bluuebunny/crossref_metadata_2025 huggingface dataset:
One Engineers Opinion
Authors: Fisher James M.
Published: April 2024

The AISC publication Light and Heavy Industrial Buildings is currently being distributed to attendees of the ongoing AISC lecture series "Light and Heavy Industrial Buildings" and will be made available for general distribution after the completion of the lecture series. The purpose of this article is to clarify and elaborate on the material contained in Ref. 1 with respect to the determination of slenderness ratios of crane columns. The need for this discussion has been pointed out to the author by the many engineers who have already attended the lecture series. Since many of the readers of this article have not yet attended the lecture series and thus have not received Ref. 1, the material discussed here will be presented in an independent manner.
Torsional Strength and Stiffness of Steel Structures
Authors: Shermer Carl L.
Published: April 2024

The torsional strength and stiffness of steel structures might seem to many to be a rather forbidding topic, but it can be quite simple for a wide variety of common steel structures such as bridges, towers, laced structural members, hydraulic gates and others. In undergraduate courses in Strength of Materials, all engineering students learn the derivation and use of the torsion formulas as applied to circular shafts. Some may learn that in a thin-walled tube of any cross section the shearing force per unit of length around the periphery of a cross section is a constant and is equal to the torsional moment divided by twice the area enclosed within the cross section. That is about as far as most undergraduate students go with the torsion problem. However, that same simple thinwalled tube formula, v = M/2Ao, is applied to box girders and it also can be applied to many trussed structures, or to structures containing both plates and truss forms. Consider a trussed box as shown in Fig. 1. With the front face open, that is, without being braced, the box offers no effective resistance to the twisting shown. Let the amount of twist be measured by the angle, fi, as seen in the top view. Other displacements can then be determined in terms of fi and the overall dimensions of the box by going through steps through , as indicated on the figure. The angle fi is measured in radians and is small enough so that, without significant error, the sin fi and the tan fi can be set equal to fi and the cos fi can be taken as unity.
Analysis and Design of a Web Connection in Direct Tension
Authors: Anand Subhash C. , Bertz Richard F.
Published: April 2024

Light bracing composed of a tension plate welded to the web of a column or beam section is employed quite often in the design of steel structures. Generally, the strength of a web in carrying the tensile load is of primary concern. There are two analysis procedures which have been suggested for the strength analysis of the web. The first is an elastic method suggested by Blodgett, and the second, an ultimate strength yield line method proposed by Kapp. Experimental tests have indicated that the strength of these connections are, in general, much greater than the strength predicted by either the elastic or the yield line theories. Therefore, a study was undertaken to further investigate the behavior of this connection type in the plastic range by use of the finite element technique.
Book Review: Structural Design of Tall Steel Buildings, Vol. SB
Authors: Haaijer Geerhard
Published: April 2024

Structural Design of Tall Steel Buildings
Stability of Metal Structures--A World View (Part 1)
Authors: SSRC ECCS
Published: April 2024

Theoretical and experimental research on the stability of metal structures and the resulting practical design methods have been developed through independent efforts, mainly in Europe, North America, and Japan. A world literature on this type of research exists and evidently has been exchanged. However, the lack of communication between research bodies in different areas of the world, and the lack of any plan to coordinate the various research methodologies and practical design rules, has led to significant differences in philosophical approach.
Structural Details in Industrial Buildings
Authors: Fisher James M.
Published: April 2024

The recent AISC lecture series on "Light and Heavy Industrial Buildings" generated considerable discussion concerning details and design assumptions relative to (1) steel joist and joist girder systems and (2) column anchor bolts. These two topics, although unrelated, were of major concern to many engineers and fabricators in attendance. This concern centered around the apparent lack of application of structural engineering principles to designs and details. The purpose of this paper is to point out design and detailing problem areas associated with these topics, to help designers avoid structural problems in future designs.
Eccentrically Braced Frame Construction--A Case History
Authors: Libby James R.
Published: April 2024

The building described in this paper is the proposed new Bank of America Regional Office and Branch Bank Building located in San Diego, California. The building is currently under construction. Completion is scheduled for December 1981. The building has a tower incorporating frames having joints with intentionally built-in eccentricities. The joint eccentricity is illustrated in Figs. 1 and 2. In Fig. 1, one sees an elevation of a frame having joints referred to in this presentation as "eccentric." In Fig. 2, a detail of an eccentric joint is shown. Providing this eccentricity is, of course, exactly what engineers were taught to avoid during their years of formal education. The motivation for providing the eccentricity is to achieve a framing configuration that will deform in a highly energy-absorbing manner when subjected to severe ground shaking of the type associated with great earthquakes. Concentrically braced frames do not have the ability to absorb large amounts of energy when subjected to seismically-induced forces. The means of achieving the large energy-absorbing capability consists of detailing the eccentric link in a manner that assures an inelastic moment capacity that is larger than the inelastic shear strength. For interesting and comprehensive descriptions of the technical aspects of this type of framing, how it performs under very high loads and the principles used in their design, the works of Roeder, Popov and Teal are recommended references. In a seismic structural design this is a relatively new and unique design concept. One might wonder why it would be used. The principal purpose of this paper is to describe why eccentrically braced frames were selected for the San Diego Bank of America building.
Computing The Effective Plastic Moment
Authors: Carskaddan Phillip S. , Haaijer Geerhard , Grubb Michael A.
Published: April 2024

The effective-plastic-moment approach does not exclude any shapes from plastic design; additionally, it permits plastic design methods to be employed in the rating of existing members. For plastic design, the most efficient distribution of material occurs when the effective flange yield strength is not below the actual compression flange yield strength. Furthermore, for a symmetrical section of a given depth, the effective plastic moment is optimum when 22.5% of the web area is moved from the web to the flanges, starting from a web area that makes the web fully effective. The effectiveplastic- moment approach is applicable to sections that are symmetric, unsymmetric, hybrid, and composite in negative bending.
Seismic Steel Framing Systems for Tall Buildings
Authors: Popov Egor P.
Published: April 2024

A number of steel framing systems can be used to develop the required lateral strength, stiffness, and ductility for resisting forces caused by earthquakes. Moment-resisting frames and braced frames are by far the most widely used systems for this purpose. More recently, a number of major buildings were designed and built in California employing the concept of eccentric bracing. In this approach the line of action in a brace is deliberately offset from a common joint point. Any bracing scheme in which a component of an axial force in a brace is transferred through shear in a beam can be classified as an eccentrically braced frame. The spread K-bracing is a well-known example. A number of other bracing schemes can be devised using this concept. This type of hybrid construction is very versatile and fulfills the essential requirements for seismic design. This paper reviews the advantages and disadvantages of the three framing systems noted above. The choice of a particular framing system depends on a large number of factors. Functional requirements or close spacing of columns may mandate moment-resistant framing. Conventional bracing may be fully acceptable in applications where moderate ductility of frames suffices. In some applications, eccentric bracing may be the most economical. Because of the newness of this system of framing, some design guidelines are given. Experimental results are provided on the behavior of the critical elements for each system of framing.
Effective Column Length—Tier Buildings
Authors: Higgins T.R.
Published: April 2024

The revision of the AISC Specification adopted in November, 1961 contained a large number of new provisions reflecting extensive research sponsored by the Institute during the previous decade. Yet none of these have provoked as much discussion (and misunderstanding) as those in Sect. 1.8 which relate allowable axial stress in compression to an effective column length instead of to the actual unbraced length as in earlier editions. Oddly enough, the underlying theory here is by no means new. Why, then, is it only now receiving recognition in American specifications? The answer lies in two recent developments both of which place greater emphasis than previously on the possibility of overall frame instability; the introduction of high strength steels and the trend towards light wall constructions.
Discussion: Steel Cable Creates Novel Structural Space Systems
Authors: Gould Phillip L.
Published: April 2024

Discussion
The Steel Framed Dome
Authors: Stevens David E. , Odom Gerald S.
Published: April 2024

Many engineers when first confronted with the design of a steel framed dome are dismayed by the complexity of these often highly indeterminate, three dimensional space frames. Furthermore, on locating references in the literature, many are further confused to find that there is no unanimity of opinion among the various investigators as to proper methods of analysis and design. Despite the fact that domes are one of the oldest structural forms in existence and that recent years have seen a revival of this form and a growth of its popularity, few scientific investigations have been made. Opinions vary widely from those who advocate rigorous methods of analysis based on deformations or simultaneous displacements to those who advocate analysis by simple statics.Many steel framed domes have been designed and built in recent years. However, despite the increasing popularity of this type of structure, little new design information has beenpublished. For this reason, engineers who wish to investigate the steel framed dome for the first time can find little guidance based on the practical experience of others. The purpose of this paper is to provide a practical discussion of the analysis and design of the Schwedler dome,one of the more popular types of steel framed domes. Included are a design example and a list of references. The opinions expressed herein are those of the authors, based on both field and office experience over the past fifteen years and upon a study and evaluation of those publications listed in the bibliography at the end of this paper.
Considerations in the Design of Bolted Joints for Weathering Steel
Authors: Brockenbrough R.L.
Published: April 2024

In this discussion, some of the fundamentals that govern the behavior and design of bolted joints, in general, are first reviewed. Then, considerations that are particularly important in the design of joints in bare weathering steel are presented. The discussion is primarily concerned with highstrength bolts, since such bolts are the ones primarily used in construction today. High-strength bolts were introduced about 25 years ago, and have gained wide acceptance for the construction of bridges, buildings, and structures of all types. Most are furnished to the requirements of ASTM specification A325, which includes three types distinguished by chemical composition: Type 1, a medium-carbon steel; Type 2, a lowcarbon martensite steel; and Type 3, a weathering steel. All have a minimum tensile strength of 120 ksi for bolt diameters from 0.5-to 1 in., and 105 ksi for bolt diameters from 1.08 to 1.5 in. Also used for some higher load applications are ASTM A490 alloy bolts, which have a minimum tensile strength of 150 ksi for bolt diameters from 0.5-to 1 in. Both A325 and A490 bolts are quenched and tempered.
Buckling of One-Story Frames
Authors: Schilling Charles G.
Published: April 2024

Two buckling modes can occur in building frames: (1) column buckling of one or more individual members and (2) frame buckling. The two modes can be investigated independently. In the first mode, the column is supported against lateral movements at both ends, but bows between the ends. The surrounding frame provides the lateral support at the ends. In the second mode, the top of the frame moves laterally with respect to the bottom. This paper deals primarily with frame buckling, but also discusses the interrelationship between the two modes. Specifically, it presents a conservative method of determining the frame buckling load from an ordinary (first-order) analysis and suggests compatible methods of checking column buckling of individual members. Methods of calculating the buckling load of frames have been discussed in papers too numerous to mention here. However, the state-of-the-art is adequately covered in two recent books: the Council on Tall Buildings' volume on steel design and the Structural Stability Research Council's guide to structural stability. These two references describe the two main methods of considering frame buckling: effective-length methods and PD methods. To account for the frame buckling mode, the effectivelength methods use effective lengths greater than the actual lengths of the columns. Charts give the effective lengths for single frames that are symmetric with respect to both loading and geometric properties, but the application of these charts is difficult and confusing for more complex frames.
Introduction to the Proposed AISC Load and Resistance Factor Design Specification
Authors: Edinger John A.
Published: April 2024

The proposed AISC Load and Resistance Factor Design Specification is now undergoing a one year period of public review and comment. This culminates efforts over the past years by many individuals who have contributed significantly to the draft specification. The intent of this paper is to provide a brief introduction to the proposed LRFD Specification by briefly discussing the basic load and resistance formulation, load and resistance factors, and providing a comparison with the present Allowable Stress Design Specification.
End-Plate Moment Connections- Their Use and Misuse
Authors: Griffiths John D.
Published: April 2024

Up until about 1960, many field-bolted moment connections were of the split tee-stub type (Fig. 1). These connections were used in power house construction, in multistory office buildings and other structures where moment capacity was required between beams and columns. They served well, and thousands are still doing their duty reliably in some of our older structures. In later years, end plates have been set in place of the split tee-stub connections.
Fast Check for Laterally Supported Beam Capacity
Authors: Odeh M. David
Published: April 2024

The purpose of this article is to arrive at a "rule of the thumb" method to determine the total uniform load capacity of a laterally supported simple beam, with the only known data being (a) steel beam designation and (b) span. No other data or references are required. It was found through analysis that the section properties of any rolled steel beam section are "built into" the beam designation, i.e. depth and weight.
Note on Beam-Column Moment Amplification Factor
Authors: Iwankiw Nestor R.
Published: April 2024

This short note has been prepared to clarify and explainthe theoretical derivation of the expressions shown in Table CI.6.1 of the AISC Specification Commentary.
Finite Element Modeling of Girders with Large Web Openings
Authors: Watwood V.B. , Berak E.G.
Published: April 2024

In finite element modeling, the objective is to simulate the actual behavior of a loaded structure so that the resulting structural stress predictions are sufficient to make design decisions. Very often it is not economically viable to generate a single mathematical model able to accurately reflect all the phenomena related to the behavior of a particular structure. In such situations, it is necessary to consider multiple models, some or all of which are reasonable compromises of accuracy vs. cost. The final choice of the model depends on engineering judgment, and differing situations demand different considerations. The primary purpose of this paper is to discuss some of the tradeoffs involved for one particular type of structure. The structure considered here can be described as a multi-celled girder, which contains manholes placed in vertical plates called bulkheads. These access openings need to be provided for construction as well as for inspection. This type of structure is encountered in large mining and earthmoving equipment. The behavior of plate shear walls in buildings, and diaphragms in box girders that contain manholes, is similar to the bulkheads analyzed here. The primary interest here lay with the bulkheads containing the manholes. Many of these manholes exist in a given structure, hence an accurate, but economical model is sought to enable the designer to determine the extent of stress concentration for each configuration.
Bolted Shear Connections with Painted Surfaces
Authors: Frank Karl H , Yura Joseph A. , Fouad Fouad H.
Published: April 2024

In high-strength bolted shear connections, the load transfer between plate components is initially provided by the frictional forces developed by bolt clamping forces and friction characteristics of contact surfaces. A connection which relies on this slip resistance to transfer load is called a friction connection. When the slip resistance is exceeded, the connection slips into bearing to develop the bearing strength (bearing connection). Prior to 1974, paints on the contact surfaces were prohibited in friction connections because some early tests showed they affected adversely the slip load. The fabricator had to mask off the connection area, thus increasing the cost when friction joints and painted steel were specified. In exposed environments, the unpainted contact surfaces resulted in crevice corrosion and a subsequent deterioration of the structural painting system. Design criteria for bolted joints are given in the Specification for Structural Joints Using ASTM A325 or A490 Bolts prepared by the Research Council on Structural Connections (RCSC). The RCSC Specification gives allowable friction forces for nine different contact surface conditions based on a probability of slip concept developed by Fisher and Struik. Three types of paint were recognized for friction surface: organic and inorganic zinc-rich paint and vinyl wash. Many coatings and painting systems, especially vinyl and epoxies, which show significant improvement in corrosion protection, have been developed. Since such coatings are not reflected in the RCSC Specification, their status for use on friction surfaces is unknown.
Adjusting the Beam-line Method for Positive-moment Yielding
Authors: Carskaddan Phillip S. , Haaijer Geerhard , Grubb Michael A.
Published: April 2024

The beam-line method is a convenient tool for the analysis of nonlinear building connections and inelastic rotations over the interior supports of highway bridge girders. However, the method presently presumes that a bending member remains elastic in positive bending. While this presumption may be acceptable at low load levels, residual stresses in rolled beams and welded girders combined with applied stresses are known to create inelastic behavior at moderate load levels and above. The purpose of this paper is to demonstrate how positive moment yielding may be accounted for in the beam-line method. As a result, the method may then be applied throughout the elastic range, the inelastic range and up to mechanism formation. An example problem will illustrate the adjusted method, and then some potential applications will be discussed.
Anchorage of Steel Building Components to Concrete
Authors: Marsh M. Lee , Burdette Edwin G.
Published: April 2024

Anchorage of steel building components to concrete is a fact of life. It has been used, and will continue to be used, in essentially all steel industrial structures. It would seem logical that the behavior and consequently the design principles concerning such anchorages are as well understood, for instance, as those concerning flexure of the components themselves. However, such has not always been the case. Because of this situation, recent work has been undertaken to enhance understanding of anchorage behavior. Much of this work has been brought about as a result of the stringent quality assurance programs of the nuclear power industry with the corresponding stringent design requirements for anchorage to concrete. While the nuclear industrys design requirements are rather rigorous relative to the needs of the industrial building industry, much of the information obtained to meet these requirements can be utilized in industrial building applications. The purpose of this paper is to describe various types of anchorage devices, discuss their behavior and present appropriate design guidelines for implementation in industrial building construction.
A General Solution for the Governing Bending Equation
Authors: Moore II
Published: April 2024

The allowable bending stress Fb for most wide-flange sections is governed only by AISC Eq. 1.5-7, and Eq. 1.5-6 never need to be checked for these sections. Those wideflange sections for which Fb is determined by Eq. 1.5-6, and the unbraced lengths for which these forms govern, are easily identified by simultaneous solution of the bending equations for the common roots of length for any given yield stress Fy and bending coefficient Cb. Tables of these sections and a general solution for determining the governing bending equation are presented in this paper. The tables are useful supplements to Stockwells simplification of the bending equations and to Burgett and Tides extension of the use of the beam charts to designs with bending coefficients greater than unity. The tables and their use are presented in the body of this paper; simultaneous solutions of the bending equations for common roots of length are given in the appendix.
Automated Search for Optimal Standard Sections
Authors: Ginsburg S. , Kaaz G.
Published: April 2024

Microcomputers provide the engineer with practical tools for structural analysis and design. Beyond the obvious analysis, usually performed by using canned programs, there are many useful operations for which the microcomputer can be employed. This paper describes one such application, the search for minimum-weight cross sections. Done manually, this is a tedious job for the designer. Even when automated optimization is performed, the task of choosing a standard section still remains. An efficient search algorithm is described here, which can easily be adopted by practitioners, especially if they use BASIC for programming. The method is demonstrated by several examples where a minimum area is chosen from the table of W shapes in the AISC Manual of Steel Construction.
New Design Criteria for Gusset Plates in Tension
Authors: Hardash Steve G. , Bjorhovde Reidar
Published: April 2024

Gusset plates are common fastening elements used in fabricated steel structures such as trusses or braced-frame structures. In the latter case, their primary purpose is to transfer either tensile or compressive loads from a bracing member to a beam and column joint. Current gusset plate design is based primarily on elastic analyses for determining critical sections and stresses. No known failures or adverse behavior have been noted, but substantial differences in the factor of safety against ultimate load exist because of the assumptions involved. Therefore, it is important to develop an improved design method, with the goal of providing economy of design and consistent levels of safety. The ultimate-strength approach fulfills these requirements. To date, a few experimental studies have been conducted to determine the behavior and ultimate strength of gusset plate connections. However, additional tests have been needed to develop a design method based on ultimate strength behavior. It is the purpose of this paper to describe a number of gusset plate tests that were performed, and to develop rational criteria that incorporate all of the primary strength parameters.
Procedure for a Design and Analysis of Hanger-type Connections
Authors: Astaneh-Asl Abolhassan
Published: April 2024

The AISC Manual Part 4, gives a procedure for design of hanger-type connections. An examination of the procedure reveals some difficulties that can easily be removed by modifying the procedure.
Writing for Publication: The Engineers Obligation
Authors: Friedstein Harriet
Published: April 2024

The engineering professional has an obligation to the discipline to communicate, either through papers delivered at topical conferences or through journals and magazines. This article describes the advantages and disadvantages of writing for publication. Once the key is established for the need to write for the profession, some basic guidelines are offered for the novice. Suggestions are given on how to get started; how to generate ideas into articles; what to do in the actual writing process from first to final draft. Finally, the author offers some suggestions for turning the draft into a polished manuscript. In our technological society, we need more technically competent writers for the multitudes of journals and magazines that proliferate. Non-fiction informational articles compose the largest percentage of published works today. Should we assume that all these writers are professional journalists? True, some are, but a great many are not. Their interests in technical subjects and their skills in writing have given them a chance to communicate with the reader. However, writing is not to be limited to the journalism majors.
Design Loads for Seated-beam in LRFD
Authors: Garrett Jr. J.H. , Brockenbrough R.L.
Published: April 2024

For many years, the AISC Manual of Steel Construction has provided allowable loads for various types of connections for supporting a simple beam on a column. The most economical of these is the seated-beam connection where the end reaction is supported by an unstiffened angle bolted or welded to the column. When plans were made to develop a new Manual based on the AISC Load and Resistance Factor Design Specification, it was necessary to review the methods used to determine the allowable loads in the 1980 Manual. This paper presents a summary of that work to show the basis for the load capacities in both Manuals. It is shown that, for some applications, the economy of the seated-beam connection should be enhanced with the new LRFD Specification.
Some Design Considerations for Composite-frame Structures
Authors: Griffis Lawrence G.
Published: April 2024

Over the past 25 years, numerous innovative structural systems have evolved in tall building design where structural steel and reinforced concrete have been combined to produce a building having the advantages of each material. The use of these so-called composite-frame structures has as its underlying principle the combination of these two distinctive and different building materials to benefit from the advantages of both—namely, the inherent stiffness and economy of reinforced concrete and the speed of construction, strength and light weight of structural steel. The term composite-frame structure has taken on numerous meanings in recent years in utilizing several different building materials. As used here, it is taken to mean a building employing a structural steel and composite metal deck floor system and concrete encased steel columns. The composite beams use headed studs (shear connectors) to achieve composite action between the steel and concrete. The bare steel columns carry the initial gravity, construction and lateral loads until such time as the concrete is cast around them to form composite columns capable of resisting the total gravity and lateral loads of the completed structure.
The Disposable Knee-bracing Technique in Steel Frames
Authors: Aristizabal-Ochoa J. Dario
Published: April 2024

A new technique of lateral bracing of steel-framed structures has been suggested by this writer. This technique, denoted as the Disposable Knee Bracing (DKB), combines two elements—the knee element and the diagonal brace element. The diagonal brace element, whose primary function is to provide the required level of lateral stiffness to the frame, is simply connected to an inclined knee member. The knee-brace member, which is rigidly connected at the ends, is designed to be the first line of dissipation of energy during severe earthquakes without significantly decreasing the lateral stiffness or strength of the frame. This energy dissipation is achieved by the formation of flexural hinges at the ends and midspan of the knees. The knee members should yield by fully developing three plastic hinges prior to any occurrence of yielding elsewhere in the frame during severe earthquakes, so that, during more destructive after shocks the second line of defense, the frame itself, might yield. Further details of this technique are presented elsewhere.
Erecting the Staggered-truss System: A View from the Field
Authors: Hassler Arthur E.
Published: April 2024

The staggered-steel truss system has been used as the major supporting element for many years. Projects using this truss system are economical, easy to fabricate and erect. and as a result beat out all other framing systems. This paper deals with a building recently completed which used the staggered steel truss system. The project is the Resorts International Hotel in Atlantic City, N.J.
Computer-aided Design of Horizontally Curved Girders by the V-load Method
Authors: Poellot Jr.
Published: April 2024

We have seen a design approach for curved bridges that is extremely simple and easily understood. The V-Load Method is not only a valuable tool from the practical stand-point, but familiarity with the method should contribute to the engineer's overall "feel"� of the curved girder problem. Although curved girder analysis and design by the V-Load Method is straightforward, it is not a procedure that can be done readily by longhand. But it can be done by a variety of manageable, fast-running computer programs, starting with Program V-LOAD.
Design for Eccentric and Inclined Loads on Bolt and Weld Groups
Authors: Iwankiw Nestor R.
Published: April 2024

The 8th Edition AISC Manual of Steel Construction introduced the ultimate strength, instantaneous center of rotation method for computation of the tabulated bolt and weld group eccentricity coefficients C. As discussed in detail by Tide1 and Brandt, this marked a major departure from the traditional and conservative elastic analysis employed in the 7th Edition AISC Manual (and previous editions) and which many design textbook authors still emphasize. The reason for the change was the ultimate strength method better reflected the ductility and load redistribution capability within the group by explicit consideration of each connectors characteristic load-deformation curve. The ultimate strength methods connector shape factor effect, somewhat analogous to the plastic section modulus to elastic section modulus ratio for steel beams, consequently accounts for this increase in connection strength. Unfortunately, this type of nonlinear analysis is certainly more complex, it involves trial iterations until satisfactory numerical convergence, thus, is probably only suitable for computerized solutions for those cases not covered by the Manual.
A Practical P-Delta Analysis Method for Type FR and PR Frames
Authors: Lui E.M.
Published: April 2024

In the stability design of frameworks, attention must be given to the additional moment developed as a result of member and frame amplification effects from compressive axial loads. These secondary moments may have a deleterious effect on the strength and stability of the frame and so they must be reckoned with in the analysis and design processes. These are various approaches ranging from very simple to rather rigorous by which a designer can employ to account for these second-order effects. A simple and effective method of second-order frame analyses was presented in this paper. The method accounts for the P-d and P-D effects by the use of pseudo loads obtained from a first-order analysis of the frame. The method is quite versatile in that it is applicable riot only to rectangular Type FR frames but also to nonrectangular Type PR frames. The validity of the method has been demonstrated and it is therefore recommended for general use.
Plastic Collapse Load of Continuous Composite Plate Girders
Authors: Kubo Masahiro , Galambos Theodore
Published: April 2024

Composite beams and girders with a reinforced concrete slab have different moment-curvature characteristics, depending on whether the moment is positive or negative. It is usually assumed for the maximum strength of the negative moment section that the concrete slab does not carry tensile stresses, but the reinforcing steel bars are considered to act compositely with the steel section. In the Load Factor Design (LFD) method of the AASHTO Standard Specifications for Highway Bridges, the maximum strength of laterally braced I-shaped sections is determined based on the provision of compact or noncompact sections. A compact section is defined as a section that can reach the plastic moment and rotate inelastically at this constant plastic moment. Recently (1986), the AASHTO Guide Specification for Alternate Load Factor Design Procedures was published for the design of steel beam bridges using braced compact sections. This procedure was adopted as a logical extension of the existing LFD method and it is based on the Autostress Design (ASD) procedures. The resistance of continuous beam bridges is determined by the plastic-mechanism method. In this method, a considerable amount of plastic rotation is required at the negative moment sections of intermediate supports, and so the concept of an effective plastic moment was applied. The ultimate load was assumed to be reached when a composite section in positive bending reached the plastic moment. The usefulness of this method was confirmed by design examples and loading tests of an actual bridge.
Design of Tee Framing Shear Connections
Authors: Astaneh-Asl Abolhassan , Nadar Marwan N.
Published: April 2024

Tee framing connections are listed as one of the shear connections in the AISC Manual11 and are used in steel structures as simple connections. However, the published information on actual behavior and design of this type of connection is very limited. Figure 1 shows typical applications of tee connections in steel structures. The fasteners in tee connections can be either weld lines or bolts. There are four variations of tee connections with various combinations of bolts and welds. Based on interviews with steel fabricators, it appears that the degree of popularity of four connections in Fig. 2 is in the order of types "a", "c", "d" and "b" where type "a" is the most popular and efficient one. This paper is concerned with the behavior and design of tee connections shown as "a" in Fig. 2 where the tee section is bolted to the beam web and welded to the support.
What Structural Engineers and Fabricators Need to Know About Weld Metal
Authors: Miller Duane K.
Published: April 2024

To supply structural engineers and fabricators with the mechanical properties data needed to ensure good weldment design, manufacturers of consumables utilize standard filler metal qualification tests developed by the American Welding Society. Tensile properties are thus reported. Too frequently, engineers expect the results of these tightly controlled tests to be directly applicable to the properties of welded connections made in the shop or in the field. They are not. Both the structural engineer and the fabricator need to be aware of the ways in which many variables may affect the properties of the weld deposit. This paper will examine the purpose of filler metal qualification tests, the controls for these tests, and how production welds may deviate from the tests. Finally, guidelines will be discussed to enable the engineer to predict trends and assure that required strength levels are achieved.
Survey of Existing Studies on the Strength and Deformation of Spherical Joints in Steel Space Trusses
Authors: Uduma K. , Olowokere O.D. , Arciszewski T.
Published: April 2024

In order to accurately predict the behavior of space trusses, it is necessary not only to account for the actual framing members, but also to be able to predict the response of the joints holding these members together. Moreover, to design the joint, one must consider not only the qualitative variables describing the joint, but also the stress distributions and deformations within the joint, under assumed design loads. In this paper, a survey of existing studies on the strength and deformation of spherical joints in steel space trusses is given. Remarks on the limitations of such studies are made and a need for a greater in-depth treatment in such studies is suggested.
Some Practical Aspects of Column Base Selection
Authors: Ricker David T.
Published: April 2024

The following three methods can be used effectively to prepare a landing site for the erection of a column: Leveling plates, Leveling nuts and Preset base plates.
Cambering Steel Beams
Authors: Ricker David T.
Published: April 2024

Natural mill camber is the out-of-straightness remaining after the initial rolling, cooling, and straightening of the member at the mill. Tolerances for natural mill camber are listed in the AISC Manual of Steel Construction. Induced camber is that which is applied subsequent to the initial rolling and straightening process. Induced cambering can be done at either the rolling mill or the fabricating shop. Tolerances for induced camber are also listed in the AISC Manual of Steel Construction.
Allowable Bending Stress of Steel Pipes
Authors: Chakrabarti S.K.
Published: April 2024

Allowable Bending Stress of Steel Pipes
Closure: A Practical P-Delta Analysis Method for Type FR and PR Frames
Authors: Lui Eric M.
Published: April 2024

Closure
Discussion: A Practical P-Delta Analysis Method for Type FR and PR Frames
Authors: Carskaddan Phillip S.
Published: April 2024

Discussion
Correction: Performance of Large Seismic Steel Moment Connections Under Cyclic Loads
Authors: Popov Egor P. , Tsai K.C.
Published: April 2024

Correction
Automated Second-Order Elastic Analysis for Steel Space Frames
Authors: Folse Michael D. , Harris Barton H.
Published: April 2024

The magnification of bending moments and deflections due to interaction between axial compression and transverse loads is popularly known as second-order elastic effects. The American Institute of Steel Construction (AISC) specifications for building construction require inclusion of second-order elastic effects in the design of steel structures. In the past, these effects have been approximated by multiplying moments obtained through a linear analysis by a magnification factor. It is simpler and generally more accurate to compute second-order elastic effects within a displacement method computer analysis program. Several different approaches to automated computation are possible. Two methods of including second-order elastic effects in space frame analysis are described herein along with a FORTRAN computer program which executes the stiffness modification method while checking steel wide flange beam-columns for compliance with the AISC Load and Resistance Factor Design (LRFD) Specification.
Electronic Spreadsheet Tools for Semi- Rigid Frames
Authors: Ackroyd Michael H.
Published: April 2024

This paper describes a personal computer software tool for automating the analysis computations for semi-rigid steel frames. The computations are based partly on a design procedure proposed earlier by the author and partly on approximate modeling techniques developed for flexiblyconnected building frames. The computations are implemented in an electronic spreadsheet providing a fully interactive design medium that can be readily accessed by office practitioners.
Tables for Equal Single Angles in Compression
Authors: Walker Wayne W.
Published: April 2024

Tables for Equal Single Angles in Compression
Stiffness Reduction Factor for LRFD of Columns
Authors: Harichandran Ronald S.
Published: April 2024

The stiffness reduction factors (SRFs) given in Table A of the LRFD Manual1 has an error that needs to be corrected. The error occurs in adopting the technique originally proposed by Yura in the context of ASD to LRFD. It is well known that when using the standard alignment charts to determine the effective length factor K of a column, the restraint factors G should reflect the inelastic behavior of the column.
Buckling of Prestressed Steel Girders
Authors: Bradford Mark A.
Published: April 2024

Prestressing of steel girders, in order to gain economy of material, is starting to become popular in the United States. An inherent danger in the stressing operation is loss of stability of the girder between the points of attachment of the tendon. The paper presents design charts for the elastic buckling load induced by stressing an eccentric tendon, and uses this to obtain a design buckling strength in accordance with the LRFD Specification.
Beam Design in PR Braced Steel Frames
Authors: Zandonini Riccardo , Zanon Paolo
Published: April 2024

Recent American and European Codes allow the actual behavior of joints to be taken into account in frame design. The AISC-LRFD specifications introduce the concept of partially restrained construction and state the basic design requirements. Eurocode 3 permits "semi-continuous" frames and specifies basic criteria for the analysis of this type of structure as well as for the classification and modeling of the moment-rotation of beam-to-column joints. This consistent development in Code recommendations recognizes, on the one hand, the significant influence joint response has on the overall frame performance; on the other hand, it reflects a state of knowledge which is now sufficient to enable practicing engineers to undertake the design of partially restrained frames at the required level of reliability. Studies of the stability of this form of framework were recently carried out, the main problems related to the analysis investigated, and design methods established. The most important aspect, as to practical purposes, is the capability of approximating the moment-rotation curve of the joint. Satisfactory prediction models were proposed in the past few years, covering the most popular connection forms. Research work is currently underway to set up more refined models as well as to extend their scope.
The Significance and Application of Cb in Beam Design
Authors: Zuraski Patrick D.
Published: April 2024

The basic provisions related to design and evaluation of bending members in the structural steel specifications, either according to Load and Resistance Factor Design (LRFD) or Allowable Stress Design (ASD), typically are first presented from the point of view that the magnitude of bending moment is constant throughout the entire distance between points of lateral support for the compression flange. Then, to account for variations in moment, one multiplies the expression associated with constant moment by a correction factor Cb to arrive at a result which predicts the actual bending strength (or allowable stress) for a specific moment gradient. What one accomplishes is to account for changes that occur in the force within the compression flange of the beam throughout the unbraced length. A procedure for selecting beams in situations involving non-uniform moment is suggested within the prelude to the charts of design moments in the LRFD manual, but only in extremely brief fashion. The purpose of this paper is to review the principles associated with the application of Cb, and to elaborate on the procedure briefly suggested in the LRFD manual for selecting beams which experience non-uniform moment.
Distortion-Induced Cracking During Transit
Authors: Roddis W.M. Kim
Published: April 2024

During the last twenty years, there has been a growing awareness of distortion-induced cracking in bridges. Comparable interest in this behavior has not been generated within the building community. Distortion-induced fatigue cracking is indeed a more common problem in bridges, arising from cyclic distortions not only during handling and shipping but also during service. Bridge service conditions are much more likely to induce cyclic distortions than building service conditions. However, handling and shipping conditions are similar for both building and bridge components. It would therefore be beneficial if the topic of distortion-induced cyclic stress as a possible cause of fatigue cracking during shipment were more widely understood in the steel industry. This paper reviews the characteristics of distortion-induced cracking as seen in bridges, presents a detailed example of cracking in building trusses due to cyclic distortions during transit, summarizes the conditions that lead to this type of cracking during shipment, discusses the effect of cracking on structural performance, and provides recommendations for prevention of this type of damage.
Lessons from Crane Runways
Authors: Mueller John E.
Published: April 2024

Many engineers consider the design of a mill building to be 90 percent judgment and 10 percent perspiration. While the exact percentages are debatable, there is little question that judgment forms an important part of the design of such structures, particularly with regard to basic load assumptions and the evaluation of "indeterminates"—those mathematical problems with too many variables for exact solution. Some of the questions that must be resolved by the designer are: How many cranes can be expected to operate simultaneously in the general vicinity of a particular column? How often, if ever, will all cranes pick up their maximum loads with the trolleys adjacent to the column? What lateral thrusting forces can occur simultaneously? What allowance should be made for impact? Would the plant be in operation when there is maximum snow load on the roof? How stiff is the variable stiffness truss? How much resistance to rotation will the foundation afford?