band structure calculated with transfer matrix theory for an infinite beam, as well as the frequency response function calculated with the finite element method for a finite Timoshenko beam with finite local resonators. This finite Timoshenko beam was manufactured and Vibration experiments generated an experimental frequency response function curve showing a Vibration gap as expected. The existence of low frequency gaps in Timoshenko beams with local resonators provides a method of Flexural Vibration control of beams.
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complete Flexural Vibration band gaps in membrane like lattice structures
Physics Letters A, 2006Co-Authors: Yaozong Liu, Gang Wang, Jing Qiu, Honggang ZhaoAbstract:The propagation of Flexural Vibration in the periodical membrane-like lattice structure is studied. The band structure calculated with the plane wave expansion method indicates the existence of complete gaps. The frequency response function of a finite periodic structure is simulated with finite element method. Frequency ranges with Vibration attenuation are in good agreement with the gaps found in the band structure. Much larger attenuations are found in the complete gaps comparing to those directional ones. The existence of complete Flexural Vibration gaps in such a lattice structure provides a new idea for Vibration control of thin plates.
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Flexural Vibration band gaps in euler bernoulli beams with locally resonant structures with two degrees of freedom
Physical Review B, 2006Co-Authors: Yaozong Liu, Gang Wang, Honggang Zhao, Jing QiuAbstract:Using the transfer matrix theory, we provided the band structure of Flexural waves in an Euler-Bernoulli beam with locally resonant structures, with two degrees of freedom, i.e., a resonator with vertical and rotational Vibration. The frequency response function of a finite periodic system was calculated by the finite element method. The material damping of rubber makes the gaps wider in the calculation. These theoretical results show a good agreement with those of the experiment. The measured result provides an attenuation of over $20\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$ in the frequency range of the band gaps. The existence of low-frequency band gaps in such a beam provides a method of Flexural Vibration control of beams.
Daisuke Koyama - One of the best experts on this subject based on the ideXlab platform.
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two dimensional noncontact transportation of small objects in air using Flexural Vibration of a plate
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2015Co-Authors: Ryota Kashima, Daisuke Koyama, Mami MatsukawaAbstract:This paper investigates a two-dimensional ultrasonic manipulation technique for small objects in air. The ultrasonic levitation system consists of a rectangular vibrating plate with four ultrasonic transducers and a reflector. The configuration of the vibrator, the resonant frequency, and the positions of the four transducers with step horns were determined from finite element analysis such that an intense acoustic standing-wave field could be generated between the plates. A lattice Flexural Vibration mode with a wavelength of 28.3 mm was excited on the prototype plate at 24.6 kHz. Small objects could get trapped in air along the horizontal nodal plane of the standing wave. By controlling the driving phase difference between the transducers, trapped objects could be transported without contact in a two-dimensional plane. When the phase difference was changed from 0° to 720°, the distance moved by a small particle in the orthogonal direction was approximately 29 mm, which corresponds with the wavelength of the Flexural Vibration on the vibrating plate.
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plate shaped non contact ultrasonic transporter using Flexural Vibration
Ultrasonics, 2014Co-Authors: Takahiko Ishii, Daisuke Koyama, Kentaro Nakamura, Yosuke Mizuno, Kana Harada, Yukiyoshi UchidaAbstract:We developed a plate-shaped non-contact transporter based on ultrasonic Vibration, exploiting a phenomenon that a plate can be statically levitated at the place where its gravity and the acoustic radiation force are balanced. In the experiment, four piezoelectric zirconate titanate elements were attached to aluminum plates, on which lattice Flexural Vibration was excited at 22.3 kHz. The vibrating plates were connected to a loading plate via flexible posts that can minimize the influence of the flexure induced by heavy loads. The distribution of the Vibration displacement on the plate was predicted through finite-element analysis to find the appropriate positions of the posts. The maximum levitation height of this transporter was 256 μm with no load. When two vibrating plates were connected to a loading plate, the maximum transportable load was 4.0 kgf.
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Two-dimensional noncontact transportation of small objects in air using Flexural Vibration of a plate
2014 IEEE International Ultrasonics Symposium, 2014Co-Authors: Ryota Kashima, Daisuke Koyama, Mami MatsukawaAbstract:Noncontact transportation techniques are required in the production process of medicine such as tablets and capsules to solve the problem that the surface of these small objects is polluted and cracked. Our group has been investigating the noncontact transportation technique of small objects in air over long distances using ultrasound. Ultrasound manipulation techniques enable precise positioning for small objects without contact by using high-intensity acoustic standing-wave fields. This report investigates an ultrasound transport of small objects in two dimensions. The configuration of an aluminum vibrating plate and four transducers with a step horn were determined by finite element analysis. A reflector was installed parallel to the vibrator with a distance of approximately 8 mm to generate an acoustic standing wave in air between two plates. The lattice Flexural Vibration mode with the wavelength of 29 mm was excited on the vibrating plate at 24.8 kHz. By controlling the phase differences of transducers, the nodal lines of the Flexural Vibration of the plate and the acoustic standing wave in air could be shifted to x and y directions, which enabled the manipulation of the small particles in two-dimensional plane. When the phase difference was changed from 0 to 720°, the moving distance of a polystyrene particle was approximately 28.0 mm, which corresponds with the wavelength of Flexural Vibration on the vibrating plate.
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ultrasound bubble filter using the Flexural Vibration of a cylinder for an extracorporeal circulation circuit
Sensors and Actuators A-physical, 2013Co-Authors: Koji Mino, Daisuke Koyama, Manami Kataoka, Kenji Yoshida, Kentaro Nakamura, Masayoshi Omori, Shigeki Kawarabata, Masafumi Sato, Yoshiaki WatanabeAbstract:Abstract An ultrasound bubble filter without a mesh structure was developed for extracorporeal circulation. The filter utilizes an ultrasound standing-wave field generated by Flexural Vibration and removes micro air bubbles from the circulation. The ultrasound filter consists of an aluminum cylinder, two annular ultrasound transducers, and three connectors to the flow path. The configuration of the filter was determined through finite element analysis computations. Flexural Vibrations at 46 and 199 kHz were generated in prototypes with lengths of 69 and 130 mm. Two driving modes (both standing-wave and traveling-wave modes) were used to evaluate the filtering characteristics in a water circulation system. The bubble size decreased by increasing the input voltage to the filter; the average diameter changed from 60 to under 10 μm when the input voltage changed from 0 to 200 V. The total volume of air in the main flow estimated from the size distribution of the bubbles decreased to 1% for the 130-mm-long filter excited with the traveling-wave mode.
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Noncontact Ultrasonic Transport of Liquid Using a Flexural Vibration Plate
Applied Physics Express, 2012Co-Authors: Mingjie Ding, Daisuke Koyama, Kentaro NakamuraAbstract:We have succeeded in the noncontact transportation of ethanol droplets inside a semi cylindrical acoustic waveguide. The waveguide was composed of a Vibration bottom plate and a semi cylindrical reflector, and a propagating acoustic field was excited in the waveguide. The droplet was levitated at the nodal position of the standing wave mode in the cross section of the waveguide and transported by the traveling wave component in the horizontal direction. The transportation distance was 65 mm and the terminal velocity reached 2.3 m/s when the droplet was 1.5 mm in diameter and 1.38 g in weight.
Rongqiang Liu - One of the best experts on this subject based on the ideXlab platform.
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Vibration band gaps in double vibrator pillared phononic crystal plate
Journal of Applied Physics, 2016Co-Authors: Haojiang Zhao, Hongwei Guo, Rongqiang Liu, Mingxing Gao, Zongquan DengAbstract:This paper proposes a double-vibrator three-component pillared phononic crystal plate and theoretically studies the properties of Vibration band gaps of this plate. The band structures and the displacement fields of the eigenmodes are calculated by the finite element method. Comparing the transmission power spectrums of the Vibrations in the plate, the Flexural Vibration gap is proved more useful than the longitudinal Vibration gap. The influence of the lattice constant, the height, and diameter of the pillars on the Flexural Vibration gaps are investigated. A supercell composed of the uni-vibrator and the double-vibrator unit cells is also investigated, and the analysis shows that the starting frequencies of the gaps in this supercell structure depend on the features of its pillars. This research can be used in the low frequency Vibration insulation of plate structures.
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Flexural Vibration band gaps in a double side phononic crystal plate
Journal of Applied Physics, 2015Co-Authors: Haojiang Zhao, Hongwei Guo, Zongquan Deng, Rongqiang LiuAbstract:Using the finite element method, we theoretically study the Vibration properties of a phononic crystal plate composed of a square array of composite cylindrical pillars on both sides of a thin homogeneous plate. The dispersion relations, the displacement fields of the eigenmodes, and the power transmission spectra are given to estimate the starting and cutoff frequency of the Flexural Vibration band gaps. We investigate the evolution of the Flexural Vibration band gaps in the double-side phononic crystal plate, with the height and diameter of the pillars on both sides arranged from a symmetrical distribution to an asymmetrical distribution. Numerical results show that the enlargement of the bandwidth of Flexural Vibration band gaps in both symmetrical and asymmetrical double-side phononic crystal plates depends strongly on the rise of the cutoff frequency of the gaps. The two pillars with an asymmetrical heights or diameters divide the first Flexural Vibration band gap into two gaps. These propagation properties of Flexural Vibration in the double-side plate can be utilized to design low-frequency Vibration insulation and band-pass filters.