Civil and Environmental Engineering Commons^™

Buckling Behaviour Of Cold-Formed Thin-Walled Members By Spline Finite Strip Analysis, Joachim Lindner, Y. L. Guo

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

Local,distortional and overall buckling (including overall flexural buckling and overall flexural-torsional buckling) behaviour of cold-formed thin-walled columns is presented which is based on an inelastic spline finite strip analysis. The columns are loaded centrally at the ends. The increment of yield stresses in the corner area due to cold-forming work, together with a more real stress-strain curve of material, that exhibits continuous strain hardening for the stress above the proportional limit of material, are involved in the analysis. The cold-formed section is divided into two different types of strips, one is a flat plate strip on the central part of …

Core Loaded Thin-Walled Sleeved Column System, S. Hariharan, K. Mahadevan, Venkatakrishnan Kalyanaraman

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

In conventional columns, the load carrying capacity is governed by the yield strength of the material and its buckling strength. The yield strength of the compression member is governed by the mechanical property of the material and its area of cross section while its elastic buckling strength depends on the least flexural stiffness (EI) ofthe cross section and its effective unsupported length. The elastic flexural buckling strength of a compression member is given by the well known Euler equation. In practice the strength of conventional compression members is less than bot.h the yield strength and Euler buckling strength due to …

Experiments On Lipped Channel Flexural Members, Maria E. Moreyra, Teoman Pekoz

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

A series of tests were conducted on lipped channel flexural members to study the behavior of edge stiffened elements. The details and the results of these tests as well as tests by others are discussed in this paper. All the test results are compared with those predicted by the AISI Specification.

Strength Of Stiffened Plates With Openings, Mahen Mahendran, N. E. Shanmugam, J. Y. Richard Liew

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

The load-deflection and ultimate strength behaviour of longitudinally stiffened plates with openings was studied using a second-order elastic post-buckling analysis and a rigid-plastic analysis. The ultimate strength was predicted from the intersection point of elastic and rigid-plastic curves and the Perry strut formula. Comparison with experimental results shows that satisfactory prediction of ultimate strength can be obtained by this simple method. Effects of the size of opening, the initial geometrical imperfections and the plate slenderness ratio on the strength of perforated stiffened plates were also studied.

Behavior Of Connections Between Shs Columns & W-Section Beams, Uk Sun Kim, Jong Suk Lee, Young Bong Kwon

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

Connections between SHS (Square Hollow Section) columns and W-section beams are generally fabricated by welding with or without endplates in the factory. These welded connections possess some finite degree of rotational stiffness which falls between fully rigid and ideally pinned joints. The influence of partially restrained connections on structural response not only changes the moment distribution but also increases frame drift. In this paper, a series of connection tests joining SHS column and W-section beam were executed and the test results compared with theoretical values. A method to utilize nonlinear moment-rotation relations of beam-to-column connections in steel framed structures is …

Light-Gauge Engineering In Today's Marketplace - The Challenges, Gene Farach, Robert C. Grupe Jr.

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

Light-gauge has tremendous potential in the construction industry. It is a material which affords more carrying capacity per less weight. Thus less material needs to be used which leads to a reduction in labor and subsequent reduction in cost, light-gauge is a durable, recyclable product, environmentally friendly in keeping with today's concern for the world around us. It is resistant to insects such as termites, mold mildew, rotting, drying out, warping and non combustible. However the reality remains that if research and development is not undertaken soon, the window of current demand may be short lived. We must accept that …

Seismic Response Of Single-Storey Steel Buildings, R. Tremblay, S. F. Stiemer

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

Nonlinear time step dynamic analyses have been performed on 24 rectangular single-storey steel framed buildings including a metal roof deck diaphragm and steel bracing bays along their exterior walls. The structures were designed according to current Canadian codes and were subjected to site specific ensembles of historical earthquake accelerograms. The analyses indicated that larger in-plane deformations and bending moments developed in the diaphragm compared to the values expected from the equivalent lateral force procedure commonly used in design. The distribution of the shear forces in the diaphragm was also found to deviate significantly from the linear distribution assumed in design. …

Comparison Of A Non-Linear Purlin Model With Tests, Catherine J. Rousch, Gregory J. Hancock

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

A non-linear elastic analysis has been developed for determining the lateral deflections of, and stresses in, the unconnected flanges of simply-supported and continuous channel and Z-section purlins screw-fastened to sheeting and subject to either wind uplift or gravity loading. The analysis incorporates a model, based on a combination of those developed by Pekoz and Soroushian, and Thomasson, which depicts the unconnected purlin flange as a beam-column. The restraint against lateral deflection is provided primarily by the sheeting, and is represented by a linear extensional spring of stiffness k located at the level of the unconnected purlin flange. To verify the …

Study On The Load-Bearing Capacity Of Cold-Formed Sigma Purlins, Markku Laine, Pentti Makelainen

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

Experimental investigations conducted on the structural behaviour and ultimate load carrying capacity of cold-formed sigma purlins are reported. Three different purlin systems, i.e. the double spanning, the sleeved and the overlap system, were investigated. In addition to the full- scale tests on 2-span purlin - sheeting system with screw fastening and with continuous, sleeved and overlapped central supports, tests on single span purlins were also conducted for finding out bending moment and shear capacity values at the central support of a multiple span sigma purlin. Analytical considerations for modelling the cross-sectional behaviour of the sigma purlin itself and the local …

The Analysis Of Restrained Purlins Using Generalised Beam Theory, C. Jiang, Philip Leach, J. Michael Davies

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

A paper presented at the Eleventh Speciality Conference in 1992(1) introduced the Generalized Beam Theory (GBT) and illustrated its use. It was used in ftrst-order analyses t0 calculate the stress distribution in a cross section takeing account of cross section distortion, and in second-order bifurcation problems to calculate the critical buckling load of a free cross section subject to axial load. Subsequent papers(2,3) have given more detailed information on the basis of GBT and used its second-order facilities to investigate the buckling of sections under both uniform and non-uniform bending moment. This paper extends the use of GBT to consider …

Bending And Shear Behavior Of Web Elements With Openings, Roger A. Laboube, Ming-Yang Shan, Wei-Wen Yu

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

Cold-formed steel C-sections are frequently used as wall studs and floor joists in both commercial and residential construction. To facilitate installation of ancillary systems such as electrical wiring and plumbing, the C-section is manufactured with a web opening. Although the opening offers construction advantages, it may degrade the structural integrity of the member. To quantify the degrading effect of a web opening, a study has been conducted at the University of Missouri-Rolla (UMR). The UMR study included the loading conditions of bending, shear, web crippling and the combinations thereof. This paper summarizes the results of an experimental study of the …

Perforated Webs Subjected To End-One-Flange Loading, Roger A. Laboube, James E. Langan, Wei-Wen Yu

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

A study of structural behavior was conducted and a design equation was developed that accounts for the degradation in web crippling capacity caused by web openings for unreinforced single web cold-formed steel flexural members subjected to the End-One-Flange (EOF) loading condition. The research findings enable the current EOF design provisions for sections without web openings to be modified by a reduction factor equation to obtain the web crippling capacity for sections with web openings. The modified capacity is considered for the web crippling capacity in the absence of bending moment for the same cross section and load bearing length.

Reference Section Method For Local Web Buckling, T. K. Sooi, Reynaud Serrette, Teoman Pekoz

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

The present AISI effective width approach for determining flexural section capacities of sections with slender webs requires an iterative approach. A simplified method, called the Reference Section Method or RSM, which eliminates the need for iteration is presented and discussed. The reference section is defined as one that is similar to the actual section except for the web height. This simplified method is based on the premise that the flexural capacity of a section with slender webs is proportional to that of a reference section with compact web. The ratio of the web height of the actual section to that …

Flexural Capacity Of Continuous Span Standing Seam Panels: Gravity Load, Reynaud Serrette, Teoman Pekoz

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

The standing seam panel is one of the most practical and economical roofing systems developed in recent years. Construction of the roof system requires that the panel legs be overlapped and crimped. Under gravity load, the crimped outstanding leg of the connected panels may be subject to distortional buckling. A design method was previously suggested for estimating the distortional buckling strength of the outstanding leg of a single simply supported standing seam panel. In this paper, an approximate method is present for estimating the capacity of a system of interconnected continuous span standing seam panels. Experimental results for three full-scale …

Behaviour Of Cold-Formed Shs Beam-Columns, Raef M. Sully, Gregory J. Hancock

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

This paper describes a test programme conducted into the behaviour of cold-formed, compact square hollow section beam columns. The tests were conducted in a purpose built test rig capable of applying load and moment in a constant ratio. The test specimens were pin-ended specimens loaded, with varying load/moment ratios, at two different ratios of end moment. The results of the tests were simulated using a finite element programme. This finite element programme was used to find maximum second order elastic moments, for the section tested, at varying ratios of end moment. The results of this numerical investigation are compared with …

Cold-Formed Steel Sections For Transmission Towers, David Odaisky, Dimos Polyzios, Glenn Morris

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

Hydro-electric transmission towers are traditionally built using hot-rolled angles. However cold formed angles are becoming more popular as replacements for hot-rolled angles, especially in the smaller angle sizes. In addition to conventional 90° angles, a wide range of shapes can be produced, in sizes to suit individual project requirements. In particular, cold-forming can be used to provide stiffening lips to prevent local buckling of thin wide elements, to optimize shapes so that longer unbraced lengths can be used, and to create shapes such as 60° angles for triangular towers. A research project was carried out at the University of Manitoba …

Elastoplastic Large Deflection Analysis Of Cold-Formed Members Using Spline Finite Strip Method, Shi-Lin Chen, Shao-Fu Li, Shan-Feng Fang

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

The elastoplastic large deflection behaviour of cold-formed members is analysed by a nonlinear spline finite strip method. The method is developed using the principle of virtual work, based on the total Lagrangian description. It is used to deal with problems of geometric and material nonlinearity. The displacement function of a strip is expressed as the product of transverse interpolation polynomials and longitudinal B3-splines. The effect of arbitrary initial imperfections is taken into consideration. The influence of cold-bending residual stress on the local and overall behaviour of cold-formed lipped angle columns is investigated especially. The numeric examples show that the method …

Review Of Concepts Concerning Bond Of Steel Decking, Mark Patrick, Russell Q. Bridge

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

It is well established that bond between deformed reinforcing bars and concrete is produced by three distinct actions: chemical adhesion; friction; and mechanical interlock. However, researchers of composite slab behaviour do not generally agree on the actions which produce bond between steel decking and concrete, and the concepts they have developed in this regard are reviewed.

Slip And Separation At Interface Of Composite Slabs, Li An, Krister Cederwall

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

Resistance of composite elements at the sheet-concrete interface was determined from a small-scale test. The influence of resistance at the interface, especially the vertical resistance, on the behavior of composite slabs was studied by a finite element method. The results showed that the horizontal shear resistance affected greatly on the capacity of the composite slabs. However, the vertical resistance did not influence much on the capacity and it can be neglected in the analysis.

An Innovative Cold-Formed Floor System, John R. Hillman, Thomas M. Murray

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

Optimizing the use of building materials has always been one of the primary goals of engineers. It is a constant challenge to seek innovative methods to build lighter weight structures. Sometimes this is achieved through the development of new building materials, other times it can be accomplished by creating entirely new types of structural systems. Often lightweight structures can be more asthetically pleasing because of their stream-lined appearance. However, in general the motivating factor in building lightweight structures is to reduce the overall cost. One portion of a structure which offers tremendous potential for weight reduction is the floor system. …

Design Of A Purlin System, C. Jiang, D. St. Quinton

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

This paper is concerned with the design of cold-formed steel structural members which span between the frames of a building and carry cladding which is usually either single- or double-skin profiled metal sheeting or a sandwich panel. The cladding is fIxed to these purlins or sheeting rails at regular intervals and the performance in service, and therefore the design, is strongly influenced by interaction with the sheeting. The connection between the purlins and the supporting structure also has a significant influence on performance so that, historically, the emphasis has tended to be on empirical methods of design rather than detailed …

Stainless Steel Tubular Joints - Tests And Design Of X- And K-Joints In Square Hollow Sections, Ben Young, Kim J. R. Rasmussen

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

The paper describes a test program on welded stainless steel X- and K-joints fabricated from square hollow section brace members and chords. The X-joints were tested in compression and tension using different ratios of brace width to chord width. The K-joints were tested by varying the ratio of brace width to chord width, the angle between chord and brace members, and the preload applied to the chord. A total of 23 tests were performed. Design rules are proposed for X- and K-joints by adopting the rules of the CIDECT Recommendations for carbon steel tubular structures and replacing the yield stress …

The Lateral Torsional Buckling Strength Of Cold-Formed Stainless Steel Beams, G. J. Van Den Berg, P. J. Bredenkamp

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

The findings of an investigation of the lateral torsional buckling strength of cold-formed stainless steel beams are reported in this study. The sections under consideration are cold-formed lipped channel sections spot-welded back to back to form doubly-symmetric lipped I-beams. The beams were fabricated from a modified AISI Type 409 stainless steel, designated Type 3CR12 corrosion resisting steel. The purpose of this study is to compare the experimental lateral torsional buckling strengths of doubly-symmetric beams to the theoretical predictions proposed by the ASCE Specification for the Design of Cold-Formed Stainless Steel Structural Members. It was concluded in this investigation that an …

The Strength Of Partially Stiffened Stainless Steel Compression Members, Y. Buitendag, G. J. Van Den Berg

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

The instability of partially stiffened stainless steel compression members due to local buckling of the flange element or flange and lip interaction has not been studied before. In this investigation the critical local buckling and post-buckling behaviour of cold-formed partially stiffened stainless steel compression elements is studied. It is concluded in this investigation that a plasticity reduction factor should be used to evaluate the critical local buckling stress as well as the effective width to calculate the ultimate capacity of partially stiffened stainless steel compression members.

Web Crippling Of Stainless Steel Cold-Formed Beams, S. A. Korvink, G. J. Van Den Berg

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

The results of an investigation on the web crippling strength of cold-formed stainless steel channel sections are presented in this paper. The steels under consideration are AlSI Type 430 stainless steel and a modified AlSI Type 409, designated Type 3CR12 corrosion resisting steel. The lipped channel sections were manufactured by a press braking process. Beams were tested in pairs, lips facing, in an interior-one-flange loading configuration. Experimental results were compared with the theoretical predictions given in the 1991 edition of the Specification for the Design of Cold-Formed Stainless Steel Structural Members. It was concluded in this study that the experimental …

Design And Analysis Of Constrained Layer Damping Treatments For Bending And Torsion, Kimberly J. Balkema

Theses and Dissertations

In this dissertation, different aspects of constrained layer damping treatments on beams of various geometries are studied. First, the optimal length of a constrained layer damping treatment mounted on a surface in linear strain is identified as a function of the relative stiffnesses of the damping layers and the non-uniformity of the surface stain. The analysis extends previous work that considered the case of uniform surface strain. Sixth order sandwich beam theory is then modified for use with a rectangular beam covered with a segmented constrained layer damping treatment. Non-dimensional variables are used to simplify the form of the problem. …

Ccfss Technical Bulletin August 1994, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Ccfss News August 1994, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Effects Of Thickness And Curvature On The Natural Frequencies Of Cylindrical Composite Shells, Jose L. Monteverde E.

Theses and Dissertations

An analytical study is performed to determine the dynamic response, natural frequencies and mode shapes, of deep composite cylindrical shells, including the effect of through the thickness shear strain. The DSHELL finite element program is used to predict the first four natural frequencies and the results are compared to a reference using the Galerkin technique. The program was extended to problems considering simply supported-free boundary conditions. As is well know, the free boundary is rather difficult to represent using the Galerkin technique approach. The mode shapes are created by plotting a surface-contour plot of the eigenvector output from DSHELL.

A …

Structural Behavior Of Perforated Web Elements Of Cold-Formed Steel Flexural Members Subjected To Web Crippling And A Combination Of Web Crippling And Bending, James E. Langan, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE A study of structural behavior was conducted and design equations were developed that account for the degradation in web crippling capacity caused by web openings for single web cold-formed steel flexural members. The sections were subjected to a concentrated load applied to one flange. The load application satisfied the AISI definition for either End-One-Flange or Interior-One-Flange loading. The research findings enable the current design provisions for sections without web openings to be modified by a reduction factor equation to obtain the web crippling capacity for sections with web openings. The modified capacity is considered for the web crippling capacity …