The Experts below are selected from a list of 1593 Experts worldwide ranked by ideXlab platform

Daniel Hochlenert - One of the best experts on this subject based on the ideXlab platform.

  • nonlinear stability analysis of a Disk Brake model
    Nonlinear Dynamics, 2009
    Co-Authors: Daniel Hochlenert
    Abstract:

    It has become commonly accepted by scientists and engineers that Brake squeal is generated by friction-induced self-excited vibrations of the Brake system. The noise-free configuration of the Brake system loses stability through a flutter-type instability and the system starts oscillating in a limit cycle. Usually, the stability analysis of Disk Brake models, both analytical as well as finite element based, investigates the linearized models, i.e. the eigenvalues of the linearized equations of motion. However, there are experimentally observed effects not covered by these analyses, even though the full nonlinear models include these effects in principle.

  • minimal models for Disk Brake squeal
    Journal of Sound and Vibration, 2007
    Co-Authors: Utz Von Wagner, Daniel Hochlenert, Peter Hagedorn
    Abstract:

    Numerous publications on the modeling of Disk Brake squeal can be found in the literature. Recent publications describe the onset of Disk Brake squeal as an instability of the trivial solution resulting from the non-conservative friction forces even for a constant friction coefficient. Therefore, a minimal model of Disk Brake squeal must contain at least two degrees of freedom. A literature review of minimal models shows that there is still a lack of a minimal model describing the basic behavior of Disk Brake squeal which can easily be associated to an automotive Disk Brake. Therefore, a new minimal model of a Disk Brake is introduced here, showing an obvious relation to the technical system. In this model, the vibration of the Disk is taken into account, as it plays a dominant role in Brake squeal. The model is analyzed with respect to its stability behavior, and consequences in using it in the optimization of Disk Brake systems are discussed.

  • Disk Brake squeal: Modeling and active control
    2006 IEEE Conference on Robotics Automation and Mechatronics, 2006
    Co-Authors: Thira Jearsiripongkul, Daniel Hochlenert
    Abstract:

    Considerable effort is spent in the design and testing of Disk Brakes of modern passenger cars. This effort can be reduced if refined mathematical-mechanical models are used for studying the dynamics of these Brakes before prototypes are available. The present paper is devoted to the modeling of a floating caliper Disk Brake, special regard being given to the suppression of squeal. A simplified model for the dynamics of a floating caliper Disk Brake is presented. The model includes the Brake Disk, modeled as a flexible rotating plate, caliper and Brake pads. In the model all the prominent features of squeal are reproduced, such as e.g. independence of the frequency on the speed, etc. For a moderately wide frequency range (1-5 kHz) the transverse vibration of the Disk plays a significant role in squeal. The pad stiffness and damping coefficient are modeled by distributed nonlinear springs and linear dampers, respectively. In a test rig built in Darmstadt, the model is validated. In addition, the set-up also permits active control of some of the Brake's parameters. So far all the experimental results seem to agree very well with our model. © 2006 IEEE.

Hirokazu Takagi - One of the best experts on this subject based on the ideXlab platform.

  • Computational thermo-fluid analysis of a Disk Brake
    Computational Mechanics, 2016
    Co-Authors: Kenji Takizawa, Takashi Kuraishi, Shinichiro Tabata, Tayfun E. Tezduyar, Hirokazu Takagi
    Abstract:

    We present computational thermo-fluid analysis of a Disk Brake, including thermo-fluid analysis of the flow around the Brake and heat conduction analysis of the Disk. The computational challenges include proper representation of the small-scale thermo-fluid behavior, high-resolution representation of the thermo-fluid boundary layers near the spinning solid surfaces, and bringing the heat transfer coefficient (HTC) calculated in the thermo-fluid analysis of the flow to the heat conduction analysis of the spinning Disk. The Disk Brake model used in the analysis closely represents the actual configuration, and this adds to the computational challenges. The components of the method we have developed for computational analysis of the class of problems with these types of challenges include the Space---Time Variational Multiscale method for coupled incompressible flow and thermal transport, ST Slip Interface method for high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces, and a set of projection methods for different parts of the Disk to bring the HTC calculated in the thermo-fluid analysis. With the HTC coming from the thermo-fluid analysis of the flow around the Brake, we do the heat conduction analysis of the Disk, from the start of the breaking until the Disk spinning stops, demonstrating how the method developed works in computational analysis of this complex and challenging problem.

  • Computational thermo-fluid analysis of a Disk Brake
    Computational Mechanics, 2016
    Co-Authors: Kenji Takizawa, Takashi Kuraishi, Shinichiro Tabata, Tayfun E. Tezduyar, Hirokazu Takagi
    Abstract:

    © 2016 Springer-Verlag Berlin Heidelberg We present computational thermo-fluid analysis of a Disk Brake, including thermo-fluid analysis of the flow around the Brake and heat conduction analysis of the Disk. The computational challenges include proper representation of the small-scale thermo-fluid behavior, high-resolution representation of the thermo-fluid boundary layers near the spinning solid surfaces, and bringing the heat transfer coefficient (HTC) calculated in the thermo-fluid analysis of the flow to the heat conduction analysis of the spinning Disk. The Disk Brake model used in the analysis closely represents the actual configuration, and this adds to the computational challenges. The components of the method we have developed for computational analysis of the class of problems with these types of challenges include the Space–Time Variational Multiscale method for coupled incompressible flow and thermal transport, ST Slip Interface method for high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces, and a set of projection methods for different parts of the Disk to bring the HTC calculated in the thermo-fluid analysis. With the HTC coming from the thermo-fluid analysis of the flow around the Brake, we do the heat conduction analysis of the Disk, from the start of the breaking until the Disk spinning stops, demonstrating how the method developed works in computational analysis of this complex and challenging problem.

Kenji Takizawa - One of the best experts on this subject based on the ideXlab platform.

  • Computational thermo-fluid analysis of a Disk Brake
    Computational Mechanics, 2016
    Co-Authors: Kenji Takizawa, Takashi Kuraishi, Shinichiro Tabata, Tayfun E. Tezduyar, Hirokazu Takagi
    Abstract:

    We present computational thermo-fluid analysis of a Disk Brake, including thermo-fluid analysis of the flow around the Brake and heat conduction analysis of the Disk. The computational challenges include proper representation of the small-scale thermo-fluid behavior, high-resolution representation of the thermo-fluid boundary layers near the spinning solid surfaces, and bringing the heat transfer coefficient (HTC) calculated in the thermo-fluid analysis of the flow to the heat conduction analysis of the spinning Disk. The Disk Brake model used in the analysis closely represents the actual configuration, and this adds to the computational challenges. The components of the method we have developed for computational analysis of the class of problems with these types of challenges include the Space---Time Variational Multiscale method for coupled incompressible flow and thermal transport, ST Slip Interface method for high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces, and a set of projection methods for different parts of the Disk to bring the HTC calculated in the thermo-fluid analysis. With the HTC coming from the thermo-fluid analysis of the flow around the Brake, we do the heat conduction analysis of the Disk, from the start of the breaking until the Disk spinning stops, demonstrating how the method developed works in computational analysis of this complex and challenging problem.

  • Computational thermo-fluid analysis of a Disk Brake
    Computational Mechanics, 2016
    Co-Authors: Kenji Takizawa, Takashi Kuraishi, Shinichiro Tabata, Tayfun E. Tezduyar, Hirokazu Takagi
    Abstract:

    © 2016 Springer-Verlag Berlin Heidelberg We present computational thermo-fluid analysis of a Disk Brake, including thermo-fluid analysis of the flow around the Brake and heat conduction analysis of the Disk. The computational challenges include proper representation of the small-scale thermo-fluid behavior, high-resolution representation of the thermo-fluid boundary layers near the spinning solid surfaces, and bringing the heat transfer coefficient (HTC) calculated in the thermo-fluid analysis of the flow to the heat conduction analysis of the spinning Disk. The Disk Brake model used in the analysis closely represents the actual configuration, and this adds to the computational challenges. The components of the method we have developed for computational analysis of the class of problems with these types of challenges include the Space–Time Variational Multiscale method for coupled incompressible flow and thermal transport, ST Slip Interface method for high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces, and a set of projection methods for different parts of the Disk to bring the HTC calculated in the thermo-fluid analysis. With the HTC coming from the thermo-fluid analysis of the flow around the Brake, we do the heat conduction analysis of the Disk, from the start of the breaking until the Disk spinning stops, demonstrating how the method developed works in computational analysis of this complex and challenging problem.

In Lee - One of the best experts on this subject based on the ideXlab platform.

  • finite element analysis of transient thermoelastic behaviors in Disk Brakes
    Wear, 2004
    Co-Authors: Jihoon Choi, In Lee
    Abstract:

    Abstract A transient analysis for thermoelastic contact problem of Disk Brakes with frictional heat generation is performed using the finite element method. To analyze the thermoelastic phenomenon occurring in Disk Brakes, the coupled heat conduction and elastic equations are solved with contact problems. The numerical simulation for the thermoelastic behavior of Disk Brake is obtained in the repeated Brake condition. The computational results are presented for the distributions of pressure and temperature on each friction surface between the contacting bodies. Also, thermoelastic instability (TEI) phenomenon (the unstable growth of contact pressure and temperature) is investigated in the present study, and the influence of the material properties on the thermoelastic behaviors (the maximum temperature and contact ratio on the friction surfaces) is investigated to facilitate the conceptual design of the Disk Brake system. Based on these numerical results, the thermoelastic behaviors of the carbon–carbon composites with excellent mechanical and thermal properties are also discussed.

Thira Jearsiripongkul - One of the best experts on this subject based on the ideXlab platform.

  • Disk Brake squeal: Modeling and active control
    2006 IEEE Conference on Robotics Automation and Mechatronics, 2006
    Co-Authors: Thira Jearsiripongkul, Daniel Hochlenert
    Abstract:

    Considerable effort is spent in the design and testing of Disk Brakes of modern passenger cars. This effort can be reduced if refined mathematical-mechanical models are used for studying the dynamics of these Brakes before prototypes are available. The present paper is devoted to the modeling of a floating caliper Disk Brake, special regard being given to the suppression of squeal. A simplified model for the dynamics of a floating caliper Disk Brake is presented. The model includes the Brake Disk, modeled as a flexible rotating plate, caliper and Brake pads. In the model all the prominent features of squeal are reproduced, such as e.g. independence of the frequency on the speed, etc. For a moderately wide frequency range (1-5 kHz) the transverse vibration of the Disk plays a significant role in squeal. The pad stiffness and damping coefficient are modeled by distributed nonlinear springs and linear dampers, respectively. In a test rig built in Darmstadt, the model is validated. In addition, the set-up also permits active control of some of the Brake's parameters. So far all the experimental results seem to agree very well with our model. © 2006 IEEE.

  • A Simplified Model of The Floating Caliper Disk Brake With Respect to High Frequency Noise
    Thammasat International Journal of Science and Technology, 2006
    Co-Authors: Thira Jearsiripongkul
    Abstract:

    High frequency noise from a vehicle is always a concern for any automotive industry looking for passenger comfort. This also holds for the different types of Brake noise, which is a source of discomfort both to passengers and passers-by. Intensive research on high frequency noise (between 15 kHz) has been carried out. A simplified model of the floating caliper Disk Brake has been proposed by the author with the aim to predict the onset of high frequency noise. Many possible grounds have been put for the reasons behind this high frequency noise, for example, stick-slip phenomenon, geometry instability, and flutter type instability. Flutter type instability resulting from nonconservative restoring forces is assumed to be the reason behind this panicular noise in this model. The stability of the model is studied in term of the friction coefficient between the Brake Disk and the Brake pad. Some parameters, such as braking pressure, damping coefficient of the Brake lining, and rotational speed of the Brake Disk, are also examined and compared with the stability of the system.