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

  • effects of panel zone strength and Beam web connection method on seismic performance of reduced Beam Section steel moment connections
    Journal of Structural Engineering-asce, 2005
    Co-Authors: Sangwoo Jeon, Chiaming Uang
    Abstract:

    This paper presents test results on eight reduced Beam Section (RBS) steel moment connections. The testing program addressed web connection type (bolted versus welded) and panel zone (PZ) strength as the key variables. Specimens with medium PZ strength were designed to promote energy dissipation from both PZ and RBS regions such that expensive doubler plates were not needed. Both strong and medium PZ specimens with a welded web connection were able to provide satisfactory connection rotation capacity for special moment-resisting frames. However, specimens with a bolted web connection performed poorly due to premature brittle fracture of the Beam flange at the weld access hole. A plausible explanation for the higher incidence of base metal fracture in bolted web specimens was presented based on the measured strain data. Test results from this study and by others showed that panel zones could easily develop a plastic rotation of 0.01 rad without causing distress to the Beam flange groove welds. At this deformation level, the amount of Beam distortion (i.e., buckling) was about one half that developed in strong PZ specimens. A criterion for a balanced PZ strength that improves the plastic rotation capacity while reducing the amount of Beam buckling is proposed.

  • Cyclic performance of a type of steel Beam to steel-encased reinforced concrete column moment connection
    Journal of Constructional Steel Research, 2002
    Co-Authors: Chung-che Chou, Chiaming Uang
    Abstract:

    Abstract Two full-scale subassemblies with steel-encased reinforced concrete (SRC) columns and steel Beams were tested to evaluate the seismic performance of the connection details. For ease of construction, continuity plates were eliminated and less transverse reinforcement than that specified in the NEHRP seismic provisions was used in the connection region. The reduced Beam Section was introduced to reduce the shear demand on the connection. In addition, two doubler plates were placed away from the column web to enhance the connection shear resistance. This study showed that: (1) the stringent requirement for the transverse reinforcement could be relaxed; (2) the offset doubler plates were able to resist a significant amount of connection shear; and (3) the inner concrete strut could be mobilized in the two-sided moment connection, but not in the one-sided moment connection.

  • Cyclic Response and Design Recommendations of Reduced Beam Section Moment Connections with Deep Columns
    Journal of Structural Engineering, 2002
    Co-Authors: Brandon Chi, Chiaming Uang
    Abstract:

    Design engineers frequently use deep columns in steel special moment resisting frames to control drift. As the reduced Beam Section (RBS) moment connection is becoming popular after the 1994 Northr...

  • CYCLIC RESPONSE AND DESIGN RECOMMENDATIONS OF WEAK-AXIS REDUCED Beam Section MOMENT CONNECTIONS
    Journal of Structural Engineering, 2002
    Co-Authors: Chad S. Gilton, Chiaming Uang
    Abstract:

    In a study of previous weak-axis moment connection tests it was noticed that the most common failure mode was brittle fracture initiating near the edge of the Beam flange groove weld. The cause was...

  • cyclic stability criteria for steel moment connections with reduced Beam Section
    Journal of Structural Engineering-asce, 2001
    Co-Authors: Chiaming Uang
    Abstract:

    A statistical study was performed to evaluate the cyclic instability of steel moment connections with reduced Beam Sections. Based on test results of 55 full-scale specimens, regression analyses were performed to evaluate the relationships between response quantities (plastic rotation capacity and strength degradation rate) and slenderness parameters for buckling. Regressions analyses performed on a linear and a nonlinear model showed that the response quantities are highly dependent on the slenderness ratio of web local buckling, not lateral-torsional buckling. Relationships between the response quantities and the slenderness ratios for both web and flange local buckling modes were developed. For a target plastic rotation capacity, the limiting width-thickness ratio of web local buckling for seismic design is presented. An investigation of the concrete slab effect showed that it would increase both the strength and plastic rotation capacity of the reduced Beam Section Beams under positive bending. Under negative bending, however, the slab only enhanced the plastic rotation capacity slightly, implying that the slab cannot be counted on to brace the Beam bottom flange.

Dimitrios Lignos - One of the best experts on this subject based on the ideXlab platform.

  • deterioration modeling of steel components in support of collapse prediction of steel moment frames under earthquake loading
    Journal of Structural Engineering-asce, 2011
    Co-Authors: Dimitrios Lignos, Helmut Krawinkler
    Abstract:

    Reliable collapse assessment of structural systems under earthquake loading requires analytical models that are able to capture component deterioration in strength and stiffness. For calibration and validation of these models, a large set of experimental data is needed. This paper discusses the development of a database of experimental data of steel components and the use of this database for quantification of important parameters that affect the cyclic moment-rotation relationship at plastic hinge regions in Beams. On the basis of information deduced from the steel component database, empirical relationships for modeling of precapping plastic rotation, postcapping rotation, and cyclic deterioration for Beams with reduced Beam Section (RBS) and other-than-RBS Beams are proposed. Quantitative information is also provided for modeling of the effective yield strength, postyield strength ratio, residual strength, and ductile tearing of steel components subjected to cyclic loading.

  • fragility assessment of reduced Beam Section moment connections
    Journal of Structural Engineering-asce, 2010
    Co-Authors: Dimitrios Lignos, Dimitrios Kolios, Eduardo Miranda
    Abstract:

    This paper presents fragility functions to estimate the probability of reaching or exceeding different damage states in reduced Beam Section (RBS) Beam-to-column moment connections of steel moment resisting frames. The fragility functions are developed using results from 71 experimental tests that have been conducted on RBS connections during the past 14 years. The main sources of uncertainty considered are specimen-to-specimen variability of the interstory drifts associated with the various damage states and the epistemic uncertainty arising from using a limited number of experimental data and from interpreting experimental results. Quantitative measures for each of these two kinds of uncertainty were developed using statistical procedures. For a given peak interstory drift ratio the fragility functions developed herein permit the estimation of the probability of experiencing five different levels of damage in RBS moment connections.

Kehchyuan Tsai - One of the best experts on this subject based on the ideXlab platform.

  • special perforated steel plate shear walls with reduced Beam Section anchor Beams i experimental investigation
    Journal of Structural Engineering-asce, 2009
    Co-Authors: Darren Vian, Michel Bruneau, Kehchyuan Tsai
    Abstract:

    This paper presents results of an experimental investigation of specially detailed ductile perforated steel plate shear walls SPSWs designed to accommodate utility passage, and having anchor Beams with reduced Beam Sections connections. Single-story, single-bay SPSW frames are subjected to quasi-static cyclic loading up to their maximum strength and displacement capacity. The tested specimens also had low yield strength steel infill panels. Two specimens make allowances for penetration of the panel by utilities. The first, having multiple holes specially laid out in the steel panel, also has the characteristic of reduced panel strength and stiffness compared to the corresponding SPSW having a solid panel. The second such specimen utilizes quarter-circle cutouts in the panel corners, which are reinforced to transfer the panel forces to the adjacent framing. A SPSW with solid panel is also tested for reference purposes. All specimens resisted an imposed input history of increasing displacements to a minimum drift of 3%. The perforated panel reduced the elastic stiffness and overall strength of the specimen by 15% as compared with the solid panel specimen.

  • testing of full scale two story steel plate shear wall with reduced Beam Section connections and composite floors
    Journal of Structural Engineering-asce, 2008
    Co-Authors: Michel Bruneau, Chihhan Lin, Kehchyuan Tsai
    Abstract:

    A two-phase experimental program was generated on a full-scale two-story steel plate shear wall with reduced Beam Section connections and composite floors, to experimentally address the replaceability of infill panels following an earthquake and the seismic behavior of the intermediate Beam. In Phase I, the specimen was pseudodynamically tested, subjected to three ground motions of progressively decreasing intensity. The buckled panels were replaced by new panels prior to submitting the specimen to a subsequent pseudodynamic test and cyclic test to failure in Phase II. It is shown that the repaired specimen can survive and dissipate significant amounts of hysteretic energy in a subsequent earthquake without severe damage to the boundary frame or overall strength degradation. It is also found that the specimen had exceptional redundancy and exhibited stable force-displacement behavior up to the story drifts of 5.2 and 5.0% at the first and second story, respectively. Experimental results from pseudodynamic and cyclic tests are compared to seismic performance predictions obtained from a dual strip model using tension only strips and from a monotonic pushover analysis using a three-dimensional finite-element model, respectively, and good agreement is observed.

James M Ricles - One of the best experts on this subject based on the ideXlab platform.

  • experimental evaluation of reduced Beam Section connections to deep columns
    Journal of Structural Engineering-asce, 2006
    Co-Authors: Xiaofeng Zhang, James M Ricles
    Abstract:

    An experimental study was conducted to investigate the seismic behavior of reduced Beam Section (RBS) moment connections to a deep wide-flange column. The test matrix for the experimental program consisted of six full-scale interior RBS connections, where the column for the specimens ranged in depth from a W24 to a W36 wide flange Section. Five of the specimens had a composite floor slab, with the remaining specimen having no floor slab and a supplemental lateral brace at the end of the RBS. The results from the study show that a composite floor slab provides restraint to the Beams, reducing the magnitude of Beam top and bottom flange lateral movement in the RBS, column twist, and strength degradation due to Beam instability in the RBS. The performance of each of the test specimens was found to meet the seismic connection qualification criteria in Appendix S of the AISC seismic provisions. The results of the experimental study were used to develop a procedure for predicting the torque applied to a column from an RBS connection.

Michel Bruneau - One of the best experts on this subject based on the ideXlab platform.

  • special perforated steel plate shear walls with reduced Beam Section anchor Beams ii analysis and design recommendations
    Journal of Structural Engineering-asce, 2009
    Co-Authors: Darren Vian, Michel Bruneau, Ronny Purba
    Abstract:

    This paper presents a comparison of analytical and experimental results from an investigation of specially detailed ductile perforated steel plate shear walls (SPSWs). These SPSWs had low yield strength steel infill panels, anchor Beams with reduced Beam Sections connections, and were specially detailed to accommodate utility passage through the wall while remaining ductile. Finite-element models of full SPSWs and subelement strips are developed using the finite element software package ABAQUS/Standard to facilitate a comparison with experimental results and to investigate the influence of localized distribution of panel stress and strain between perforations. Based on the analytical and experimental results, recommendations for the design of these special detailed perforated SPSWs are presented.

  • special perforated steel plate shear walls with reduced Beam Section anchor Beams i experimental investigation
    Journal of Structural Engineering-asce, 2009
    Co-Authors: Darren Vian, Michel Bruneau, Kehchyuan Tsai
    Abstract:

    This paper presents results of an experimental investigation of specially detailed ductile perforated steel plate shear walls SPSWs designed to accommodate utility passage, and having anchor Beams with reduced Beam Sections connections. Single-story, single-bay SPSW frames are subjected to quasi-static cyclic loading up to their maximum strength and displacement capacity. The tested specimens also had low yield strength steel infill panels. Two specimens make allowances for penetration of the panel by utilities. The first, having multiple holes specially laid out in the steel panel, also has the characteristic of reduced panel strength and stiffness compared to the corresponding SPSW having a solid panel. The second such specimen utilizes quarter-circle cutouts in the panel corners, which are reinforced to transfer the panel forces to the adjacent framing. A SPSW with solid panel is also tested for reference purposes. All specimens resisted an imposed input history of increasing displacements to a minimum drift of 3%. The perforated panel reduced the elastic stiffness and overall strength of the specimen by 15% as compared with the solid panel specimen.

  • testing of full scale two story steel plate shear wall with reduced Beam Section connections and composite floors
    Journal of Structural Engineering-asce, 2008
    Co-Authors: Michel Bruneau, Chihhan Lin, Kehchyuan Tsai
    Abstract:

    A two-phase experimental program was generated on a full-scale two-story steel plate shear wall with reduced Beam Section connections and composite floors, to experimentally address the replaceability of infill panels following an earthquake and the seismic behavior of the intermediate Beam. In Phase I, the specimen was pseudodynamically tested, subjected to three ground motions of progressively decreasing intensity. The buckled panels were replaced by new panels prior to submitting the specimen to a subsequent pseudodynamic test and cyclic test to failure in Phase II. It is shown that the repaired specimen can survive and dissipate significant amounts of hysteretic energy in a subsequent earthquake without severe damage to the boundary frame or overall strength degradation. It is also found that the specimen had exceptional redundancy and exhibited stable force-displacement behavior up to the story drifts of 5.2 and 5.0% at the first and second story, respectively. Experimental results from pseudodynamic and cyclic tests are compared to seismic performance predictions obtained from a dual strip model using tension only strips and from a monotonic pushover analysis using a three-dimensional finite-element model, respectively, and good agreement is observed.