The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
G. Ravichandran - One of the best experts on this subject based on the ideXlab platform.
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Heterodyne Diffracted Beam Photonic Doppler Velocimeter (DPDV) for Pressure-Shear Shock Experiments
Dynamic Behavior of Materials Volume 1, 2018Co-Authors: Michael Mello, Christian Kettenbeil, Moriah Bischann, Zev Lovinger, G. RavichandranAbstract:We present details on the design and validation of a heterodyne diffracted beam photonic Doppler velocimeter (DPDV) for pressure-shear plate impact (PSPI) shock experiments. The fiber optic interferometer collects symmetrically diffracted 1st order beams produced by a thin, specular, metallic grating deposited on the rear surface of the impacted target plate and separately interferes each of these beams with a reference beam of a slightly increased wavelength. The resulting interference signals contain an upshifted carrier signal with a constant frequency at zero Particle Velocity. Signal frequency content in recorded waveforms from PSPI experiments is extracted using a moving-window DFT algorithm and then linearly combined in a post- processing step to decouple and extract the Normal and transverse Velocity history of the rear target surface. The 0th order (Normally reflected) beam can also be interfered in a separate heterodyne PDV configuration to obtain an additional, independent measurement of the Normal Particle Velocity. An overview of the DPDV configuration is presented along with a discussion of the interferometer sensitivities to transverse and Normal Particle velocities. Results from a Normal impact experiment conducted on Y-cut quartz are presented as experimental validation of the technique.
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Heterodyne transverse velocimetry for pressure-shear plate impact experiments
Journal of Applied Physics, 2018Co-Authors: Christian Kettenbeil, Michael Mello, Moriah Bischann, G. RavichandranAbstract:Pressure-shear plate impact experiments have traditionally relied on free space beam interferometers to measure transverse and Normal Particle velocities at the rear surface of the target plate. Here, we present two different interferometry schemes that leverage heterodyne techniques, which enable the simultaneous measurement of Normal and transverse velocities using short-time Fourier transforms. Both techniques rely on diffracted 1st order beams that are generated by a specular, metallic grating deposited on the rear surface of the target plate. The diffracted beam photonic Doppler velocimetry technique interferes each 1st order beam with a reference of slightly higher wavelength to create a constant carrier frequency at zero Particle Velocity. The second technique interferes the 1st order beams with each other and employs an acousto-optic frequency shifter on the +1st order beam to create a heterodyne transverse velocimeter. For both interferometer techniques, the 0th order beam is interfered in a heterodyne photonic Doppler velocimetry arrangement to obtain a measurement of the Normal Particle Velocity. An overview of both configurations is presented along with a derivation of the interferometer sensitivities to transverse and Normal Particle velocities as well as design guidelines for the optical system. Results from Normal impact experiments conducted on Y-cut quartz are presented as the experimental validation of the two proposed techniques.
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Heterodyne diffracted beam photonic Doppler velocimeter (DPDV) for measurement of transverse and Normal Particle velocities in pressure-shear plate impact experiments
2018Co-Authors: Michael Mello, Christian Kettenbeil, Moriah Bischann, G. RavichandranAbstract:Pressure-shear plate impact (PSPI) experiments have traditionally relied on free space beam interferometers such as the transverse displacement interferometer (TDI) and Normal displacement interferometer (NDI) or Normal Velocity interferometer (NVI), to measure transverse and Normal velocities at the rear surface of the target plate [1]. Alternative interferometer schemes feature a dual beam VISAR arrangement [2] and a recently developed all fiber-optic TDI-NDI/PDV configuration [3]. Here, we present a heterodyne diffracted beam PDV (DPDV) which interferes a pair of symmetrically diffracted 1st order beams produced by a thin, specular, metallic grating deposited on the rear surface of the target plate. Each beam is collected by a fiber-optic probe and directed to interfere with a reference beam of a slightly increased wavelength to create an upshifted carrier signal frequency at zero Particle Velocity. Signal frequencies are extracted from the two fringe records using a moving-window DFT algorithm and then linearly combined in a post processing step to decouple the Normal and transverse velocities. The 0th order beam can also be interfered in a heterodyne PDV to obtain an additional independent measurement of the Normal Particle Velocity [4]. An overview of the DPDV configuration is presented along with a derivation of the interferometer sensitivities to transverse and Normal Particle velocities. Results from a Normal impact experiment conducted on y-cut α-quartz are presented as experimental validation.
Lin Geng - One of the best experts on this subject based on the ideXlab platform.
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Reconstructing non-stationary surface Normal Velocity of a planar structure using pressure-Velocity probes
Applied Acoustics, 2018Co-Authors: Lin Geng, Feng XieAbstract:Abstract An acoustic method based on the time domain plane wave superposition method is proposed to reconstruct the non-stationary surface Normal Velocity of an impacted planar structure by measuring the Normal Particle Velocity. In this method, the time-evolving Normal Particle Velocity on the hologram plane is first measured by pressure-Velocity probes; then, the Normal Particle Velocity spectrum on a virtual source plane is used to establish the relationship between the time-evolving Normal Particle Velocity on the hologram plane and the time-evolving surface Normal Velocity on the structural plane; finally, the Normal Particle Velocity spectrums can be solved by an iterative solving process and are used to calculate the non-stationary surface Normal Velocity of the planar structure. An experiment of a planar steel plate impacted by a steel ball is presented to examine the ability of the proposed method, where the time-evolving Normal Particle Velocity and pressure on the hologram plane measured by pressure-Velocity probes are used as the inputs of the proposed method and the pressure-based reconstruction method, respectively, and a laser Doppler vibrometry is used to measure the surface Normal Velocity of the plate as the reference for comparisons. The comparison results demonstrate that the proposed method is effective in reconstructing the non-stationary surface Normal Velocity in both time and space domains and can provide more accurate results than that of the pressure-based reconstruction method.
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Reconstruction of instantaneous surface Normal Velocity of a vibrating structure using interpolated time-domain equivalent source method
Mechanical Systems and Signal Processing, 2018Co-Authors: Lin Geng, Feng Xie, Xiao-zheng ZhangAbstract:Abstract Interpolated time-domain equivalent source method is extended to reconstruct the instantaneous surface Normal Velocity of a vibrating structure by using the time-evolving Particle Velocity as the input, which provides a non-contact way to overall understand the instantaneous vibration behavior of the structure. In this method, the time-evolving Particle Velocity in the near field is first modeled by a set of equivalent sources positioned inside the vibrating structure, and then the integrals of equivalent source strengths are solved by an iterative solving process and are further used to calculate the instantaneous surface Normal Velocity. An experiment of a semi-cylindrical steel plate impacted by a steel ball is investigated to examine the ability of the extended method, where the time-evolving Normal Particle Velocity and pressure on the hologram surface measured by a Microflown pressure-Velocity probe are used as the inputs of the extended method and the method based on pressure measurements, respectively, and the instantaneous surface Normal Velocity of the plate measured by a laser Doppler vibrometry is used as the reference for comparison. The experimental results demonstrate that the extended method is a powerful tool to visualize the instantaneous surface Normal Velocity of a vibrating structure in both time and space domains and can obtain more accurate results than that of the method based on pressure measurements.
Xiao-zheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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Reconstruction of instantaneous surface Normal Velocity of a vibrating structure using interpolated time-domain equivalent source method
Mechanical Systems and Signal Processing, 2018Co-Authors: Lin Geng, Feng Xie, Xiao-zheng ZhangAbstract:Abstract Interpolated time-domain equivalent source method is extended to reconstruct the instantaneous surface Normal Velocity of a vibrating structure by using the time-evolving Particle Velocity as the input, which provides a non-contact way to overall understand the instantaneous vibration behavior of the structure. In this method, the time-evolving Particle Velocity in the near field is first modeled by a set of equivalent sources positioned inside the vibrating structure, and then the integrals of equivalent source strengths are solved by an iterative solving process and are further used to calculate the instantaneous surface Normal Velocity. An experiment of a semi-cylindrical steel plate impacted by a steel ball is investigated to examine the ability of the extended method, where the time-evolving Normal Particle Velocity and pressure on the hologram surface measured by a Microflown pressure-Velocity probe are used as the inputs of the extended method and the method based on pressure measurements, respectively, and the instantaneous surface Normal Velocity of the plate measured by a laser Doppler vibrometry is used as the reference for comparison. The experimental results demonstrate that the extended method is a powerful tool to visualize the instantaneous surface Normal Velocity of a vibrating structure in both time and space domains and can obtain more accurate results than that of the method based on pressure measurements.
Christian Kettenbeil - One of the best experts on this subject based on the ideXlab platform.
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Heterodyne Diffracted Beam Photonic Doppler Velocimeter (DPDV) for Pressure-Shear Shock Experiments
Dynamic Behavior of Materials Volume 1, 2018Co-Authors: Michael Mello, Christian Kettenbeil, Moriah Bischann, Zev Lovinger, G. RavichandranAbstract:We present details on the design and validation of a heterodyne diffracted beam photonic Doppler velocimeter (DPDV) for pressure-shear plate impact (PSPI) shock experiments. The fiber optic interferometer collects symmetrically diffracted 1st order beams produced by a thin, specular, metallic grating deposited on the rear surface of the impacted target plate and separately interferes each of these beams with a reference beam of a slightly increased wavelength. The resulting interference signals contain an upshifted carrier signal with a constant frequency at zero Particle Velocity. Signal frequency content in recorded waveforms from PSPI experiments is extracted using a moving-window DFT algorithm and then linearly combined in a post- processing step to decouple and extract the Normal and transverse Velocity history of the rear target surface. The 0th order (Normally reflected) beam can also be interfered in a separate heterodyne PDV configuration to obtain an additional, independent measurement of the Normal Particle Velocity. An overview of the DPDV configuration is presented along with a discussion of the interferometer sensitivities to transverse and Normal Particle velocities. Results from a Normal impact experiment conducted on Y-cut quartz are presented as experimental validation of the technique.
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Heterodyne transverse velocimetry for pressure-shear plate impact experiments
Journal of Applied Physics, 2018Co-Authors: Christian Kettenbeil, Michael Mello, Moriah Bischann, G. RavichandranAbstract:Pressure-shear plate impact experiments have traditionally relied on free space beam interferometers to measure transverse and Normal Particle velocities at the rear surface of the target plate. Here, we present two different interferometry schemes that leverage heterodyne techniques, which enable the simultaneous measurement of Normal and transverse velocities using short-time Fourier transforms. Both techniques rely on diffracted 1st order beams that are generated by a specular, metallic grating deposited on the rear surface of the target plate. The diffracted beam photonic Doppler velocimetry technique interferes each 1st order beam with a reference of slightly higher wavelength to create a constant carrier frequency at zero Particle Velocity. The second technique interferes the 1st order beams with each other and employs an acousto-optic frequency shifter on the +1st order beam to create a heterodyne transverse velocimeter. For both interferometer techniques, the 0th order beam is interfered in a heterodyne photonic Doppler velocimetry arrangement to obtain a measurement of the Normal Particle Velocity. An overview of both configurations is presented along with a derivation of the interferometer sensitivities to transverse and Normal Particle velocities as well as design guidelines for the optical system. Results from Normal impact experiments conducted on Y-cut quartz are presented as the experimental validation of the two proposed techniques.
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Heterodyne diffracted beam photonic Doppler velocimeter (DPDV) for measurement of transverse and Normal Particle velocities in pressure-shear plate impact experiments
2018Co-Authors: Michael Mello, Christian Kettenbeil, Moriah Bischann, G. RavichandranAbstract:Pressure-shear plate impact (PSPI) experiments have traditionally relied on free space beam interferometers such as the transverse displacement interferometer (TDI) and Normal displacement interferometer (NDI) or Normal Velocity interferometer (NVI), to measure transverse and Normal velocities at the rear surface of the target plate [1]. Alternative interferometer schemes feature a dual beam VISAR arrangement [2] and a recently developed all fiber-optic TDI-NDI/PDV configuration [3]. Here, we present a heterodyne diffracted beam PDV (DPDV) which interferes a pair of symmetrically diffracted 1st order beams produced by a thin, specular, metallic grating deposited on the rear surface of the target plate. Each beam is collected by a fiber-optic probe and directed to interfere with a reference beam of a slightly increased wavelength to create an upshifted carrier signal frequency at zero Particle Velocity. Signal frequencies are extracted from the two fringe records using a moving-window DFT algorithm and then linearly combined in a post processing step to decouple the Normal and transverse velocities. The 0th order beam can also be interfered in a heterodyne PDV to obtain an additional independent measurement of the Normal Particle Velocity [4]. An overview of the DPDV configuration is presented along with a derivation of the interferometer sensitivities to transverse and Normal Particle velocities. Results from a Normal impact experiment conducted on y-cut α-quartz are presented as experimental validation.
Feng Xie - One of the best experts on this subject based on the ideXlab platform.
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Reconstructing non-stationary surface Normal Velocity of a planar structure using pressure-Velocity probes
Applied Acoustics, 2018Co-Authors: Lin Geng, Feng XieAbstract:Abstract An acoustic method based on the time domain plane wave superposition method is proposed to reconstruct the non-stationary surface Normal Velocity of an impacted planar structure by measuring the Normal Particle Velocity. In this method, the time-evolving Normal Particle Velocity on the hologram plane is first measured by pressure-Velocity probes; then, the Normal Particle Velocity spectrum on a virtual source plane is used to establish the relationship between the time-evolving Normal Particle Velocity on the hologram plane and the time-evolving surface Normal Velocity on the structural plane; finally, the Normal Particle Velocity spectrums can be solved by an iterative solving process and are used to calculate the non-stationary surface Normal Velocity of the planar structure. An experiment of a planar steel plate impacted by a steel ball is presented to examine the ability of the proposed method, where the time-evolving Normal Particle Velocity and pressure on the hologram plane measured by pressure-Velocity probes are used as the inputs of the proposed method and the pressure-based reconstruction method, respectively, and a laser Doppler vibrometry is used to measure the surface Normal Velocity of the plate as the reference for comparisons. The comparison results demonstrate that the proposed method is effective in reconstructing the non-stationary surface Normal Velocity in both time and space domains and can provide more accurate results than that of the pressure-based reconstruction method.
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Reconstruction of instantaneous surface Normal Velocity of a vibrating structure using interpolated time-domain equivalent source method
Mechanical Systems and Signal Processing, 2018Co-Authors: Lin Geng, Feng Xie, Xiao-zheng ZhangAbstract:Abstract Interpolated time-domain equivalent source method is extended to reconstruct the instantaneous surface Normal Velocity of a vibrating structure by using the time-evolving Particle Velocity as the input, which provides a non-contact way to overall understand the instantaneous vibration behavior of the structure. In this method, the time-evolving Particle Velocity in the near field is first modeled by a set of equivalent sources positioned inside the vibrating structure, and then the integrals of equivalent source strengths are solved by an iterative solving process and are further used to calculate the instantaneous surface Normal Velocity. An experiment of a semi-cylindrical steel plate impacted by a steel ball is investigated to examine the ability of the extended method, where the time-evolving Normal Particle Velocity and pressure on the hologram surface measured by a Microflown pressure-Velocity probe are used as the inputs of the extended method and the method based on pressure measurements, respectively, and the instantaneous surface Normal Velocity of the plate measured by a laser Doppler vibrometry is used as the reference for comparison. The experimental results demonstrate that the extended method is a powerful tool to visualize the instantaneous surface Normal Velocity of a vibrating structure in both time and space domains and can obtain more accurate results than that of the method based on pressure measurements.
