Structural Engineering Commons^™

Structural Performance And Economics Of High-Rise Buildings Under Seismic And Wind Loads, Nadeem Hussain

Theses

High-rise buildings have a priority when considering the potential consequences from natural hazards since they represent concentrated human and monetary assets. The use of high strength materials is promoted in this class of structures to effectively use floor areas, control vibrations and expedite construction. There is a pressing need to investigate the relationship between structural performance and economics of high-rise buildings with different material strengths under lateral loads, particularly seismic loads that control the design of a wide range of buildings.

To realistically represent the modern high-rise construction, five 60-story reinforced concrete (RC) buildings with varying material strengths, ranging from …

An Experimental Study On Bond Strength Of Reinforcing Steel In Self-Consolidating Concrete, Trevor J. Looney, Mahdi Arezoumandi, Jeffery S. Volz, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An experimental investigation was conducted to compare the bond strength of reinforcing steel in self-consolidating concrete (SCC) with conventional concrete (CC). This study investigated two different compressive strengths of SCC as well as CC. the experimental program consisted of 24 pull-out specimens as well as 12 full-scale beams (three for each concrete type and strength). the pull-out specimens were based on RILEM recommendations, and the beam specimens were tested under a simply supported four-point loading condition. the CC test results served as a control and were used to evaluate the results from the SCC pull-out and beam specimen tests. Furthermore, …

Definition Of Common Conventions For Education Of Cfs System Design, Semih Göksel Yıldırım

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

CFS system of which can be used in the field of low rise residentials, are included in industrialised building systems due to installation principles of the system. Widespreading of the usage of an industrialised building system depends on the widespreading of the system design datum. Therefore, education of CFS system design is required in order to increase the system usage. Also, awareness of CFS system in the levels of public authorities and technical staff can be increased by education. The aim of this paper is to develop an education model for CFS system design by using open building concept. The …

Numerical And Experimental Investigation Of Cold-Formed Steel Double Angle Members Under Compression, W. F. Maia, L. C. M. Vieira Jr., B. W. Schafer, M. Malite

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

This paper presents a numerical and experimental study of double angle members connected by batten plates under concentric and eccentric axial compression. The number of batten plates is varied to study the influence on the nominal axial strength. Numerical analyses are able to accurately predict the behavior and strength found in the experiments, except for long columns under eccentric axial compression where the composite section failed in major-axis flexural buckling. Two design hypotheses are compared to the results obtained: (i) non-composite action (no interaction between angles), with only local, flexural, and flexural-torsional buckling considered; (ii) composite action (full interaction between …

The 1st Student Competition On Cold-Formed Steel Design, Cheng Yu, Cristopher Moen

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

The first Student Competition on Cold-Formed Steel Design (CFS Competition) was held at the University of North Texas in 2011. The CFS Competition was initiated by Cheng Yu through a National Science Foundation CAREER award. The objective of the CFS Competition is to promote higher education in coldformed steel structural design and to encourage students to use creative thinking skills to solve engineering problems. The subject of the first CFS Competition is to design an optimal thin-walled cold-formed steel cross section under several pre-defined restrictions. The CFS Completion received total 78 entries from students in 5 different countries. The judging …

Towards The Design Of Cold-Formed Steel Foam Sandwich Columns, S. Szyniszewski, B. H. Smith, V. M. Zeinoddini, J. F. Hajjar, S. R. Arwade, B. W. Schafer

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

In this paper a design method for the compressive capacity of sandwich panels comprised of steel face sheets and foamed steel cores is derived and verified. Foamed steel, literally steel with internal voids, provides the potential to mitigate many local stability issues through increasing the effective width-to thickness of the component for the same amount of material. Winter’s classical effective width expression was generalized to the case of steel foam sandwich panels. The provided analytical expressions are verified with finite element simulations employing brick elements that explicitly model the steel face sheets and steel foam cores. The closed-form design expressions …

Dynamic Time-History Analysis On Wind-Induced Response Of Light-Weight Roof System, X. K. Jing, Y. Q. Li, D. J. Gong

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

Severe damage to light-weight roof system occur when exposed to strong wind loading. Damage investigations and wind load-bearing capacity tests of light-weight roof system reveal that the connection damage of roof sheeting and fastener is the most serious. Wind pressure distributions on the roof of gabled steel frame measured in a wind tunnel are described. Secondly, illustrated by the example of the classic standing-lock roof system, the wind-induced forces for the concealed clips estimated by the building code and time-history analysis based on wind tunnel test, respectively, are compared. The results indicate that the uniform gust factor used in the …

Experimental Analysis Of Beam-To-Upright Connections In Cold-Formed Steel Storage Pallet Racks, Tuo Wang, Xianzhong Zhao, Yiyi Chen

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

A research program is currently in progress at Department of Building Engineering of Tongji University with the aim of investigating the behavior of cold-formed steel storage pallet racks under static and dynamic loading. This paper presents preliminary experimental analysis on the monotonic behavior of beam-to-upright connections. In the experimentation, the set-up was specially designed to accommodate precise requirement of boundary conditions and the measurement method was refined from the general ones used in rack design codes. It is shown that deformation modes of the connections were similar before failure while the failure modes were different depending on the specific constructional …

Experimental And Numerical Investigations Of High Strength Cold-Formed Lapped Z Purlins Under Combined Bending And Shear, Cao Hung Pham, Annabel F. Davis, Bonney R. Emmett

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

Plain C or Z- sections are two of the most common cold-formed steel purlins in use for roof systems throughout the world. Especially for Z- sections, their lapping ability provides continuity and double thickness material at the support regions results in greater performance and more economical designs. At the region just outside the end of the lap, the purlin may fail under a combination of high bending and shear. Design methods for these sections are normally specified in the Australian/New Zealand Standard for Cold-Formed Steel Structures (AS/NZS 4600:2005) or the North American Specification for Cold- Formed Steel Structural Members (2007). …

Mechanisms Of Block Shear Failure Of Bolted Connections, Lip H. Teh, Drew D. A. Clements

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

This paper examines the mechanisms for block shear failure postulated in the design provisions specified in the North American Specification for the Design of Cold-formed Steel Structural Members 2007 and AS/NZS 4600:2005 Coldformed Steel Structures. It explains that there is only one feasible mechanism for the limit state of conventional block shear failure, that which involves shear yielding and tensile rupture. It proposes an equation that provides more accurate results compared to the code equations in predicting the block shear capacities of bolted connections in steels having minimal strain hardening. A resistance factor of 0.8 for the proposed equation is …

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

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

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

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 …

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

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 …

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 …

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

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 …

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 …