Structural Engineering Commons^™

Advanced Modeling Of Cold-Formed Steel Walls Under Fire, J. C. Batista Abreu, N. Punati, K. R. Prasad, B. W. Schafer

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

This paper discusses an advanced finite element model able to simulate the structural response of cold-formed steel walls during standard fire tests. The model includes experimental thermo-mechanical properties of materials, geometric imperfections, and temperature distributions on studs and sheathing boards. The model is capable of reasonably predicting the thermal bowing of walls, and estimating the shape, size and amount of joint openings between gypsum boards over time of fire exposure. Numerical results validated with experimental data indicate that the maximum out-of-plane displacements due to thermal gradients occur near the wall mid-height. Early in the heating process, joint openings develop on …

Development Of A Method To Generate A Simplified Finite Element Model For An Electrical Switchboard Cabinet, Edwin Lim, Barry J. Goodno, James I. Craig

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

Electrical switchboards are one of the key pieces of equipment used in operations of most critical facilities such as hospitals and emergency services buildings. Unfortunately, past observations have shown that the switchboard cabinet and its contents may be vulnerable to damage or failure during an earthquake. An electrical switchboard cabinet is a complex structure typically constructed using cold-formed steel frame members enclosed by steel panels and containing a variety of switchgear and bus bars. The panels are usually fastened to the steel members by screws, and the steel members are connected together by bolts or screws. The structural behavior of …

Full-Scale Experimental And Numerical Study About Structural Behavior Of Thin-Walled Cold-Formed Steel Building Affected By Ground Settlements Due To Land Subsidence, Jose A. Ortiz-Lozano, Luis A. Hernández-Castillo, Martin Hernández-Marín, Jesús Pacheco-Martínez, Mario E. Zermeño-Deleón, Raúl Salinas-Salinas

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

Land subsidence phenomenon due to ground water withdrawal is a current problem in many places around the world, particularly in the shallows of Mexico. This causes ground differential settlements that affect structures, mainly dwellings and buildings based on reinforced concrete and masonry. Eventually, these structural materials do not exhibit an adequate performance beyond a certain level of angular distortion. This work presents the experimental and numerical results about a study regarding the performance of a full-scale thin-walled cold-formed steel building affected by angular distortions simulating ground differential settlements due to land subsidence. The experimental stage consisted in the design and …

Design Method For Cold-Formed Thin-Walled Steel Beams With Built-Up Box Section, Ying-Lei Li, Yuan-Qi Li

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

Built-up sections has been extensively used in cold-formed thin-walled steel structures. The structural behaviour and moment capacity of built-up box beams, which is consisted of nested C and U-sections, are the major concerns in this paper. A finite element model for built-up box beams was firstly developed and validated by existing test results. The effects of screw configuration and the global buckling behaviour of built-up box beams were investigated by parametric analysis. Then, the simple superposition method and equivalent cross-section method were introduced and adopted to estimate the moment capacity of built-up box beams bending about major or minor axis. …

Design Of Industrial Cold-Formed Steel Rack Upright Frames For Loads In Cross-Aisle Direction, Francesc Roure, Teoman Peköz, M. Rosa Somalo, Jordi Bonada, M. Magdalena Pastor, Miquel Casafont

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

This paper summarizes research on the cross-aisle stiffness and strength of industrial cold-formed steel rack upright frames for loads in cross-aisle direction. Tests were carried out at the Universitat Politècnica de Catalunya, Barcelona, Spain on joints as well as entire upright frames. A possible rather simple analysis procedure is developed and described.

Characterization Of Cold-Formed Steel Framed Diaphragm Response Under In-Plane Loading And Influence Of Non-Structural Gypsum Panels, Patrick Latreille, Violetta Nikolaidou, Colin A. Rogers, Dimitrios G. Lignos

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

The in-plane response of CFS framed diaphragm structures subjected to seismic excitation is not well understood. At present, the North American AISI S400 Standard does not include a seismic design procedure for CFS framed diaphragms for use in Canada, and offers limited information for their use in the US. In addition, the effect of non-structural components on the lateral strength and stiffness of the diaphragm component has yet to be explored. In an effort to provide insight into the complex nature of the diaphragm structure and the influence of non- structural components an experimental program was initiated in the Jamieson …

Resistance Of Arc Spot Welds – Update To Provisions, B. Paige Blackburn, Thomas Sputo

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

The AISI S100-12 provisions for arc spot welds have not be reviewed since 1999. This study performs a comprehensive analysis of the entire arc spot weld data base including data from four new research studies and reconsiders AISI S100-12 resistance equations with data from 450 specimens. Most AISI S100-12 equations were found to be conservative, particularly for sheet tearing failure modes. However, the equation for arc spot weld fracture under tensile load was found to poorly predict the data base test results. AISI S100-12 provision improvements are recommended not only for the resistance equations and factors, but also for the …

Finite Element Modeling Of Concrete Shrinkage In Composite Deck Slabs, Vitaliy V. Degtyarev

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

This paper presents finite element models of composite deck slabs subjected to restrained concrete shrinkage. The models created in ANSYS and validated against test data were based on the assumption of the full shear interaction between the deck and the concrete and accounted for concrete creep, cracking, and nonlinear stress-strain relationship. Concrete shrinkage was modeled by temperature changes applied to concrete. The effects of different shrinkage profiles, concrete creep, and deck slab properties on the long-term concrete and deck strains are presented. Future research work is outlined.

A Combined Direct Analysis And Direct Strength Approach To Predict The Flexural Strength Of Z-Purlins With Paired Torsion Braces, Michael W. Seek, Chris Ramseyer, Ian Kaplan

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

A series of 12 Base Tests for Z-section purlins with paired interior torsional braces and one flange attached to a flexible horizontal diaphragm are evaluated with the Direct Strength Method. Rather than use the conventional constrained bending stress approximation, a direct analysis philosophy is adopted where cross section stress distributions are calculated using a displacement compatibility approach. With a flexible diaphragm typical of a standing seam roof system, these stresses can deviate substantially from the constrained bending approximation and can significantly impact predicted local and distortional buckling behavior. The displacement compatibility approach incorporates estimates of load imbalances and second order …

Simulating The Seismic Performance Of Cold-Formed Steel Framed Buildings Using Corrugated Sheet Shear Walls, Wenying Zhang, Mahsa Mahdavian, Yuanqi Li, Cheng Yu

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

Cold-formed steel framed shear wall sheathed with corrugated steel sheets is a promising shear wall system for low- and mid-rise constructions at high wind and seismic zones due to its advantages of non-combustibility, high shear strength, and high shear stiffness. A lot of work has been done on this subject. However, all the previous work is focused on the wall panel levels and more research work is needed on the entire building systems. The objective of this paper is to investigate the response of a cold-formed steel framed building with corrugated sheet sheathing subjected to earthquake excitation primarily through nonlinear …

Behavior Of Steel Sheet Sheathed Cold-Formed Steel Walls Subjected To Combined Lateral And Vertical Loads, Pengchun Jia, Wenying Zhang, Mahsa Mahdavian, Nathan Derrick, Cheng Yu

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

This paper presents an experimental investigation of the behavior of cold-formed steel (CFS) framed walls sheathed by steel sheets subjected to both lateral and gravity loads. The research focuses were on the collapse limit of the CFS shear wall using steel sheet sheathing and the shear resistance of CFS bearing walls. The test results showed that the gravity load has limited impact to the CFS shear wall’s behavior and performance. The CFS bearing wall could provide considerable shear resistance and it shall be considered in numerical modeling CFS buildings.

Experimental Tests For The Seismic Response Evaluation Of Cold-Formed Steel Shear Walls Sheathed With Nailed Gypsum Boards, Luigi Fiorino, Vincenzo Macillo, Maria Teresa Terracciano, Tatiana Pali, Bianca Bucciero, Raffaele Landolfo

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

The European project named "Energy Efficient LIghtweight-Sustainable-SAfe- Steel Construction" (Project acronym: ELISSA) is devoted to the development and demonstration of cold-formed steel (CFS) modular systems. In particular, these systems are nano-enhanced prefabricated lightweight steel skeleton/dry wall construction with improved thermal, vibration/seismic and fire performance, resulting from the inherent thermal, damping and fire spread prevention properties. The different building performances are studied and improved by means of experimental and numerical activities organized on three scale levels: micro-scale, meso-scale and macro-scale. In particular, the evaluation of the seismic performance is carried out at the University of Naples by means tests on connections …

Seismic Modeling And Incremental Dynamic Analysis Of The Cold-Formed Steel Framed Cfs-Nees Building, J. Leng, S. G. Buonopane, B. W. Schafer

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

The objective of this paper is to present seismic modeling of a two-story cold-formed steel (CFS) framed building. The selected building, known as the CFSNEES building, was designed to current U.S. standards and then subjected to full-scale shake table tests under the U.S. National Science Foundation Network for Earthquake Engineering Simulation (NEES) program. Test results showed that the building’s stiffness and capacity was considerably higher than expected and the building suffered only non-structural damage and no permanent drift, even at maximum considered earthquake (per ASCE 7 and the selected California site) level. Past modeling, including that of the authors, largely …

Experimental Investigation Into Steel Storage Rack Beam-To-Upright Bolted Connections, Liusi Dai, Xianzhong Zhao, Chong Ren

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

For unbraced steel storage racks, the down-aisle stability depends largely on the performance of beam-to-upright connections and column bases. Boltless connections are generally used in order to make rack structures easy to assemble and feasible to adjust the storey height. Recently, storage racks are designed to carry large amounts of goods and they are therefore raise a considerable height, which makes the improvement of the structural stability to be sufficiently important. Under the circumstances, tab-connected beam-to-upright connections with bolts are gradually used in steel storage racks. Compared with boltless connections, the stiffness, strength and ductility of the bolted connections are …

Tilt Bearing Capacity Of Single-Shear Bolted Connections Without Washers, Mehmet E. Uz, Lip H. Teh

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

This paper examines the accuracy of design equations specified in the North American and European codes for cold-formed steel structures in determining the ultimate tilt bearing capacity of single-shear single-row bolted connections without washers in flat steel sheets. It points out that the code equations do not properly distinguish the tilt bearing failure mode from the conventional bearing failure mode, which is typical of double-shear connections and single-shear connections with washers. The tilt bearing capacity is affected by the width of the connected sheet, and its capacity does not vary linearly with either the sheet thickness or the bolt diameter. …

Behaviour Of Cold-Formed Steel Semi Rigid Connections, Ruby Freya, R. Senthil, W. Jeoffray Merin, R. Saravanakumar, Krishna Kuber, M. Gowtham

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

Ductility and inelastic performance are important considerations in aseismic design of buildings. The dissipation of energy due to inelastic deformation is predominantly required in the connections like beam column joints. It is necessary to design these joints as semi rigid for its economic and structural benefits. Semi-rigid connections have highly nonlinear behaviour that makes the analysis and design of frames difficult and complicated. Steel structures are highly regarded for their seismic performance. It is required to understand and study the inelastic behavior of steel connections which would help in an economical and simpler design. This paper involves the modeling of …

Shear Behavior Of Screw Connection Between Cold-Formed Steel And Gypsum Sheathing At Elevated Temperatures, Wei Chen, Yihong Ye

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

The screw connections between cold-formed steel (CFS) and gypsum sheathing play an important role in the axial and lateral performance of CFS wall panels. Previous researches were mainly focus on the shear behavior of such screw connections at room temperature. This paper carried out a preliminary experimental investigation on the mechanical performance of screw connections with single layer gypsum sheathing at elevated temperatures. Limited to the cavity dimension of the furnace, the single-lap test of CFS coupon -fastener-sheathing connection was adopted and compared with the previous test results of sheathing-to-profile screw connections at room temperature. The failure of screw connections …

Monotonic And Cyclic Backbone Response Of Single Shear Sheathing-To- Cold-Formed Steel Screw-Fastened Connections, F. Tao, R. Cole, C. D. Moen

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

Monotonic and cyclic backbone load-deformation response models for single shear plywood, oriented-strand board, and gypsum board sheathing to cold-formed steel screw-fastened connections are developed with support from an experimental program. Connection strength, stiffness, and the probability of screw shear failure are correlated to fastener bearing strength of the two connected plies. Cyclic strength and stiffness degradation was negligible. Cyclic excursions resulted in increased connection stiffness from the screw bearing hardening the ply material and locking in the plies.

Behaviour Of Cold-Formed Steel Trusses With Concentric And Eccentric Joint Arrangements Using The Howick Rivet Connector, Amin Ahmadi, Colin K. L. Yee, Harry J. S. Shepherd, G. Charles Clifton, Raj Das, James B. P. Lim

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

This paper considers the behaviour of a cold-formed steel truss system that uses a novel pinned connector for the joints, to be referred to as the Howick Rivet connector (HRC). Use of the HRC allows a pinned concentric joint arrangement to be formed, as well as the more usual eccentric joint arrangement used in tests described in the literature. However, with the concentric joint arrangement, it is necessary to remove part of the lips of the channel-sections being connected, thus creating a discontinuity in the lips. This paper assesses the effect of this discontinuity. Full-scale truss tests are first described. …

Design Of New Cold Rolled Purlins By Experimental Testing And Direct Strength Method, V. B. Nguyen, B. Cartwright, M. A. English

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

New cold roll formed channel and zed sections for purlins, namely UltraBEAMTM2 and UltraZEDTM2, have been developed by Hadley Industries plc using a combined approach of experimental testing, finite element modelling and optimisation techniques. The new sections have improved strength to weight ratio by increasing the section’s strength by using stiffeners in the section webs. The European standards, Eurocode 3, use a traditional Effective Width Method to determine the strength of a cold formed steel member. However, the design of the new sections UltraBEAMTM2 and UltraZEDTM2 using this method is very complicated in calculating the effective section properties as these …

Seismic Performance Investigation Of Cold-Formed Steel Framed Shear Walls With Steel Sheathing, Feng Ruo-Qiang, Xu Peng-Hui

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

Cold-formed steel (CFS) framed shear walls with steel sheet sheathing can achieve higher shear resistance compared to conventional CFS framed shear walls. Experimental and numerical investigation of seismic behavior was present on two CFS shear walls sheathed with steel sheet for the base layer combined with gypsum wallboards for the face layer on both sides. Monotonic shear and cyclic loading tests were conducted on wall specimens. The failure mechanism, bearing capacity, stiffness and ductility of specimens were obtained. On the basis of rational simplification of CFS framed shear walls, the finite element software ABAQUS was used to simulate the monotonic …

Sheathing Overlapping And Attachment Methods For Cold-Formed Steel Shear Walls With Corrugated Steel Sheathing, Mahsa Mahdavian, Wenying Zhang, Cheng Yu

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

Cold-formed steel (CFS) shear walls sheathed with corrugated steel sheathing are a feasible solution to non-combustible high structural performance CFS shear walls in mid-rise buildings. Corrugated steel sheathings have high in-plane strength and stiffness due to the cross sectional shape of the sheet. This paper presents an experimental study on two specific issues: (1) the sheathing overlapping configurations and their impact to the shear wall performance, (2) the attachment method for sheathing to framing. For the overlapping issue, one overlap and two overlaps in the corrugated sheets were experimentally investigated, it was found that the overlap differences did not cause …

Material Properties Of Cold-Rolled Thin-Walled Steel Plates At Elevated Temperatures, Zhen Nie, Yuanqi Li

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

It is highly important to clarify the high temperature mechanical properties in the design of cold-formed steel structures under fire condition due to the unique deterioration feature in material properties under fire environment and associated reduction to the mechanical performance of members. This paper presents the material properties of coupons cut from raw cold-rolled thin-walled steel plates at elevated temperatures. A set of high temperature extensometer with a range of 12.5mm relative to 50mm gauge was employed in the experiments, which could collect more displacement data between the gauge scope before the coupon fail. The coupons were extracted from original …

On The Direct Strength Design Of Cold-Formed Steel Columns Falling In Local-Distortional Interactive Modes, André Dias Martins, Dinar Camotim, Pedro Borges Dinis

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

This paper present and discusses proposals for the codification of efficient design approaches for cold-formed steel columns affected by local-distortional (L-D) interaction. These proposals, based on the Direct Strength Method (DSM), were developed, calibrated and validated on the basis of experimental and numerical (shell finite element) failure load data concerning columns with several cross-section shapes and obtained from investigations carried out by various researchers. Three types of L-D interaction are taken into account, namely “true L-D interaction”, “secondary local bifurcation L-D interaction” and “secondary distortional bifurcation L-D interaction”. Moreover, previously available DSM-based design approaches to handle column L-D interactive failures …

Buckling Strength Of Cold-Formed Circular Steel Column Subjected To Axial Load, Ayana Ito, Nobutaka Shimizu, Keiichi Sato, Yoshimichi Kawai

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

In this study, the global buckling behavior of a cold-formed circular steel column was discussed with a focus on the effects of its mechanical properties and initial imperfections on the behavior. As the first step, the stress–strain curves of the column under tensile and compressive loads as well as its residual stresses were investigated. Subsequently, a finite element analysis was conducted to clarify if the analysis properly simulated the stub column behavior. The analysis results obtained using measured compressive stress–strain curves and residual stresses agreed well with experimental results. Finally, another finite element analysis was performed on the long column …

Proposal For Codification Of A Dsm Design Approach For Cold-Formed Steel Short-To Intermediate Angle Columns, Pedro Borges Dinis, Dinar Camotim

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

This paper presents a proposal for the codification of an efficient design approach for cold-formed steel short-to-intermediate equal-leg angle columns, consisting of a slight modification of a design approach developed by Dinis & Camotim (2015) and based on the Direct Strength Method (DSM). After (i) collecting the available experimental and numerical failure load data, comprising fixed-ended and pin-ended columns with several geometries (cross-section dimensions and length) and reported by various researchers, and (ii) briefly reviewing the mechanical reasoning behind the proposed procedures, the search for new/simpler expressions to provide the DSM design curves is addressed. Their merits are assessed through …

Experimental Investigation Of Cold-Formed C-Sections With Central Square Holes In Shear, Cao Hung Pham, Andreas Pelosi, Thomas Earls, Gregory J. Hancock

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

The North American Specification S100:2012 Edition has recently included DSM design rules for unperforated channel sections in shear. However, there are no rules presented in this standard for the DSM in shear for sections with holes. Recently, a testing program has been performed at the University of Sydney to determine the ultimate strength of high strength cold-formed C-sections with a thickness of 1.5 mm and central square holes of varying sizes. Three different sizes of the square holes were chosen for testing. For thin sections, the DSM shear curve was found to be applicable for design of sections with square …

Wei-Wen Yu International Specialty Conference On Cold-Formed Steel Structures 2016: Recent Research And Developments In Cold-Formed Steel Structures, Wei-Wen Yu Center For Cold-Formed Steel Structures

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

No abstract provided.

Analyses Of Thin-Walled Sections Under Localised Loading For General End Boundary Conditions – Part Ii: Buckling, Van Vinh Nguyen, Gregory J. Hancock, Cao Hung Pham

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

Thin-walled sections under localised loading may lead to buckling of the sections. This paper briefly introduces the development of the Semi-Analytical Finite Strip Method (SAFSM) for buckling analyses of thin-walled sections under localised loading for general end boundary conditions. This method is benchmarked against the Finite Element Method (FEM).

For different support and loading conditions, different functions are required for flexural and membrane displacements. In Part 1- Pre-buckling described in a companion paper at this conference, the analysis provides the computation of the stresses for use in the buckling analyses in this paper. Numerical examples of buckling analyses of thin-walled …

Web Crippling Strength Of Cold-Formed Duplex Stainless Steel Lipped-Channel Sections With Web Openings Subjected To Interior-One-Flange Loading, Amir M. Yousefi, James B. P. Lim, Asraf Uzzaman, Ying Lian, G. Charles Clifton, Ben Young

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

Cold-formed stainless steel sections are becoming more widely used in the residential and commercial sectors due to their high corrosion resistance and high strength-to-weight ratio. However, their susceptibility to web crippling at points of concentrated loading is well-known to be an important design issue. In addition, web openings are also become popular, as they improve ease of installation of services. This paper presents the results of an investigation into the effect of web crippling on cold-formed duplex stainless steel lipped channel-sections, having such openings, under the interior-one-flange (IOF) loading condition. 742 non-linear elasto-plastic finite element analyses are undertaken, with web …