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Richard Sause - One of the best experts on this subject based on the ideXlab platform.

  • Experimental and analytical investigation of system of horizontally curved bridge girders with tubular top Flanges
    Structure and Infrastructure Engineering, 2018
    Co-Authors: Richard Sause, Kourosh Mahvashmohammadi
    Abstract:

    The behaviour of horizontally curved bridge girders with a tubular top Flange and a flat plate Bottom Flange (i.e., a TFG1) was investigated experimentally and analytically. The investigation focus...

  • experimental study of a self centering beam column connection with Bottom Flange friction device
    Journal of Structural Engineering-asce, 2009
    Co-Authors: Michael Wolski, James M Ricles, Richard Sause
    Abstract:

    A new beam-to-column connection for earthquake-resistant moment-resisting frames is introduced. The connection has a beam Bottom Flange friction device (BFFD) and posttensioned (PT) high-strength steel strands running parallel to the beam. The BFFD provides energy dissipation to the connection and avoids interference with the floor slab. The PT strands produce self-centering connection behavior. The connection behavior requires minimal inelastic deformation of the connection components and the beams and columns, and requires no field welding. A series of seven large-scale tests were performed to investigate the effect of the BFFD friction force, connection details, and the loading history on the performance of the connection under cyclic loading. The test results indicate that the BFFD provides reliable energy dissipation, and that the connection remains damage-free under the design earthquake.

  • self centering mrfs with Bottom Flange friction devices under earthquake loading
    Journal of Constructional Steel Research, 2009
    Co-Authors: Jun Iyama, James M Ricles, Richard Sause
    Abstract:

    Abstract A Bottom Flange friction device (BFFD) has been developed as an energy dissipation device for self-centering post-tensioned steel beam-to-column connections for moment-resisting frames (MRFs). The BFFD is located beneath the beam to avoid interference with a floor slab. Since the BFFD is attached to only one Flange, a connection with a BFFD has an asymmetric behavior with different positive and negative moment capacities. To investigate the behavior of a self-centering MRF with BFFDs, static and dynamic analyses were performed, and the results were compared to those of a similar frame with connections that have a symmetric behavior. It was found that the asymmetric behavior of the MRF with BFFDs leads to increased inelastic strain in the beam top Flange, which may lead to beam Flange buckling. These inelastic strains can be reduced by using longer top Flange reinforcing plates.

  • Experimental Study of a Self-Centering Beam–Column Connection with Bottom Flange Friction Device
    Journal of Structural Engineering, 2009
    Co-Authors: Michael Wolski, James M Ricles, Richard Sause
    Abstract:

    A new beam-to-column connection for earthquake-resistant moment-resisting frames is introduced. The connection has a beam Bottom Flange friction device (BFFD) and posttensioned (PT) high-strength steel strands running parallel to the beam. The BFFD provides energy dissipation to the connection and avoids interference with the floor slab. The PT strands produce self-centering connection behavior. The connection behavior requires minimal inelastic deformation of the connection components and the beams and columns, and requires no field welding. A series of seven large-scale tests were performed to investigate the effect of the BFFD friction force, connection details, and the loading history on the performance of the connection under cyclic loading. The test results indicate that the BFFD provides reliable energy dissipation, and that the connection remains damage-free under the design earthquake.

Wonkee Hong - One of the best experts on this subject based on the ideXlab platform.

  • development of structural composite hybrid systems and their application with regard to the reduction of co2 emissions
    Indoor and Built Environment, 2010
    Co-Authors: Wonkee Hong, Seonchee Park, Seungil Kim, Jin-min Kim, Seung-geun Lee, Daiyoung Yune, Taeho Yoon, Boong Yeol Ryoo
    Abstract:

    This paper discusses the development of a new structural composite hybrid system that is able to replace a conventional residential structural system in which space is partitioned using concrete walls. The new structural system consists of structural tees and wide Flange steel beams, with the Bottom Flange and/or portion of the web partially encased in pre-cast concrete, which is then mechanically anchored by headed stud shear connectors both to the Bottom Flange and the web of the structural tees. In composite frame built apartments, materials known to be heavy carbon dioxide (CO2) emitters can then be either excluded or reduced with consequent reduction in CO2 emissions. This study has investigated 36 selected multi-residential apartment buildings of linear shape to compare the CO2 emissions of the new composite hybrid and conventional multi-residential apartments. The CO2 emissions resulting from the composite hybrid apartments were reduced to approximately 75—80% in comparison to the emissions occurri...

  • composite beam composed of steel and pre cast concrete modularized hybrid system mhs part ii analytical investigation
    Structural Design of Tall and Special Buildings, 2009
    Co-Authors: Wonkee Hong, Jinmi Kim, Seonchee Park, Seungil Kim, Seunggeu Lee, Hocha Lee, Kijoo Yoo
    Abstract:

    This paper introduces the concept of a wide Flange steel beam with the Bottom Flange encased in pre-cast concrete. These composite beams utilize the merits of both steel and concrete materials. The effective interaction between the two materials can reduce the size of the steel beams. The reinforcement and the concrete are pre-integrated with the Bottom Flange of the steel beam at a manufacturing plant. In this paper, the analytical investigation of the flexural moment strength of the composite beams at both the yield limit state and the maximum load limit state is performed and compared with the experimental results. The depth of the equivalent rectangular stress block of the beams is obtained using an equilibrium equation when both the compression steel reinforcements are present. The post-yield behaviour of the composite beams is also investigated based on the normalized effective stiffness versus the normalized drift ratio . The stiffness of the composite beams degrades gradually with sufficient ductility and dissipating energy capability. A six-step procedure provides a fast, effective and accurate way of investigating the post-yield behaviour of the composite beams. Copyright © 2008 John Wiley & Sons, Ltd.

  • Composite beam composed of steel and pre‐cast concrete. (Modularized Hybrid System, MHS) Part II: analytical investigation
    The Structural Design of Tall and Special Buildings, 2009
    Co-Authors: Wonkee Hong, Seonchee Park, Seungil Kim, Jin-min Kim, Seung-geun Lee, Ho-chan Lee, Ki-joon Yoon
    Abstract:

    This paper introduces the concept of a wide Flange steel beam with the Bottom Flange encased in pre-cast concrete. These composite beams utilize the merits of both steel and concrete materials. The effective interaction between the two materials can reduce the size of the steel beams. The reinforcement and the concrete are pre-integrated with the Bottom Flange of the steel beam at a manufacturing plant. In this paper, the analytical investigation of the flexural moment strength of the composite beams at both the yield limit state and the maximum load limit state is performed and compared with the experimental results. The depth of the equivalent rectangular stress block of the beams is obtained using an equilibrium equation when both the compression steel reinforcements are present. The post-yield behaviour of the composite beams is also investigated based on the normalized effective stiffness versus the normalized drift ratio . The stiffness of the composite beams degrades gradually with sufficient ductility and dissipating energy capability. A six-step procedure provides a fast, effective and accurate way of investigating the post-yield behaviour of the composite beams. Copyright © 2008 John Wiley & Sons, Ltd.

  • composite beam composed of steel and precast concrete modularized hybrid system mhs part i experimental investigation
    Structural Design of Tall and Special Buildings, 2008
    Co-Authors: Wonkee Hong, Seonchee Park, Seungil Kim, Jin-min Kim, Seung-geun Lee, Ki-joon Yoon, Ho-chan Lee
    Abstract:

    An experimental investigation of composite beams composed of wide Flange steel and precast concrete is presented. The Bottom Flange of the steel section is encased in precast concrete. Utilizing the merits of both steel and concrete material, the size of the steel beams can be reduced without sacrificing performance. The Bottom Flange of the steel beam is reinforced with concrete at a manufacturing plant, eliminating the use of temporary pour forms. The composite beams were tested to investigate how the size of the wide Flange steel and how the top and Bottom reinforcements influence the behaviour of the beams. Flexural load carrying capacity, load displacement relationships and failure modes were examined. The test specimens were T-shaped composite beams with slabs, each measuring 10-m long. The flexural moment strength of all of the composite beams—at both the yield limit state and the maximum load limit state—was measured and compared with the analytical flexural capacity. The stiffness degradation, ductility and dissipating energy capabilities of the composite beams were investigated based on the hysteresis curves. The composite beams tested in this study successfully reduced both the floor height of the building and the size of the steel beams needed to meet code requirements. Copyright © 2008 John Wiley & Sons, Ltd.

Fa-xing Ding - One of the best experts on this subject based on the ideXlab platform.

  • Seismic behavior of Bottom-Flange-bolted type through-diaphragm connection considering the slab effect
    Engineering Structures, 2021
    Co-Authors: Xizhe Nie, Chao Zhang, Fa-xing Ding, Wei Guo
    Abstract:

    Abstract In composite beam connections, floor slabs are bonded to the upper Flange of supporting beams, which leads to an upward shift of the neutral axis and an increased deformation demand at the Bottom Flange. Hence, premature fracture failures at the Bottom Flange were prevalent in past earthquake disasters. The Bottom-Flange-bolted upper-Flange-welded (BFB-UFW) through-diaphragm CFST column connection employs the bolted Bottom Flange connection instead of the traditional welded Flange design to reduce the risk of fracture failures. In this study, cyclic loading tests were performed on BFB-UFW connections with composite slabs to investigate the combined effect of asymmetric beam Flange connections and composite slabs on seismic performance. The results indicated that the BFB-UFW connections provided pinched hysteretic relations that caused by plate sliding behaviors at the Bottom Flange connection. The bare beam connection displayed a higher negative moment strength compared to the positive one. The composite slab imposed a higher strengthening effect on the upward bending strength compared to the downward one. The two asymmetric strength developments complemented each other, thereby leading to similar levels of upward and downward bending strengths in the composite beam connections. Under large drift ratio rotations, buckling tendencies of upper beam Flanges were restrained by the composite concrete slab. The bolted Bottom Flange connection allowed a large deformation capacity through the relative slips of the Bottom Flange, which then minimized the plastic strains and stress concentrations at the Bottom Flange. Therefore, composite beam BFB-UFW connections displayed good deformation ability with a steady strength increase before the 0.04 rad drift ratio rotations. The specimen with a weak Bottom Flange connection displayed the early initiation of plate sliding and increased rotation concentrations near the column.

  • Seismic performance and working mechanism of innovate Bottom-Flange-bolted type through-diaphragm connections
    Structures, 2020
    Co-Authors: Man Mengke, Chao Zhang, Fa-xing Ding
    Abstract:

    Abstract The traditional welded-Flange through-diaphragm CFST column connections may develop fracture failures at Bottom Flanges. The Bottom-Flange-bolted upper-Flange-welded (BFB-UFW) connection adopts a bolted connection between the Bottom Flange and the Bottom diaphragm to reduce the early fracture risk. However, the asymmetric connection design would cause different moment bearing mechanisms and then influence the seismic performance of the connection. In this study, cyclic tests were performed on two BFB-UFW connections and one traditional welded-Flange connection to investigate detailed working mechanisms and the influence of the Bottom bolts on seismic performances of the connection. The BFB-UFW displayed good deformation abilities with the maximum drift ratio being higher than 5%. The bolted Bottom Flange connection could alleviate the deformation demand on beam Flanges through relative plate sliding behaviors. Bolt slips in the Bottom Flange connection led to pinched hysteretic loops. The BFB-UFW connection with a strong Bottom Flange connection exhibited higher negative strengths than the positive bending strengths due to the Poisson effect and the asymmetric supporting effect from the Bottom diaphragm. The BFB-UFW connection belongs to the semi-rigid full-strength type. Therefore, this connection can be applied to a moment resisting frame, but the stiffness, strength and ductility of the connection must be considered in structural design.

Ashkan Baharmast - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of Column-Tree Moment Resisting Connection with End Plates and Haunched Beam (RESEARCH NOTE)
    International Journal of Engineering, 2015
    Co-Authors: Ashkan Baharmast
    Abstract:

    The column-tree constructional schemes allows for a reliable and convenient erection of moment resisting steel frames. Strengthening of column-tree connection with a haunch part can significantly improve seismic behavior of whole system. In the current study behavior of column-tree connections with haunched beams and end plate splices have been investigated. Special attention was paid for evaluation of the effect of haunch section length and presence of the beams Bottom Flange. Nonlinear finite element analysis has been used for numerical analyses. The results indicate an improvement of the load bearing capacity of specimens when a longer haunch was used and also when beam Bottom Flange existed in the haunch part. A direct relation between haunch length and the amount of stress in splice plates was also observed. However all connections showed ductile behavior during cyclic analysis, specimens with longer haunch revealed more desirable behavior. It was concluded that despite some deficiencies observed during the numerical tests, in presence of a longer haunch and also the beam's Bottom Flange, a noticeable improvement of the general behavior of connection can be achieved.

Terry J Wipf - One of the best experts on this subject based on the ideXlab platform.

  • repair of steel composite beams with carbon fiber reinforced polymer plates
    Journal of Composites for Construction, 2004
    Co-Authors: A H Alsaidy, F W Klaiber, Terry J Wipf
    Abstract:

    One significant cause of deterioration of steel bridge structures is the corrosion due to extensive use of deicing salts in winter weather. The investigation presented in this paper focused on the behavior of steel composite beams damaged intentionally at their tension Flange to simulate corrosion and then repaired with carbon fiber-reinforced polymer (CFRP) plates attached to their tension areas side. Damage to the beams was induced by removing part of the Bottom Flange, which was varied between no damage and loss of 75% of the Bottom Flange. All beams were tested to failure to observe their behavior in the elastic, inelastic, and ultimate states. To help implement this strengthening technique, a nonlinear analytical procedure was also developed to predict the behavior of the section/member in the elastic, inelastic, and ultimate states. The test results showed a significant increase in the strength and stiffness of the repaired beams. Through the use of CFRP plates, all damaged beams were fully restored to their original (undamaged state) strength.