1st Edition

Structural Damping Applications in Seismic Response Modification

    581 Pages 136 B/W Illustrations
    by CRC Press

    Rapid advances have been made during the past few decades in earthquake response modification technologies for structures, most notably in base isolation and energy dissipation systems. Many practical applications of various dampers can be found worldwide and, in the United States, damper design has been included in building codes. The current design process is simple and useful for adding supplemental damping up to a reasonable level—but it is not as useful with higher levels of damping.

    Taking a different approach, Structural Damping: Applications in Seismic Response Modification considers the dynamic responses of structures with added damping devices as systems governed by the combined effect of the static stiffness, period, and damping—or "dynamic stiffness"—of the structure-device system. This formulation supplies additional information for higher-level supplemental damping design that current provisions may not adequately cover. The authors also propose a more comprehensive consideration of the core issues in structural damping, which provides a useful foundation for continued research and development in seismic response modification technologies for performance-based engineering.

    The book includes design examples, based on the authors’ research and practical experience, to illustrate approaches that include higher-level supplemental damping to complement the use of the current NEHRP/ASCE-7 provisions. A self-contained resource on damping design principles, this book helps earthquake engineers select the most effective type of damper and determine the amount and configuration of damping under given working conditions.

    VIBRATION SYSTEMS

    Free and Harmonic Vibration of Single-Degree-of-Freedom Systems
    Model of Linear SDOF Vibration Systems
    Dynamic Magnification
    Energy Dissipation and Effective Damping

    Linear Single-Degree-of-Freedom Systems with Arbitrary Excitations
    Periodic Excitations
    Transient Excitations
    Random Excitations
    Earthquake Responses of SDOF Linear Systems

    Linear Proportionally Damped Multi-Degree-of-Freedom Systems
    Undamped MDOF Systems
    Proportionally Damped MDOF Systems
    Modal Participation and Truncation
    Base Shear and Lateral Force
    Natural Frequency and Mode Shape Estimation
    Coefficient Matrix for Proportional Damping

    Multi-Degree-of-Freedom Systems with General Damping
    State Equation and Conventional Treatment
    Damper Design for Nonproportionally Damped Systems
    Overdamped Subsystems
    Responses of Generally Damped Systems and the Design Spectra
    Modal Participations and Modal Criteria

    PRINCIPLES AND GUIDELINES FOR DAMPING CONTROL

    Principles of Damper Design
    Modeling of Damping
    Rectangular Law, Maximum Energy Dissipation per Device
    Damping Adaptability
    Design and Control Parameters
    Damping Force-Related Issues

    System Nonlinearity and Damping of Irregular Structures
    Nonlinear Systems
    Irregular MDOF System
    Minimizing Damping Nonproportionality
    Role of Damping in Nonlinear Systems

    DESIGN OF SUPPLEMENTAL DAMPING

    Linear Damping Design
    Overview of Design Approaches
    MSSP Systems Simplified Approach
    Proportionally Damped MDOF Systems Approach
    Design of Generally Damped Systems
    Damper Design Issues
    Damper Design Codes
    Brief Summary of Damping Design of Linear Systems

    Nonlinear Damping
    Overview of Design Approaches
    Equivalent Linear Systems Approach with Bilinear Dampers
    Equivalent Linear Systems Approach with Sublinear Dampers
    Nonlinear Response Spectra Approach with Sublinear Dampers
    Nonlinear Response Spectra Approach with Bilinear Dampers

    Index

    Chapters include a summary and references.

    Biography

    Dr. Zach Liang is a research professor in the Department of Mechanical and Aerospace Engineering at the State University of New York at Buffalo.

    Dr. George C. Lee is a SUNY Distinguished Professor in the Department of Civil, Structural and Environmental Engineering at the State University of New York at Buffalo.

    Dr. Gary F. Dargush is Professor and Chair of the Department of Mechanical and Aerospace Engineering (MAE) at the State University of New York at Buffalo.

    Dr. Jianwei Song is a senior research scientist in the Multidisciplinary Center for Earthquake Engineering Research in the Department of Civil, Structural and Environmental Engineering at the State University of New York at Buffalo.