Engineering Commons^™

Columns Under Loads Of Varying Eccentricity, J. Rhodes

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A series of tests on small lipped channel section columns is reported in this paper. The columns were loaded with varying degrees of eccentricity. The eccentricity of loading was produced by offsetting the loading line from the neutral axis of the section, and the offset could be set to a different degree at each end of the column. By this means the effect of moment variation along the column could be examined experimentally and the results compared with the predictions of different design codes for this type of loading. The predictions of the 1986 AISI Specification, the British Standard and …

Tests Of Cold-Formed Channel Columns, Ben Young, Kim J. R. Rasmussen

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The paper presents a series of tests on cold-formed plain and lipped channel columns, compressed between fixed and pinned ends. While it is well-known that local buckling of pin-ended channel columns induces overall bending, this phenomenon does not occur in fixed-ended channel columns which remain straight after local buckling and only bend when overall buckling occurs. These fundamentally different effects of local buckling on the behaviour of pin-ended and fixed-ended channel sections lead to inconsistencies in traditional design approaches, which account for full or partial rotational end restraint solely by using effective lengths. A series of tests was performed on …

A European Design Code For Pallet Racking, M. H. R. Godley, J. Michael Davies

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The work leading to a European design code for pallet racking started almost 25 years ago. Many difficulties were encountered in the early days of this work. Notable were the absence of a consistent safety philosophy between the various countries of Europe and the existence of procedures with which the manufacturers were comfortable but which were potentially unsafe. There were also difficulties in defining acceptable standard. test procedures. The emergence of Eurocode 3, especially Part 1.3 dealing with cold formed sections, provided a new impetus to the work because here was a European code which provided the required basis for …

Fire Resistance On Bearing Wall Using Steel & Gypsum, In-Kyu Kwon, Kwang Choi, Jee Nam-Yong

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The conventional loadbearing wall systems generally used in Korea are composed of concrete and brick. Which materials have many defaults like long-term construction period and cost increase. Recently in us, a rapid increase in the usage of cold-formed steel section in housing and commercial building construction can widely be seen. The loadbearing wall assembly composed of light gauge-steel and gypsum board can preferably be applied to residential and commercial building of 5 stories or below. In order that light-gauge steel framing can be prevalently introduced in our domestic housing market, the wall assembly must have sufficient fire-resistant performance. Fire-resistant tests …

Seismic Design Of Light Gauge Steel Structures: A Discussion, Reynaud Serrette

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

In a highly competitive and aggressive construction market, designers are always looking for new, proven ways to design safe, economical building structures. This is even more relevant in tract residential construction where a few dollars saved on one detail can affect who is awarded a project. In residential construction, a complete load bearing light gauge steel (LGS) system is now somewhat commonplace in the United States. Architects and engineers who once designed almost exclusively with other conventional materials are now consider LGS as an alternative. Although, it is feasible to make a direct substitution of LGS for conventional wood framing, …

Testing Of Cold Formed Steel Floor Joists With Bearing Stiffeners, Reynaud M. Schuster, S. R. Fox

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The application of lightweight steel framing (LSF) in residential construction has been growing in the past few years and is bringing forth some issues in Cold Formed Steel Design Specifications that need to be addressed. The area of interest of this paper is the requirement for bearing stiffeners in both the CSA-SI36(1) Standard and the AISI(2) Specification. Specifically, both of these documents require that all cross-sectional elements of a bearing stiffener must be fully effective. This restriction is difficult to meet in practice since almost all LSF members are subject to local buckling, hence are no longer fully effective. A …

A Study On The Flexural Behavior Of Profiled Composite Beams, Gu Rok Yang, Yong Seo Hwang, Young Bong Kwon

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

An analytical study on the behavior of composite beams, which are composed of cold-formed steel sheeting and normal strength concrete, is described. An analytical method to trace the nonlinear behavior of a composite beam is developed to include the nonlinear material properties of steel sheeting, reinforcing steel bar and concrete. However, since the method is complex and tedious to use, two simple formulas for the nonlinear moment-curvature relation of the composite beam have been proposed. A simple power model, which has been originally used to predict the flexural capacity of the beam to column connections, is proposed as the first …

Cold-Formed Shear Connectors For Composite Constructions, Maximiliano Malite, Walter A. Nimir, Jose Jairo De Sales, Roberto Martins Goncalves

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Construction employing composite steel-concrete structures has been increasingly applied in building and bridge structures, and solutions involving cold-formed profiles have recently appeared which, in many cases, have resulted in reduced costs. Because constructions using composite steel-concrete structures, involving cold-formed profiles, are not covered by current Brazilian Codes, it is necessary to investigate the issue. This paper, therefore, presents the results of an experimental analysis (24 push-out tests) made for two types of connectors: U-profile and angle, with two plate thicknesses: 2.65 mm and 4.76 mm, evaluating their strength and their load-slip behavior. The tests were performed on test specimens adapted …

Accelerated Test Development For Coil-Coated Steel Building Panels, K. M. Lawson, H. H. Lawson, H. E. G. Rommal, A. C. Tiburcio

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper discusses the experimental design and the preliminary findings of an ongoing project designed to establish an accelerated laboratory test that would rank coating system performance the same as their performance in atmospheric exposure. A total of ten materials are included in the program: four substrates each with two coating systems and one substrate with two additional coating systems. Samples were installed at four atmospheric exposure sites: Middletown, OH, Daytona Beach, FL, Monroeville, PA, and Halifax, NS, Canada. Three different orientations were utilized at each of the exposure sites and a variety of building panel features were included on …

Ductility Measurements Of Thin G550 Sheet Steels, Colin A. Rogers, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Cold formed structural members are fabricated from sheet steels which must meet various material requirements prescribed in applicable national design standards. These requirements ensure that; I) stress concentrations can be redistributed and 2) members and connections can undergo a minimum amount of displacement without a loss in structural performance. The Australian / New Zealand, AS/NZS 4600, and both North American, CSA-S136 and AlSI, Cold Formed Steel Design Standards allow for the use of thin (t < O.9mm), high strength (fy = 550MPa) sheet steels if the yield stress and ultimate strength are reduced to 75% of their minimum specified values. This paper provides a summary of results detailing the ductility and net cross-section tensile resistance of G550 sheet steels (to Australian Standard AS 1397) tested as solid and perforated coupons. Material properties of the test specimens are compared wIth the Dhalla and Winter requirements for ductility and ultimate strength to yield stress ratio. limit states tensile design equations are calibrated according to procedures defmed by the American Iron and Steel Institute (AlSI) Commentary.

Technique And Qualities Of Beams With Expanded Metal Sections, M. Hellsten

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The rotary expander technique can be used for manufacturing Lattice framework from a single strip of sheet metal by integrating expanded metal with solid sheet. This technique can be used to distribute the material in a tubular, or open profile to where it's best needed. Valuable qualities possible to are: - low weight and optimal strength - low energy transmission (noise and heat) - soft deformation and favorable energy absorbing properties - good fatigue resistance - high flexibility in design and product qualities These qualities are useful in applications like: - light and strong steel framing systems for buildings - …

Bearing Design Of Thin Sheet Steel Screwed Connections, Colin A. Rogers, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The 1996 Australian / New Zealand AS/NZS 4600 and North American; CSA-S136, AISI Cold Formed Steel Design Standards allow for the use of thin (t < 0.9 mm in AS/NZS 4600), high strength (fy = 550 MPa) sheet steels if the yield stress and ultimate strength are reduced to 75% of their minimum specified values. At present, these reduced material properties must be used in the design of screwed connections which undergo bearing and bearing/tilting failure. Previous research has illustrated the need for design standards to include a gradated bearing coefficient method to account for the behaviour of thin high strength sheet steels, instead of a gross reduction in material properties. This paper provides a summary of results detailing the behaviour of screwed connections tested in shear which have failed in the bearing and bearing/tilting modes. Recommendations concerning the adequacy of current design standards with respect to a proposed formulation which can be used to more accurately predict the shear resistance of screwed connections which fail in the bearing and bearing/tilting modes are presented.

Behaviour Of Thin G550 Sheet Steel Screwed Connections, Colin A. Rogers, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper provides a summary of results detailing the behaviour of screwed connections tested in shear, which were composed of thin G550 and G300 sheet steels (to the 1993 Australian Standard AS 1397). Recommendations concerning the adequacy of current design standards with respect to the design of thin sheet steel screwed connections are made.

Understanding Pullover, Jonathan Sabia Kreiner, Duane S. Ellifritt

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Self drilling screws are often used for attaching roof and wall panels to structural framing and are subjected to tensile loads caused by negative wind pressures. Pullover failure is often associated with this loading condition, which occurs when It fastener pulls through a metal panel but remains attached to the structural framework underneath. The American lron and Steel Institute (AISI) has developed several standard tests for pullover and has included a design criterion for pullover in their specification. However, previous research at the University of Florida has found one particular test and the AISI Specification Section E4.4.2 to be un-conservative. …

Web Crippling Of Cold Formed Steel Members, K. Prabakaran, R. M. Schuster

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A new design expression for web crippling of cold formed steel members has been developed. An extensive statistical analysis was performed using published test data from Canada, the United States, Sweden and France to develop new expressions for the web crippling strength of cold formed steel members under four different loading cases, i.e. (1) end one-flange loading (EOF), (2) interior one-flange loading (lOF), (3) end two-flange loading (ETF) and (4) interior two-flange loading (lTF). I-sections made of two channels connected back-to-back, Z-sections, channels and multiple web sections (decks) were considered. Comparisons were made with the web crippling expressions presented in …

Shift Of The Effective Centroid Of Channel Columns, Ben Young, Kim J. R. Rasmussen

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

In the design of pin-ended channel columns, it is necessary to account for the shift of the effective centroid caused by local buckling. The current American Iron and Steel Institute (AISI 1996) Specification and the Australian/New Zealand Standard (AS/NZS 4600-1996) for cold-formed steel structures calculate the shift by use of effective widths. However, the ability of the effective width rules to accurately predict this shift has not been experimentally assessed. In this paper, recent tests on fixed-ended channel columns are used to obtain values of the shift of the effective centroid, including its variation with the applied load. In the …

Experimental Procedures For Stub Column Tests, Y. Pu, M. H. R. Godley, R. G. Beale

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

In this paper a total of 36 stub columns was tested by two different experimental procedures, namely the FEM and AISI procedures, to investigate the difference in the ultimate load between these procedures. Of these 26 were carried out in the pin-ended condition according to FEM, the rest were in the fixed-end condition according to AlSI specification. It is shown that the failure loads obtained by the two experimental procedures were very close to each other. Both procedures worked well. The AISI procedure is recommended as the standard procedure.

Rotational Stiffnesses Of Semi-Rigid Baseplates, X. Feng, M. H. R. Godley, R. G. Beale

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The paper describes a test procedure to determine the rotational stiffnesses and moment-curvature relationships of semi-rigid baseplates of cold-formed structures. The influence of the modulus of the foundation subgrade on baseplate performance is determined. Increasing the axial load applied to a baseplate is shown to increase the ultimate moment-rotation capacity of a baseplate.

Frequently Asked Questions Concerning The Aisi Base Test And The Use Of The Aisi Anchorage Equations, Roger A. Laboube, Thomas M. Murray, Joe N. Nunnery, James M. Fisher

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The AISI Base Test Method was first introduced into the 1996 AISI Specification. Section C3.1.4 of the Specification provides a method for determining the nominal moment strength of a C- or Z- section under gravity load in the plane parallel to the web with the top flange supporting a standing seam roof system. A standing seam roof system is defined as a roof system in which the side laps between the roof panels or deck are arranged in a vertical position above the roof line, and the roof panel system is secured to the purlins by means of concealed hold …

Study On Light-Gauge Steel Roof Trusses With Rosette Connections, Pentti Makelainen, Jyrki Kesti, Olli Kaitila, Kimmo J. Sahramaa

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper describes the Rosette-joining system and its possibilities in roof-truss structures in the span range of 8 to 12 meters (26 to 39 ft). The test programme that was carried out to verify the behaviour of the Rosette-joint and the thin-walled sections is described. The test results are given and analysed where they currently exist. The results are compared with values calculated according to the 1996 U.S. (AISI) [3] code supported by a distortional buckling analysis according to the Australian / New Zealand Standard (AS) [4] and FE Analysis results.

Extension Of The Generalized Hebbian Algorithm For Principal Component Extraction, Fredric M. Ham, Inho Kim

Electrical Engineering and Computer Science Faculty Publications

Principal component analysis (PCA) plays an important role in various areas. In many applications it is necessary to adaptively compute the principal components of the input data. Over the past several years, there have been numerous neural network approaches to adaptively extract principal components for PCA. One of he most popular learning rules for training a single-layer linear network for principal component extraction is Sanger's generalized Hebbian algorithm (GHA). We have extended the GHA (EGHA) by including a positive-definite symmetric weighting matrix in the representation error-cost function that is used to derive the learning rule to train the network. The …

Investigation Of A Cyclic Laterally Loaded Model Pile Group, Robb E.S. Moss, Joseph A. Caliendo, Loren R. Anderson

Civil and Environmental Engineering

In certain regions of the world, designing deep foundations to withstand seismic loading is a reality. Seismic loading of structures and foundations reaches its most critical state as a cyclic lateral force. The response of soils and foundations to repetitive lateral forces is highly complex, relegating most design methods to be based upon overly conservative rules-of-thumb. The primary objective of this research was to analyze the mechanics of seismic loading on pile groups in clay soils. To achieve this a model testing facility was constructed to house a fully instrumented 1 X 5 model pile group that was subjected to …

Fuzzy Logic Control Of A Model Airplane, Jon C. Ervin, Sema E. Alptekin

Industrial and Manufacturing Engineering

Common uses of fuzzy logic control today are found in relatively simple applications in products. These applications only scratch the surface of the potential of fuzzy logic control in complex mechatronic systems. In order to demonstrate the utility of fuzzy logic in complex device control, a fuzzy logic fly-by-wire system has been developed for a model airplane. The model airplane is a complex system of several critical inputs that require rapid processing and action in order to maintain flight stability. In addition, payload and power constraints severely limit the size, weight and processing power of the hardware to be carried …

Processing Of Hydroxylapatite Coatings On Titanium Alloy Bone Prostheses, Michael A. Nastasi, Timothy E. Levine, James W. Mayer, Vincent B. Pizziconi

Department of Mechanical and Materials Engineering: Faculty Publications

Processing of hydroxylapatite Sol-gel films on titanium alloy bone prostheses. A method utilizing non-line-of-Sight ion beam implantation and/or rapid thermal processing to provide improved bonding of layers of hydroxylapatite to titanium alloy Substrates while encouraging bone ingrowth into the hydroxylapatite layers located away from the substrate, is described for the fabrication of prostheses. The first layer of hydroxylapatite is mixed into the Substrate by the ions or rapidly thermally annealed, while Subsequent layers are heat treated or densified using ion implantation to form layers of decreasing density and larger crystallization, with the outermost layers being Suitable for bone ingrowth.

Method For Improving The Pozzolanic Character Of Fly Ash, John G. Groppo Jr., Thomas L. Robl, Charles J. Mccormick

Center for Applied Energy Research Faculty Patents

A method for improving the pozzolanic character of fly ash includes the steps of first hydraulically classifying and then flotation separating the fly ash in order to reduce particle size distribution and remove carbon. The method also includes the steps of spiral concentrating separated coarse particles to recover iron, pyrite and marcasite and screening the fly ash to remove ultra-light carbon and plant debris.

Acuta Enews October 1998, Vol.27, No. 10

ACUTA Newsletters

In This Issue

FCC Approves Two-Way Digital ITFS and MDS Communications

Recognizing Our Best

Board Report

DC at a Glance

Positions Available

Welcome New Members

Microstructures And Mechanical Properties Of Two-Phase Alloys Based On Nbcr2, Katherine C. Chen, Paul G . Kotula, Carl M. Cady, Michael E. Mauro, Dan J. Thoma

Materials Engineering

A two-phase, NbCrTi alloy (bcc + C15 Laves phase) has been developed using several alloy design methodologies. In efforts to understand processing-microstructure-property relationships, different processing routes were employed. The resulting microstructures and mechanical properties are discussed and compared. Plasma arc melted (PAM) samples served to establish baseline, as-cast properties. In addition, a novel processing technique, involving decomposition of a supersaturated and metastable precursor phase during hot isostatic pressing (HIP), was used to produce a refined, equilibrium two-phase microstructure. Quasi-static compression tests as a function of temperature were performed on both alloy types. Different deformation mechanisms were encountered based upon temperature …

Modern Water Control And Management Practices In Irrigation: Impact On Performance, Charles M. Burt, Stuart W. Styles

BioResource and Agricultural Engineering

This research addressed the basic questions of what levels of water delivery service are presently provided by irrigation projects having some aspect of modernization; what hardware and software features impact those levels of service; whether modern water control and management practices in irrigation make a positive difference in performance; and what universal lessons can be learned and applied.

Ole Miss Engineer 1998

Ole Miss Engineer

No abstract provided.

Closure To Discussion: Failure Case Studies And Engineering Ethics In Engineering Mechanics Courses, Norbert J. Delatte

Civil and Environmental Engineering Faculty Publications

No abstract provided.