bluuebunny/crossref_metadata_2025 huggingface dataset:
Cantilever Beam Framing Systems
Authors: Hemstad Michael
Published: April 2024

Cantilever beam framing is a multiple-span system of framing which is more efficient than simple beam framing, but simpler to design and erect than continuous beam systems. It involves cantilevering the beam from one span past a support a short distance into the next span, where it supports the end of the next beam using a simple shear connection. This is shown in Figure 1 for two-span and three-span configurations. The configurations are identified as SC (suspended span/cantilever), CSC (cantilever/suspended span/cantilever), and SCS (suspended span/cantilever/suspended span). Cantilever framing systems are a reasonable and economical alternative to simple span and continuous beam framing systems. While more demanding analytically than simple span framing, in buildings with large bays they will typically be the most economical system available. In large buildings with regular repetitive layouts, this additional design effort is offset by the construction savings realized. Using the simplified methods and equations described in this paper, these systems are viable for many routine designs.
Probabilistic Modeling of Steel Moment Frames with Welded Connections
Authors: Song Jianlin , Ellingwood Bruce R.
Published: April 2024

Improved building practices for earthquake-resistant design and evaluation rely on accurate nonlinear analysis procedures and a rational approach to dealing with uncertainties. To address building performance issues and support probability based evaluation of steel buildings, two steel moment-resisting frames (WSMF) that suffered damage to welded connections in the Northridge Earthquake are evaluated using deterministic and stochastic approaches. Nonlinear dynamic analyses of these two buildings utilize a new degrading hysteretic connection model that incorporates the effects of weld fractures. The role of inherent randomness and modeling uncertainties in ground motion and structural resistance in forecasting or explaining observed building performance is examined for one of the buildings, leading to a probabilistic description of building performance and insights that are useful for condition assessment and performance based design.
Discussion: The Effects of Over-Compressing ASTM F959 Direct Tension Indicators on A325 Bolts Used in Shear Connections
Authors: Ricker David
Published: April 2024

Discussion
Repair of Existing Steel Moment Frame Buildings Damaged from Earthquakes Using Fracture Tough Weld Overlays
Authors: Simon Warner , Anderson James , Compton Jack , Hayes Walter , Maranian Peter
Published: April 2024

This paper reports the first phase of a research and testing effort by a volunteer group of Metallurgists, Structural Engineers, Testing Engineers, and Welding Engineers who have developed methods of repairing existing earthquake damaged steel moment frame connections, using fracture tough weld overlays enabling the joint to be considered as a Dynamic Load Weld (DLW). This follows the well reported damage to Steel Moment Frame Buildings observed following the January 17, 1994 Northridge Earthquake. Subject to more research and testing, the methods may eventually prove suitable for modification of existing steel moment frame buildings and new construction, along with application in other industries.
Errata: Beam-Column Base Plate Design—LRFD Method
Authors: Drake Richard M. , Elkin Sharon J.
Published: April 2024

Errata
Steel Plate Shear Walls—An Overview
Authors: Kulak Goeffrey L. , Kennedy D.J.L. , Driver Robert G. , Medhekar Manoj
Published: April 2024

Steel plate shear walls are an innovative lateral loadresisting system capable of effectively bracing a building against both wind and earthquake forces. The system consists of vertical steel infill plates one story high and one bay wide connected to the surrounding beams and columns. The plates are installed in one or more bays for the full height of a building to form a stiff cantilever wall. North American practice is to use unstiffened plates. Steel plate shear walls are well-suited for new construction, and they offer a relatively simple means for the seismic upgrading of existing steel or concrete structures. Several researchers have conducted tests on single-story and small-scale multistory laboratory specimens. The most significant physical testing has been that of a large-scale four-story, single bay specimen. Tested under controlled cyclic loading to determine its behavior under an idealized severe earthquake event, it endured 30 cycles of loading, including 20 cycles in the inelastic range. It showed excellent ductility and energy dissipation characteristics, and exhibited stable behavior at very large deformations and after many cycles of loading. Both a non-linear finite element model and a plane frame analysis model suitable for design office use are available. The seismic performance of the steel plate shear wall concept has been further evaluated using a hypothetical multi-story building located in Vancouver, Canada. The examination was done in accordance with the National Building Code of Canada. The seismic response is assessed with a linear static analysis and a response spectrum analysis, both standard analysis procedures in seismic design practice. A nonlinear static "pushover"ť analysis was also performed to determine the inelastic static response. The inelastic dynamic response was obtained from nonlinear dynamic time history analyses using a set of appropriately selected earthquake accelerograms.
Strength of Singly Symmetric I-Shaped Beam-Columns
Authors: Galambos Theodore V.
Published: April 2024

The AISC-LRFD Specification provides a conservative prediction of the strength of singly symmetric I-shaped beam-columns bent about the axis of symmetry if the compression flange is larger than the tension flange. This paper presents a more economic method that bases the in-plane capacity on the attainment of the full plastic capacity of the cross-section, and the lateral-torsional strength on an inelastic modification of the elastic buckling solution. The proposed derivations are based on essentially the same philosophy as the ones for the doubly symmetric wide-flange design rules in the AISC Specification. However, for singly symmetric shapes it is not possible to arrive at simple approximate empirical interaction equations. The proposed methods are of necessity spreadsheet oriented, and an appendix to this paper provides a sample calculation scheme using the MATHCAD software as the vehicle of calculation.
Influence of Bolt-Line Eccentricity on WT Tension Member Capacity
Authors: Barth Karl E. , Orbison James G. , Bartels Peter A.
Published: April 2024

This paper focuses on the influence of connection eccentricity (as defined by the perpendicular distance between the bolt-gage line and the elastic neutral axis) on the capacity of WT sections designed as tension members. A series of eight Grade 50, WT6x7 short tension member specimens (specimens were 36 in. in length) were tested to determine their ultimate load capacity. The experimental tests were performed by loading the specimens through the stem in direct tension. The WTs were fabricated with varying edge distances (4 total nominal edge distances) and with both punched and drilled holes. The experimental failure loads are compared with the design resistance predicted by the AISC Load and Resistance Factor Design Specification for Structural Steel Buildings, hereinafter referred to as "the specification" (AISC, 1993). It is shown that sections with small eccentricities perform reasonably well when compared with predicted resistance. However, as the eccentricity is increased, the specification is unconservative in predicting the failure load.
Errata: Design Tables for Top- and Seat-Angle with Double Web-Angle Connections
Authors: Kim Yosuk , Chen Wai-Fah
Published: April 2024

Errata
Elastic Design Charts for the Rapid Selection of Web Bolts for Composite Steel Bridge Splices
Authors: Sheikh-Ibrahim Firas I.
Published: April 2024

Selection of the web bolts for steel bridge girder splices requires a trial and error procedure. A group of bolts is initially selected, and its resistance is checked against the required resistance. If the provided resistance is less than required, a new group of bolts is selected and the procedure is repeated until an acceptable design is achieved. In this paper, elastic design charts for the rapid selection of web bolts are presented along with three design examples. The charts are developed to be used for composite bridge girder splices at either the strength limit state or the service limit state, but can be used for any other eccentric shear connection. The charts can be used for connections with bolted depths ranging from 900 mm to 2000 mm, eccentricity-to-bolted-depth ratios up to 1.5, design forces applied at 0° to 80° from the vertical axis, a uniform vertical bolt spacing, and a horizontal bolt spacing of 75 mm. The required bolt pattern can be determined directly from the charts for a known bolted depth, eccentricity, vertical design shear, angle of the design force line of action, and factored resistance of one bolt.
Steel Shell Roof Structures
Authors: Nilson Arthur H.
Published: April 2024

The advantages of shell structures for enclosing large, column-free areas are well known. While reinforced concrete has dominated the field of shell construction for many years, recent developments have indicated the feasibility of using steel for certain singly- and doubly-curved roofs. Steel shells are attractive and highly versatile. They are extremely light in weight, well suited to the preassembly of parts, and do not require the elaborate formwork and scaffolding during construction that is associated with concrete shells. Steel shells may be constructed using the standard light gage steel roof deck panels available from many sources in the United States and abroad. A few of the more common panels are shown in cross section in Fig. 1. Used in shell structures, the panels carry normal loads by their flexural strength, but in addition are designed to resist membrane shear loads acting in the plane of their surface. While various shell forms have been built using such panels, there are certain limitations. Standard panels can not be curved much in the direction of their length, and it is not advisable to curve them transversely, except for the most elementary corrugated sections. However, plane subelements can be used as components of curved shells. In addition, most panels can be warped to a certain degree about an axis parallel to their length.
One Engineers Opinion (Lateral Support)
Authors: Milek Jr. William A.
Published: April 2024

One Engineers Opinion
Analysis of Curved Steel Girder Bridges
Authors: Lavelle Francis H.
Published: April 2024

In recent years, with the introduction of highway interchanges in cities, a demand for curved bridges has developed. A typical city interchange is one proposed for Interstate Highway 95 in Providence, R. I., for which most of the ramps are on structure. Steel girder bridges are a good solution to this type of problem. Many such horizontally curved bridges have been built, but generally the steel girders have been straight. However, if one knew with reasonable certainty how to design curved steel girders, there would be definite advantages.
Errata: Column Stability in Type 2 Construction
Authors: De Falco Fred , Marino Frank J.
Published: April 2024

Errata
A Plastic Method For Unbraced Frame Design
Authors: Daniels J. Hartley
Published: April 2024

Frequently, because of architectural or functional requirements, no structural bracing can be permitted in the plane of a multi-story frame. Furthermore, with the trend in modern building design towards light curtain wall construction, larger window areas, and removable interior partitions, the bracing effect provided by cladding is often small or unreliable. Because of this situation the designer is faced with the design of an unbraced multi-story frame in which the bare structural skeleton of columns and girders must resist all applied gravity and lateral loads. Certain initial steps in the design of unbraced frames are identical to the same steps in braced frame design. For example, the dimensional layouts in both designs, being based on architectural and functional requirements, will likely be similar. The assignment of load systems and their distribution to the plane frame will be the same. The working loads will also be increased by the same load factors in each design.
Discussion: Design Aids--Minimum Depth and Allowable Bending Stress
Authors: Marrone Adolph A.
Published: April 2024

Discussion
Design of Free Flange Moment Connection
Authors: Choi Jaehyung , Stojadinovic BoÅ¾idar , Goel Subhash C.
Published: April 2024

The Free Flange connection is a new public-domain beam-to-column moment connection developed at The University of Michigan. This connection is designed to alleviate excessive local deformation and shear force overload of beam flanges in pre-Northridge fully-restrained steel moment connections. These design goals were achieved by cutting the web of the beam back and away from the column, thus creating portions of the beam flanges that are not constrained by the web. Such free portions of beam flanges significantly reduce connection deformation constraints; allow the flange steel to yield freely; and help to redirect most of the shear force back into the web connection. Seven full size Free Flange connection specimens were tested to validate the design concept, check the design procedure, and prequalify the connection for use in practice. The connection was prequalified for the tested beam and column sizes, with all specimens exceeding 0.04 radian total rotations before failure, and behaving in a ductile manner. The original Free Flange connection design procedure was modified based on the observed specimen behavior. The new design procedure is presented and compared to the Free Flange connection design procedure in the FEMA 350Design Guidelines.
Design Recommendations for Bolted Rectangular HSS Flange-Plate Connections in Axial Tension
Authors: Willibald S. , Packer Jeffrey A. , Puthli R.S.
Published: April 2024

In recent years the use of closed sections/tubes as structural members has increased significantly. Designers all around the world approve of the advantages that round as well as rectangular hollow structural sections (HSS) can offer, such as uniform strength and stiffness independent of the loading direction, high torsional and buckling strength and the aesthetic appearance. Splicing structural members is a common practice in construction to allow for long spanning trusses, changes in cross sections and transportation to site, to name but a few. The results of an experimental investigation of four bolted flange-plate connections between rectangular hollow structural sections, with bolts on all four sides, have been presented. A brief overview of different design methods for bolted flange-plate connections for square and rectangular hollow structural sections under tension load has also been given. A comparison of the load predictions of the various methods for the specimens in the experimental program supports the use of the design procedure that can be found in the AISC HSS Connections Manual (AISC, 1997).
Errata: Strengthening of Existing Composite Beams Using LRFD Procedures
Authors: Miller John P.
Published: April 2024

Errata
Strength of Joints that Combine Bolts and Welds
Authors: Kulak Geoffrey L. , Grondin Gilbert Y.
Published: April 2024

The capacity of each connector type in a shear-splice type of joint is reflected by its shear strength and shear deformation characteristics. When two or more types of fasteners share the load, it is clear that it is not satisfactory to simply combine the ultimate strength of each individual fastener type. Each of the different fastening elements has a different ductility and, in general, each reaches its ultimate strength at a different value of overall connection deformation. The strength of joints that combine bolts and fillet welds that act in the same shear plane has been examined. The study has shown that the rules provided in the AISC LRFD Specification do not adequately reflect the actual strength of this type of joint. Using test results from the University of Alberta and others, expressions are presented for the capacity of the various elements that make up a bolted-welded joint. These expressions enable the capacity of a combined bolted-welded joint to be predicted with a reasonable degree of accuracy. The examination showed that transverse fillet welds do not work well in combination with bolts because of the limited ductility of the former.
Assessment of the Fire Resistance Test with Respect to Beams in Real Structures
Authors: Lamont Susan , Lane Barbara , Usmani Asif , Drysdale Dougal
Published: April 2024

Historically fire resistance design of structures has been based upon single element behavior in the standard fire resistance test. Engineers have always recognized that whole frame structural behavior in fire cannot be described by a test on a single element. However, it is only in relatively recent years since the Broadgate phase 8 fire (SCI, 1991) and the subsequent Cardington frame fire tests that researchers have fully nvestigated and understood the behavior of whole structures in response to fire. The University of Edinburgh in collaboration with Imperial College and Corus (formally British Steel) have played a major role in this field of research through the UK Department of Environment and Transport in the Regions (DETR), Partners in Technology (PiT) project. Significant progress towards a complete understanding of the structural behavior of highly redundant composite steel frames in fire has been achieved (Edinburgh University, 2000). It has been shown that the fire resistance test has little relevance to the behavior of structural elements as part of highly indeterminate structures typical of modern, composite steel frame buildings. The test methods are particularly inadequate when the end conditions during service are unknown and the beam is tested as simply supported, i.e. no consideration of restraint is made. By including the effect of restraint in a simple beam model the temperature at which "runaway" occurs is greatly increased. The reasons for this, i.e. the changing load-carrying mechanisms involved as catenary action develops as a result of the deflected shape have also been explained.
A Comparison of Australian and American Design of Double Angle Connections
Authors: Carrato Peter J.
Published: April 2024

A large boiler support structure for a coal-fired power plant in Australia was designed by a structural engineer in the United States. Approximately 9,000 tons (8,181 tonnes) of structural steel for this project was supplied from a steel fabricator in China, using shop drawings prepared by an American detailing firm. A registered professional engineer from the designer's Australian offices supervised the work in the United States to ensure compliance with local codes and standards. Member sizes were selected from ASTM shapes, using the provisions of the Australian Standard for steel structures AS4100 (Council of Standards, 1998). However, to expedite steel delivery, it was decided to allow the detailing firm to prepare connection designs using the American Institute for Steel Construction's (AISC), Specification for Structural Steel Buildings—Allowable Stress Design and Plastic Design (ASD) (AISC, 1989). Demonstrating the compatibility of connection designs prepared using these two methods highlighted the unique difference between simple code compliance, and the art of connection design. The intent of this study is not to establish the appropriate limit states for a clip angle connection. There are numerous references that deal with this topic (Birkemoe and Gilmor, 1978; Munse, Bell and Chesson, 1959). The purpose is also not to demonstrate that one country's design approach is either superior to or less conservative than that of another country. What has been shown is that, given a structural design problem as common as a clip angle, two different approaches to engineering, based on training and experience, can interpret relatively similar design specifications, to produce significantly different results.
Discussion: A Technical Note - Derivation of the LRFD Column Design Equations
Authors: Lu Le-Wu
Published: April 2024

Discussion
Closure: Comparison of Design Specifications for Design of Pipe and Round HSS Pedestrian Guardrail Systems
Authors: Sputo Thomas
Published: April 2024

Closure
Elastic and Plastic Section Moduli of Steel Angles About Principal Axes
Authors: Ding Yongcong , Madugula Murty K.S.
Published: April 2024

Steel angles are frequently subjected to bending moment due to self-weight, wind load, eccentricity of connections, etc. Depending on the width-to-thickness ratios and unbraced length-to-width ratios, they can develop full plastic moment of resistance under transverse loads. AISC Manual of Steel Construction (Third Edition) gives the elastic and plastic section moduli about the geometric axes (X and Y axes) only and not about the principal axes. There is a need to calculate elastic and plastic section moduli of angle sections about the principal axes for use in determining their bending strength. Based on the simplified assumption that the cross-section consists of two rectangles (i.e., ignoring the effect of toe and heel radii), formulas to locate the major and minor plastic principal axes and to determine the corresponding section moduli are derived in this technical note. The results of the computations for all of the angle sections listed in the AISC Manual (Third Edition) are tabulated.
Fabrication Aids for Cold Straightening I-Girders
Authors: Gergess Antoine , Sen Rajan
Published: April 2024

Fabrication out-of-straightness in steel girders can be rectified using heat straightening or cold straightening. While heat straightening has been extensively researched, little information is available on cold straightening where loads are used to achieve the same result. This paper provides an analytical framework for an innovative cold straightening (also referred to as cold bending) system developed by a fabricator. Maximum safe limits on loads, out-of-straightness and load frame configurations that are consistent with prevailing "Load and Resistance Factor Design" (LFRD) criteria are proposed. Fabrication aids for Grade 250 (Fy = 36 ksi) and 345 (Fy = 50 ksi) steel are developed and their application illustrated by three numerical examples.
Discussion: Using Moment and Axial Interaction Equations to Account for Moment and Shear Lag Effects in Tension Members
Authors: Grondin Gilbert Y.
Published: April 2024

Discussion
Errata: Steel Plate Shear Walls Are Not Plate Girders
Authors: Berman Jeffrey W. , Bruneau Michel
Published: April 2024

Errata
Current Steel Structures Research No. 04
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
A Comparison of the Krawinkler and Scissors Models for Including Beam Column Joint Deformations in the Analysis of Moment Resisting Steel Frames
Authors: Charney Finley A. , Marshall Justin
Published: April 2024

Current codes and specifications require that the flexibility of the beam-column joint region of moment resisting frames be included in structural analysis. The two most popular analytical models for modeling the joint are the Krawinkler model and the Scissors model. Each of these models represent a mechanical analog of the joint, with the joint being represented as an assembly of rigid links and rotational springs. This paper provides a complete derivation for the nonlinear spring properties to be used in the Krawinkler and Scissors models, and through nonlinear static and dynamic analysis, shows that the models, when properly used, produce similar but not identical results. It is further shown that the properties for the two models are not interchangeable; the spring properties derived for the Krawinkler model may not be used directly in the Scissors model. Unfortunately, several references that recommend the use of the Scissors model erroneously suggests that the spring properties for this model are the same as those derived for the Krawinkler model. This paper quantifies the effect that this assumption has on the computed nonlinear static and dynamic response of a moment frame, and shows that the result of the error may have a negative impact on the economy of steel moment frames.
Solutions for Enhancing the Fire Endurance of HSS Columns Filled with High Strength Concrete
Authors: Kodur V.K.R.
Published: April 2024

Steel-concrete composite columns offer a number of benefits and are often used in multistorey buildings and industrial structures. In this paper the fire performance of high strength concrete-filled steel hollow structural section (HSS) columns is presented for various types of concrete filling. A comparison is made of the fire resistance performance of HSS columns filled with normal strength concrete (NSC) and high strength concrete (HSC). The factors that influence the behaviour of HSC-filled HSS columns, under fire conditions, are discussed and solutions are suggested for enhancing fire resistance of these columns.
In-Plane Properties and Modeling of Reduced Beam Sections
Authors: Dumonteil Pierre
Published: April 2024

In the seismic design of steel frames, one of the objectives is to provide ductile beams capable of energy dissipation through the formation of plastic hinges (or "fuses"). With wide-flange shapes, it is desirable to force these hinges away from the brittle zones near the column faces by reducing the beam section at some specified distance from these faces. Obviously, the cuts change the overall elastic properties of the reduced beam sections (RBS). However, the cuts also affect the fixed-end actions used in the elastic analysis of the structure. The first objective of this paper will be to compute not only the stiffness properties of RBS, but also the fixed-end actions. Most structural analysis programs found in design offices do not let the designer input stiffness matrices and fixed end actions. Input of beam elements is usually limited to prismatic or tapered beams. The second objective will be to show how this difficulty may be overcome by modeling a RBS with three prismatic beam elements of suitable properties. Some very simple frames will be used as examples to compare interstory drifts, and examine the Q33 method proposed by Iwankiw and Mohammadi in an earlier paper. Coincidentally, these calculations lead to the observation that beam shear deformation is not always negligible.
Current Steel Structures Research No. 06
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Discussion: Flexible Moment Connections for Unbraced Frames Subject to Lateral Forces â€” A Return to Simplicity
Authors: Foley Christopher M , Schaad John A.
Published: April 2024

Discussion
Failure of Welded Moment Resisting Connections
Authors: Short Andrew , Woerner Wolfram W. , Ferguson George , Clifton G. Charles
Published: April 2024

Potential failure modes in moment resisting connections (MRCs) subject to seismic loads must be controlled, so that adverse modes such as brittle fracture are avoided and ductile modes develop in a predictable manner. To simulate volumetric imperfections in fillet welds, an unfused region was created by removing a section of the weldment, thus creating a full-depth lack of penetration imperfection. Five large-scale MRC specimens were tested, with these imperfections varying in both size and location. Critical "loss of area" parameters for establishing a threshold are determined for the minimum required deformation capacity of a connection and for establishing a threshold between desirable and undesirable failure mechanisms. Increasing the resistance to deformation in the panel zone is considered likely to provide enhanced weld performance. This paper also provides evidence and discussion of the effect of strong and very strong panel zones on the integrity of connection welds.
Evolution of Shear Lag and Block Shear Provisions in the AISC Specification
Authors: Geschwindner Louis F.
Published: April 2024

The American Institute of Steel Construction (AISC) has published two standards for design of steel structures for the past 19 years, an allowable stress specification, ASD, and a limit states specification, LRFD. The AISC Committee on Specifications has developed a new standard that includes provisions for design according to both ASD and LRFD. For connection design, the specification evolved as provisions from the previous specifications were integrated into the new provisions. This paper highlights the provisions for shear lag and block shear from the 2005 AISC Specification for Structural Steel Buildings provisions and the changes that have taken place from previous editions of the specifications.
Errata: Strengthening Open-Web Steel Joists
Authors: Fisher James M.
Published: April 2024

Errata
Seismic Performance of a 62-Story Steel Frame Hotel Tower
Authors: Hines Eric M. , Henige Richard A.
Published: April 2024

This paper introduces the seismic design and performance of a 62-story hotel tower in Beijing, China, and discusses conceptual conflicts that arose during the design process between code provisions and expected seismic behavior. For instance, while the IBC 2000 requires such a tower to be designed as a Special Moment Resisting Frame, pushover analysis studies (not permitted by FEMA 350 for such a tall building, but allowed by the design review board for collapse analysis during this design process) suggested that inelastic rotation demands were on the order of the 2002 AISC requirements for Intermediate Moment Resisting Frames. Furthermore, while axial force demands in the columns resulting from the pushover analyses exceeded the demands calculated according to the AISC building overstrength factor of 3.0, these high axial load demands clearly resulted from the pushover analysis loading pattern derived from the tower's fundamental mode shape. Time history analyses showed that both the extent of plastic hinging and the magnitude of overturning forces under actual earthquake demands were significantly lower than the levels produced from response spectrum and pushover analyses. Finally, in a capacity spectrum assessment under maximum considered earthquake (MCE) response spectrum loads, ductile capacity in the beams did very little to enhance the tower's performance. Several of these results were easily explained by the fact that the Chinese Code response spectrum controlling the design was artificially high for longer periods. This code requirement implied that increased strength, not increased ductility, would improve the tower's ability to withstand MCE demands according to a capacity spectrum assessment. The purpose of this paper is to identify these conflicts in the context of a real project where circumstances prevented the coordination of consistent seismic design criteria.
Development and Application of Large-Size Shear Studs to Steel Girder Bridges
Authors: Badie Sameh S. , Girgis Amgad , Tadros Maher K. , Nguyen Nghi
Published: April 2024

This paper presents the development and recent applications of 31.8 mm (1¼ in.) studs to steel girder bridges. The new studs have double the cross-sectional area of 22.2 mm (7/8 in.) studs, resulting in a reduction of the number of studs needed to achieve full composite action with the concrete deck by 50%. Use of the 31.8 mm (1¼ in.) studs has many advantages: (1) increase of fabrication and construction speed, (2) ease of deck construction, (3) ease of deck removal, and reduction of the possibility of damage to studs and girder top flange during that removal, and (4) enhancement of the safety of field personnel during construction because more space on the top flange is available for walking. Experimental investigation of the 31.8 mm (1¼ in.) stud showed that the stud fatigue and ultimate capacities can be conservatively determined using current AASHTO bridge specifications to achieve full-composite action.
Seismic Design of Steel Joist Girder Structures
Authors: Kim Uksun , Leon Roberto T. , Galambos Theodore V.
Published: April 2024

Current seismic design provisions emphasize detailing that results in large system ductility and energy dissipation. This may not be the best approach for flexible structures that may be able to withstand large earthquakes in the elastic range or with very limited inelasticity. Among these types of structures are tall one-story frames often constructed utilizing joist girder systems. The main objective of this study is to provide a safe and efficient seismic design methodology for steel joist girder structures; typically one-story industrial or commercial structures intended primarily to carry light roof loads. A new design procedure based on the weak column—strong beam concept is developed and experimental and analytical verification studies are described. A full-scale cyclic test and pushover analyses show that the intended mechanism can be achieved if the required design strength of the joist girder members and connection to column are based on a column flexural strength of 1.2RyMpc. This design requirement is needed in order to avoid a buckling failure of the compression angle members of a joist girder and failure of connections at the end of the joist girder.
Current Steel Structures Research No. 12
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Errata: Geometric Formulas for Gusset Plate Design
Authors: Chambers Janice J. , Bartley Tony C.
Published: April 2024

Errata
Reduced Beam Section Spring Constants
Authors: Mortensen Bart , Chambers Janice J. , Bartley Tony C.
Published: April 2024

A moment connection that includes a wide flange beam with trimmed flanges is commonly known as a Reduced Beam Section (RBS) connection. Accurate analysis of frames incorporating RBS beams requires knowledge of the elastic stiffness matrix of RBS beams. In lieu of using this stiffness matrix, an RBS beam can be modeled as an Euler-Bernoulli frame element with rotational springs at each end, which can be easily implemented in structural analysis software. This paper presents the derivation of the formula for the spring constants of an RBS beam and validates it. From a study of the spring constants for a plethora of RBS beams, it was found that a strong linear relationship exists between the minimum plastic section modulus of RBS beams and their spring constants. This paper has direct applicability to the practical and accurate determination of the elastic drift of a moment frame with RBS connections.
Current Steel Structures Research No. 14
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
A Comparison of Frame Stability Analysis Methods in ANSI AISC 360-05
Authors: Carter Charles J. , Geschwindner Louis F.
Published: April 2024

Two simple unbraced frames are used to illustrate the application of the following four frame stability analysis methods:

1. The Second-Order Analysis Method (ANSI/AISC 360-05, Section C2.2a)
2. The First-Order Analysis Method (ANSI/AISC 360-05, Section C2.2b)
3. The Direct Analysis Method (ANSI/AISC 360-05, Appendix 7)
4. The Simplified Method (13th Ed. Steel Construction Manual page 2-12; AISC Basic Design Values cards)
Errata: Design Aid for Triangular Bracket Plates Using AISC Specifications
Authors: Shakya Shilak , Vinnakota Sriramulu
Published: April 2024

Errata
Errata: Reduced Beam Section Spring Constants
Authors: Mortensen Bart , Chambers Janice J. , Bartley Tony C.
Published: April 2024

Errata
Discussion: Block Shear Equations Revisited...Again
Authors: Driver Robert G.
Published: April 2024

Discussion
Experimental Evaluation of Kaiser Bolted Bracket Steel Moment-Resisting Connections
Authors: Adan Scott M. , Gibb William
Published: April 2024

The Kaiser bolted bracket (KBB) is a new beam-to-column moment connection that consists of proprietary cast high-strength steel brackets that are fastened to the flanges of a beam and then bolted to a column. This fully restrained connection is designed to eliminate field welding in steel moment frame construction. This paper summarizes the development of bolted bracket connections and presents the results of seven full-scale KBB tests. These tests were conducted to evaluate the connection for both the retrofit of existing and the construction of new steel moment frames. More specifically the tests were intended to assess the ductility of the connection under cyclic inelastic loading and to qualify their performance with respect to code requirements.
Message from the Editor
Authors: Grubb Keith A.
Published: April 2024

Editor's Note
Current Steel Structures Research No. 20
Authors: Bjorhovde Reidar
Published: April 2024

The strength and behavior of connections under monotonic and cyclic loads are addressed in one of the projects presented in this paper. One of the interesting features of this study is the hybrid nature of the connections, whereby elements of different steel grades are used in the connections, to achieve improved performance as well as economy. Such thinking has also gone into examinations of the behavior of tubular (HSS) members in structures, for which two major projects have recently been initiated in Europe. Structural stability and the assessment of first and second order effects are examined in a project that aims at improving how these parameters are treated, using an energy-based solution. Last, but not least, a major research effort has focused on how to extend service life and performance for a range of different types of welded joints and structures.
Notes on the Impact of Hole Reduction on the Flexural Strength of Rolled Beams
Authors: Geschwindner Louis F.
Published: April 2024

The use of phi (resistance factor) = 0.9 and omega (safety factor) = 1.67 with the provisions in Section F13.1 of AISC 360-05 (AISC, 2005) to account for the reduction in flexural strength for a beam with holes in the tension flange has been questioned several times since the publication of the Specification for Structural Steel Buildings in 2005. The intent of this paper is to review and provide justification for the use of the resistance/safety factors within the 2005 Specification provisions for the impact on flexural strength of holes in the tension flange.
Tables for Eccentrically Loaded WT Shapes in Compression
Authors: Gordon Mark E.
Published: April 2024

WT shapes are often used for bracing, and they are typically connected to their supports with gusset plates on the flange. This attachment creates an eccentric axial load on the WT, which is not considered by design tables in the 13th edition AISC Manual of Steel Construction. This paper demonstrates one method for generating design tables that account for this eccentric loading.
Current Steel Structures Research No. 22
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Current Steel Structures Research No. 23
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Singly Symmetric Combination Section Crane Girder Design Aids
Authors: Johnson Patrick C. , Laman Jeffrey A.
Published: April 2024

Crane runway girders are distinguished by long, unbraced lengths and biaxial bending. Combination sections consisting of a W-shape with a channel cap are typically efficient for these conditions, but time consuming to design due to the iterative process required due to biaxial bending and the complex stability equations provided in the 2005 AISC Specification. This paper presents developed Zx (plastic section modulus) tables and flexural strength graphs and introduces a trial section selection method. Included herein are updated design charts to allow for fast and efficient analysis of the typical combination sections provided in Table 1-19 of the 13th edition AISC Steel Construction Manual. Also presented is an overview of crane girder design procedures and an abbreviated design example.
Analysis and Design of Steel Slit Panel Frames (SSPFs) for Seismic Areas
Authors: Cortes Gustavo , Liu Judy
Published: April 2024

The steel slit panel frame (SSPF) system is a new seismic force-resisting system (SFRS) intended for areas of high seismicity. The main components in an SSPF are steel beams and columns and steel slit panels (SSPs). SSPs are steel plates with rows of vertical slits cut at equidistant spaces. Links (small columns) are formed between the slits. When the panel is subjected to shear load, these links behave as beams in double curvature, reaching their plastic moment capacity at both ends. Beams are simply connected to the columns in the SSPF. The SSPs provide all the stiffness, strength and energy dissipation in the system. This paper presents the design of the SSP and the SSPF system. This paper also presents two prototype buildings which were designed for a site in Los Angeles, California. Finally, a simplified model developed for analyzing SSPs is presented.
Closure: Design and Behavior of Multi-Orientation Fillet Weld Connections
Authors: Callele Logan J. , Driver Robert G. , Grondin Gilbert Y.
Published: April 2024

Closure
Discussion: Design and Behavior of Multi-Orientation Fillet Weld Connections
Authors: James Robert A.
Published: April 2024

Discussion
On the Need for Stiffeners for and the Effect of Lap Eccentricity on Extended Single-Plate Connections
Authors: Thornton William A. , Fortney Patrick J.
Published: April 2024

The design procedure for extended single-plate connections presented in the 13th edition of the Steel Construction Manual contains many design checks to ensure satisfactory performance but does not include a check of lateral-torsional stability of the extended single plate, which resembles a double-coped beam. Research has shown that coping of beams can reduce the lateral-torsional buckling strength of beams. This paper presents a proposal to use the double-coped-beam concept to ensure the lateral-torsional stability of the extended plate. The question of stiffeners and the effect of the small eccentricity due to the lapping of the plate with the beam web will also be addressed.
Seismic Design and Response of Crane-Supporting and Heavy Industrial Steel Structures
Authors: Richard Julien , Koboevic Sanda , Tremblay Robert
Published: April 2024

This paper presents an analytical study of the seismic behavior of two different types of industrial buildings; a regular mill-type crane-supporting steel structure and an irregular heavy industrial building housing a vertical mechanical process. For both structures, the seismic response is examined through elastic time-history dynamic analyses in order to validate the predictions from the equivalent static force procedure and the response spectrum analysis method prescribed in current building codes. The analyses also serve to assess the inelastic demand in crane-supporting structure. For the crane-supporting structure, analyses are performed for sites in Montreal and Vancouver in Canada and in Seattle in the United States. The results show that the median horizontal displacement and acceleration from the time-history analyses are generally well predicted by the code analysis methods. Inelastic response in these buildings is likely to develop in the form of buckling of the lower column segment, a failure mode that exhibits limited ductility. For the tall irregular building, the analyses are performed for the Montreal site only. The results show the equivalent static method provides fair displacements estimate, but may lead to unconservative predictions of column and brace forces. Response spectrum analysis method, as prescribed in design codes, appears to provide appropriate prediction of the seismic response of such highly irregular structures. For both building types, a good prediction from response spectrum and time-history analysis methods is possible only when a sufficient number of modes are used.
Repairable Seismic Moment Frames with Bolted WT Connections: Part II
Authors: McManus Patrick S. , Pucket Jay A.
Published: April 2024

A moment frame lateral load-resisting system was developed in which inelastic deformations due to seismic loading were intended to be isolated to easily replaceable WT components. Fully bolted connections were utilized to facilitate simple component installation and replacement. In Part I of this series, WT components for the moment frame system were modeled using finite element analysis. Full-scale component testing was performed to verify analytical results. Parameters taken from modeling and testing results were used to develop design provisions. In Part II of this series, an example building was designed using the provisions developed and analyzed under simulated earthquake accelerations to develop appropriate seismic performance factors. WT components designed using recommended geometric parameters resulted in desirable behavior. Recommended design equations correlated well to experimental test results. Experimental results suggested WT components designed using the recommended provisions exhibit adequate low-cycle fatigue performance and deflection capacity to be used with wide flange beams up to a nominal depth of 30 in. (762 mm). Nonlinear time-history analysis suggests seismic performance factors currently published for steel special moment frame systems are appropriate for the proposed WT moment frame system.
Applications of Pretensioned Anchor Rods in Industrial Facilities
Authors: Fang Shu-Jin
Published: April 2024

Base plate and anchor rod connections are key structural components. A great majority of anchor rods are designed, placed and installed without pretensioning, usually because the structures are considered to be statically loaded. Applications of pretensioned anchor rods are less common and generally limited to certain industrial facilities. This paper provides a brief overview of the current state of the practice regarding pretensioned anchor rods and reviews selected recent pretensioned anchor rod applications in power industry facilities.
Current Steel Structures Research No. 29
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
AASHTO LRFD Provisions for the Seismic Design of Steel Plate Girder Bridges
Authors: Itani Ahmad M.
Published: April 2024

Recent earthquakes have exposed the vulnerability of steel plate girder superstructures to seismic forces. Damage has occurred in cross frames and their connections, shear connectors, and steel plate girders. These earthquakes have revealed the shortcomings of U.S. bridge design specifications for these types of bridges. Section 6 of the AASHTO LRFD specifications does not have any seismic design provisions for steel plate girder bridges. Recently, these specifications have adopted seismic design provisions that are proposed by the authors for steel superstructures to overcome this shortcoming. The adopted specifications are the result of analytical and experimental investigations by various researchers and work published by many seismic provisions and guide specifications. This paper summarizes the new seismic design provisions and outlines the background behind them.
Current Steel Structures Research No. 31
Authors: Bjorhovde Reidar
Published: April 2024

Current Steel Structures Research
Allowable Loads on Beams without Lateral Support
Authors: Mataya John
Published: April 2024

Beams with unbraced lengths along the compression flange greater than Lc or Lu require the designer to consider factors other than section modulus alone, since torsional properties and the lateral bending strength of the compression flange influence the ability of the beam to resist lateral buckling. This paper presents tables developed to aid the designer in rapidly selecting the most economical WF or I section for laterally unsupported beams.