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Chungche Chou - One of the best experts on this subject based on the ideXlab platform.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco-Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco–Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs. Copyright © 2005 John Wiley & Sons, Ltd.

Chiaming Uang - One of the best experts on this subject based on the ideXlab platform.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco-Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco–Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs. Copyright © 2005 John Wiley & Sons, Ltd.

Cole C Mcdaniel - One of the best experts on this subject based on the ideXlab platform.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco-Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco–Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs. Copyright © 2005 John Wiley & Sons, Ltd.

Frieder Seible - One of the best experts on this subject based on the ideXlab platform.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco-Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs.

  • performance evaluation of shear links and orthotropic bridge deck panels for the new san francisco oakland bay bridge
    Earthquake Engineering & Structural Dynamics, 2005
    Co-Authors: Chiaming Uang, Frieder Seible, Cole C Mcdaniel, Chungche Chou
    Abstract:

    This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the Design of the new East Span for the San Francisco–Oakland Bay Bridge. Cyclic testing of full-scale built-up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500-year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic Design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced-scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the Design Earthquake. The post-buckling behavior was associated with the buckling direction and the type of ribs. Copyright © 2005 John Wiley & Sons, Ltd.

Izuru Takewaki - One of the best experts on this subject based on the ideXlab platform.

  • scaling of Design Earthquake ground motions for tall buildings based on drift and input energy demands
    Earthquakes and Structures, 2011
    Co-Authors: Izuru Takewaki, H Tsujimoto
    Abstract:

    Rational scaling of Design Earthquake ground motions for tall buildings is essential for safer, risk-based Design of tall buildings. This paper provides the structural Designers with an insight for more rational scaling based on drift and input energy demands. Since a resonant sinusoidal motion can be an approximate critical excitation to elastic and inelastic structures under the constraint of acceleration or velocity power, a resonant sinusoidal motion with variable period and duration is used as an input wave of the near-field and far-field ground motions. This enables one to understand clearly the relation of the intensity normalization index of ground motion (maximum acceleration, maximum velocity, acceleration power, velocity power) with the response performance (peak interstory drift, total input energy). It is proved that, when the maximum ground velocity is adopted as the normalization index, the maximum interstory drift exhibits a stable property irrespective of the number of stories. It is further shown that, when the velocity power is adopted as the normalization index, the total input energy exhibits a stable property irrespective of the number of stories. It is finally concluded that the former property on peak drift can hold for the practical Design response spectrum-compatible ground motions.

  • response of nonlinear single degree of freedom structures to random acceleration sequences
    Engineering Structures, 2011
    Co-Authors: Abbas Moustafa, Izuru Takewaki
    Abstract:

    Current seismic codes specify Design Earthquake loads as single events. The structure, however, may experience multiple ground accelerations in a short period of time. The evidence from recent Earthquakes confirms this scenario. For instance, the 2004 Niigata Earthquake consisted of two acceleration sequences. An Earthquake of repeated sequences can cause more damage to the structure than a single ordinary event, due to the accumulation of inelastic deformations. However, information on repeated acceleration sequences is currently limited. This paper proposes a simple stochastic model for representing repeated acceleration sequences. Subsequently, the model is used in investigating the response of nonlinear single-degree-of-freedom (SDOF) structures to random Earthquakes of repeated sequences. The ground acceleration is represented as a stationary Gaussian random process modulated by an envelope function of repeated character. The structural response is quantified in terms of the input and hysteretic energies, ductility demand, damage indices and failure probability. Numerical demonstrations of the response of nonlinear SDOF systems to acceleration sequences are provided.

  • critical excitation methods in Earthquake engineering
    2006
    Co-Authors: Izuru Takewaki
    Abstract:

    After the March 11, 2011, Earthquake in Japan, there is overwhelming interest in worst-case analysis, including the critical excitation method. Nowadays, seismic Design of structures performed by any seismic code is based on resisting previous natural Earthquakes. Critical Excitation Methods in Earthquake Engineering, 2e, develops a new framework for modeling Design Earthquake loads for inelastic structures. The 2e, includes three new chapters covering the critical excitation problem for multi-component input ground motions, and that for elastic-plastic structures in a more direct way are incorporated and discussed in more depth. Finally, the problem of Earthquake resilience of super high-rise buildings is discussed from broader viewpoints. Solves problems of Earthquake resilience of super high-rise buildings Three new chapters on critical excitation problem for multi-component input ground motions Includes numerical examples of one and two-story models

  • nonstationary random critical excitation for acceleration response
    Journal of Engineering Mechanics-asce, 2001
    Co-Authors: Izuru Takewaki
    Abstract:

    The critical excitation method is promising as a robust method for accounting for inherent uncertainties in predicting forthcoming Earthquake events and for constructing Design Earthquake ground motions in a reasonable way. Most of the proposed theories are based on deterministic approaches and deal with displacement responses. A stochastic acceleration response index is treated here as the objective function to be maximized. The power (area of power spectral density function) and the intensity (magnitude of power spectral density function) are fixed and the critical excitation is found under these restrictions. It is shown that the original idea for stationary random inputs can be utilized effectively in the procedure for finding a critical excitation for nonstationary acceleration responses of nonproportionally damped structural systems. Several numerical examples are presented to demonstrate the characteristics of generalized time-varying frequency response functions for models with various stiffness and damping distributions.

  • nonstationary random critical excitation for nonproportionally damped structural systems
    Computer Methods in Applied Mechanics and Engineering, 2001
    Co-Authors: Izuru Takewaki
    Abstract:

    During the last three decades, the critical excitation methods have been developed extensively to account for inherent uncertainties in predicting forthcoming Earthquake events and to construct Design Earthquake ground motions in a reasonable way. Most of the proposed theories are based on deterministic approaches. In contrast to the conventional critical excitation methods, a stochastic response index is treated in this paper as the objective function to be maximized. The power (area of power spectral density, PSD, function) and the intensity (magnitude of PSD function) are fixed and the critical excitation is found under these restrictions. It is shown that the original idea for stationary random inputs can be utilized effectively in the procedure for finding a critical excitation for nonstationary random vibrations of nonproportionally damped structural systems. The key for finding the new nonstationary random critical excitation is the exchange of the order of the double maximization procedures with respect to time and to the PSD function.