Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 30 of 46
Full-Text Articles in Engineering
Effect Of Bracing Stiffness On Buckling Strength Of Cold-Formed Steel Columns, Pratyoosh Gupta, George E. Blandford, S. T. Wang
Effect Of Bracing Stiffness On Buckling Strength Of Cold-Formed Steel Columns, Pratyoosh Gupta, George E. Blandford, S. T. Wang
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
A three-dimensional second-order analysis is used to study the effect of brace stiffness on the buckling strength of cold-formed steel columns. The finite element formulation uses an iterative updated Lagrangian scheme to include the second-order geometric non-linear effects in the space frame element as well as the connection element used to model a brace. Lateral brace stiffness required to achieve full bracing for a two-dimensional column, and lateral and torsional brace stiffnesses required for a three-dimensional cold-formed steel column are studied. The strength requirement for various brace components, the effects of column initial imperfections, and the impact of varying warping …
Towards A Numerical Procedure For Composite Slab Assessment, Howard D. Wright, Milan Veljkovic
Towards A Numerical Procedure For Composite Slab Assessment, Howard D. Wright, Milan Veljkovic
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
Composite slab design relies upon adequate shear bond resistance between the steel and concrete. This is achieved by friction between the materials and the mechanical interlock of embossments pressed in the steel. The behaviour of this shear bond resistance is complex and is obtainable only from model tests. This paper explores the potential for numerical modelling to provide the required design information.
Interaction Of Flange/Edge - Stiffened Cold Formed Steel C - Sections, Colin A. Rogers, R. M. Schuster
Interaction Of Flange/Edge - Stiffened Cold Formed Steel C - Sections, Colin A. Rogers, R. M. Schuster
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
A revision to the Canadian Standard (S136-94)[1] and the American Specification (AISI- 89)[2], in which the procedure to calculate the effective width of an edge-stiffened compressive flange is modified, has been proposed by Dinovitzer et al.[3]. The proposal involves a change of the equations for the flange plate buckling coefficients of Case II compressive elements, which eliminates a discontinuity in the effective width formulation. The modified local buckling procedure was compared with the current Canadian Cold Formed Steel Standard using a program of beam tests at the University of Waterloo[4] and data available in the literature[8,9, 10, 11,12]. Statistical results …
Effective Width Of A Simple Edge-Stiffener Subjected To A Stress Gradient, Colin A. Rogers, R. M. Schuster
Effective Width Of A Simple Edge-Stiffener Subjected To A Stress Gradient, Colin A. Rogers, R. M. Schuster
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The most recent editions of the North American Design Standards present a unified effective width approach for the design of compressive elements. This paper outlines a comparison of various modifications to the existing procedure used to calculate the effective width of a simple edge-stiffener subjected to a stress gradient. The comparison involves three methods where the magnitude of the compressive stress is altered, and two stress gradient methods where the plate bucking coefficient is based on the ratio of compressive stresses at the top and bottom of the flat width of the simple edge-stiffener. Analysis of these methods was carried …
The Effects Of Perforation Length On The Behaviour Of Perforated Elements In Compression, J. Rhodes, M. Macdonald
The Effects Of Perforation Length On The Behaviour Of Perforated Elements In Compression, J. Rhodes, M. Macdonald
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The compressional behaviour of stub columns having perforations in the form of slots of different length is examined on the basis of testing. Plain channels of a specified geometry are considered, and the geometry examined follows that of a test programme previously carried out to examine the effects of perforation location on stub column strength. Two different perforation layouts, and two material thicknesses are considered and systematic variation in the slot length is carried out for each layout and thickness. It is found that the stub column compression capacity reduces as the perforation length increases. The test results are compared …
The Modulus Of Elasticity Of Steel - Is It 200 Gpa?, Mahen Mahendran
The Modulus Of Elasticity Of Steel - Is It 200 Gpa?, Mahen Mahendran
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
In cold-formed steel construction, the use of a range of thin, high strength steels (0.35 mm thickness and 550 MPa yield stress) has increased significantly in recent times. A good knowledge of the basic mechanical properties of these steels is needed for a satisfactory use of them. In relation to the modulus of elasticity, the current practice is to assume it to be about 200 GPa for all steel grades. However, tensile tests of these steels have consistently shown that the modulus of elasticity varies with grade of steel and thickness. It was found that it increases to values as …
Buckling Experiments On Hollow Flange Beams With Web Stiffeners, Mahen Mahendran, P. Avery
Buckling Experiments On Hollow Flange Beams With Web Stiffeners, Mahen Mahendran, P. Avery
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
A new cold-formed and resistance welded section known as the Hollow Flange Beam (HFB) has been developed recently in Australia. In contrast to the common lateral torsional buckling mode of I-beams, this unique section comprising two stiff triangular flanges and a slender web is susceptible to a lateral distortional buckling mode of failure involving lateral deflection, twist and cross-section change due to web distortion. This lateral distortional buckling behaviour has been shown to cause significant reduction of the available flexural strength of HFBs. An investigation using finite element analyses and large scale experiments was carried out into the use of …
Determination Of Purlin R-Factors Using A Non-Linear Analysis, Catherine J. Rousch, Gregory J. Hancock
Determination Of Purlin R-Factors Using A Non-Linear Analysis, Catherine J. Rousch, Gregory J. Hancock
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
In both Australia and the U.S.A., the design procedure for purlins under wind uplift loading is based on the use of reduction factors (R-factors), which allow for the flexural-torsional or nonlinear twisting behaviour of purlins with screw-fastened sheeting. To date, all R-factors have been determined by testing. However, in the future it may be more efficient to obtain R-factors from numerical models to minimise testing. This paper shows how a numerical model of the twisting behaviour of channel and Z-section purlins can be used to generate R-factors. Comparisons between experimentally determined and numerically based R-factors are made.
Recent Research And Developments In Cold-Formed Steel Design And Construction, Roger A. Laboube, Wei-Wen Yu
Recent Research And Developments In Cold-Formed Steel Design And Construction, Roger A. Laboube, Wei-Wen Yu
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
Golden Anniversary of the AISI Specification - The 1996 AISI Specification - A New AISI Cold-Formed Steel Design Manual - Design of Cold-Formed Steel Stiffened Elements with Multiple Longitudinal Intermediate Stiffeners - A Probablistic Examination of the Ultimate Strength of Cold-Formed Steel Elements - Effective Width of a Simple Edge-Stiffener Subjected to Stress Gradient - The Effects of Perforation Length on the Behaviour of Perforated Elements in Compression - Interaction of Flangel/Edge-Stiffened Cold-Formed Steel C-Sections - Cold-Formed Steel Flat Width Ratio Limits, d/t and d/w - Comparison of the Distortional Buckling Method for Flexural Members with Tests - Design of …
Design Of Thin-Walled Beams For Distortional Buckling, C. Jiang, J. Michael Davies
Design Of Thin-Walled Beams For Distortional Buckling, C. Jiang, J. Michael Davies
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The bending behaviour of cold-formed steel beams is far from simple. The double symmetry associated with hot-rolled I-sections is generally uneconomical and the use of thin-walled slender elements means that local buckling of parts of the cross-section in compression may be a significant design factor leading to additional asymmetry of behaviour. Furthermore, the modern tendency to introduce additional folds in order to control local buckling and to produce more favourable global section properties also serves to aggravate the tendency towards distortional buckling. Generalised Beam Theory (GBT) has wide application to the analysis and design of cold-formed beams and can provide …
A New Aisi Cold-Formed Steel Design Manual, Richard C. Kaehler, Paul A. Seaburg
A New Aisi Cold-Formed Steel Design Manual, Richard C. Kaehler, Paul A. Seaburg
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The Specification Committee of the American Iron and Steel Institute is currently developing a new Cold Formed Steel Design Manual. The work is being done under contract with Computerized Structural Design with oversight provided by AISI Subcommittee 26 - Design Manual. This paper describes the purpose and contents of this Manual. It is expected the Manual will be published in conjunction with the new edition of the Specification for the Design of Cold-Formed Steel Structural Members early in 1997. The Manual will contain the combined versions of the Allowable Stress Design and Load and Resistance Factor Design Specifications in addition …
Golden Anniversary Of The Aisi Specification, Wei-Wen Yu, Don S. Wolford, Albert L. Johnson
Golden Anniversary Of The Aisi Specification, Wei-Wen Yu, Don S. Wolford, Albert L. Johnson
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The use of cold-formed steel members in building construction began in about the 1850's in the United States and Great Britain. However, such thin-walled steel members were not widely used for buildings until after 1946 When the first edition of the Specification for the Design of Light Gage Steel Structural Members was published by the American Iron and Steel Institute (AISI, 1946). This first design standard was based primarily on the research work sponsored by the Institute at Cornell University under the direction of Professor George Winter after 1939 (Winter, 1959a and 1959b). It was revised subsequently by the AISI …
The 1996 Aisi Specification, Roger L. Brockenbrough
The 1996 Aisi Specification, Roger L. Brockenbrough
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The first edition of the AISI specification was adopted in 1946. Thus, the new specification represents fifty years of progress in the formal structural application of cold-formed steel. The continued efforts of the Committee on Specifications and the sponsorship of the American Iron and Steel Institute have made this fifty years of progress in cold-formed steel a reality. The new specification combines ASD and LRFD provisions in a single document. This affords the design engineer the opportunity to become familiar with both methods and facilitates the use of whichever method is preferred. In addition, the new specification includes a number …
A Probabilistic Examination Of The Ultimate Strength Of Cold-Formed Steel Elements, Benjamin W. Schafer, Mircea Gigoriu, Teoman Pekoz
A Probabilistic Examination Of The Ultimate Strength Of Cold-Formed Steel Elements, Benjamin W. Schafer, Mircea Gigoriu, Teoman Pekoz
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
This paper investigates the ultimate strength of cold-formed steel plates in uniform compression and pure bending with the goal of determining the statistical characteristics (mean and variance) of the ultimate strength. Plate thickness, longitudinal residual stress magnitude, and imperfection magnitude are considered as random variables. Based on existing data appropriate distributions are determined for these three random variables. Using ABAQUS for the strength prediction, two methods: Monte Carlo simulation and Taylor series approximation, are employed to determine statistical characteristics of the plates. The results are compared to the deterministic approach of the AISI Cold-Formed LRFD Specification.
Design Of Cold-Formed Steel Stiffened Elements With Multiple Longitudinal Intermediate Stiffeners, Benjamin W. Schafer, Teoman Pekoz
Design Of Cold-Formed Steel Stiffened Elements With Multiple Longitudinal Intermediate Stiffeners, Benjamin W. Schafer, Teoman Pekoz
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
Current specification procedures for calculating the bending strength of members with multiple longitudinal intermediate stiffeners in the compression flange have been found to be inadequate. A new procedure for calculating the effective width of stiffened elements with multiple intermediate stiffeners is presented. The new method introduces the calculation of a buckling coefficient for overall buckling of the entire stiffened element as a unit, and local buckling of the subelement plates between stiffeners. The expression for calculating overall buckling is derived and verified via comparison to numerical methods. The minimum buckling coefficient from the two modes (local and overall) is used …
Additional Design Considerations For Bolted Connections, Roger A. Laboube, Wei-Wen Yu
Additional Design Considerations For Bolted Connections, Roger A. Laboube, Wei-Wen Yu
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
A multi-year study was conducted at the University of Missouri-Rolla which focused on such topics as deformation characteristics of bearing type connections; strength of bearing and tensile type failure modes of flat sheet connections; tensile strength of staggered bolt patterns in flat sheet connections; and tensile strength of bolted connections for angle and channel sections. The intent of this research was to verify the present design approach for bolted connections and to expand the design methodology to include additional limit states, in particular the effect of deformation of the bolt hole and the influence of shear lag in angle and …
Performance Of Self-Tapping Screws In Lap-Shear Metal-To-Metal Connections, Reynaud Serrette, Victor Lopez
Performance Of Self-Tapping Screws In Lap-Shear Metal-To-Metal Connections, Reynaud Serrette, Victor Lopez
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The basic design requirement for screws in light gauge steel construction is the strength of the screw in a given application (metal-to-metal, wood-to-metal, or metal-to-wood) based on the body diameter of the screw. This statement is clearly obvious from the current AISI screw specifications for lap shear metal-to-metal connections. Recent research has shown that the performance of a screw fastener may also depend on other features of the screw including the head and thread style, and the method of installation (stripped versus unstripped screws). The data presented in this paper address these issues for lap shear connections designed with No. …
Shear Behavior Of Self Drilling Screws Used In Low Ductility Steel, Randy L. Daudet, Roger A. Laboube
Shear Behavior Of Self Drilling Screws Used In Low Ductility Steel, Randy L. Daudet, Roger A. Laboube
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The results of 264 shear tests conducted on self drilling screws are presented. The tests conducted include single screws in single shear, two screws in single shear, and single screws in double shear. The performance and behavior of self drilling screws in low ductility steel are compared to the performance and behavior of screws in normal ductility steel. Results are compared to the 1986 AISI specification with 1989 addenda, and the recently approved AISI specification for self drilling screws which will be included in the next edition of the AISI code. Also, new equations are presented for the tilting/bearing limit …
Cold-Formed Steel Design By Spreadsheet Program, Scott A. Burns
Cold-Formed Steel Design By Spreadsheet Program, Scott A. Burns
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
This paper demonstrates how to use advanced features of a spreadsheet program to design cold-formed steel members efficiently. The example presented in the paper concerns a hat section in flexure which is to be designed for maximum bending strength with a restriction on the total amount of steel that can be used. The nature of the formulas and data entered into the spreadsheet program are presented.
Cold-Formed Steel Sections Experimental Data Base, Dan Dubina, Mircea Georgescu, Dorina Goina, Viorel Ungureanu
Cold-Formed Steel Sections Experimental Data Base, Dan Dubina, Mircea Georgescu, Dorina Goina, Viorel Ungureanu
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
Thin-walled cold-formed member critical load in the coupling point of overall/local buckling modes is defined, together with critical load erosion factor (ψ). A calibration method for (ψ) using an experimental database called DATACOST is presented.
Evaluation And Modelling Of The Material Properties For Analysis Of Cold-Formed Steel Sections, Nabil Abdel-Rahman, K. S. Sivakumaran
Evaluation And Modelling Of The Material Properties For Analysis Of Cold-Formed Steel Sections, Nabil Abdel-Rahman, K. S. Sivakumaran
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The results of two series of experimental investigations to evaluate the mechanical properties and the residual stresses of cold-formed steel (CFS) sections are reported in this paper. These investigations were performed on channel-shaped CFS sections manufactured using cold-roll forming technique. Tensile coupon tests were used to evaluate the mechanical properties at different positions of the channel sections. Electrical resistance strain gauges with an "Electrical Discharge Machining" cutting technique were used to establish the magnitudes and the distributions of residual stresses within the channel sections. Based on the experimental results, appropriate analysis models for the stress-strain relationship, the variation of the …
Geometric Imperfections And Residual Stresses For Use In The Analytical Modeling Of Cold-Formed Steel Members, Benjamin W. Schafer, Teoman Pekoz
Geometric Imperfections And Residual Stresses For Use In The Analytical Modeling Of Cold-Formed Steel Members, Benjamin W. Schafer, Teoman Pekoz
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
Geometric imperfections and residual stresses influence the behavior and ultimate strength of cold-formed steel members. Advanced analytical models (i.e. nonlinear finite element models) must reflect this by including appropriate geometric imperfections and residual stresses. To date, little has been done to summarize the existing literature on these topics. As a result, no consensus exists for what magnitudes or distributions should be used when including geometric imperfections and residual stresses in the analysis, In this paper existing literature is reviewed and a new series of measurements carried out with the goal of providing basic guidelines for the use of geometric imperfections …
An Explicit Approach To Design Of Stainless Steel Columns, Jacques Rondal, Kim J. R. Rasmussen
An Explicit Approach To Design Of Stainless Steel Columns, Jacques Rondal, Kim J. R. Rasmussen
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The paper describes a design procedure for stainless steel columns failing by flexural buckling. In the approach, the stress strain-curve is assumed to be expressed as a Ramberg-Osgood curve, defined in terms of the initial modulus (Eâ‚€), the 0.2% proof stress (σ₀.â‚‚) and the parameter n. It is shown that the column curve can be described in terms of the Ramberg-Osgood parameters by adopting a Perry-curve as basic strength curve and expressing the imperfection paranleter in terms of Eâ‚€, σ₀.â‚‚ and n. By using a Perry-curve, the design procedure is explicit. This contrasts the iterative approach described in the ASCE-LRFD …
The Strength Of Partially Stiffened Stainless Steel Compression Members, W. Reyneke, G. J. Van Den Berg
The Strength Of Partially Stiffened Stainless Steel Compression Members, W. Reyneke, G. J. Van Den Berg
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
In this study the effect of the non-linear behaviour of stainless steels on the local buckling strength of partially stiffened compression elements is studied. The steel under investigation is a Type 304 stainless steel. Doubly symmetric hat section columns were manufactured by a press braking process and tested as stub columns to exclude overall buckling interaction. The different plasticity reduction factors' suggested in the ASCE stainless steel design specification for stiffened and unstiffened compression elements are used to compare experimental results with theoretical predictions. It is concluded that the ASCE and South African stainless steel design specifications overestimate the local …
Burst Strength Of Type 304l Stainless Steel Tubes Subjected To Internal Pressure And External Forces, J. Pretorius, P. Van Der Merwe, G. J. Van Den Berg
Burst Strength Of Type 304l Stainless Steel Tubes Subjected To Internal Pressure And External Forces, J. Pretorius, P. Van Der Merwe, G. J. Van Den Berg
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The findings of an investigation concerning the burst strength of cold-formed Type 304L stainless steel tubes subjected to internal pressure and static external forces are reported in this study. The use of cold-formed stainless steel longitudinally welded tube in pressurised processes in industry are limited due to the belief that seamless tubes have superior resistance to internal pressure. The primary objective of this study was to experimentally and theoretically describe the failure criteria for thin-walled longitudinally welded Type 304L stainless steel tubes subjected to internal pressure and static external point loads and torsion loads. Due to the diversity of the …
Cold Formed Steel Flat Width Ratio Limits, D/T And DI/W, Colin A. Rogers, R. M. Schuster
Cold Formed Steel Flat Width Ratio Limits, D/T And DI/W, Colin A. Rogers, R. M. Schuster
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
This paper reports the findings of an investigation of the flat width ratio limit for simple edge-stiffeners of channels in bending. Willis & Wallace concluded that the lip flat width ratio limit, d/t, should have a value of 14 based on a comparison of the 1980 and 1986 editions of the American Iron and Steel Institute (AISI) Cold Formed Steel Specification. This conclusion was made using the results of only three channel beam tests with various lip sizes, Case III flanges and locally unstable webs. The CAN/CSA-S136 Technical Committee adopted the recommendations of Willis & Wallace and included the lip …
Comparison Of The Distortional Buckling Method For Flexural Members With Tests, Colin A. Rogers, R. M. Schuster
Comparison Of The Distortional Buckling Method For Flexural Members With Tests, Colin A. Rogers, R. M. Schuster
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
For thin-walled flexural members composed of certain geometric proportions and/or made of high-strength steel, a mode of buckling at half-wavelengths intermediate between local buckling and flexural-torsional or flexural buckling can occur. The mode is most common for edge (lip) stiffened members such as C and Z-sections, and involves rotation of the lip-flange component about the flange-web junction. This mode is commonly called distortional buckling. Presented in this paper is a design method for distortional buckling of flexural members recently submitted for ballot with the AISI Specification Committee for Cold-Formed Steel Structures. Currently, the North American Cold-Formed Steel Design Standards do …
Comparison Of Tests Of Purlins With And Without Cleats, Michael Celeban, Dan Popovic, Gregory J. Hancock
Comparison Of Tests Of Purlins With And Without Cleats, Michael Celeban, Dan Popovic, Gregory J. Hancock
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The paper describes a series of tests on Z-section purlins lapped over three spans and subject to wind uplift loading. The purlins were not attached to the rafters by cleats. Sheeting was screw-fastened to the purlins and a range of bridging (bracing) members was used to prevent lateral deflection and twisting. The results of the tests are compared with earlier tests with the same configurations but including cleats at the supports.
Deflection Design Of Cold-Formed Rhs Steel Beams, Xiao-Ling Zhao, Kwong-Ping Kiew
Deflection Design Of Cold-Formed Rhs Steel Beams, Xiao-Ling Zhao, Kwong-Ping Kiew
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
The moment-deflection results of cold-formed RHS (rectangular hollow section) steel beams are examined. A simple design approach is proposed to account for the effect that material nonlinearity has on deflection. A general expression is also derived to predict the deflection of cold-formed RHS steel beams.
Finite Element Analysis Of Hollow Flange Beams With Web Stiffeners, P. Avery, Mahen Mahendran
Finite Element Analysis Of Hollow Flange Beams With Web Stiffeners, P. Avery, Mahen Mahendran
CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)
A new cold-formed and resistance welded section known as the Hollow Flange Beam (HFB) has been developed recently in Australia. In contrast to the common lateral torsional buckling mode of I-beams, this unique section comprising two stiff triangular flanges and a slender web is susceptible to a lateral distortional buckling mode of failure involving lateral deflection, twist, and cross-section change due to web distortion. This lateral distortional buckling behavior has been shown to cause significant reduction of the available flexural capacity of HFBs. An investigation using finite element analyses and large scale experiments was carried out into the use of …