The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform

Yuming Fang - One of the best experts on this subject based on the ideXlab platform.

  • Thermoelastic damping in flexural vibration of bilayered microbeams with Circular Cross-Section
    Applied Mathematical Modelling, 2020
    Co-Authors: Yuming Fang, Pu Li, Hongyue Zhou
    Abstract:

    Abstract Predicting of thermoelastic damping (TED) is crucial in the design of micro-resonators with composite structures. Several analytical models were developed to evaluate TED in bilayered and three-layered microbeams in the past. However, the previous models focus on the microbeams with rectangular Cross-Section. This paper aims to study the TED in a bilayered microbeam with Circular Cross-Section. The temperature field is approximated by using sine series and Bessel series in the Circular Cross-Section. An analytical full model for TED in flexural vibration of bilayered microbeam is presented in the form of an infinite series. A simple model is also developed by retaining only the first term. The simulation results of the present model have a good agreement with those of the finite element method (FEM). The results indicate that well-resolved two peaks of TED are typically observed in the bilayered microbeams in which the value of k2/C2 is much less or higher than that of k1/C1. The present model is not a rapidly converging infinite series for most of the bilayered microbeams. The present model is more suitable for the long slender beams.

  • Thermoelastic damping in Circular Cross-Section micro/nanobeam resonators with single-phase-lag time
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Hongyue Zhou, Pu Li, Yuming Fang
    Abstract:

    Abstract Estimating thermoelastic damping (TED) is a crucial and significant procedure for the design of the high quality-factor micro/nanobeam resonators operated in vacuum. However, most of the previous TED models were derived by employing the classical thermoelasticity theory established on the Fourier heat conduction. These existing models all focused on beam resonators with rectangular Cross-Section. In this work, employing the generalized thermoelasticity theory of single-phase-lag model, an analytical TED model is derived for Circular Cross-Section micro/nanobeams considering the non-Fourier heat conduction. The influences of non-Fourier effect on TED behaviors and the temperature field of the Circular Cross-Section beam are examined. The single- and multiple-peak phenomena of TED spectrum under the non-Fourier effect are studied. The results indicate that TED in Circular Cross-Section beams is significantly dependent on the equilibrium temperature and the ratio of single-phase-lag time to thermal relaxation time. In addition, the temperature distribution in the beam exhibits distinct differences due to the non-Fourier effect.

  • thermoelastic damping in Circular Cross Section micro nanobeam resonators with single phase lag time
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Hongyue Zhou, Pu Li, Yuming Fang
    Abstract:

    Abstract Estimating thermoelastic damping (TED) is a crucial and significant procedure for the design of the high quality-factor micro/nanobeam resonators operated in vacuum. However, most of the previous TED models were derived by employing the classical thermoelasticity theory established on the Fourier heat conduction. These existing models all focused on beam resonators with rectangular Cross-Section. In this work, employing the generalized thermoelasticity theory of single-phase-lag model, an analytical TED model is derived for Circular Cross-Section micro/nanobeams considering the non-Fourier heat conduction. The influences of non-Fourier effect on TED behaviors and the temperature field of the Circular Cross-Section beam are examined. The single- and multiple-peak phenomena of TED spectrum under the non-Fourier effect are studied. The results indicate that TED in Circular Cross-Section beams is significantly dependent on the equilibrium temperature and the ratio of single-phase-lag time to thermal relaxation time. In addition, the temperature distribution in the beam exhibits distinct differences due to the non-Fourier effect.

  • thermoelastic damping in microrings with Circular Cross Section
    Journal of Sound and Vibration, 2016
    Co-Authors: Pu Li, Yuming Fang, Jianrun Zhang
    Abstract:

    Abstract Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular Cross-Section. The temperature field in the rectangular Cross-Section is one-dimensional. This paper deals with TED in the microrings with Circular Cross-Section. The temperature field in the Circular Cross-Section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with Circular Cross-Section. Only the two-dimensional heat conduction in the Circular Cross-Section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

Hongyue Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Thermoelastic damping in flexural vibration of bilayered microbeams with Circular Cross-Section
    Applied Mathematical Modelling, 2020
    Co-Authors: Yuming Fang, Pu Li, Hongyue Zhou
    Abstract:

    Abstract Predicting of thermoelastic damping (TED) is crucial in the design of micro-resonators with composite structures. Several analytical models were developed to evaluate TED in bilayered and three-layered microbeams in the past. However, the previous models focus on the microbeams with rectangular Cross-Section. This paper aims to study the TED in a bilayered microbeam with Circular Cross-Section. The temperature field is approximated by using sine series and Bessel series in the Circular Cross-Section. An analytical full model for TED in flexural vibration of bilayered microbeam is presented in the form of an infinite series. A simple model is also developed by retaining only the first term. The simulation results of the present model have a good agreement with those of the finite element method (FEM). The results indicate that well-resolved two peaks of TED are typically observed in the bilayered microbeams in which the value of k2/C2 is much less or higher than that of k1/C1. The present model is not a rapidly converging infinite series for most of the bilayered microbeams. The present model is more suitable for the long slender beams.

  • thermoelastic damping in Circular Cross Section micro nanobeam resonators with single phase lag time
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Hongyue Zhou, Pu Li, Yuming Fang
    Abstract:

    Abstract Estimating thermoelastic damping (TED) is a crucial and significant procedure for the design of the high quality-factor micro/nanobeam resonators operated in vacuum. However, most of the previous TED models were derived by employing the classical thermoelasticity theory established on the Fourier heat conduction. These existing models all focused on beam resonators with rectangular Cross-Section. In this work, employing the generalized thermoelasticity theory of single-phase-lag model, an analytical TED model is derived for Circular Cross-Section micro/nanobeams considering the non-Fourier heat conduction. The influences of non-Fourier effect on TED behaviors and the temperature field of the Circular Cross-Section beam are examined. The single- and multiple-peak phenomena of TED spectrum under the non-Fourier effect are studied. The results indicate that TED in Circular Cross-Section beams is significantly dependent on the equilibrium temperature and the ratio of single-phase-lag time to thermal relaxation time. In addition, the temperature distribution in the beam exhibits distinct differences due to the non-Fourier effect.

  • Thermoelastic damping in Circular Cross-Section micro/nanobeam resonators with single-phase-lag time
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Hongyue Zhou, Pu Li, Yuming Fang
    Abstract:

    Abstract Estimating thermoelastic damping (TED) is a crucial and significant procedure for the design of the high quality-factor micro/nanobeam resonators operated in vacuum. However, most of the previous TED models were derived by employing the classical thermoelasticity theory established on the Fourier heat conduction. These existing models all focused on beam resonators with rectangular Cross-Section. In this work, employing the generalized thermoelasticity theory of single-phase-lag model, an analytical TED model is derived for Circular Cross-Section micro/nanobeams considering the non-Fourier heat conduction. The influences of non-Fourier effect on TED behaviors and the temperature field of the Circular Cross-Section beam are examined. The single- and multiple-peak phenomena of TED spectrum under the non-Fourier effect are studied. The results indicate that TED in Circular Cross-Section beams is significantly dependent on the equilibrium temperature and the ratio of single-phase-lag time to thermal relaxation time. In addition, the temperature distribution in the beam exhibits distinct differences due to the non-Fourier effect.

  • A Thermoelastic Damping Model for the Cone Microcantilever Resonator with Circular Cross-Section
    IOP Conference Series: Materials Science and Engineering, 2017
    Co-Authors: Pu Li, Hongyue Zhou
    Abstract:

    Microbeams with variable Cross-Section have been applied in Microelectromechanical Systems (MEMS) resonators. Quality factor (Q-factor) is an important factor evaluating the performance of MEMS resonators, and high Q-factor stands for the excellent performance. Thermoelastic damping (TED), which has been verified as a fundamental energy lost mechanism for microresonators, determines the upper limit of Q-factor. TED can be calculated by the Zener's model and Lifshits and Roukes (LR) model. However, for microbeam resonators with variable Cross-Sections, these two models become invalid in some cases. In this work, we derived the TED model for cone microcantilever with Circular Cross-Section that is a representative non-uniform microbeam. The comparison of results obtained by the present model and Finite Element Method (FEM) model proves that the present model is valid for predicting TED value for cone microcantilever with Circular Cross-Section. The results suggest that the first-order natural frequencies and TED values of cone microcantilever are larger than those of uniform microbeam for large aspect ratios (l/r 0). In addition, the Debye peak value of a uniform microcantilever is equal to 0.5ΔE, while that of cone microcantilever is about 0.438ΔE.

Pu Li - One of the best experts on this subject based on the ideXlab platform.

  • Thermoelastic damping in flexural vibration of bilayered microbeams with Circular Cross-Section
    Applied Mathematical Modelling, 2020
    Co-Authors: Yuming Fang, Pu Li, Hongyue Zhou
    Abstract:

    Abstract Predicting of thermoelastic damping (TED) is crucial in the design of micro-resonators with composite structures. Several analytical models were developed to evaluate TED in bilayered and three-layered microbeams in the past. However, the previous models focus on the microbeams with rectangular Cross-Section. This paper aims to study the TED in a bilayered microbeam with Circular Cross-Section. The temperature field is approximated by using sine series and Bessel series in the Circular Cross-Section. An analytical full model for TED in flexural vibration of bilayered microbeam is presented in the form of an infinite series. A simple model is also developed by retaining only the first term. The simulation results of the present model have a good agreement with those of the finite element method (FEM). The results indicate that well-resolved two peaks of TED are typically observed in the bilayered microbeams in which the value of k2/C2 is much less or higher than that of k1/C1. The present model is not a rapidly converging infinite series for most of the bilayered microbeams. The present model is more suitable for the long slender beams.

  • Thermoelastic damping in Circular Cross-Section micro/nanobeam resonators with single-phase-lag time
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Hongyue Zhou, Pu Li, Yuming Fang
    Abstract:

    Abstract Estimating thermoelastic damping (TED) is a crucial and significant procedure for the design of the high quality-factor micro/nanobeam resonators operated in vacuum. However, most of the previous TED models were derived by employing the classical thermoelasticity theory established on the Fourier heat conduction. These existing models all focused on beam resonators with rectangular Cross-Section. In this work, employing the generalized thermoelasticity theory of single-phase-lag model, an analytical TED model is derived for Circular Cross-Section micro/nanobeams considering the non-Fourier heat conduction. The influences of non-Fourier effect on TED behaviors and the temperature field of the Circular Cross-Section beam are examined. The single- and multiple-peak phenomena of TED spectrum under the non-Fourier effect are studied. The results indicate that TED in Circular Cross-Section beams is significantly dependent on the equilibrium temperature and the ratio of single-phase-lag time to thermal relaxation time. In addition, the temperature distribution in the beam exhibits distinct differences due to the non-Fourier effect.

  • thermoelastic damping in Circular Cross Section micro nanobeam resonators with single phase lag time
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Hongyue Zhou, Pu Li, Yuming Fang
    Abstract:

    Abstract Estimating thermoelastic damping (TED) is a crucial and significant procedure for the design of the high quality-factor micro/nanobeam resonators operated in vacuum. However, most of the previous TED models were derived by employing the classical thermoelasticity theory established on the Fourier heat conduction. These existing models all focused on beam resonators with rectangular Cross-Section. In this work, employing the generalized thermoelasticity theory of single-phase-lag model, an analytical TED model is derived for Circular Cross-Section micro/nanobeams considering the non-Fourier heat conduction. The influences of non-Fourier effect on TED behaviors and the temperature field of the Circular Cross-Section beam are examined. The single- and multiple-peak phenomena of TED spectrum under the non-Fourier effect are studied. The results indicate that TED in Circular Cross-Section beams is significantly dependent on the equilibrium temperature and the ratio of single-phase-lag time to thermal relaxation time. In addition, the temperature distribution in the beam exhibits distinct differences due to the non-Fourier effect.

  • A Thermoelastic Damping Model for the Cone Microcantilever Resonator with Circular Cross-Section
    IOP Conference Series: Materials Science and Engineering, 2017
    Co-Authors: Pu Li, Hongyue Zhou
    Abstract:

    Microbeams with variable Cross-Section have been applied in Microelectromechanical Systems (MEMS) resonators. Quality factor (Q-factor) is an important factor evaluating the performance of MEMS resonators, and high Q-factor stands for the excellent performance. Thermoelastic damping (TED), which has been verified as a fundamental energy lost mechanism for microresonators, determines the upper limit of Q-factor. TED can be calculated by the Zener's model and Lifshits and Roukes (LR) model. However, for microbeam resonators with variable Cross-Sections, these two models become invalid in some cases. In this work, we derived the TED model for cone microcantilever with Circular Cross-Section that is a representative non-uniform microbeam. The comparison of results obtained by the present model and Finite Element Method (FEM) model proves that the present model is valid for predicting TED value for cone microcantilever with Circular Cross-Section. The results suggest that the first-order natural frequencies and TED values of cone microcantilever are larger than those of uniform microbeam for large aspect ratios (l/r 0). In addition, the Debye peak value of a uniform microcantilever is equal to 0.5ΔE, while that of cone microcantilever is about 0.438ΔE.

  • thermoelastic damping in microrings with Circular Cross Section
    Journal of Sound and Vibration, 2016
    Co-Authors: Pu Li, Yuming Fang, Jianrun Zhang
    Abstract:

    Abstract Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular Cross-Section. The temperature field in the rectangular Cross-Section is one-dimensional. This paper deals with TED in the microrings with Circular Cross-Section. The temperature field in the Circular Cross-Section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with Circular Cross-Section. Only the two-dimensional heat conduction in the Circular Cross-Section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

Karl Iagnemma - One of the best experts on this subject based on the ideXlab platform.

  • tracked vehicle with Circular Cross Section to realize sideways motion
    International Conference on Robotics and Automation, 2009
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Steve Peters, Martin Udengaard, Karl Iagnemma
    Abstract:

    In this video, a novel tracked mechanism for sideways motion is presented. The tracked mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional tracked mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.

  • ICRA - Tracked vehicle with Circular Cross-Section to realize sideways motion
    2009 IEEE International Conference on Robotics and Automation, 2009
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Steve Peters, Martin Udengaard, Karl Iagnemma
    Abstract:

    In this video, a novel tracked mechanism for sideways motion is presented. The tracked mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional tracked mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.

  • crawler vehicle with Circular Cross Section unit to realize sideways motion
    Intelligent Robots and Systems, 2008
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Martin Udengaard, Steven C Peters, Karl Iagnemma
    Abstract:

    In this paper, a novel crawler mechanism for sideways motion is presented. The crawler mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional crawler mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.

  • IROS - Crawler vehicle with Circular Cross-Section unit to realize sideways motion
    2008 IEEE RSJ International Conference on Intelligent Robots and Systems, 2008
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Martin Udengaard, Steven C Peters, Karl Iagnemma
    Abstract:

    In this paper, a novel crawler mechanism for sideways motion is presented. The crawler mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional crawler mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.

Kenjiro Tadakuma - One of the best experts on this subject based on the ideXlab platform.

  • tracked vehicle with Circular Cross Section to realize sideways motion
    International Conference on Robotics and Automation, 2009
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Steve Peters, Martin Udengaard, Karl Iagnemma
    Abstract:

    In this video, a novel tracked mechanism for sideways motion is presented. The tracked mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional tracked mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.

  • ICRA - Tracked vehicle with Circular Cross-Section to realize sideways motion
    2009 IEEE International Conference on Robotics and Automation, 2009
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Steve Peters, Martin Udengaard, Karl Iagnemma
    Abstract:

    In this video, a novel tracked mechanism for sideways motion is presented. The tracked mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional tracked mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.

  • crawler vehicle with Circular Cross Section unit to realize sideways motion
    Intelligent Robots and Systems, 2008
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Martin Udengaard, Steven C Peters, Karl Iagnemma
    Abstract:

    In this paper, a novel crawler mechanism for sideways motion is presented. The crawler mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional crawler mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.

  • IROS - Crawler vehicle with Circular Cross-Section unit to realize sideways motion
    2008 IEEE RSJ International Conference on Intelligent Robots and Systems, 2008
    Co-Authors: Kenjiro Tadakuma, Riichiro Tadakuma, Keiji Nagatani, Kazuya Yoshida, Martin Udengaard, Steven C Peters, Karl Iagnemma
    Abstract:

    In this paper, a novel crawler mechanism for sideways motion is presented. The crawler mechanism is of Circular Cross-Section and has active rolling axes at the center of the circles. Conventional crawler mechanisms can support massive loads, but cannot produce sideways motion. Additionally, previous crawler edges sink undesirably on soft ground, particularly when the vehicle body is subject to a sideways tilt. The proposed design solves these drawbacks by adopting a Circular Cross-Section crawler. A prototype has been developed to illustrate the concept. Motion experiments confirm the novel properties of this mechanism: sideways motion and robustness against edge-sink. Motion experiments, with a test vehicle are also presented.