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2012

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Articles 1141 - 1170 of 6303

Full-Text Articles in Engineering

An Efficient Genetic Algorithm For The Design Optimization Of Cold-Formed Steel Portal Frame Buildings, Duoc T. Phan, James B. P. Lim, Tiku T. Tanyimboh, Wei Sha Aug 2012

An Efficient Genetic Algorithm For The Design Optimization Of Cold-Formed Steel Portal Frame Buildings, Duoc T. Phan, James B. P. Lim, Tiku T. Tanyimboh, Wei Sha

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

The design optimization of cold-formed steel portal frame buildings is considered in this paper. The real-coded genetic algorithm (GA) optimizer proposed considers both building’s topology (i.e. frame spacing and pitch) and cross-sectional sizes of the main structural members as the decision variables that are optimized. Previous GAs in the literature were characterized by poor convergence including slow progress that usually results in excessive computation times and/or frequent failure to achieve an optimal or near-optimal solution. This is the main issue addressed in this paper. In an effort to improve the performance of the conventional GA, a niching strategy is presented …


Studies On Bracing Member End Connections For Cold Formed Steel Sections, R. P. Rokade, N. Prasad Rao, R. Balagopal, S. J. Mohan Aug 2012

Studies On Bracing Member End Connections For Cold Formed Steel Sections, R. P. Rokade, N. Prasad Rao, R. Balagopal, S. J. Mohan

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

This paper is concentrated mainly on the behaviour of bracing end connections for cold formed steel lipped angle and lipped channel sections. For bracing members, only one flange is possible to connect with tower leg member or supporting member, which causes uneven distribution of stresses in the end section popularly known as shear lag effect. Tension tests have been carried out to simulate the bracing end connections. Special test rig has been assembled and end fittings fabricated such that the load will be applied as concentric load at the pulling end and on the other end load is transferred through …


Permanent Stability Bracing Of Cfs Trusses, Sowri Rajan, William L. Babich Aug 2012

Permanent Stability Bracing Of Cfs Trusses, Sowri Rajan, William L. Babich

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

Permanent stability bracing of Cold-Formed Steel (CFS) roof/floor trusses is needed for the three major planes in a truss: Top chord, Bottom Chord and Web. Primary function of bracing is to prevent lateral instability of members as well as stiffen the overall roof/floor system. Brace force is dependent on the magnitude of applied loads and the level of out-of-planeness permitted. Traditionally, 2% of the axial compression force in a member is used as the brace (restraint) force, which is based on an out-of-plane deflection of L/200 where L is the member length. Continuous Lateral Restraint (CLR) forces are accumulated from …


Steel Cold-Formed Trussed Girders With Joint Eccentricities - Improvements On Design And Performance By Numerical And Experimental Analysis, Eduardo De M. Batista, Alexandre Landesmann, Juarez M. Franco Aug 2012

Steel Cold-Formed Trussed Girders With Joint Eccentricities - Improvements On Design And Performance By Numerical And Experimental Analysis, Eduardo De M. Batista, Alexandre Landesmann, Juarez M. Franco

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

Long span light roof systems of industrial buildings are frequently designed with cold-formed steel members, leading to competitive solution which allows liberating useful internal space inside the building. This type of structural solution is usually cost saving if it is combined with standardization of the manufacturing process thus enabling specialized solution. This is the case of a family of trussed girders ranging from 0.6 to 1.8 m depth, developed by the steel structures manufacturer and addressed to a standard system for general application enabling to bridge up to 40 m span of light roof construction. Typical buckling behavior of the …


Slip Modulus Of Cold-Formed Steel Members Sheathed With Wood Structural Panels, A. L. Northcutt, K. W. Kramer, S. F. Stephens Aug 2012

Slip Modulus Of Cold-Formed Steel Members Sheathed With Wood Structural Panels, A. L. Northcutt, K. W. Kramer, S. F. Stephens

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

Cold-formed steel framing sheathed with wood structural panels is a common method of construction for wall, roof and floor systems in cold-formed steel structures. Since wood structural panels are attached with screws at relatively close spacing, a certain amount of composite behavior will be present. The benefit of composite behavior is not currently being taken advantage of in the design of these structural systems. While composite effects are present, they are not yet being accounted for in design due to a lack of statistical data. To determine the amount of composite action taking place in these systems, the slip modulus …


Design Of Nonstructural Members In Accordance With Aisi S220, Roger A. Laboube, H. Chen, J. W. Larson Aug 2012

Design Of Nonstructural Members In Accordance With Aisi S220, Roger A. Laboube, H. Chen, J. W. Larson

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

AISI S220, the North American Standard for Cold-Formed Steel Framing - Nonstructural Members, was developed in 2011 to help clearly delineate and eliminate confusion between the requirements for cold-formed steel structural members and nonstructural members. This paper is intended as an introduction to this standard and as an illustrative guide for applying the provisions to the design of nonstructural members.


Finite Element Analyses Of Lipped Chanel Beams With Web Openings In Shear, P. Keerthan, M. Mahendran Aug 2012

Finite Element Analyses Of Lipped Chanel Beams With Web Openings In Shear, P. Keerthan, M. Mahendran

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

Cold-formed steel members are increasingly used as primary structural elements in buildings due to the availability of thin and high strength steels and advanced cold-forming technologies. Cold-formed lipped channel beams (LCB) are commonly used as flexural members such as floor joists and bearers. Shear behaviour of LCBs with web openings is more complicated and their shear capacities are considerably reduced by the presence of web openings. However, limited research has been undertaken on the shear behaviour and strength of LCBs with web openings. Hence a numerical study was undertaken to investigate the shear behaviour and strength of LCBs with web …


Constrained Shape Optimization Of Cold-Formed Steel Columns, J. Leng, Z. Li, J. K. Guest, B. W. Schafer Aug 2012

Constrained Shape Optimization Of Cold-Formed Steel Columns, J. Leng, Z. Li, J. K. Guest, B. W. Schafer

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

The objective of this paper is to introduce appropriate constraints in the shape optimization of a cold- formed steel column such that the resulting optimized shapes retain the strength benefits of unconstrained optimal solutions combined with practical manufacturing and constructional needs. Unconstrained shape optimization of cold-formed steel columns, where the cross-section that maximizes axial capacity is found, has previously been performed. Here, practical manufacturing and construction constraints are introduced into the optimization algorithm. Members with three lengths: 2 ft, 4 ft, and 16 ft, are considered. Optimized sections from multiple runs show uniformity and bear a close resemblance to unconstrained …


Behavior And Strength Of Cold-Formed Steel Framed Shear Walls Sheather With Composite Panels, Cheng Yu, Chao Li Aug 2012

Behavior And Strength Of Cold-Formed Steel Framed Shear Walls Sheather With Composite Panels, Cheng Yu, Chao Li

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

The cold-formed steel (CFS) framed shear wall sheathed with noncombustible panels is an ideal solution for low- and mid-rise buildings when combustible materials are not allowed by the code for certain circumstances. The CFS framed shear wall using steel sheet panel is a commonly used by the industry to fulfill the noncombustible material requirement. However compared to OSB or plywood panels, the steel sheet panel offers significantly lower strength and stiffness. To overcome the disadvantages of steel sheet shear wall, a test program was recently conducted at the University of North Texas to investigate the behavior and strength of CFS …


Seismic Performance Of Steel Sheathed Cold-Formed Steel Shear Walls, Mehran Zeynalian Dastjerdi, Hamid Reza Ronagh Aug 2012

Seismic Performance Of Steel Sheathed Cold-Formed Steel Shear Walls, Mehran Zeynalian Dastjerdi, Hamid Reza Ronagh

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

In this paper the performance of steel sheathed cold-formed steel shear walls is evaluated by testing seven full scale walls under cyclic and monotonic loading. Of particular interest are the specimens’ maximum lateral load capacity and deformation behaviour. The study also looks at the failure modes of the system and investigates the main factors contributing to the ductile response of the CFS walls in order to suggest improvements so that the steel shear walls respond plastically with a significant drift and without any risk of brittle failure, such as failure in the connections. The walls tested are of different configurations …


Effects Of Cold-Formed Steel Framed Gypsum Partition Walls On The Seismic Response Of A Medical Facility, Ryan Davies, Rodrigo Retamales, Gilberto Mosqueda, Andre Filiatrault, Don Allen Aug 2012

Effects Of Cold-Formed Steel Framed Gypsum Partition Walls On The Seismic Response Of A Medical Facility, Ryan Davies, Rodrigo Retamales, Gilberto Mosqueda, Andre Filiatrault, Don Allen

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

The first experimental phase of the NEES Nonstructural Grand Challenge Project: “Simulation of the Seismic Performance of Nonstructural Systems” investigated the in-plane hysteretic behaviors of thirty-six full-scale cold-formed steel framed gypsum partition walls. Results of quasi-static reverse cyclic and dynamic testing on sixteen wall configurations including walls with commercial and institutional construction details and innovative connection techniques are first briefly reviewed. Thereafter, six tri-linear hysteretic models of partition walls with pinching behavior and strength and stiffness degradation are developed based on the experimental data for use in a finite element analysis platform. The partition wall models, represented by shear spring …


The Influence Of The Aspect Ratio On The Lateral Response Of The Sheathed Cold Formed Steel Walls, O. Iuorio, L. Fiorino, V. Macillo, M. T. Terracciano, R. Landolfo Aug 2012

The Influence Of The Aspect Ratio On The Lateral Response Of The Sheathed Cold Formed Steel Walls, O. Iuorio, L. Fiorino, V. Macillo, M. T. Terracciano, R. Landolfo

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

The influence of the aspect ratio on the lateral response of cold formed steel walls is analyzed by three design methodologies. In particular the prediction provided by the AISI Lateral Design, that is at the moment the main document for the design of CFS buildings under horizontal loads, is compared with the results obtained by applying the principles of mechanics and with those provided by non-linear finite element models. This paper presents and discusses in terms of strength and stiffness the validity of the different design methodologies in case of non-conventional wall aspect ratios comparing the numerical results with available …


Characterizaiton Of Cold-Formed Steel Shear Wall Behavior Under Cyclic Loading For The Cfs-Nees Building, P. Liu, K. D. Peterman, C. Yu, B. W. Schafer Aug 2012

Characterizaiton Of Cold-Formed Steel Shear Wall Behavior Under Cyclic Loading For The Cfs-Nees Building, P. Liu, K. D. Peterman, C. Yu, B. W. Schafer

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

The objective of this paper is to provide a full hysteretic characterization of OSB sheathed cold-formed steel (CFS) shear walls designed for use in the National Science Foundation funded Network for Earthquake Engineering Simulation (NEES) project: CFS-NEES (www.ce.jhu.edu/cfsnees). The shear walls were designed for a two-story ledger-framed building (i.e., the CFS-NEES building) that will undergo full-scale shake table testing at the University of Buffalo NEES site. Shear walls in real construction, such as the CFS-NEES building, have details that differ from the shear walls tested and provided for strength prediction in standards such as AISI-S213-07. Differences include: (a) ledger (rim …


Design Capacity Determination Assisted By Testing Based On Lrfd Method, Y. Q. Li, L. P. Wang, Z. Y. Shen Aug 2012

Design Capacity Determination Assisted By Testing Based On Lrfd Method, Y. Q. Li, L. P. Wang, Z. Y. Shen

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

In some special circumstances of structural design, adequate calculation models are not available in current specifications or they cannot be used directly for new materials or structural configurations. In these cases, tests of the prototype units may be accepted as an alternative to calculation. If this alternative procedure is adopted, corresponding requirements and evaluation of test results should apply. In this paper, a complete procedure of determining the design capacity of the test specimens based on statistical analysis and Load and resistance factor design (LRFD) method was presented: characteristic value of experimental resistance was obtained from the minimum value of …


Critical Elastic Shear Buckling Stress Hand Solution For C- And Z-Sections Including Cross-Section Connectivity, Kevin Aswegan, Cristopher D. Moen Aug 2012

Critical Elastic Shear Buckling Stress Hand Solution For C- And Z-Sections Including Cross-Section Connectivity, Kevin Aswegan, Cristopher D. Moen

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

This paper presents an approximate solution for the critical elastic buckling stress of cold-formed steel C- and Z-section members including cross-section connectivity. The elastic buckling solution is developed to support the extension of the Direct Strength Method to the shear ultimate limit state, where the cross sectional critical elastic shear buckling stress (load) is employed to predict shear capacity. The shear buckling stress and buckled half-wavelength are calculated with a classical energy solution for a thin plate with edges rotationally restrained. Rotational stiffness expressions in the AISI S100-07 specification, originally derived for distortional buckling of C- and Z-sections, are used …


Behaviour Of Litesteel Beams Subject To Combined Shear And Bending Actions, P. Keerthan, D. Hughes, M. Mahendran Aug 2012

Behaviour Of Litesteel Beams Subject To Combined Shear And Bending Actions, P. Keerthan, D. Hughes, M. Mahendran

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

This paper presents the details of a numerical study of a cold-formed steel beam known as LiteSteel Beam (LSB) subject to combined shear and bending actions. The LSB sections are produced by a patented manufacturing process involving simultaneous cold-forming and electric resistance welding. They have a unique shape of a channel beam with two rectangular hollow flanges. To date, however, no investigation has been conducted into the strength of LSB sections under combined shear and bending actions. Hence a numerical study was undertaken to investigate the behaviour and strength of LSBs subject to combined shear and bending actions. In this …


Shear Buckling Of Thin-Walled Channel Sections With Complex Stiffened Webs, Song Hong Pham, Cao Hung Pham, Gregory J. Hancock Aug 2012

Shear Buckling Of Thin-Walled Channel Sections With Complex Stiffened Webs, Song Hong Pham, Cao Hung Pham, Gregory J. Hancock

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

For cold-formed channel section design in shear, the traditional approach has been to investigate shear plate buckling in the web alone. Recently, an improvement in the elastic buckling stress of the whole thin-walled channel section including flanges and lips in pure shear has been demonstrated. For webs with relatively large depth to thickness ratios, the local buckling mode in shear occurs mainly in web. The structural efficiency of such a web can be improved by adding intermediate stiffeners cold-formed longitudinally in the middle of the webs. This paper presents numerical buckling analyses implemented by means of the Semi-Analytical Finite Strip …


Load Distribution In Floor To Wall Connections, D. M. Fox, D. R. Knill, R. M. Schuster Aug 2012

Load Distribution In Floor To Wall Connections, D. M. Fox, D. R. Knill, R. M. Schuster

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

Presented in this paper is a cold formed steel load distribution system developed by iSPAN Systems LP that enables the installation of floor joists without the need to align them with the supporting wall studs. The floor joists are supported by a shear connection attached to a cold formed steel perimeter distribution member. In addition to the load distribution aspect, the system results in a simplified lateral design approach. An experimental verification study was carried out to establish the load distribution capability of the system, resulting in a simplified procedure to determine the connection requirements and load transfer characteristics to …


Behavior Of Composite Beams With Cold-Formed Steel Joists And Concrete Slab, Cheng-Tzu Thomas Hsu, Pedro R. Munoz, Sun Punurai, Yazdan Majdi, Wonsiri Punurai Aug 2012

Behavior Of Composite Beams With Cold-Formed Steel Joists And Concrete Slab, Cheng-Tzu Thomas Hsu, Pedro R. Munoz, Sun Punurai, Yazdan Majdi, Wonsiri Punurai

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

A new composite beam and floor system has been developed herein to achieve a stronger strength and ductility, as well as to yield a more economical design purpose. This new composite beam system consists of three elements: reinforced concrete slab on corrugated cold-formed metal, back to back cold-formed steel joists, and cold-formed furring shear connector. The shear connectors are screwed through the top flange of the support joists in order to provide vertical interlocking and horizontal shear resistant between the concrete slab and the cold-formed steel joists. The self-drill fasteners are used for fastening the furring shear connector through the …


Top Arc Seam Weld Shear Strength And Stiffness For Sheet-To-Sheet Connections, R. Nunna, J. Martin, J. Mattingly, P. Bodwell, D. Boltz, K. Cullum, Roger A. Laboube Aug 2012

Top Arc Seam Weld Shear Strength And Stiffness For Sheet-To-Sheet Connections, R. Nunna, J. Martin, J. Mattingly, P. Bodwell, D. Boltz, K. Cullum, Roger A. Laboube

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

The North American Specification for the Design of Cold-Formed Steel Structural Members does not provide specific design guidance for sheet-to-sheet top arc seam welds in shear. A collaborative industry study has developed design guidance for both strength and stiffness of the connection to facilitate analytical evaluation of floor and roof diaphragm assemblies and wall assemblies. The test program was performed per AISI S905 and addressed material ductility, weld length, sheet thickness and the distribution of the force being transferred by the weld connection.


Experimental Study On Interaction Between Local And Distortional Buckling Of High Strength Cold-Formed Lipped Channel Columns, L. Jiang, B. K. He, Y. Q. Li Aug 2012

Experimental Study On Interaction Between Local And Distortional Buckling Of High Strength Cold-Formed Lipped Channel Columns, L. Jiang, B. K. He, Y. Q. Li

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

The distortional buckling behavior of 550MPa high strength cold-formed lipped channel columns under axial compression loads have been studied. The test results of 16 specimens show that local buckling may appear before distortional buckling and it makes the distortional buckling occur in advance. This interaction of local and distortional buckling has an adverse effect on bearing capacity of columns. But the design methods for distortional buckling in Specification AS/NZS 4600 and Direct Strength Method (DSM) haven’t considered such interaction. Based on the test results, a method revised from DSM which could account for the adverse interaction has been suggested. The …


Cold-Forming Effect Investigation On Cold-Formed Thick-Walled Steel Hollow Sections, Y. Q. Li, D. H. Wen, L. P. Wang, Z. Y. Shen Aug 2012

Cold-Forming Effect Investigation On Cold-Formed Thick-Walled Steel Hollow Sections, Y. Q. Li, D. H. Wen, L. P. Wang, Z. Y. Shen

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

No abstract provided.


Numerical Modelling And Calibration Of Cfs Framed Shear Walls Under Dynamic Loading, I. Shamim, C. A. Rogers Aug 2012

Numerical Modelling And Calibration Of Cfs Framed Shear Walls Under Dynamic Loading, I. Shamim, C. A. Rogers

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

This paper describes the numerical modeling using OpenSees of steel sheathed cold-formed steel framed shear wall test specimens under dynamic loading. Two modeling phases were carried out; the first phase comprised non-linear models calibrated using existing reversed cyclic shear wall test data, and the second phase involved more advanced models calibrated using data from dynamic shake table tests of single- and double-storey shear walls as well as other ancillary test programs. The second phase models incorporated the behaviour of the hold-downs, floor framing and blocked bare frame, in addition to the sheathing. The final calibrated models were able to accurately …


Novel Cold-Formed Steel Elements For Seismic Applications, Alireza Bagheri Sabbagh, Mihail Petkovski, Kypros Pilakoutas, Rasoul Mirghaderi Aug 2012

Novel Cold-Formed Steel Elements For Seismic Applications, Alireza Bagheri Sabbagh, Mihail Petkovski, Kypros Pilakoutas, Rasoul Mirghaderi

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

Novel cold-formed steel (CFS) elements are investigated in this paper for seismic resistant multi-storey moment frames. Premature local buckling and low out-of-plane stiffness are known as the main structural deficiencies of CFS sections with thin-walled elements. These lead to low energy dissipation capacity of the structures made up of CFS sections as the main load bearing members in seismic events. In order to improve the energy dissipation capacity of CFS members, an innovative CFS beam section with curved flanges is developed by numerical FE analysis and experimental work. A web bolted through plate CFS beam-column connection is used to limit …


Seismic Computational Analysis Of Cfs-Nees Building, J. Leng, B. W. Schafer, S. G. Buonopane Aug 2012

Seismic Computational Analysis Of Cfs-Nees Building, J. Leng, B. W. Schafer, S. G. Buonopane

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

The objective of this paper is to explore computational modeling of a coldformed steel framed building subjected to earthquake excitation. The selected two-story building will be subjected to full-scale motion on a shaking table in 2013 as part of the National Science Foundation funded Cold-Formed Steel – Network for Earthquake Engineering Simulation (CFS-NEES) project. The ledger-framed building employs load bearing cold-formed steel members throughout (wall, floors, and roofs) and employs OSB sheathed shear walls and an OSB sheathed diaphragm for the lateral force resisting system. Two- and three-dimensional analysis models capable of providing vibration, pushover, linear and nonlinear time history …


Improved Reliability Determination When Testing Cold-Formed Steel Components, V. M. Zeinoddini, B. W. Schafer Aug 2012

Improved Reliability Determination When Testing Cold-Formed Steel Components, V. M. Zeinoddini, B. W. Schafer

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

The objectives of this paper are to (a) determine the sensitivity of the reliability calculations in Chapter F of the AISI Specification (AISI-S100-07) to controlling load combinations and loading ratios, and (b) develop a more robust alternative for the use of Chapter F. To complete this study the bias factors and variances for all loading conditions are established. In addition, a range of practical load ratios is agreed upon. Parametric studies are performed to explore load case and load ratio dependency for use in the determination of the resistance factor, Φ; specifically, the pre-factor term CΦ and the load variance …


Testing Of Connectors For Cold-Formed Steel Construction - Challenges, Recent Innovation, And Future Direction, Timothy M. Stauffer, Hien Kim Nguyen Aug 2012

Testing Of Connectors For Cold-Formed Steel Construction - Challenges, Recent Innovation, And Future Direction, Timothy M. Stauffer, Hien Kim Nguyen

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

As cold-formed steel construction continues to evolve, manufacturers are making advances in prefabricated connectors for use in a variety of applications. Often, establishing available strengths for connectors requires testing. This paper will examine some of the challenges associated with testing of these products. Available standards and criteria will be discussed, and an overview of potential difficulties with their use will be presented. Test programs conducted by one manufacturer during recent product development will be presented to illustrate some of the challenges and highlight innovations made to address them. Finally, based on experience gained through extensive testing and product development, recommendations …


Self-Shape Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. The Aug 2012

Self-Shape Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. The

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

This paper presents the optimisation of cold-formed steel open columns using the recently developed self-shape optimisation method that aims to discover new profile shapes. The strength of the cold-formed steel sections is calculated using the Direct Strength Method, and the rules developed in the present work to automatically determine the local and distortional elastic buckling stresses from the Finite Strip and constrained Finite Strip Methods are discussed. The rules are verified against conventional and optimum sections yielded in this research, and found to accurately predict the elastic buckling stresses. The principles behind the self-shape optimisation method are summarised herein and …


Innovative Cross-Section Shapes For Built-Up Cfs Columns. Experimental Investigation, Iveta Georgieva, Luc Schueremans, Lincy Pyl, Lucie Vandewalle Aug 2012

Innovative Cross-Section Shapes For Built-Up Cfs Columns. Experimental Investigation, Iveta Georgieva, Luc Schueremans, Lincy Pyl, Lucie Vandewalle

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

Innovative cross-section shapes for built-up columns from cold-formed steel (CFS) profiles are evaluated experimentally. The goal is to obtain highly stable members with reduced sensitivity to bucking effects and initial imperfections, and therefore, higher strength-to-weight ratios. The columns have been designed following the principles of the direct strength method [1], with the ambition to exclude (or reduce) various buckling effects from the column response to compressive loads. Cross-section proportions and bolt spacing have been adapted, in order to interfere with the distortion of individual profiles and the overall buckling of the columns. Experiments show that, through proper design and insight …


Compressive Strength Tests And Design Of Cold-Formed Plain And Dimpled Steel Columns, V. B. Nquyen, C. J. Wang, D. J. Mynors, M. A. English, M. A. Castellucci Aug 2012

Compressive Strength Tests And Design Of Cold-Formed Plain And Dimpled Steel Columns, V. B. Nquyen, C. J. Wang, D. J. Mynors, M. A. English, M. A. Castellucci

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

This paper presents the experiments and design formulae of cold-formed plain and dimpled steel columns. A series of compression tests on plain and dimpled channel columns were conducted over a range of different geometries and the strength of the columns were investigated. The change in strength of the dimpled columns resulting from the cold working associated with the dimpling process was considered. The results showed that the buckling and ultimate strengths of dimpled steel columns were up to 33% and 26% greater than plain steel columns, respectively. The test results were evaluated by comparing buckling and ultimate loads of plain …