bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Strength Bolting
Authors: Munse W.H.
Published: April 2024

Just twenty years ago Professor Wilbur Wilson, a Professor of Structural Engineering at the University of Illinois, played a major role in the founding of the Research Council on Riveted and Bolted Structural Joints, the group largely responsible for high-strength bolting as we know it today. Since then, thousands of tests have been conducted on high-strength bolts and bolted connections, specifications for high-strength bolting have been issued by the Council, and many millions of high-strength bolts have been used in bridges and buildings. The high-strength bolt rapidly took its place in the structural field and has now become the "workhorse" fastener for steel structures. Although this fastener has proven to be extremely effective, occasionally trouble has been encountered and questions have been raised concerning high-strength bolting. Whenever such trouble has been encountered, it has almost always been as the result of a lack of understanding or improper application of the Councils specification. To help counteract this problem, an attempt will be made herein to provide some of the "whys" and "wherefores" of high-strength bolting. Some of the questions that are raised regarding high-strength bolting will be examined, consideration will be given to some of the changes that were introduced in the September, 1966 revision of the Research Councils specifications for high-strength bolting, and finally, some of the possible future changes and new applications of high-strength bolting will be discussed.
Errata: Ponding of Two-Way Roof Systems
Authors: Marino Frank J.
Published: April 2024

Errata
Errata: Discussion: Design Aids: Minimum Depth and Allowable Bending Stress
Authors: Marrone Adolph A.
Published: April 2024

Errata
Horizontally Curved Steel Girders; Fabrication and Design
Authors: Thatcher W.M.
Published: April 2024

The use of horizontally curved steel girders in bridge construction is relatively new. In 1961 there were probably not more than half a dozen bridges built with curved girders. In the American Bridge Div. of U. S. Steel Corporation, total inquiries for bridges using curved girders had only amounted to approximately 1,500 tons by the end of 1965. However, in 1966 alone inquiries amounted to more than 1,600 tons. These guidelines are based on the supposition that misalignment between the span and the abutments can be tolerated. If not, the bearing devices must act in a plane tangent to the curve at the end bearing, and the effect of restricted movement must be considered in the design of the span and the bearings. As knowledge is further developed on the design and fabrication of curved girders, they will become more and more commonplace as highway bridge structures which fit particular locations as economically and esthetically as possible.
Hyperboloid Space Frames for Tower Structures
Authors: Levinton Zusse
Published: April 2024

In recent years the quest for esthetics in structural design has resulted in a number of new forms, utilizing shells, folded plates and other sophisticated shapes in reinforced concrete and metals. Rather pleasing effects have been achieved by exposing the structural framing on the exterior of building walls in checkered and diamond patterns. In the design of towers, graceful shapes and patterns of framing have been obtained by following the geometry of hyperboloids and other curved surfaces. While glamour, display and advertisement may be the factors inspiring some lavish architecture, there is still a need for esthetic treatment of more prosaic structures serving industrial and utilitarian purposes. One problem recognized by many architects and engineers is the water tower or elevated tank of conventional utilitarian design, an uninspiring sight at its best, and more often a blot on the landscape and a blight to the neighborhood. More attention is being given to improvement in appearance of water towers. Generally, better architectural treatment involves greater costs. More pleasing shapes of the tank proper, such as spheres and spheroids are not costly in themselves. The supporting tower structure, however, is more of a problem. Among recent designs, esthetic solutions are provided by rigid frames of steel or concrete, by metal shells as main supporting structure or as cover for interior framing, and by massive architectural masonry.
Discussion: High-Strength Bolting
Authors: Kulak Goeffrey L.
Published: April 2024

Discussion
Errata: Design of Beam-Columns
Authors: Hooper Ira
Published: April 2024

Errata
One Engineers Opinion (Beam Splice)
Authors: Marino Frank J.
Published: April 2024

One Engineers Opinion
Discussion: A Prestressed Steel Space Frame
Authors: Shah Manu , Rogers Paul
Published: April 2024

Discussion
Flange Bending in Single Curvature
Authors: Dowswell Bo
Published: April 2024

Local bending of beam and column flanges is a common design consideration in steel structures. In most cases, the flange bends in double curvature due to the restraining effect of the connecting element. When a restraining force is not present, the flange will deform in single curvature. Common cases of single-curvature bending occur at the bottom flange of monorail beams and at hanger rod connections. In this paper, the equivalent width method was explored in an effort to determine design procedures for elastic and plastic strength of flanges in single-curvature bending.This paper compares the available procedures for designing flanges bent in single curvature. New finite element models and yield line analyses are used to verify, expand and improve the existing design methods. Design recommendations are made for both elastic and ultimate strength approaches. Recommendations are also made for interaction of the local bending strength with longitudinal stresses in the flange. The effects of closely spaced loads and loads acting near the ends of members are also addressed.
Continuous for Live Load Steel Girder Construction in the Northern Panhandle of West Virginia
Authors: Ream Anthony , Beining William
Published: April 2024

This paper presents two recently constructed steel girder bridges in the northern panhandle of West Virginia featuring simple for dead load—continuous for live load (SDCL) construction. The design, fabrication, construction and maintenance of this structure type are explored in addition to positive impacts on traffic control.
Existing Simple Steel Spans Made Continuous: A Retrofit Scheme for the I-476 Bridge over the Schuylkill River
Authors: Griffith Thomas , Milius John A.
Published: April 2024

The rehabilitation of the SR 476 Bridge over the Schuylkill River near Philadelphia, Pennsylvania, converted existing steel multigirder simple spans into three- and four-span continuous units. Employing a design method typically used for construction of new simple-span-made-continuous (SSMC) steel girder bridges, it is believed to be the first bridge rehabilitation project in Pennsylvania to use such a scheme. The rehabilitation design upgraded load capacity of the girders to meet current LRFD code requirements. The SSMC design, coupled with other deck joint elimination techniques, was able to reduce the combined number of deck joints on the northbound and southbound structures from 25 to 8. With nearly all previous steel deterioration occurring at deck joints, this substantial reduction in deck joints will aid in extending the remaining life of the bridge. This paper will illustrate the construction methods employed for conversion of the bridge from multiple simple spans to continuous spans. The paper will also provide detailed insight into the many design requirements for this structural conversion, from substructure retrofits and sequential bearing replacements to superstructure continuity and full-depth concrete diaphragm details.
The Chevron Effect - Not an Isolated Problem
Authors: Fortney Patrick J. , Thornton William A.
Published: April 2024

Many connection elements are modeled as rectangular members under various combinations of shear, flexural, torsional and axial loads. Strength design is now used for steel members and connections; therefore, the traditional method of combining loads using beam theory needs to be updated to comply with strength design philosophy. Due to the extensive research available on the plastic interaction of rectangular members, a review of existing equations forms the basis of this paper. In cases where existing research is unavailable, new derivations are provided. An interaction equation is developed for strength design of rectangular connection elements under any possible loading combination.
Effect of Link-Beam Stiffener and Brace Flange Alignment on Inelastic Cyclic Behavior of Eccentrically Braced Frames
Authors: Imani Reza , Bruneau Michel
Published: April 2024

Finite element analysis was used to investigate the effects of the misalignment of the brace flange-to-beam connection point with the link-end stiffener (referred to as the offset in the paper) on the ductility of eccentrically braced frames (EBF). The offset was speculated to be a possible reason for the unexpected EBF failures observed in the aftermath of the Christchurch earthquake series of 2010 and 2011. EBF models with different detailing at the offset area were analyzed under monotonic and cyclic displacements. Results showed severe stress and strain concentration in the offset area, preventing the EBF from developing its expected ductility, and suggested possible initiation of a failure from the part of link flange located in the offset area. Simulation using the ductile fracture model implemented in ABAQUS resulted in a fracture pattern in agreement with the actual failed EBF. Results from analyses on different detail configurations showed that removal of the offset by modifying the brace section to build an ideal case, or by a simple change in the location of the link stiffener, can mitigate the problem of possible premature failure, with the latter solution being slightly less effective but much easier to be used in practice.
Steel Structures Research Update: Resilient Steel Plate Shear Walls
Authors: Liu Judy
Published: April 2024

Steel Structures Research Update
Strength of Beams in Beam-to-Column Connections with Holes in the Tension Flange
Authors: Swanson James A.
Published: April 2024

A discussion of several approaches to predicting the flexural strength of beams with holes in the tension flanges is presented. Experimental data pertinent to the discussion is then presented, summarized and analyzed. It is observed that although provisions in the AISC 360-16 specification predict a net section fracture of the tension flanges in a number of the experiments, many of those beams were able to achieve their full plastic moment prior to failure. Two alternative models are proposed as improvements to the provisions in AISC 360-16; the merits and limitations of those models are discussed.
Kinematics of Self-Centering Steel Plate Shear Walls with NewZ-BREAKSS Post-Tensioned Rocking Connection
Authors: Dowden Daniel M. , Bruneau Michel
Published: April 2024

This paper presents information on the combined contribution of post-tensioning and beam-to-column joint rocking connections in self-centering steel plate shear walls (SC-SPSWs) with the NewZ-BREAKSS connection (i.e., NZ-SC-SPSW). Detailed free-body diagrams developed and presented in this paper provide insights on the basic, fundamental kinematic behavior of this lateral force-resisting system. The fundamental equations presented provide information on the behavior of SC-SPSWs and are suitable to facilitate design. These are needed for the implementation and understanding of these types of self-centering steel frame systems.
Shear Capacity of High-Strength Bolts in Long Connections
Authors: Tide Raymond H.R.
Published: April 2024

Current design codes reduce the shear strength of individual bolts to account for potentially uneven distribution of force among the bolts including a 0.75/0.90 (83.3%) step function at 38 in. Available test data indicate there is no justification for a bolt shear strength reduction, especially the step function, due to the length of connection, provided that second-order effects are limited and gross and net section areas slightly exceed the AISC Specification limits (2010). A practical, empirical solution is proposed that maintains a reliability, ?, slightly greater than 4.0 for all connection lengths, using the current AISC resistance factor, ?, of 0.75.
Investigation of Web Post Compression Buckling Limit State and Stiffener Requirements in Castellated Beams
Authors: Menkulasi Fatmir , Moen Christopher D. , Eatherton Matthew R. , Kuruppuarachchi Dinesha
Published: April 2024

The research presented in this paper addresses the need for a design method to estimate the nominal capacity of castellated beams against concentrated loads. The limit state investigated is that of web post buckling due to compression loads. The purpose of the paper is twofold: (1) to investigate the limit state of web post buckling due to compression loads and (2) to quantify the enhanced capacity of the web post against concentrated loads when stiffeners are provided. Five castellated beam depths are considered, which cover a wide range of the available depths. For each beam section, three load cases are investigated: (1) center of load aligns with the middle of web post, (2) center of load aligns with the center of the hole, and (3) center of load aligns with a point half-way between the center of web post and center of hole. For each load position, two cases are considered: one without a stiffener and one with full-height transverse stiffeners. Each case is investigated using nonlinear finite element analysis to examine the behavior of the web post to failure. The efficiency of stiffeners to increase the resistance of castellated beams against concentrated loads is examined. For each investigated beam depth and stiffener arrangement, the loads that cause failure are noted. In addition, a simplified approach for checking the limit state of web post buckling in compression is proposed.
A Boundary Stress Model for Fillet-Welded Connection Plates
Authors: Callele Logan
Published: April 2024

A common structural steel connection design problem is to size a fillet-welded plate boundary for an eccentric shear and/or normal force. Three common design models for dealing with the design of the fillet-welded plate boundary are reviewed, and a new model is presented. The new model is derived to produce designs similar to the instantaneous center of rotation method; however, the model offers an explicit solution by assuming a stress distribution on the boundary that designers can easily confirm or modify in daily practice.
Effective Shear Plane Model for Tearout and Block Shear Failure of Bolted Connections
Authors: Teh Lip H. , Deierlein Gregory G.
Published: April 2024

In spite of many revisions to the block shear requirements of the AISC Specification, the model in the current Specification can result in calculated strengths and failure modes that are inconsistent with published test data. The inconsistencies are primarily related to the assumed interaction of tensile and shear resisting mechanisms, combined with the definition of net and gross shear planes that are unrealistic. Using recently published test results of single-bolt connections in mild and high-strength steel plates, the shear failure planes are observed to be neither the assumed net nor gross shear planes, which are the basis of the current design provision, but rather effective shear planes with a calculated area that is between the net and gross areas. Based on the tensile rupture and shear yielding mechanism, and assuming that the steel on the effective shear planes is fully strain hardened, a simpler and more accurate block shear design equation is proposed. The new equation is straightforward to implement as it requires a simple rearrangement of existing design variables to determine an effective shear failure area. Through verifications against 161 gusset plate specimens, tested by independent researchers around the world, the proposed equation is shown to be significantly more accurate than the current AISC, Canadian, European and Japanese block shear design provisions. A resistance factor of 0.85 is recommended for use with the proposed equation, based on the available statistics from tests and well-established LRFD reliability principles. An example is presented to illustrate the impact of the proposed design provision, which can result in significantly fewer bolts per connection and/or smaller gusset plates, leading to simpler and more economical designs.
Steel Structures Research Update: Strongback Steel-Braced Frames for Improved Seismic Behavior in Buildings
Authors: Liu Judy
Published: April 2024

While current AISC provisions have greatly improved the seismic behavior of conventional braced frame systems, they still have a tendency to form weak stories. The strongback system was developed as a method of delaying or preventing weak-story behavior. Conceptually, the inclusion of an “essentially elastic” backbone, or strongback, enforces a nearly uniform drift distribution, thereby engaging adjacent stories upon the initiation of inelastic behavior in the opposite braces. Ongoing work on the strongback braced frame is highlighted. The research is led by Dr. Stephen Mahin, professor at the University of California–Berkeley, and Byron L. and Elvira E. Nishkian, professors of structural engineering. Dr. Mahin currently leads the SimCenter as part of the Natural Hazards Engineering Research Infrastructure (NHERI) and was recently awarded an AISC grant to research and develop a possible design method for the strongback system.
Framing Strategies for Enhanced Robustness in Steel Buildings
Authors: Cortes Gustavo , Chicchi Rachel , Liu Judy
Published: April 2024

This paper describes the use of stiff-story framing to increase robustness in steel buildings subjected to column loss. Two case study buildings were designed; building A features a perimeter moment frame structure, while building B utilizes chevron-braced frames. The lateral-force-resisting systems (LFRSs) and stiff stories of these two prototype buildings were then modified to create different configurations in order to study which configurations were more robust. A linear static alternate path analysis was performed for each of the configurations, and the effectiveness in resisting column loss was determined. Based on the results from the analyses, two indices that quantify vulnerability and framing efficiency were developed that can be used by designers to evaluate framing alternatives. Cost and aesthetic considerations were explored as well. Evaluation of alternative configurations shows that tying the stiff story into the LFRS and supporting all exterior columns with the stiff-story framing will increase system robustness.
Behavior of Deep, Wide-Flange Steel Beam-Column Members in Seismic Applications
Authors: Pettersson Frida , Rassati Gian Andrea , Swanson James A. , Burns Thomas M.
Published: April 2024

This study involves a parametric analytical investigation of the behavior of deep columns with one-sided reduced beam section (RBS) connections for application in special moment frames (SMFs). Earlier studies led to the prequalification of RBS moment connections for column sizes up to W14 sections; however, the use of deeper columns in SMFs would be advantageous because of their ability to economically control drift. Information on deep column behavior using an RBS moment connection is limited, and this study investigates this behavior using a total of 40 assemblies designed according to the 2016 AISC Seismic Provisions. Four column sections were investigated—W14×426, W24×192, W27×194, and W30×191—each subjected to five levels of axial load, two levels of panel zone strength, and modeled conservatively without floor slab restraint. The study concluded (1) that increased column depth does not have a negative impact on the behavior of the connection as long as the axial loads in the columns are below 80% of the design capacity and (2) that deep columns can be considered as a valid alternative to W12 and W14 sections that are commonly used for RBS connections in SMFs, as long as they are properly detailed.
Errata: Local Stability of Double-Coped Beams
Authors: Dowswell Bo , Whyte Robert
Published: April 2024

Errata to original paper in Vol. 51, No. 1, 2014
Steel Structures Research Update: The Role of Gravity Framing in the Seismic Performance of Steel Buildings
Authors: Liu Judy
Published: April 2024

Ongoing work on the seismic performance of steel buildings is highlighted. Dr. Michael Engelhardt leads the University of Texas at Austin team of Dr. Patricia Clayton, Dr. Todd Helwig, Dr. Eric Williamson, and Ph.D. student Sean Donahue. The research fills knowledge gaps with respect to the role of the gravity framing in the seismic response of steel buildings. Beam-to-column connections in gravity load-resisting frames are typically designed as “simple shear” or “pin” connections with no flexural strength or stiffness. However, these simple shear connections do have some flexural resistance. With consideration of these connections acting compositely with the floor slab, the flexural strength and stiffness increase. Given the number of gravity frame connections in a typical steel building, their overall contribution to the seismic response of the structure could be significant. However, the available data on cyclic behavior of simple shear connections are limited. The current research is expanding the database with a series of large-scale experiments and developing models and tools to quantify the role of the gravity framing in the seismic performance of steel buildings.
Quantifying Inelastic Force and Deformation Demands on Buckling Restrained Braces and Structural System Response
Authors: Marshall Justin D. , Saxey Brandt , Xie Zhongliang
Published: April 2024

Buckling-restrained braced frames (BRBF) have become a very popular lateral-resisting system due to their balanced, full hysteresis and the ability to tailor stiffness, within limits, and strength to meet specific design requirements. This paper reports the results of an analytical investigation on the performance of buckling-restrained braces (BRB) and the global performance of BRBF with a focus on the ductility and overstrength demands on the braces. Nonlinear analytical models of various three- and six-story steel frames were subjected to a suite of earthquake records to determine the demands on the BRB elements and the overall frame response. The structure variations include the location (i.e., seismic hazard), seismic importance factor, Ie, brace configuration (chevron versus single diagonal), and BRB yielding core length. The analysis also investigates the ratio of the impact of an error in the approximation of the BRB elastic stiffness on the system performance.
Simplified Transformative Approaches for Evaluating the Criticality of Fracture in Steel Members
Authors: Connor Robert J.
Published: April 2024

There has been considerable research and interest in the topic of fracture-critical members (FCM) during the past decade. As a result, the entire concept of what constitutes an FCM is being revisited, and many long-standing ideas and opinions related to this classification of members are being shown to be overly conservative. Significant advances in the understanding of fracture mechanics, material and structural behavior, fatigue crack initiation, fatigue crack growth, fabrication technology, and inspection technology have allowed other industries to address fracture—or, more importantly, control of fracture—in a more integrated manner. After years of research, new stand-alone AASHTO guide specifications that give codified direction on how to perform 3D system analysis to verify system redundancy, as well as guide specifications to evaluate internal member-level redundancy of mechanically fastened built-up members for both new and old bridges, have been proposed. Additional research demonstrating the benefits of exploiting the improved toughness of modern high-performance steel (HPS) grades has been completed. Through these advances, it is now possible to create an integrated fracture control plan (FCP) combining the original intent of the 1978 FCP with modern materials, design, fabrication, and inspection methodologies. Further, an integrated FCP provides economic benefits and improved safety to owners by allowing for a better allocation of resources by setting inspection intervals and scope based on sound engineering rather than based simply on the calendar. In summary, an integrated FCP encompassing material, design, fabrication, and inspection can ensure fracture is no more likely than any other limit state, ultimately allowing for a better allocation of owner resources and increased steel bridge safety. This paper summarizes some of the recent advancements related to the topic of the FCM and provides a suggested approach to providing more rational treatment of such members without compromising reliability.
Investigation on the Performance of a Mathematical Model to Analyze Concentrically Braced Frame Beams with V-Type Bracing Configurations
Authors: Hadad Alireza Asgari , Fortney Patrick J.
Published: April 2024

The chevron effect and the corresponding mathematical model used to predict the beam shear force and bending moment demands on beams in concentrically braced frames with V- or inverted V-type (also known as chevrons) configurations is studied in this paper. The common analysis approach considers beam span, work point location, and a concentrated force representing the unbalanced vertical forces of the braces while ignoring any local effects resulting from the brace connection geometry. The assumptions and load distribution mechanisms in the connection region that have been discussed in earlier literature are presented, and the performance of the mathematical model based on chevron effect (CE method) is examined by comparing its results with the results of a net vertical force method (NVF) in addition to those obtained by finite element analysis. The analysis procedure recently proposed for beams in chevron concentrically braced frames is used to design the beams in a group of 20 beam-gusset assemblies. The results revealed the presence of the chevron effect in chevron beams. It also showed the CE method is able to estimate the beam maximum shear force and bending moment. Additionally, the stress distribution along the gusset-to-beam interface is studied.
Technical Note: Unbraced Length Requirements for Steel Special Cantilever Column Systems
Authors: Walter Robert J. , Uang Chia-Ming
Published: April 2024

AISC Seismic Provisions Section E6.4b for steel special cantilever column systems (SCCS) requires clarification based on inquiries to the AISC Steel Solution Center. In the 2016 edition, it is unclear if bracing is required for all special cantilever columns or for columns with unbraced lengths that exceed the maximum beam brace spacing of Lb per Section D1.2a for moderately ductile members. Instead of using Equation D1-2, which is applicable to I-shaped beams only, equations for SCCS columns have been derived for both I-shaped members and rectangular HSS or box-shaped members. The proposed revision provides specific situations when bracing is required.
Technical Note: Internal Second-Order Stiffness: A Refined Approach to the Rm Coefficient to Account for the Influence of P-? on P-?
Authors: Sabelli Rafael , Griffis Lawrence
Published: April 2024

One component of the B2 amplifier method of addressing second-order effects is the RM coefficient, which represents the influence of P-? on P-? effects. This paper presents the background for RM based on LeMessurier’s paper, “A Practical Method of Second-Order Analysis: Part 2—Rigid Frames,” (1977), and makes explicit the simplifications entailed in the AISC Specification for Structural Steel Buildings (AISC, 2016b) formulation for this coefficient. These simplifications, while providing for reliable strength design, can overestimate the P-? effect for typical building applications, especially if applied to drift. A simple formula for RM based on the work of LeMessurier permits a more precise estimate, which can be used as a component of both force and displacement amplifiers presented in this paper. This explicit approach to the RM coefficient provides the basis for clear presentation of the relationships first-order and second-order stiffness (both internal and external), including the distinct effects of P-? and P-? stiffness reductions on equilibrium at the second-order displacement.
Determination of Capacities of Eccentric Stiffeners Part 1: Experimental Studies
Authors: Alvarez Rodilla J. , Kowalkowski Keith
Published: April 2024

Forty column specimens were experimentally tested with an effort to identify the effective stiffener capacities of eccentric stiffeners when used within moment connections of beams connecting to column flanges. Three test methods were performed described as (1) single tension with load pulling away from the column specimen, (2) single compression with load applied toward the column specimen, and (3) double compression with load applied toward the column specimen and with a reaction plate directly opposite from the applied load. The sizes were selected with a range of slenderness ratios for the web and flange and to study multiple concentrated load limit states using AISC Specification Section J10 (AISC, 2016b). For each column size and test method, four column specimens were tested: (1) without stiffeners, (2) with stiffeners concentric with the applied load, (3) with stiffeners at a low eccentricity of 2 in. or 3 in., and (4) with stiffeners at a high eccentricity of 4 in. or 6 in. For column specimens tested without stiffeners and for compression tests, the maximum loads compared favorably to those predicted for web local crippling and were significantly higher than those predicted for web compression buckling (double compression tests) and web local yielding. For single tension tests, the maximum load always exceeded that predicted for the limit states of flange bending and web local yielding.
Lateral-Torsional Buckling Research Needs and Validation of an Experimental Setup in the Elastic Range
Authors: Slein Ryan , Buth Joshua S. , Latif Wajahat , Kamath Ajit M. , Alshannaq Anmar A. , Sherman Ryan J. , Scott David W.
Published: April 2024

The AISC Specification Chapter F I-section member flexural resistance equations are a central part of structural steel design in the United States. The provisions of Sections F4 and F5 address general singly and doubly symmetric I-section members. Analytical studies and experimental tests subsequent to the implementation of these provisions within the 2005 AISC Specification suggest that the corresponding inelastic lateral-torsional buckling (LTB) and tension flange yielding (TFY) resistance equations can be improved, resulting in significantly larger predicted strengths in certain cases and somewhat smaller predicted strengths in other cases. Additional large-scale experimental tests, specifically pushing into the inelastic LTB range, need to be conducted to further investigate these predictions. The broad objective of the additional tests is to achieve a target reliability index of b = 2.6 for building design at a live-to-dead load ratio of 3.0 throughout the design space involving all types of statically determinate I-section flexural members. This paper discusses the need for these tests, specifically focusing on the details of how the test fixtures and bracing systems were configured to minimize incidental restraint, which is a critical consideration when conducting flexural experimental testing. The paper discusses the validation of the testing system by comparison of elastic buckling experimental results to analytical and numerical solutions.
Closure: Investigation on Performance of a Mathematical Model to Analyze Concentrically Braced Frame Beams with V-Type Bracing Configurations
Authors: Hadad Alireza Asgari , Thornton William
Published: April 2024

The discussion-paper published by Roeder et al. (2021), hereafter referred to as the responders for clarity, disputes the results published by Hadad and Fortney (2020), and the chevron effect (CE) analysis method published by Fortney and Thornton (2015, 2017) based on the responders’ earlier research results and their understanding of the behavior of chevron beams. This paper provides the reply to the disputed topics.
Buckling of Conventional and High-Strength Vanadium Steel Single- and Double-Angle Compression Members and Truss Subassemblies: Experimental and Computational Correlation Study
Authors: Citipitioglu Ahmet. , Talaat Mohamed M. , Mayes Ronald L. , Webster Mark D. , Kan Frank W.
Published: April 2024

High-strength, low-alloy vanadium (HSLA-V) steel offers higher strength and toughness than conventional steel. The resulting lighter weight and more slender structural members are more susceptible to buckling in compression. This study establishes an understanding of buckling in this material and the ability to predict it analytically. A series of conventional ASTM A572 Grade 50 steel and HSLA-V (nominal Grade 80) steel angle compression members were tested at Lehigh University’s Advanced Technology for Large Structural Systems (ATLSS) laboratory. A general-purpose finite element (FE) software was used in this study to simulate the buckling and post-buckling behavior of the structural members. The objective of these simulations was to establish confidence in the ability to accurately predict buckling response. The influence of the following modeling parameters on the accuracy of the compression angle member simulation results was investigated: variation in material stress-strain relationship, residual stresses, and the shape and magnitude of geometric imperfections. For the truss subassembly simulations, the influence of the following parameters was also investigated: bracing and boundary element stiffness and design code assumptions of end conditions.
Reliability of HSS Cross Connections in Branch Axial Compression
Authors: Rudman Dillon F. , Xi Quanhan , Tousignant Kyle
Published: April 2024

A method was recently proposed, by Wei and Packer (2021), for application of the 2016 AISC Specification to rectangular HSS sidewall instability. The proposal was based on evidence from prior research and collated data from international experiments. Herein, this topic is further updated with very recent research, and suggested improvements by others. An expanded database containing both experimental and numerical (finite element) tests of rectangular HSS-to-HSS cross connections with chord sidewall failure is hence amassed, totaling 227 tests. An analysis of this data reinforces the recent recommendations.A review is given of methods in use for determining the structural reliability of steel members and connections. Based on this, a reliability study is performed on the recent recommendations, using various closed-form reliability methods as well as Monte Carlo simulation, to determine appropriate resistance factors for use with nominal-strength design equations for HSS sidewall instability. The influence of many variables, in particular chord sidewall slenderness, live-to-dead load ratio, as well as material and geometric properties, on the structural reliability of full-width rectangular HSS-to-HSS cross-connections under branch axial compression is studied.
Steel Structures Research Update: Future Hot-Rolled Asymmetric Steel I-Beams
Authors: Liu Judy
Published: April 2024

Ongoing research on future hot-rolled asymmetric steel I-beams is highlighted. This study is currently under way at Texas A&M University, led by Dr. Matthew Yarnold, Assistant Professor in the Department of Civil and Environmental Engineering. Dr. Yarnoldâ€™s research interests include building structural systems, bridge infrastructure, hybrid building energy-structure performance, and engineering education. Dr. Yarnold has been recognized for his teaching and research with the Robert J. Dexter Memorial Award, ASCE Nashville Branch Engineering Educator of the Year, an AISC Early Career Faculty Award, and AISCâ€™s Milek Fellowship. The four-year Milek Fellowship is supporting this research on the behavior of hot-rolled asymmetric I-beams. The research team is part way through year three of the four-year study. Selected results from a manufacturing study, full-scale experiments, and an initial sizing study are highlighted, along with a preview of future work.
Test on Diaphragm Behavior of Dry-Floor System with Steel-Edged Gypsum Planks
Authors: Jeng Fang Pen
Published: April 2024

The U. S. Steel Corporation and the U. S. Gypsum Company have cooperated in testing a lightweight "dry" steel-edged gypsum-plank floor system for steelframed apartment buildings. Less dead weight, reduced construction time, and all-weather installation are the chief advantages of the dry floor. In actual service, floors, in addition to meeting the performance criteria with regard to vertical loading, sound transmission, and fire resistance, can also act as diaphragms distributing lateral loads from unbraced areas into braced frames. Although the diaphragm behavior of monolithic and uniform floors is relatively easily predicted by analysis, the gypsum-plank floor, being a complex composite system, cannot be easily analyzed. Therefore, a series of diaphragm tests was conducted on a full-scale floor system, and the result is reported herein. Although specific details had to be selected for the steel frame and plank floor specimen, it is recognized that other details may be more advantageous in particular building applications. The degree to which the test results apply to floors using such other details is a matter of judgement and cannot be ascertained in a general manner.
An Investigation of the Effective Concrete Slab Width for Composite Construction
Authors: Hagood Thomas A. , Guthrie Lucian , Hoadley Peter G.
Published: April 2024

This paper describes an experimental investigation for determining the effective width of a concrete slab acting compositely with a series of three rolled steel beams. The program was conducted by the Department of Civil Engineering at Vanderbilt University under the sponsorship of the American Iron and Steel Institute. The object of the program was to determine actual effective slab widths and compare them with allowable values as specified by the 1963 edition of the AISC Specification for the Design, Fabrication and Erection of Steel for Buildings. One can conclude from this study, at least within the range of parameters tested by both the authors and by Mackey and Wong, present effective slab width requirements for composite construction are conservative for interior beams. On the other hand, the results indicate that present specification requirements are reasonable for exterior beams.
Economic Study of a Braced Multi-Story Steel Frame
Authors: Williams James B. , Galambos Theodore V.
Published: April 2024

A braced frame is a steel skeleton in which the forces due to lateral load and the sway-induced second order moments are resisted by shear walls or bracing specifically designed for this purpose. Rigid framing in such frames is not designed to resist lateral forces and serves only to decrease the size of the beams. It is intended in this paper to describe the design and the cost analysis of a braced steel frame with both rigid framing and simple framing, and to determine how much the economy of using continuous girders is offset by the added cost of heavier columns and moment connections required for the girders.
Determining the Cost of Welded Joints
Authors: Donnelly J.A.
Published: April 2024

Relative cost factors are presented which relate the cost of fillet and groove welds of common sizes to the cost of a single pass ¼-in. fillet weld having an assigned cost factor of 1.00. Knowing the actual local cost of a ¼-in. fillet weld for various conditions, the relative cost factors presented may be used to determine the actual cost of welds of various kinds and sizes. The actual costs of fillet and groove welds are obviously best determined from rather precise time studies, wherein the value of all variables may be determined. Many of the variables are different for each fabricating shop. These weld cost variables include joint design, weld process, welding position, operating factor (arctime vs. total time), fit-up, local costs for material, labor, power, etc.
Steel-Plate Composite Wall to Reinforced Concrete Wall Mechanical Connection – Part 2: In-Plane and Out-of-Plane Shear
Authors: Anwar Hassan S. , Seo Jungil , Varma Amit , Nam Yoonho
Published: April 2024

In safety-related nuclear facilities, steel-plate composite (SC) walls are often used in combination with reinforced concrete (RC) walls or foundations. The design demands need to be transferred between the two different structural systems through appropriate connection design. A design procedure was developed by the authors, and it was evaluated by conducting two full scale tests for SC wall-to-RC wall mechanical connections subjected to out-of-plane flexure. This paper presents a brief description of the design procedure as well as the experimental and numerical investigations conducted to further evaluate the design procedure. The focus was on the performance, strength, and governing failure mode of SC wall-to-RC wall mechanical connection under in-plane and out-of-plane shear. The investigation results include global force-displacement and applied force-strain responses. The paper also presents overall damage progression in terms of concrete cracking patterns. The experimentally observed and numerically predicted results indicate that the proposed connection design procedure is suitable and conservative for SC wall-to-RC wall mechanical connections.
Overstrength of I-Shaped Shear Links for EBF Design
Authors: Sim Hyoung-Bo , Fang Xiao.-Jun , Uang Chia-Ming
Published: April 2024

Past experimental research on EBF indicated that the link overstrength, particularly that for short (i.e., shear) links, could be much higher than that specified in the AISC Seismic Provisions, thus potentially leading to an unsafe design of beams, columns, and gusset connections per the capacity design requirements. This study aims to identify key factors contributing to the high overstrength and to derive an expression to predict the overstrength of short links. Available experimental data were first collected, and main parameters affecting the overstrength were identified from the database and used for a multi-variate regression analysis. It was found that the following two parameters affect the link overstrength the most: (1) the Fu/Fy ratio between the actual tensile strength and yield stress and (2) Kw, a factor that represents the contribution of localized bending of link flanges. The link length, to a lesser extent, also affects the overstrength. A predictive overstrength equation based on these three parameters was proposed for capacity design of EBF with short links.
Electroslag Welding Applications for Steel Building Construction in Japan: A State-of-the-Art Review
Authors: Harada Yukihiro , Iyama Jun , Matsumoto Yuka , Oki Koji
Published: April 2024

Electroslag welding (ESW) is advantageous for the improvement of the efficiency of welding thick steel plates, and the application of ESW has been gradually spreading to civil structures such as steel bridges and steel building structures. This paper presents a review of state-of-the-art ESW application for steel building structures in Japan. A brief history of the development of ESW technology, which involves the installation of interior diaphragm plates in welded built-up box columns for high-rise steel buildings, is first introduced, followed by a recent recommendation for the design and fabrication of ESW joints to prevent brittle fracture under earthquake loading.
Effects of Accident Thermal Loading on In-Plane Shear Behavior of Steel-Plate Composite Walls
Authors: Bhardwaj Saahastaranshu R. , Sener Kadir C. , Varma Amit H.
Published: April 2024

Structural walls in safety-related nuclear facilities are required to be designed for seismic and accident thermal (due to postulated high-energy pipe break events) loading combination. Current U.S. and international codes provide limited guidance for analysis and design of walls for this loading combination. This paper describes the experimental results and observations from tests conducted on a laboratory-scale (1:4 to 1:5) test unit representing steel-plate composite (SC) walls subjected to combined in-plane (seismic) and accident thermal loading. The test unit was subjected to surface temperatures of up to 450°F in combination with cyclic in-plane loading. Results of similar experiments recently conducted in Japan are also summarized (with surface temperatures up to 570°F). Surface heating combined with the low thermal conductivity and high specific heat of concrete resulted in nonlinear thermal gradients through the thickness of the specimens. These nonlinear thermal gradients and the associated self- or internal restraint led to extensive concrete cracking. This concrete cracking reduced the initial and secant stiffness of the specimens. The initial stiffness of the heated specimens reduced to 30 to 40% of the initial stiffness of the control (unheated) specimen. The secant stiffness of the heated specimens reduced up to 50% of the secant stiffness of the control (unheated) specimen. However, the in-plane shear strength of the heated SC specimens was still approximately 10 to 30% greater than the nominal in-plane shear strength calculated, for the limit state of steel plate von Mises yielding, using AISC N690 equations and measured material properties. Evaluation of the experimental results and observations suggests that the in-plane shear strength of SC walls subjected to typical accident surface temperatures (up to 570°F) can be estimated conservatively using the current provisions of AISC N690. The stiffness for accident thermal loading combinations can be considered to reduce from cracked composite stiffness at ambient temperature to fully cracked—that is, steel-only stiffness as the surface temperature increases up to typical accident value.
Strength of I-Girders with Narrow Panels Subjected to Concentrated Loads
Authors: Chacón Rolando , Fargier-Gabaldon Luis B.
Published: April 2024

This technical note deals with the strength of web panels under concentrated loads, with emphasis on girders with closely spaced transverse stiffeners (commonly referred to as narrow panels). A review of experimental data and data from simulations suggest that girders with closely spaced panels exhibit substantially higher strength to concentrated loads than that calculated in accordance with the 2016 AISC Specification for Structural Steel Buildings. A simple equation to account for a fraction of the excess in strength is proposed.