Engineering Commons^™

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 …

The Effects Of Bolt Pretension, In-Plane Eccentricity, And Friction On The Ductility Of Block Shear Connections, Kevin M. Zmetra

Master's Theses

Block shear is a complex failure mechanism in bolted and welded steel components such as gusset plates, webs of coped beams, angles and tees. It presumes a combination of tension rupture and shear yield. Multiple variables affect the block shear capacity and ductility of a connection. This study investigates the effects of bolt pretension, connection eccentricity and friction force transfer through a series of destructive experiments followed by refined finite element simulation. Clamping forces create a complex triaxial stress field compounded by the stress concentration at the bolt holes. In-plane load eccentricity with respect to the centerline of the connection …

Modal Identification Of Cold-Formed Steel Members In Shell Finite Element Models, Z. Li, S. Ádány, B. W. Schafer

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

This paper illustrates new capabilities for modal identification of shell Finite Element Method (FEM) models of thin-walled cold-formed steel members. The separation of general deformations into fundamental buckling deformation classes: local, distortional, global, shear, and transverse extension, originated with the constrained Finite Strip Method (cFSM) and is extended here to shell element based FEM analysis. The cFSM base vectors for general end boundary conditions, previously developed by the authors, provide a series of general base functions capable of separating displacements into classes. FEM displacements are identified by minimizing error between the actual FEM displacements and those predicted by the cFSM …

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

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

No abstract provided.

Analytical Model For Cold-Formed Steel Framed Shear Wall With Steel Sheet Sheathing, Noritsugu Yanagi, Cheng Yu

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

The cold-formed steel framed shear wall sheathed with steel sheet sheathing (CFS-SSSW) is a code approved lateral force resisting system for light framed construction. The AISI Steel Framing Standards – Lateral Design (AISI S213-07) provides design provisions for CFS-SSSW. The development of the nominal strength of CFS-SSSW in AISI S213 was based on full-scale experiments which were subjected to limitations in both wall configurations and material properties. This paper presents an analytical model – the Effective Strip Model developed for predicting the nominal strength of CFS-SSSWs. The proposed analytical model and supporting design equations are further verified by experimental results. …

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 …

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 …

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

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 …

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

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 …

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 …

Direct Strength Method Of Design For Shear Of Cold-Formed Channels Based On A Shear Signature Curve, Gregory J. Hancock, Cao Hung Pham

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

Thin-walled sections in compression and/or bending may undergo one of the three modes of local, distortional or overall (Euler) buckling, or combinations of these. The Semi-Analytical Finite Strip Method (SAFSM) developed by YK Cheung has been widely used in computer software (THIN-WALL, CUFSM) to develop the signature curve of the buckling stress versus buckling half wavelength for a thin-walled section under compression or bending to allow identification of these modes. The minimum points on the signature curve are now used in the Direct Strength Method (DSM) of design of cold-formed sections in the American Specification and Australian/New Zealand Standard for …

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 …

Shear Strength Of Hollow Flange Channel Beams With Stiffened Web Openings, P. Keerthan, M. Mahendran

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

This LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel section produced using a patented manufacturing process involving simultaneous cold-forming and dual electric resistance welding. The LSBs are commonly used as floor joists and bearers with web openings in buildings. Their shear strengths are considerably reduced when web openings are included for the purpose of locating building services. Shear tests of LSBs with web openings have shown that there is up to 60% reduction in the shear capacity. Hence there is a need to improve the shear capacity of LSBs with web openings. A cost effective way to …

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

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 …

The Effects Of Web Holes On Web Crippling Strength Of Cold-Formed Steel Channels Under End-Two-Flange Loading Condition, Asraf Uzzaman, James B. P. Lim, David Nash, Jim Rhodes, Ben Young

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

Cold-formed steel sections are often used as wall studs or floor joists; such sections often include web holes for ease of installation of the services. Web crippling at points of concentrated, or localised, load or reaction in thin-walled beams is well known to be a significant problem, particularly in the case of beams with slender webs, and is of high importance in the field of cold-formed steel members, as such members are generally not stiffened against this type of loading. In this paper, a combination of experimental tests and non-linear elastoplastic finite element analyses are used to investigate the effect …

Push Tests On Innovative Shear Connector For Composite Beam With Cold-Formed Steel Section, S. O. Bamaga, M. M. Tahir, C. S. Tan

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

In this study, experimental tests were conducted to investigate the ductility and strength capacity of new shear connector. Push test specimens were prepared and tested according to EN1994-1-1 standard. The push test specimen consists of two cold-formed steel lipped channel sections oriented back-to-back to form an I-section beam, transverse metal deck and normal concrete slabs grade C25/30. Angle brackets were obtained from the same section of the beam and fastened to the web of steel beam to provide the shear connection. Two shear connectors were tested namely; “SC1” and “SC2” shear connectors. Both shear connectors showed a ductile behavior and …

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 …

An Explicit, Dynamic Finite Element Model For The Local Failure Of Cold-Formed Trapezoidal Sheeting, Hèrm Hofmeyer

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

Trapezoidal sheeting, made of cold-formed, thin-walled steel, is widely used for the construction of cladding and roofs. At an interior support, the sheeting is subject to bending moments and a concentrated load, which leads to possible failure followed by two post-failure modes: the yield-arc and yield-eye modes. Until recently, it was not fully understood why a specific post-failure mode occurs and it was suggested that mode-jumping of the compressed sheeting flange may influence the mode occurring. This paper presents new research, in which both the compressed flange in isolation and the sheeting are modeled by using an explicit, dynamic finite …

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 …

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 …

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

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 …

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.

Improved Protocols For Automated Wheelpath Crack Detection In Pavements, Daniel Patrick Byram

Graduate Theses and Dissertations

Roadway pavement distress evaluations are vital to understanding the mechanics of pavement stability, determining the distribution of rehabilitation costs, and knowing the appropriate rehabilitation strategies. Advancements in technology over the past two decades have changed the way these surveys have been performed by means of automated data collection and interpretation. More and more state agencies have invested in automated road analyzing vehicles that are able to collect high resolution images of the pavement. Fewer have adopted automated data processing software with the ability to interpret road distresses due to the common discrepancies in distress classification algorithms.

In addition to automated …

Efficacy Of A Ternary Blend In Improving Bridge Deck Concrete Durability In Tennessee, Robert Clark Nidiffer

Masters Theses

A study related to the durability of bridge deck concrete in the state of Tennessee has been ongoing at the University of Tennessee (UT) for the past decade. The most recent phase of this research was begun in the fall of 2009 with a focus on developing assessment criteria and methodology to assess the durability of bridge deck concrete in the state of Tennessee. The methodology that was used to assess the durability of Tennessee bridge deck concrete was to determine the concrete’s resistance to chloride ion penetration by way of two test methods, the Surface Resistivity (SR) test and …

Static Flexural Behaviour Of Fly Ash-Based Geopolymer Composite Beam: An Alternative Railway Sleeper, Wahid Ferdous

Wahid Ferdous

These days, the most commonly used materials for railway sleepers are timber, concrete and steel. High maintenance cost, installation issues, deterioration of materials, and environmental considerations are among the factors that prompt research and industry to seek a different and more efficient system. This research was undertaken with the aim of developing a material for sleepers which may overcome some of these problems. Through a comprehensive survey of the literature, it was decided to propose and investigate a sleeper system composed of fly ash-based geopolymer concrete and pultruded FRP profile composites. Although the engineering properties of fly ash-based geopolymer concrete …