Structural Engineering Commons^™

Experimental Seismic Behavior Of The Cfs-Nees Building: System-Level Performance Of A Full-Scale Two-Story Light Steel Framed Building, Kara D. Peterman, Rob L. Madsen, Benjamin W. Schafer

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

In the summer of 2013, testing of two full-scale cold-formed steel (CFS) framed buildings under seismic excitations took place at the Structural Engineering and Earthquake Simulation Lab (SEESL) at the University at Buffalo. Utilizing the twin shake tables, the two-story building specimens were subjected to ground motions from the 1994 Northridge earthquake. These experiments were conducted as a part of the CFS-NEES experimental effort in an attempt to advance cold-formed steel earthquake engineering and design. Two buildings were tested: the first, a specimen constructed with only structural components (CFS-framed gravity walls, shear walls, floor and roof diaphragms, with OSB sheathing …

Local Buckling Hysteretic Nonlinear Models For Cold-Formed Steel Axial Members, D. A. Padilla-Llano, C. D. Moen, M. R. Eatherton

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

This paper studies the energy dissipation and damage in thin walled members that experience local buckling and presents an approach to model cold-formed steel (CFS) axial members that experience local buckling deformations. The model is implemented in OpenSees using hysteretic models for CFS axial members calibrated using experimental responses. Results from thin-shell element simulations using ABAQUS show that energy dissipation in thin plates dissipates through inelastic strains and yielding that concentrates in damaged zones that extent approximately the length of a buckled half-wave (L_cr). Generally damage accumulates in one zone but when more than one damaged zone occurred …

Fire Resistance Prediction Of Load Bearing Cold-Formed Steel Walls Lined With Gypsum Composite Panels, Wei Chen, Jihong Ye

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

An innovative load-bearing cold-formed steel (CFS) wall lined with gypsum composite panels was developed with the goal of improving the construction efficiency and fire performance of these walls for applications in mid/high-rise buildings. The gypsum composite panel was formed by sandwiching insulation and plasterboard strips between two layers of gypsum plasterboards. Subsequently, the predicted fire resistance of these CFS walls was predicted based on our previously developed and experimentally validated modeling method. The degenerated material properties of the cold-formed steel and thermal physical property of the gypsum plasterboard and aluminum silicate wool were obtained from our pervious experimental investigations and …

Influence Of Diagonal Bracing Restraint On Cold-Formed Steel Perforated Columns Under Axial Compression, Chong Ren, Xianzhong Zhao

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

This paper presents a numerical investigation on the influence of diagonal bracing restraint on cold-formed steel perforated columns subjected to axial compression. Finite element method (FEM) is employed to analyse the structural behaviour of perforated columns. The results obtained from the present study highlight the influence of diagonal bracing restraint on post-buckling of columns, and the distortional-flexural mode interaction is also discussed. Furthermore, the accuracy of the present model is validated by comparing the results against the available experimental data.

Investigation On Seismic Performance Of Cold-Formed Steel Portal Frames, Yuanqi Li, Zhijian Xu, Yinglei Li, Yunfei Peng

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

A series of monotonous loading and hysteresis loading tests on cold-formed steel portal frames were conducted in this paper. The averaged ductility factor value of tested frames is 3.15 and the strength and stiffness degradation are not obvious during the test. The failure mode of frame is local buckling at column bases followed by local buckling at the top of columns, which lead to the dropping of frame’s load-carrying capacity. Then, the finite element model is developed and the analysis results match well with the test results. The research in this paper indicates that cold-formed steel portal frame has a …

Effect Of Stressed-Skin Action On Optimal Design Of A Cold-Formed Steel Portal Framing System, Duoc T. Phan, Andrzej M. Wrzesien, James B. P. Lim, Iman Hajirasouliha

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

Cold-formed steel portal frames can be a viable alternative to conventional hot-rolled steel portal frames. They are commonly used for low-rise commercial, light industrial and agricultural buildings. In this paper, the effect of semi-rigid joints and stressed-skin action are taken into account in the optimal design of cold-formed steel portal frames. A frame idealization is presented, the results of which are verified against full-scale. A real-coded niching genetic algorithm (RC-NGA) is then applied to search for the minimum cost for a building of span of 6 m, height-to-eaves of 3 m and length of 9 m, with a frame spacing …

Structural Strength Of Lapped Cold-Formed Steel Z-Shaped Purlin Connections With Vertical Slotted Holes, J. Liu, L. Xu, S. Fox

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

Lapped joints of cold-formed steel (CFS) Z-shaped purlins are extensively used in metal building roof systems. The research that has been carried out so far for these lapped connections is primarily focused on connections with round holes. However, the lapped connections with vertical slotted holes are extensively used in current construction practice to simplify the erection of continuous Z-shaped roof purlins. There are no design guidelines or recommendations available for CFS Z-purlin lapped connections with vertical slotted holes.

Presented in this paper are the results of an experimental study on the structural strength behaviour of lapped CFS Z-shaped purlin connections …

Direct Strength Method For Ultimate Strength Of Bolted Moment-Connections Between Cold-Formed Steel Channel Members, James B. P. Lim, Gregory J. Hancock, G. Charles Clifton, Cao Hung Pham

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

Experimental tests have previously shown that the strength of bolted moment-connections between cold-formed steel members, where the connections are formed through an array of bolts in the web, is dependent on the length of the bolt-group. This reduced strength has been observed in tests on portal frame joints as well as over-lapped purlin joints. For a short bolt-group length, in the order of the depth of the section, this paper shows that a reasonable lower bound to this reduced strength can be predicted by using the Direct Strength Method (DSM), modified to include the effect of the bimoment at the …

Towards Load-Deformation Models For Screw-Fastened Cold-Formed Steel-To-Steel Shear Connections, C. D. Moen, D. A. Padilla-Llano, S. Corner, C. Ding

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

This paper summarizes results from an experimental program considering single-fastened cold-formed steel-to-steel shear connections. Fastener motion (displacement and tilting angle) and bearing deformation occurring on the connecting members at the fastener location were captured using an automated, optical non-contact measurement procedure. The results are used to relate cold-formed steel-to-steel shear connection load-deformation response to tilting and bearing response. A general steel-to-steel single shear fastener load-deformation equation is also proposed and demonstrated.

Lateral Loading Response Of Cfs Framed Shear Wall With Cement Board Panels, N. Baldassino, M. Accorti, R. Zandonini, F. Scavazza, C. A. Rogers

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

Shear wall panels are commonly used as lateral load resisting elements to provide stability of the cold-formed steel-framed houses in Australia against wind and earthquake actions. The effectiveness of their lateral resistance behavior is obtained usually by experimental testing although it can also be done by analytical modeling. This paper presents racking test results of steel-framed wall panels with different aspect ratios sheathed with fibre cement board subjected to monotonic and cyclic loading protocol. Performance parameters of the wall panels are obtained from the experimentally observed load-deflection curves using various existing methods and evaluation method is proposed. The evaluation method …

In-Plane Behavior Of Cold-Formed Steel-Framed Shear Wall Panels Sheathed With Fibre Cement Board, Rojit Shahi, Nelson Lam, Emad Gad, Ismail Saifullah, John Wilson, Ken Watson

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

Shear wall panels are commonly used as lateral load resisting elements to provide stability of the cold-formed steel-framed houses in Australia against wind and earthquake actions. The effectiveness of their lateral resistance behavior is obtained usually by experimental testing although it can also be done by analytical modeling. This paper presents racking test results of steelframed wall panels with different aspect ratios sheathed with fibre cement board subjected to monotonic and cyclic loading protocol. Performance parameters of the wall panels are obtained from the experimentally observed load-deflection curves using various existing methods and evaluation method is proposed. The evaluation method …

Evaluation Of The Seismic Performance Of Light Gauge Steel Walls Braced With Flat Straps, Iuorio Ornella, Macillo Vincenzo, Terracciano Maria Teresa, Pali Tatiana, Fiorino Luigi, Landolfo Raffaele

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

The development of light weight steel structures in seismic area as Italy requires the upgrading of National Codes. To this end, in the last years a theoretical and experimental study was carried out at the University of Naples within the research project RELUIS-DPC 2010-2013. The study focused on "all steel design" solutions and investigated the seismic behaviour of strap braced stud shear walls. Three wall configurations were defined according to both elastic and dissipative design criteria for three different seismic scenarios. The lateral in-plane behavior of these systems were evaluated by 12 tests performed on full-scale CFS strap-braced stud wall …

Numerical Simulation On Dynamic Behavior Of A Cold-Formed Steel Framing Building Test Model, Yuanqi Li, Rongkui Ma, Zuyan Shen

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

A nonlinear dynamic numerical simulation on seismic behavior of a two-story cold-formed steel framing building full-scale shaking table test model was carried out by the way of from components to integral structure. Firstly, refined numerical model of shear wall was established, and restoring force models of screw connections between the framing and sheathings were integrated into the numerical model of shear wall. The refined numerical model of shear wall was verified by tests. Secondly, based on refined numerical model of shear wall and modified exponential “Foschi” skeleton curve, uniform restoring force skeleton curves of two typical shear walls of the …

Towards Quantifying Beneficial System Effects In Cold-Formed Steel Wood-Sheathed Floor Diaphragms, A. Chatterjee, Y. Xiang, C. D. Moen, S. R. Arwade, Benjamin W. Schafer

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

Cold-formed steel wood-sheathed floor diaphragm system behavior is analyzed from a system reliability perspective. Floor systems consisting of oriented strand board (OSB), cold-formed steel (CFS) joists, tracks and screw fasteners are modeled using shell and spring elements in ABAQUS. (Dassault-Systems ())The models consider typical seismic demand loads, with careful treatment of light steel framing diaphragm boundary conditions and OSB sheathing kinematics, i.e., two sheets pulling apart or bearing against each other at an ultimate limit state, consistent with existing experimental results. The finite element results are used to build surrogate mathematical idealizations (series, parallel-brittle and parallel-ductile) for the critical system …

Design Equations For Tensile Rupture Resistance Of Bolted Connections In Cold-Formed Steel Members, Lip H. Teh, Benoit P. Gilbert

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

This paper summarises and re-examines the authors’ previous research results concerning the tensile rupture resistance of cold-formed steel bolted connections in a flat sheet, in a channel’s web, and in one leg of an angle section. Staggered bolted connections are also included. The fundamental shortcomings of the design equations given in the 2012 North American Specification for the Design of Cold-formed Steel Structural Members are described, and the alternative design equations proposed by the authors are shown. The alternative equations are checked against laboratory test results obtained by the authors and other researchers where the bolts had not been snug-tightened …

Strain And Stress Distributions In Composite Deck Slabs: A Numerical Study, Vitaliy V. Degtyarev

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

This paper describes results of a study on strain and stress distributions in compact and slender composite deck slabs using nonlinear three-dimensional finite element models. The slabs were modeled as flexural members made of steel deck units and structural concrete fillings interconnected at the interface with nonlinear springs representing bond between two materials. The models are capable of accounting for partial interaction between the deck and the concrete, discrete concrete cracking in the slab tension zone, and nonlinear behavior of the materials and the interface. They were validated against published test data and have proved to be effective in predicting …

Acoustic Performance Of Different Cold-Formed Studs In Double-Leaf Walls By Finite Element Analysis And Experiment, V. B. Nguyen, T. Morgan, M. A. English, M. A. Castellucci

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

Cold-formed steel studs are often used in lightweight partition walls to provide structural stability but in the same time they change the acoustic performance of the whole system. The overall design of such lightweight structures for acoustic sound insulation becomes very complicated as the sound passing through stud needs to be quantified. One of the greatest challenges is to characterise the stud’s geometric effects on the sound transmission of the partition walls. This paper presents a Finite Element modelling approach and results into the acoustic performance of cold-formed studs in double-leaf walls which are placed in between a source room …

Numerical Investigation Of Cold-Formed Steel Top Hat Purlins, Asraf Uzzaman, Andrzej M. Wrzesien, Robert Hamilton, James B. P. Lim, David Nash

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

This paper considers the use of cold-formed steel top-hat sections for purlins as an alternative to conventional zed-sections. The use of such top-hat sections may be viable for use in cold-formed steel portal framing systems, where both the frame spacing and purlin span may be smaller than in conventional hot-rolled steel portal frames. Furthermore, such sections are torsionally stiffer than zed-sections, and so have a greater resistance to lateral-torsional buckling. They also do not require the installation of anti-sag rods. The paper describes non-linear elasto plastic finite element analyses conducted on top-hat sections. The results of twenty-seven tests on four …

Constrained Finite Element Method: Demonstrative Examples On The Global Modes Of Thin-Walled Members, S. Ádány

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

In this paper a novel method is presented for the modal decomposition of thin-walled members. The proposed method follows the logic of the constrained finite strip method (cFSM), however, polynomial longitudinal shape functions are applied together with a longitudinal discretization. Thus, strips are transformed into multiple shell finite elements. The longitudinal shape functions are selected in such a way that modal decomposition similar to cFSM can be realized, therefore, the new method can conveniently be described as constrained finite element method (cFEM), possessing all the modal features of cFSM, but with significantly more flexible applicability. The method is briefly presented …

The 2013 Aisi Cold-Formed Steel Design Manual, Joshua Buckholt, Richard C. Kaehler, Helen Chen

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

The 2013 edition of the AISI Cold-Formed Steel Design Manual has been published. The new edition includes updated and newly developed example problems and design aids covering new material in the 2012 edition of the AISI North American Specification for the Design of Cold-Formed Steel Structural Members (NA Specification). Also published with the Manual are the NA Specification and the Commentary.