Nonlinear Seismic Analysis of Circular Concrete-Filled Steel Tube Members and Frames

Abstract

The Newmark Structural Engineering Laboratory (NSEL) of the Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign has a long history of excellence in research and education that has contributed greatly to the state-of-the-art in civil engineering. Completed in 1967 and extended in 1971, the structural testing area of the laboratory has a versatile strong-floor/wall and a three-story clear height that can be used to carry out a wide range of tests of building materials, models, and structural systems. The laboratory is named for Dr. Nathan M. Newmark, an internationally known educator and engineer, who was the Head of the Department of Civil Engineering at the University of Illinois and the Chair of the Digital Computing Laboratory . He developed simple, yet powerful and widely used, methods for analyzing complex structures and assemblages subjected to a variety of static, dynamic, blast, and earthquake loadings. Dr. Newmark received numerous honors and awards for his achievements, including the prestigious National Medal of Science awarded in 1968 by President Lyndon B. Johnson. He was also one of the founding members of the National Academy of Engineering. Contact:Prof ABSTRACTAccurate nonlinear formulations are necessary for the assessment of structures under seismic and other extreme loading. In this work, a three-dimensional distributed plasticity beam element formulation for circular concrete-filled steel tubes has been developed for nonlinear static and dynamic analyses of composite seismic force resisting systems. A mixed basis for the formulation was chosen to allow for accurate modeling of both material and geometric nonlinearities. The formulation utilizes uniaxial cyclic constitutive models for the concrete core and steel tube that account for the salient features of each material, as well as the interaction between the two, including concrete confinement and local buckling of the steel tube. The accuracy of the formulation was verified against a wide variety of analytical and experimental results. The verification confirms the capability of the formulation to accurately produce realistic simulations of element and frame behavior. CONTENTS

Seismic performance factors for moment frames with steel‐concrete composite columns and steel beams

“…After the first initiation of local buckling, later local buckling is triggered by a stress limit. Full details of the cyclic local buckling model are presented elsewhere [11,17]. This behavior was observed experimentally by Fukumoto and Kusama [16] for rectangular steel tubes.…”

Advanced Analysis and Seismic Design of Concrete-Filled Steel Tube Structures

“…The function was calibrated to experimental data found in the literature where initiation of local buckling was clearly identifiable or was noted by the author in the original reporting (Denavit and Hajjar 2012;Tort and Hajjar 2010a). This data is denoted in Figure 3 as the "calibration data" and is shown with grey markers.…”

“…As part of the mixed beam formulation, a family of accurate uniaxial cyclic material models have been developed and reported by Tort and Hajjar (2010a) for RCFTs and Denavit and Hajjar (2012) for CCFTs. The constitutive relation for the concrete core is adapted from the rule-based model of Chang and Mander (1994).…”

“…Tort and Hajjar (2010b) developed a three-dimensional mixed beam element for the analysis of composite frames that include rectangular concrete-filled steel tube members. This finite element was adapted and further validated against an additional sets of experimental tests on circular concrete-filled steel tube members (Denavit and Hajjar 2012).…”

Thin-Walled CFST Columns for Enhancing Seismic Collapse Performance of High-Rise Steel Frames

“…Han et al (2009) experimentally studied the seismic behavior of concrete-filled steel tubular frame to reinforced concrete (RC) shear wall high-rise mixed structures [20]. Nenavit and Hajjar (2012) conducted a nonlinear seismic analysis of circular concrete-filled steel tube members and frames [21]. Nevertheless, the research on deterioration behavior and collapse-resistant capacity of high-rise CFST buildings, especially considering the effect of member deterioration, is still limited.…”