bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Burrs on the Shear Capacity of Bearing Connections
Authors: Zwerneman F.J. , Saleh Y.
Published: April 2024

Research was conducted to assess the effect of burrs on the shear capacity of bolted connections. This paper describes results relevant to the performance of bearing connections. Forty-five specimens were tested with burr heights ranging from 0 to 0.176 inches. Results show that the presence of burrs in bearing connections does not significantly reduce the shear capacity of the connection.
Critique: Comparative Effectiveness of Tightening Techniques for A490 1 1/4- in. Diameter Bolts
Authors: Sharp David F. , Flucker Ronald L.
Published: April 2024

Critique
Designing With Structural Tubing
Authors: Sherman Donald R.
Published: April 2024

Although the use of structural tubing as truss members and columns in building construction continues to increase in the U.S., it has not reached the proportion found in some countries where it approaches half the structural steel tonnage. Many designers still think of structural tubing as a new product, even though round tubes were used in some of the earliest steel structures. Steel design specifications were primarily developed from experience with hot-rolled sections and it was not until the late 1940s that criteria for circular tubes appeared in U.S. design specifications. Technology for efficiently mass producing square and rectangular structural tubes has developed in the past few decades, generating research on member and connection behavior with subsequent development of design criteria. There are a few characteristics of square and rectangular HSS that cause some member design consideration to differ from those of open profile sections. First it must be recognized that only cold-formed welded HSS are readily available in the U.S. These sections have good structural properties, although the thicknesses will usually be less than the nominal value. It should be recognized that many of the sections are thin-walled and require appropriate design criteria for columns and beams that reflect local buckling. Design criteria must also prevent local buckling when the HSS are used as braces in seismic applications. Except in an unusual situation or when plastic analysis is used, HSS beams do not require lateral bracing.
Discussion: Prestressed Steel Girders for Single Span Bridges
Authors: Kocsis Peter
Published: April 2024

Discussion
Discussion: Specifying Bolt Length for High-Strength Bolts
Authors: Flucker Ronald L.
Published: April 2024

Discussion
Steel Moment Frames with Ductile Girder Web Opening
Authors: Goel Subhash C. , Stojadinovic Bozidar , Leelataviwat Sutat
Published: April 2024

An innovative way to improve the performance of moment resisting steel frames is proposed. The upgrading scheme consists of creating rectangular (Vierendeel) openings reinforced with diagonal members in the web of girders near the mid span. Under severe seismic forces, inelastic activity will be limited only to yielding and buckling of diagonal web members and plastic hinging in T-shaped chord members of the openings. Through this scheme, not only is premature fracture of beam-to-column connections is avoided, but widespread and uncontrolled yielding, as observed in many moment frames, is also prevented. This results in improved dynamic response under severe ground motions. An actual existing moment frame building was taken as an example by applying the proposed modification scheme to the moment frames. The responses of the structure to a severe ground motion before and after modification were compared. Finally, a full scale testing of a one story subassemblage was carried out to verify the proposed modification procedure and to verify the results from computer analyses.
Practical Compactness and Bracing Provisions for the Design of Single Angle Beams
Authors: Earls C.J. , Galambos Theodore V.
Published: April 2024

This paper presents rational and practical design provisions for use with single angle beams. Compactness limits, bracing limits, and nominal moment capacity predictive equations are specified herein. Four common flexural orientations of the single angle cross section are considered. Experimentally verified nonlinear finite element modeling techniques are used extensively in this work.
Errata: Discussion - The Behavior and Load-Carrying Capacity of Unstiffened Seated Beam Connections
Authors: Carter C.J. , Thornton W.A. , Murray T.M.
Published: April 2024

Errata
Simplified Inelastic Design of Steel Girder Bridges
Authors: Schilling Charles G.
Published: April 2024

Past and present building and bridge specifications for inelastic design are discussed. The present inelastic bridge specifications apply only to compact girders and specify the mechanism method for satisfying the strength limit state. The theoretical inelastic behavior of noncompact girders subjected to moving loads is described. If these loads exceed the shakedown load, which is generally below the ultimate load predicted by the mechanism method, permanent deflections progressively increase without limit. New inelastic procedures are proposed for checking the strength and permanentdeflection limit states used in the LRFD bridge specifications. The strength check is based on the shakedown load and the permanent-deflection check is made by limiting positivebending stresses after yielding has occurred at interior supports and caused inelastic redistribution of moments. The proposed procedures apply to both compact and noncompact continuous-span girders and are much simpler than present procedures.
Belt Trusses and Basements as Virtual; Outriggers for Tall Buildings
Authors: Shankar Nair R.
Published: April 2024

The outrigger concept is in widespread use today in the design of tall buildings. In this concept, “outrigger” trusses (or, occasionally, girders) extend from a lateral load-resisting core to columns at the exterior of the building. The core may consist of either shear walls or braced frames. Outrigger systems can lead to very efficient use of structural materials by mobilizing the axial strength and stiffness of exterior columns to resist part of the overturning moment produced by lateral loading. There are, however, some important space-planning limitations and certain structural complications associated with the use of outriggers in tall buildings. A variation on the outrigger theme is the “offset” outrigger concept proposed by Brian Stafford Smith. Offset outriggers can overcome or circumvent many of the problems associated with conventional outriggers. A further, more specialized, development of the offset outrigger concept is the use of belt trusses and basements as “virtual” outriggers for tall buildings, as proposed in the present paper. A belt wall is used in this way in a tall building now under construction in Malaysia.
Design Aids for Walking Vibrations in Steel Framed Floors
Authors: Laman Jeffrey A.
Published: April 2024

Floor system vibration due to occupant activity is often ignored by designers; however, floor system vibration is an increasingly important serviceability criterion for occupant comfort and building owner satisfaction. When the floor system vibration response due to normal activity causes the occupants to become uncomfortable or annoyed, the successful use of the building is severely impaired. After-the-fact attempts to correct floor vibration problems are difficult, expensive and usually not successful. This paper briefly reviews design criteria for floor systems, studies of human response to vibration, current code requirements and the American Institute of Steel Construction (AISC) Steel Design Guide Series 11 for determining floor system vibration acceptability criteria. Several design aids are developed herein to promote the expedient verification of concrete slab on steel beam floor system acceptability as a general serviceability check during the design stage. An example is provided to demonstrate the application of the included design aids.
Seismic Performance and Design of Bolted Steel Moment-Resisting Frames
Authors: Astaneh-Asl Abolhassan
Published: April 2024

Bolted moment-resisting frames, and their predecessors riveted frames, were used for many decades prior to the use of welded frames in steel structures. Riveted and bolted steel structures have performed well during past earthquakes from the 1906 San Francisco earthquake to the infamous 1994 Northridge, Los Angeles earthquake. This paper presents information on past performance of bolted steel moment-resisting frames, a summary of shaking table tests, comparative studies of bolted and welded moment frames and a summary of results of cyclic tests of bolted top-and-bottom flange plate moment connections. The paper also presents the concept of performance-based design of steel connections using a failure mode hierarchy. In this concept, all failure modes of the connection are identified and then an order of desirability is assigned to each failure mode based on its ductility. The more ductile the failure mode is the higher its place in the hierarchy. Then, for each failure mode, design equations are developed. These equations ensure that, the more ductile failure modes, such as yielding of steel, will occur first and protect the connection from experiencing the more brittle and undesirable failure modes, such as fracture of welds, bolts or net sections. As an illustration of the procedure, this paper presents application of a proposed "hierarchical" approach to failure modes of bolted top-and bottom flange plate moment connections and provides corresponding design equations.
Errata: Design Criteria for Stiffened Seated Connections to Column Webs
Authors: Ellifritt Duane S. , Sputo Thomas
Published: April 2024

Errata
Panel Zone Yielding in Steel Moment Connections
Authors: El-Tawil Sherif
Published: April 2024

The effect of panel zone yielding on the behavior of fully restrained steel moment connections is investigated. The evolution of seismic design provisions for steel panel zones is discussed and experimental evidence is presented that suggests that an excessively weak panel zone could be detrimental to connection behavior. The observed behavior is explained through detailed inelastic finite element analyses. Based on the experimental and analytical evidence, modifications to existing seismic provisions for steel panel zones are proposed that make the provisions conceptually more transparent.
LRFD Beam-Column Graphical Design Aid
Authors: Keil William J.
Published: April 2024

A graphical design aid is presented for beam-columns, members subjected to combined loading of axial forces and bending moments, designed in accordance with the American Institute of Steel Construction's (AISC) 1993 LRFD Specification for Structural Steel Buildings. Design aids have been published in the AISC LRFD Manual of Steel Construction, 2nd Edition, addressing many facets of structural steel design. These include the beam tables, beam charts, and column tables. However, meager information is available revealing how to design a beam-column accurately and quickly. The common method is entirely based on an assumed axial load due to bending moments which is then used via trial-and-error to size a member from the column (axial load only) design tables. There are various problems with this method of design. This article presents an alternative design procedure based on the Equations H1-1a and H1-1b of the 1993 LRFD Specification for Structural Steel Buildings. The proposed design method consists of a standard set of graphs depicting the interaction diagram for steel W-shapes commonly used as column members. The diagrams are derived for structural members subjected to axial compression and strong axis bending. This new procedure also utilizes a set of linear transformation factors applied to design conditions different from the graphical standard. This method is advantageous to design engineers because it facilitates the selection of a beam-column.
The Performance and Design Checking of Chord-Angle Legs in Joist Girders
Authors: Galambos Theodore V.
Published: April 2024

The subject of this paper is the development of a design checking method for the capacity of the outstanding legs of the compression chord in joist girders subjected to eccentric reaction forces from the bearing seats of the joists bearing on these chords at panel points. Fifteen tests were performed, and, based on these tests and on plastic analysis, a conservative formula for the ultimate strength of the outstanding legs has been developed. A design checking formula is also proposed.
Relating the Seismic Drift Demands of SMRFs to Element Deformation Demands
Authors: Gupta Akshay , Krawinkler Helmut
Published: April 2024

A procedure is outlined and evaluated for estimation of beam and panel zone deformation demands for given estimates of story drift demands for regular steel moment resisting frame (SMRF) structures. The total story drift demand is related to the story plastic drift demand by estimating the story yield drift based on the weakest element at the connection. The story plastic drift demand is related to the panel zone and beam plastic deformation demands by a function based on story geometry and member properties. The procedure is verified for a series of code compliant SMRFs. It complements a process presented in the literature that permits the estimation of seismic drift demand for frame structures from the spectral displacement demand at the first mode period of the structure. The combined process should prove useful in conceptual design, in estimating deformation demands for performance assessment, and in improving basic understanding of seismic behavior of steel frame structures.
A Practical Look at Frame Analysis, Stability and Leaning Columns
Authors: Geschwindner Louis F.
Published: April 2024

Analysis and design of unbraced moment frames is a fairly regular activity in structural engineering practice yet it can be a complex structural engineering problem. Numerous analysis methodologies are available and the many commercial software packages used in practice provide a variety of approaches to the problem. This paper presented a brief discussion of the full range of approaches that might be used to carry out a structural analysis. The elastic buckling load of a frame can be determined through an eigenvalue analysis that predicts system buckling behavior. This buckling load is the load that the Kfactor is attempting to predict for individual columns. Although the K-factor has been a controversial topic from its initial introduction into the AISC Specification, it remains a useful tool to predict column capacity. Perhaps the most troubling aspect associated with the use of the Kfactor has been overlooking the assumptions included in the development of the most common predictor equations. Unbraced moment frames that do not meet the restrictive assumptions, which permit use of the nomograph pose interesting problems for the structural engineer. Such factors as leaning columns, columns supporting less than their full capacity, and inelastic behavior all must be considered in any design.
Errata: Design Concepts for Jib Cranes
Authors: Fisher James M. , Thomas Steven J.
Published: April 2024

Errata
Errata: Rational Basis for Increased Fillet Weld Strength
Authors: Iwankiw Nestor R.
Published: April 2024

Errata
Analysis Of Framed Space Structures
Authors: Baer Oliver A.
Published: April 2024

This paper presents the procedure for the analysis of general framed space structures, and rules for the determination of redundancy, stability, and statical determinacy. It is shown that practically any shape of framework as would be desired to enclose a given space can be arranged and braced so that it is rigid, stable, statically determinate and subject to rational analysis. The analysis consists of the solution by computer of a set of simultaneous equations, equal in number to the number of framing members.
Design Aids: Minimum Depth and Allowable Bending Stress
Authors: Froyton George
Published: April 2024

Minimum Depth and Allowable Bending Stress
Design of Bolts or Rivets Subject to Combined Shear and Tension
Authors: Zweig Alfred
Published: April 2024

The 1963 AISC specification introduced, in Section 1.6.3, new provisions pertaining to the combined tension and shear stresses in bolts and rivets. The formulas given in this section permit the checking of a given design but leave the design itself to a rather cumbersome cut and try procedure. The purpose of this paper is to present a simple method which enables the designer or detailer to establish the required number of bolts or rivets in a bracket connection—the most common case in which rivets or bolts are under combined action of shear and tension (see Fig. 1). The specification provides different criteria for various rivet types, high tensile bolts of the friction or bearing type and for unfinished bolts; for this reason a different analysis is required for each ofthese elements. This paper will deal, however, only with the most commonly used types, that is, ASTM A325 type high tensile bolts and A141 rivets.
Static Pullout Strength of Power Actuated Fasteners in Steel: State-of-the-Art Review
Authors: Beck Hermann , Engelhardt Michael , Glaser Neil
Published: April 2024

Power-actuated fasteners (PAFs) are high strength nails used for making attachments to steel or concrete. PAFs driven into steel are the subject of this paper. PAFs are driven into steel using either powder-actuated or pneumatically driven tools and provide an alternative to more conventional fasteners such as welds, bolts, and screws. Power-actuated fastening systems for steel have been available for over 50 years. However, relatively little research information has been published on this fastening system in journals or in other engineering research and design literature. The purpose of this paper is to provide an overview of power-actuated fastening for steel and to provide a state of the art review on the static pullout strength of individual power-actuated fasteners in steel. Much of the past research and testing information on PAFs is contained in unpublished or proprietary research or test reports that are not widely or easily available to researchers and engineers. This lack of public domain literature on PAFs for steel is the primary motivation for this paper, which summarizes test data that is not otherwise easily available.
Proposed Equal Leg Single Angle Flexural Design Provisions for Consideration in the Development of Future AISC Specification Editions
Authors: Earls Christopher J.
Published: April 2024

Currently, the design of single angle members is governed by the LRFD Specification for Design of Single Angle Members (AISC, 2000). The provisions in this document are meant to augment the more general design provisions contained in the LRFD Specification for Structural Steel Buildings (AISC, 1999) for use with single angle members. The design provisions promulgated by the LRFD Specification for Design of Single Angle Members are the result of the best information available at the time of the preparation of the document in the early 1990s. Over the past decade, new information about single angle flexural response has accumulated from experimental and analytical research efforts aimed at more accurately quantifying the behavior of single angle beams. This new information is summarized herein and recommendations are made for rational single angle design provisions for consideration and possible inclusion in Chapter F of future AISC specification editions. An appendix of proposed Specification language is provided herein. The existing single angle specification provisions in the LRFD Specification for Design of Single Angle Members (AISC, 2000) require updating in order to reflect the current state of knowledge as it relates to flexural response. The current paper proposes new specification provisions that would supersede those currently promulgated by the LRFD Specification for Design of Single Angle Members (AISC, 2000). The new specifications are presented for consideration and possible use in Chapter F of new editions of the AISC Specification. The paper has described the rationale behind these new provisions and in a sense serves as a commentary on them.
Update on the AISC Seismic Provisions
Authors: Malley James O.
Published: April 2024

Between the advent of incorporating seismic design provisions into the Uniform Building Code (UBC) in the early 1950s, and the late 1980s, the Structural Engineers Association of California (SEAOC) Seismology Committee was almost completely responsible for the content of these provisions. Spurred on by the federally funded National Earthquake Hazard Reduction Program (NEHRP), in the late 1980s and early 1990s seismic design began to be seen as more of a nationwide issue. During these years, the NEHRP program began to fund the Building Seismic Safety Council (BSSC) to develop model building code provisions for seismic design. The BSSC established a nationally represented committee structure, with technical subcommittees addressing each of the main structural materials, including structural steel. To support this effort, the American Institute of Steel Construction (AISC) established a parallel committee (TC 9) and began the development of a set of seismic design provisions for steel buildings. Over the last ten years, a rational, systematic and efficient process has been instituted to incorporate the latest developments in seismic design of steel structures into building code provisions. This system relies on the coordinated efforts of AISC, BSSC, SEAOC and AWS committees. The process provides a single point of responsibility for the development of these provisions, thus eliminating duplicative effort, and more importantly, the development of competing documents that would result in minor differences that would undoubtedly result in major confusion in application by practicing engineers.
Behavior of Transverse Fillet Welds: Parametric and Reliability Analyses
Authors: Ng Anthony K.F. , Driver Robert G. , Grondin Gilbert Y.
Published: April 2024

Transverse fillet weld specimens were tested to assess the influence of various parameters on fillet weld strength and ductility and to evaluate the level of safety being provided currently by North American design standards. Details of the test procedures and results are reported in the companion paper by Ng, Deng, Grondin, and Driver, also published in the 2nd Quarter 2004 issue of the Engineering Journal. The variables included in the study were the filler metal classification (including classifications both with and without a toughness requirement), fillet weld size and number of passes, electrode manufacturer, steel fabricator, root notch orientation, and test temperature.
Behavior of Transverse Fillet Welds: Experimental Program
Authors: Ng Anthony K.F. , Deng Kam , Grondin Gilbert Y. , Driver Robert G.
Published: April 2024

The main objective of the research presented in this paper is to expand the body of experimental results on transverse fillet welds to include the flux cored arc welding (FCAW) process and to confirm the applicability of the current provisions of the Canadian Standard, CSA—S16—01, and Appendix J2.4 of the AISC specification to a broader range of electrode types and other conditions. In particular, the selected filler metals were to possess varying levels of material toughness. The effects of wire manufacturer, steel fabricator, weld size and number of passes, root notch orientation, and ambient temperature were also investigated. A review of the literature is presented in order to obtain a better understanding of the basis for the current design equation and its limitations. A description of the comprehensive test program recently conducted at the University of Alberta to investigate the strength and behavior of transverse fillet welds is then presented. A companion paper, also published in this issue of the Engineering Journal, presents parametric and reliability analyses of the test results to evaluate the level of safety being provided by the current design equation.
Lateral-Torsional Buckling of Wide Flange Cantilever Beams
Authors: Dowswell Bo
Published: April 2024

Lateral-Torsional Buckling of Wide Flange Cantilever Beams
A Technical Note: A Direct Method for Obtaining the Plate Buckling Coefficient for Double Coped Beams
Authors: Muir Larry S. , Thornton William A.
Published: April 2024

The AISC LRFD 3rd Edition Manual of Steel Construction presents a procedure for deep and unequal depth top and bottom coped beams which extends the procedure of the AISC LRFD 2nd Edition Manual of Steel Construction, which was limited to shallow , approximately equal depth top and bottom copes. The procedure presented in the 3rd Edition Manual involves an interpolation of values from a table to determine the plate buckling coefficient. It is the purpose of this note to present a formula for the plate buckling coefficient which eliminates this interpolation.
Structural Design and Experimental Verification of a Buckling-Restrained Braced Frame System
Authors: Lopez Walterio A. , Gwie David S. , Lauck Thomas W. , Saunders C. Mark
Published: April 2024

To satisfy the seismic performance goals required by the owner, the structural engineer of record proposed to use Buckling-Restrained Braced Frames (BRBFs) as the seismic force resisting system of a new seven-story building. Because not all of the testing requirements found in the Recommended Provisions for Buckling-Restrained Braced Frames were met by the braces specific to this project, the structural engineer of record proposed conducting three frame subassemblage tests to validate their BRBF design. This article is a case study that describes a viable BRBF design methodology and the tests conducted to support it. This article summarizes some of the experimental results and discusses possible design implications of some of the experimental findings.
Preliminary Assessment for Walking-Induced Vibrations in Office Environments
Authors: Hanagan Linda M. , Kim Taehoo
Published: April 2024

This paper presents the development and application of a preliminary walking vibration assessment procedure for steel-framed office floors. Using a database of over 70,000 floor system evaluations, multivariate statistical methods were employed in the formulation. The research was undertaken to provide building design professionals with an "easier" means of checking floor system properties early in the design process, thus resulting in an economical system, while maintaining serviceability. The primary use of this evaluation is to determine whether a floor system that has been designed to meet strength and live load deflection requirements should be altered to meet walking vibration serviceability requirements.
Understanding the Response of Composite Structures to Fire
Authors: Usmani Asif S.
Published: April 2024

This paper provides a general introduction to the intricacies of the behavior of composite structures exposed to thermal loading from fire. This is not a topic many structural engineers often deal with as part of their normal practice. However, even the engineers who do have to address this issue generally follow entrenched code-based prescriptive procedures. These procedures generally require them to protect the steel based on furnace testing of individual members. The actual structural behavior is hardly ever a part of this assessment. Fortunately there is considerable interest internationally to moving towards a more rational approach for designing structures for fire, particularly within the performance-based design context. This has lead to considerable recent research in this area in the United Kingdom and Continental Europe. The University of Edinburgh has been a major contributor to this new work. This paper provides a brief description of the research that has taken place in Edinburgh and the new knowledge that has accrued from it. This work quite clearly indicates that the traditional prescriptive ways of protecting structural members from fire are flawed, particularly if actual structural behavior in response to fire is ignored. In general this leads to higher costs for fire protection but potentially it could also result in catastrophic failures.
Buckling Strength of Single Angle Compression Members in K-Series Joists
Authors: Yost Joseph Robert , Dinehart David W. , Gross Shawn P. , Pote Joseph J. , Deeney James
Published: April 2024

Single angle web members in open web steel joists are typically crimped to facilitate web placement and maintain a constant chord gap with varying web angle size. If the web members are not crimped force eccentricity will exist between the web member's area centroid and the vertical plane of symmetry for the joist. The analytical consequence of this eccentricity is that uncrimped single angle web members must be designed as eccentrically loaded columns. The resulting interaction design strength is significantly less than the concentric column analysis design strength used for crimped web members of identical cross section and slenderness. This study compares the measured and analytical strengths of like single angle L1x1x7/64 inch crimped and uncrimped web members in steel joists. Experimental results from 18 joist samples show that existing analytical assumptions associated with end fixity and beam-column interaction result in an overly conservative design methodology for both crimped and uncrimped web members.
Design Aids for Unreinforced Web Openings in Steel and Composite Beams with W-Shapes
Authors: De Souza Verissimo Gustavo , Hallal Fakury Ricardo , Lopes Ribeiro Jose Carlos
Published: April 2024

Design aids compatible with the Load and Resistance Factor Design Specification for Structural Steel Buildings were obtained from computational analyses based on AISC Design Guide No. 2 to facilitate the design of openings in webs of steel and composite beams with W-shapes. The set of design aids presented allow identification of the "neutral zone", a region in the beam web in which openings with some particular characteristics do not reduce the beam strength. It leads to economic alternatives for web openings design, constituting a useful tool, meeting an important demand of steel designers.
Evaluating Single Angle Compression Struts Using An Effective Slenderness Approach
Authors: Lutz Leroy A.
Published: April 2024

This paper describes a simple procedure for evaluating the capacity of single angle compression struts that are supported at each end by one leg to a gusset plate or directly to a leg or stem of the chord of a truss. This procedure allows the single angle to be treated for analysis and design as a pinned-end axially loaded compression member by use of an effective slenderness ratio. The procedure considers two levels of end restraint and addresses both equal and unequal-leg angles. This procedure has been added for use in the 2005 version of the American Institute of Steel Construction Specification for Structural Steel Buildings (AISC, 2005).
A Review of Steel Plate Shear Wall Design Requirements and Research
Authors: Bruneau Michel , Berman Jeffrey W. , Lopez-Garcia Diego , Vian Darren
Published: April 2024

Steel plate shear walls are rapidly becoming an appealing alternative in high seismic areas. This paper provides an overview of the current state-of-the-art in steel plate shear wall design, including the 2005 AISC Seismic Design Requirements for Special Plate Shear Walls (SPSW). This paper also discusses some of the research in support of those design requirements. The strip model, developed by others for the representation of SPSW, is described and plastic analysis results for that model and their use in design are discussed. Finally, new directions for SPSW research (to expand the range of applicability of this structural system) are presented, including the use of light-gauge and low yield-point steels and strategic hole placement. Additionally, reduced beam sections are described in the context of some recently completed and ongoing research.
Graphical Design Aid for Beam-Columns (LRFD)
Authors: Hosur Vinod , Augustine Binson
Published: April 2024

A graphical design aid and design procedure is presented for beam-columns, beams and columns considering importance of Cb factor, as the value of Cb varies from 1.0 to 2.3, which is quite significant as against conservative value of Cb, in other words, Cb = 1 used by William J. Kiel in preparing his graphical design aids. The design procedure and charts are developed taking into consideration, the equivalent uniform moment factor, Cb, unbraced length, Lb, for moment capacity and effective length, KL, for axial load capacity. Although, the design aids are developed for beam-columns, the same curves can be used for beams and columns independently.
Development of a Cast Modular Connector for Seismic-Resistant Steel Moment Frames Part II: Experimental Verification
Authors: Sumer Ali , Fleischman Robert B. , Palmer Nathan J.
Published: April 2024

A companion paper (Development of a Cast Modular Connector for Seismic-Resistant Steel Frames, Part 1: Prototype Development) describes the development of a prototype design for a cast modular connector (MC) for seismic-resistant steel moment frames. The eventual design, termed the MC "Beta"ť prototype design, was developed through a comprehensive analytical program that focused on the monotonic response of isolated connectors. Analyses of the MC Beta prototype design indicate the potential for excellent ductility and energy dissipation characteristics. This paper focuses on the prototyping and experimental verification of the MC Beta prototype. Steel foundry industry partners cast the MC Beta prototype at approximately half-scale. The scaled MC Beta prototype was tested in isolated fashion under monotonic and cyclic loading. The experimental results confirmed the performance of the analytically-based designs. The MC Beta prototype exhibited exceptional performance in terms of stable energy dissipation, far exceeding qualifying rotational ductility capacities. In direct comparisons to a WT (structural tee) section of similar stiffness and strength, the MC Beta prototype possessed greatly enhanced ductility and energy dissipation characteristics. With the MC Beta prototype developed and experimentally verified under isolated conditions, future work involves comprehensive analytical evaluation and full-scale experimental verification of beam-to-column joints containing the MC using accepted testing protocols and developing a design procedure for moment frames using the MC.
Current Steel Structures Research No. 11
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Block Shear Equations Revisited...Again
Authors: Epstein Howard I. , Aleksiewicz Lance J.
Published: April 2024

Shortly after block shear was first identified as a possible failure mode for coped beam connections, design equations to account for it were incorporated into ASD provisions. These equations never changed, partly due to ASD not being updated since 1989. However, LRFD treatment of block shear changed with each new Specification. Over the years, it was suggested that the effect of eccentricity was missing from block shear equations. On the surface it appears that the effect of eccentricity on the block shear strength of connections, as suggested by previous investigators, has now been incorporated into the latest unified Specification. For many connections, however, nothing has changed. It is the conclusion of this paper that additional important cases need to be shown in Commentary Figure C-J4.2 of the 2005 AISC Specification for which block shear equations now incorporate a new factor to account for connection eccentricity. In particular, as a minimum, angles connected by only one leg or tees connected by their flanges should also be included with other connections for which block shear capacities are now reduced.
Current Steel Structures Research No. 16
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Design Aids for Built-Up I-Shaped Beams with Slender Webs
Authors: Nasados Jr. Paul P.
Published: April 2024

Available Strength Tables for I-shaped beams with slender webs for the limit states of flexure and shear are presented. The tables were prepared in a format similar to the design aids available in the 13th Edition AISC Steel Construction Manual. The generation, applicability and limitations of the tables are discussed. An example is presented to demonstrate the usage of the Available Strength Tables.
Experimental Investigation of Fillet-Welded Joints Subjected to Out-of-Plane Eccentric Loads
Authors: Kanvinde Amit M. , Grondin Gilbert Y. , Gomez Ivan R. , Kwan Yukay
Published: April 2024

The current AISC design specification for welded connections does not make a distinction between joints subjected to eccentric loads in the plane of the weld group, and those subjected to eccentric loads not in the plane of the weld group. To address this issue, results from 60 tests on cruciform joint specimens are presented to examine the effect of combined shear and out-of-plane bending on the strength of fillet welded joints. All specimens are loaded in a three point bending configuration, such that the out-of-plane bending is resisted through a combination of tensile weld stresses and compressive bearing stresses between the connected plates. Two welding filler metals (flux-cored wires, toughness rated E70T7-K2 and non-toughness rated E70T-7), two nominal weld sizes (5/16 inch and 1/2 inch), three nominal load eccentricity ratios (0.75, 1.375 and 2.125) and three plate bearing widths (1.25 inch, 1.75 inch and 2.5 inch) are investigated. Analysis of the test data, in addition to similar data available in the literature, reveals that the current (13th Edition Steel Construction Manual) AISC design tables for eccentrically loaded welds are highly conservative (i.e. test-to-predicted load ratios are, on average, 1.75; with a coefficient of variation = 0.25) for joints with out-of-plane eccentricity. This conservatism is attributed to the disregard of plate bearing stresses that significantly alter the stress distribution in the joint. An alternate approach that explicitly incorporates this bearing effect is proposed, and the resulting strength predictions are determined to be significantly less conservative when compared to the current design standards. Limitations of the research and future work are outlined.
Discussion: Designing Compact Gussets with the Uniform Force Method
Authors: Arias Ramon F.
Published: April 2024

Discussion
Bolt Shear Design Considerations
Authors: Tide Raymond H.R.
Published: April 2024

In this paper, bolt shear capacities are reviewed using the Load and Resistance Factor Design (LRFD) philosophy. Only bolt-shear limit states are addressed, although one aspect of slip critical limit states is addressed incidentally. This paper does not consider bolt bearing limit states. Test data used to justify the adoption of ASTM A325 and A490 high-strength bolts was obtained from previous research programs. The data also included various types of rivets and Huck bolts for general comparison. First, the test data is used to evaluate the current American Institute of Steel Construction (AISC, 2005) and Research Council on Structural Connections (RCSC, 2004) bolt shear provisions and to determine the current reliability, beta, which is found to be conservative when based on a resistance factor, phi, of 0.75. The appropriateness of the phi-factor for bolt shear is addressed. Canadian (CSA S16-01) and Eurocode (EN 1993) provisions are also evaluated and shown not to be compatible with the test results. Two design equations are developed—one linear, one a step function—that result in a beta value slightly greater than 3.0, appropriate for a manufactured product. The single-step function (with a step at 38 in.) is recommended for inclusion in updated design specifications. This design provision increases the design strength by 12.5% for short connections and by 17.2% for long connections. The test data indicate that there is no need for a bolt strength reduction due to the length of the connection, provided that the connection material gross and net section areas exceed certain ratios. That ratio is a function of the connection material yield and tensile strength, the total bolt shear area and the bolt tensile strength.
Stiffener Requirements to Prevent Edge Buckling
Authors: Dowswell Bo
Published: April 2024

Steel connection elements such as gusset plates and coped beam webs feature unsupported edges that are sometimes stiffened to prevent buckling. The stiffener requirements for structural elements with large aspect ratios are well established. However, for typical connections with an aspect ratio of Â½ to 2, the existing requirements may not provide accurate results. The results from 123 elastic finite element models were analyzed to determine the stiffness requirements for edge stiffeners with smaller aspect ratios. A design procedure based on a simplified model is proposed as a starting point for stiffener design.
Closure: Critical Evaluation of Equivalent Moment Factor Procedures for Laterally Unsupported Beams
Authors: Wong Edgar , Driver Robert G.
Published: April 2024

Closure
Technical Note: New Z-BREAKSS: Post-tensioned Rocking Connection Detail Free of Beam Growth
Authors: Dowden Daniel M. , Bruneau Michel
Published: April 2024

This technical note concisely presents the details of a post-tensioned rocking moment connection (PT-RMC) concept that could be implemented in steel plate shear wall (SPSW) and moment-resisting frame (MRF) systems, along with preliminary results from limited SAP2000 cyclic nonlinear static pushover and time-history analyses that verify its anticipated behavior. The partial research results presented here could be of benefit in ongoing discussions about practical implementation and design codification of PT-RMCs [aka post-tensioned energy dissipating (PTED) or self-centering moment-resisting (SC-MRF) connections].
The Development of a New Design Procedure for Conventional Single-Plate Shear Connections
Authors: Muir Larry S. , Thornton William A.
Published: April 2024

Conventional single-plate shear connections are common and economical connections. The design procedure outlined in the 13th edition AISC Steel Construction, (AISC, 2005a), Manual relies on the bolt shear values given in the 2005 AISC Specification for Structural Steel Buildings (AISC, 2005b). The nominal bolt shear values listed in Specification Table J3.2 have historically been 20% lower than the theoretical bolt values. This reduction was provided to account for uneven force distribution among the bolts in end-loaded connections, such as bolted lap splices. The reduction served the secondary function of providing an additional factor of safety for all bolted connections designed in accordance with the Specification. The design procedure for conventional single-plate shear connections contained in the 13th edition Manual relied on this reduction to justify the practice of neglecting eccentricity in the bolt group for most configurations. The 2010 AISC Specification increases the nominal bolt shear values, necessitating a revised design procedure for single-plate shear connections in the 14th edition AISC Manual. This paper outlines the revised procedure.
Current Steel Structures Research No. 27
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Current Steel Structures Research No. 30
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Errata: Design of Bolts or Rivets Subject to Combined Shear and Tension
Authors: Zweig Alfred
Published: April 2024

Errata
A Comparison between the 2005 and 2010 AISC Specification
Authors: Bolin Eric J. , Dehlin Thomas J. , Geschwindner Louis F.
Published: April 2024

In 2010, the American Institute of Steel Construction published a revised version of its Specification for Structural Steel Buildings that replaces the 2005 edition. Changes to the Specification were minimal and improved the usability and accuracy of the document. A detailed summary of these changes are contained in this article, providing an extension to the historical reviews of previous AISC specifications presented in Appendix A1 of AISC Design Guide 15.
Current Steel Structures Research No. 33
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
A Simplified Approach for Joist Girder Moment Frame Design Using Equivalent Beam Theory
Authors: Phillip A. Knodel Andrea E. Surovek and Joseph J. Pote
Published: April 2024

The design of building structures has become a highly automated, computer-based process in which designers depend on the capabilities of commercial software for member strength checks and determination of deflections, drifts and member weights. Most commercial structural design software packages allow the user to build custom beam tables. The use of custom beam tables for joist girders requires the application of equivalent beam theory (EBT). Using EBT, section properties are determined in such a way that joist girder limit states are appropriately captured by strength checks employed by the software. By building custom beam tables, representing approximations of joist girders based on typical available chord sizes and typical ratios of weights, appropriate joist girder section properties can be estimated from almost any commercial structural software program. This paper presents the methodology for developing approximate section properties for steel joist girders that allow commercial software results to closely compare to joist manufacturer's designs.
Errata: Flange Bending in Single Curvature
Authors: Dowswell Bo
Published: April 2024

Errata
Torsional and Constrained-Axis Flexural-Torsional Buckling Tables for Steel W-Shapes in Compression
Authors: Liu D. , Davis Brad , Arber L. , Sabelli Rafael
Published: April 2024

Torsional buckling (TB), an applicable limit state for W-shape members subject to axial compression, often controls when the torsional effective unbraced length exceeds the minor-axis flexural buckling effective unbraced length. Constrained-axis flexural-torsional buckling (CAFTB) is a potential limit state for W-shape members that are constrained to buckle with the center of twist at a location other than the centroidal axis, as is the case for a typical beam with one flange braced by a diaphragm and the other unbraced. Manual calculation of the TB or CAFTB available compressive strength is a somewhat lengthy process, especially when the section is slender for axial compression, and no design aid currently exists in the AISC Manual. This paper provides tables that facilitate the determination of TB and CAFTB available compressivestrengths. Several example calculations are also provided.
Experimental Investigation of Steel Joist Design for Ductile Strength Limit State
Authors: Yost Joseph Robert , Harrington Timothy J. , Pote Joseph J. , Gross Shawn P. , Dinehart David W.
Published: April 2024

Open web steel joists are prefabricated truss assemblies designed in accordance with specifications set forth by the Steel Joist Institute (SJI). Currently, the SJI design requirement is based on capacity, with no consideration for the governing-member strength limit state. The purpose of this research is to investigate a ductile design methodology for steel joists where the primary strength limit state is characterized by tension-member yielding and large inelastic deformation, followed by a secondary strength limit state of compression member buckling. To achieve ductile behavior, a series of experimental joists were designed and manufactured using controlled over-strength ratios of relative member strengths so that tension-member yielding precluded compression-member buckling. The consequence of adjusting member strengths to induce ductile failure is a slight increase in joist weight. The experimental matrix consisted of 18 joist samples: six identical 33-ft-long K-series joists, six identical 33-ft-long LH-series joists and six identical 32-ft-long rod web joists. All joists were tested to collapse under simply supported uniform load conditions. Experimental results show that a ductile design is achievable because all 18 joists demonstrated tension-member yielding with significant deformation prior to a secondary limit state of compression member buckling.