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2010

Missouri University of Science and Technology

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Articles 1 - 30 of 729

Full-Text Articles in Engineering

A Memory Saving Vector Fast Multipole Algorithm For Solving The Augmented Efie, Yang G. Liu, Weng Cho Chew, Li (Lijun) Jun Jiang Dec 2010

A Memory Saving Vector Fast Multipole Algorithm For Solving The Augmented Efie, Yang G. Liu, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

An augmented EFIE (A-EFIE)[9], [10] has been proposed to separate the contributions of the vector potential and the scalar potential for avoiding the imbalance at low frequencies. The corresponding low frequency fast multipole algorithm (LFFMA) [11] was also developed for solving the A-EFIE. Instead of the factorization of the scalar Green's function by using scalar addition theorem in the LF-FMA, we adopt the vector addition theorem for the factorization of the dyadic Green's function to realize memory savings. We are to develop a vector fast multipole algorithm for solving the A-EFIE. © 2010 IEEE.


A High-Quality Mach-Zehnder Interferometer Fiber Sensor By Femtosecond Laser One-Step Processing, Longjiang Zhao, Lan Jiang, Sumei Wang, Hai Xiao, Yongfeng Lu, Hai-Lung Tsai Dec 2010

A High-Quality Mach-Zehnder Interferometer Fiber Sensor By Femtosecond Laser One-Step Processing, Longjiang Zhao, Lan Jiang, Sumei Wang, Hai Xiao, Yongfeng Lu, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

During new fiber sensor development experiments, an easy-to-fabricate simple sensing structure with a trench and partially ablated fiber core is fabricated by using an 800 nm 35 fs 1 kHz laser. It is demonstrated that the structure forms a Mach-Zehnder interferometer (MZI) with the interference between the laser light passing through the air in the trench cavity and that in the remained fiber core. The fringe visibilities are all more than 25 dB. The transmission spectra vary with the femtosecond (fs) laser ablation scanning cycle. The free spectral range (FSR) decreases as the trench length increases. The MZI structure is …


A Comparative Verification Of Forecasts From Two Operational Solar Wind Models, Donald C. Norquist, Warner C. Meeks Dec 2010

A Comparative Verification Of Forecasts From Two Operational Solar Wind Models, Donald C. Norquist, Warner C. Meeks

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The solar wind (SW) and interplanetary magnetic field (IMF) have a significant influence on the near‐Earth space environment. In this study we evaluate and compare forecasts from two models that predict SW and IMF conditions: the Hakamada‐Akasofu‐Fry (HAF) version 2, operational at the Air Force Weather Agency, and Wang‐Sheeley‐Arge (WSA) version 1.6, executed routinely at the Space Weather Prediction Center. SW speed (Vsw) and IMF polarity (Bpol) forecasts at L1 were compared with Wind and Advanced Composition Explorer satellite observations. Verification statistics were computed by study year and forecast day. Results revealed that both models’ mean Vsw are …


Process To Produce High Surface Area Nanoparticle Vanadium Phosphorus Oxide Catalyst And Product Derives Thereof, Yun Hin Taufiq-Yap, Ali A. Rownaghi Dec 2010

Process To Produce High Surface Area Nanoparticle Vanadium Phosphorus Oxide Catalyst And Product Derives Thereof, Yun Hin Taufiq-Yap, Ali A. Rownaghi

Chemical and Biochemical Engineering Faculty Research & Creative Works

An improved process to produce high surface area nanoparticle vanadium phosphorus oxide catalysts comprises the steps of reducing vanadium-containing compounds in an alcohol solution selected from the group consisting of isobutanol and benzyl alcohol and any combination derives thereof under reflux for 4 to 6 hours to form a suspended mixture; reacting dopants and phosphorus-containing compounds to the suspended mixture under reflux for 30 minutes to 3 hours to form precursors of the vanadium phosphorus oxide catalysts; drying the formed precursors; and calcining the dried precursors in a flow of gaseous n-butane/air mixture at 400 to 460° C. to form …


Note: Autonomous Pulsed Power Generator Based On Transverse Shock Wave Depolarization Of Ferroelectric Ceramics, S. I. Shkuratov, Jason Baird, E. F. Talantsev Dec 2010

Note: Autonomous Pulsed Power Generator Based On Transverse Shock Wave Depolarization Of Ferroelectric Ceramics, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

Autonomous pulsed generators utilizing transverse shock wave depolarization (shock front propagates across the polarization vector P0) of Pb(Zr0.52Ti0.48)O3 poled piezoelectric ceramics were designed, constructed, and experimentally tested. It was demonstrated that generators having total volume of 50 cm3 were capable of producing the output voltage pulses with amplitude up to 43 kV with pulse duration 4 µs. A comparison of high-voltage operation of transverse and longitudinal shock wave ferroelectric generators is given.


Product Technical Information, Steel Stud Manufacturers Association Dec 2010

Product Technical Information, Steel Stud Manufacturers Association

CCFSS Library (1939 - present)

No abstract provided.


Augmented Epa With Augmented Efie Method For Packaging Analysis, Zuhui Ma, Lijun Jiang, Wengcho Chew, Maokun Li, Zhiguo Qian Dec 2010

Augmented Epa With Augmented Efie Method For Packaging Analysis, Zuhui Ma, Lijun Jiang, Wengcho Chew, Maokun Li, Zhiguo Qian

Electrical and Computer Engineering Faculty Research & Creative Works

It is evident that the low frequency full wave electromagnetic modelling is necessary for IC packaging analysis. Considering the complexity, it is very difficult to solve the whole problem directly. Even though the domain decomposition method is a legitimate approach for these types of problems, the domain decomposition method based on the equivalence principle has the low frequency breakdown issue. In this paper, we developed a low frequency augmented equivalence principle algorithm (AEPA) with the augmented electric field integral equation (AEFIE) for packaging and IC analysis. On the equivalence surfaces, not only the electric current and the magnetic current, but …


Review Of Multi-Scale Electromagnetic Modeling, W. C. Chew, Lijun Jiang, H. Y. Chao, A. J. Hesford, M. K. Li, Z. G. Qian, Y. G. Liu, Y. P. Chen, Z. H. Ma, L. E. Sun, M. S. Tong, C. Davis, W. E.I. Sha Dec 2010

Review Of Multi-Scale Electromagnetic Modeling, W. C. Chew, Lijun Jiang, H. Y. Chao, A. J. Hesford, M. K. Li, Z. G. Qian, Y. G. Liu, Y. P. Chen, Z. H. Ma, L. E. Sun, M. S. Tong, C. Davis, W. E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reviews various methods to solve multiscale problems ranging from low-frequency methods to very high-frequency methods. ©2010 IEEE.


Robust Neural Network Rise Observer Based Fault Diagnostics And Prediction, James W. Fonda, S. (Sarangapani) Jagannathan, Steve Eugene Watkins Dec 2010

Robust Neural Network Rise Observer Based Fault Diagnostics And Prediction, James W. Fonda, S. (Sarangapani) Jagannathan, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

A novel fault diagnostics and prediction scheme in continuous time is introduced for a class of nonlinear systems. The proposed method uses a novel neural network (NN) based robust integral sign of the error (RISE) observer, or estimator, allowing for semi-global asymptotic stability in the presence of NN approximation errors, disturbances and unmodeled dynamics. This is in comparison to typical results presented in the literature that show only boundedness in the presence of uncertainties. The output of the observer/estimator is compared with that of the nonlinear system and a residual is used for declaring the presence of a fault when …


Decentralized State Feedback And Near Optimal Adaptive Neural Network Control Of Interconnected Nonlinear Discrete-Time Systems, Shahab Mehraeen, Jagannathan Sarangapani, Mariesa Crow Dec 2010

Decentralized State Feedback And Near Optimal Adaptive Neural Network Control Of Interconnected Nonlinear Discrete-Time Systems, Shahab Mehraeen, Jagannathan Sarangapani, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, first a novel decentralized state feedback stabilization controller is introduced for a class of nonlinear interconnected discrete-time systems in affine form with unknown subsystem dynamics, control gain matrix, and interconnection dynamics by employing neural networks (NNs). Subsequently, the optimal control problem of decentralized nonlinear discrete-time system is considered with unknown internal subsystem and interconnection dynamics while assuming that the control gain matrix is known. For the near optimal controller development, the direct neural dynamic programming technique is utilized to solve the Hamilton-Jacobi-Bellman (HJB) equation forward-in-time. The decentralized optimal controller design for each subsystem utilizes the critic-actor structure …


Cold-Formed Steel Framing Seismic Design Optimization Phase 1a: Seismic Equivalency Parameter Evaluation, American Iron And Steel Institute Nov 2010

Cold-Formed Steel Framing Seismic Design Optimization Phase 1a: Seismic Equivalency Parameter Evaluation, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.


Regeneration Of Exhausted Carbon Nano-Foam Used In Desalination Of Brackish Water, Sanjay Tewari, Bill Batchelor Nov 2010

Regeneration Of Exhausted Carbon Nano-Foam Used In Desalination Of Brackish Water, Sanjay Tewari, Bill Batchelor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Carbon Nano-Foam (CNF) has been used electrochemically for water desalination. CNF electrodes attract oppositely charged ions flowing in between them and this process is known as Capacitive De-Ionization (CDI). Once saturated these electrodes lose electrochemical adsorption and need to be replaced, this increases the cost of the treatment process as CNF is expensive. The goal of this study is to obtain optimal regeneration and predictive capability by examining CNF electrodes during regeneration and developing a model to describe desorption behavior. Various experiments were conducted to explore the effect of shorting, changing polarity of electrodes, flow velocity of water over CNF …


Cfsei Educating North American Practitioners In Principles Of Cfs Framing Design, W. D. Allen Nov 2010

Cfsei Educating North American Practitioners In Principles Of Cfs Framing Design, W. D. Allen

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

Educating North American structural engi neers in the principles of cold-formed steel (CFS) design in general, and about CFS framing in particular, has a unique set of challenges. The undergraduate curri cula virtually ignore the subjects, and only a handful of graduate programs address the issue. Several industry associations have existed for engineers, but none specialize in CFS framing. Several organizations existed in the co ld-formed steel framing marketplace, but none were set up to accommodate engi neers. This paper will review the formation, development, growth, and maturation of one such education- and engineer-focused organization within the framework of the …


A Life-Cycle Assessment Of Cold-Formed Steel Enclosures Verses Alternative Enclosures In Commerical Buildings, K. J. Van, L. Xu Nov 2010

A Life-Cycle Assessment Of Cold-Formed Steel Enclosures Verses Alternative Enclosures In Commerical Buildings, K. J. Van, L. Xu

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

In North America, the operation of buildings accounts for approximately one third of the total energy use and greenhouse gas emissions each year. Over the life of a building, the total energy use is a combination of the embodied energy in the building materials and the operating energy of the building. Building enclosures (walls and roofs) have a huge impact on both the embodied energy and the operating energy of buildings. Historically, steel has been blacklisted as a material with a high embodied energy. This has led to a misconception that steel enclosures use significantly more energy than other enclosure …


Behavior And Design Of Axially Compressed Sheathed Wall Studs, L. C. M. Vieira Jr., B. W. Schafer Nov 2010

Behavior And Design Of Axially Compressed Sheathed Wall Studs, L. C. M. Vieira Jr., B. W. Schafer

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

The objective of this paper is to summarize efforts in a multi year project dedicated to developing a reliable design method for cold - formed steel wall studs that rely on sheathing for bracing. Testing on single columns with sheathing, and full - scale walls with sheathin g, are summarized. Particular emphasis is placed on the observed limit states given the different sheathing conditions. The sheathing supplies beneficial restraint to the wall studs and the stiffness of this sheathing - based restraint is characterized exper imentally and analytically. A unique application of the Direct Strength Method of design is explored …


Cross-Aisle Stiffness Tests On Rack Upright Frames, S. R. Sajja, R. G. Beale, M. H. R. Godley Nov 2010

Cross-Aisle Stiffness Tests On Rack Upright Frames, S. R. Sajja, R. G. Beale, M. H. R. Godley

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

The US Rack Manufacturers Institution (RMI) code uses a theoretical formula derived by Timoshenko and the new Eurocode EN15512 requires testing. There is a considerable difference in the stiffn ess values determined by two approaches. This paper describes the experiments conducted on 80 full sized upright frames at Oxford Brookes University varying upright size, number of panels in the frame, aspect ratio of the panel (panel length/depth), restraints at the intermediate nodes of the frame, loading pattern, lacing pattern (channels back to back or front to front) and bolt tightness. The experimental data reported can be used in proposing revised …


Direct Strength Design Of Cold-Formed C-Sections For Shear, Cao Hung Pham, Gregory J. Hancock Nov 2010

Direct Strength Design Of Cold-Formed C-Sections For Shear, Cao Hung Pham, Gregory J. Hancock

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

The Direct Strength Method (DSM) rece ntly included in the North American Specification and Australian/New Zealand Standard AS/NZS 4600:2005 gives design rules for compression and bending. No rules are presente d at this stage for shear. Two series of tests on C-section can be used to develop and calibrate rules for design in shear. These are the University of Missouri Rolla tests of the 1970’s and recent tests on high strength C-sections at the University of Sydney. Both series of tests use a similar test rig altho ugh different levels of tension field action have been observed. Two features research …


Experimental Evaluation Of A Vehicular Access Door Subjected To Hurricane Force Wind Pressures, Tian Gao, Christopher D. Moen Nov 2010

Experimental Evaluation Of A Vehicular Access Door Subjected To Hurricane Force Wind Pressures, Tian Gao, Christopher D. Moen

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

This paper describes an experimental study of a rolling sheet door under uniform positive and negative pressure, i.e. wind pushing the door into the building and wind suction pulling the door out of the building. Rolling sheet vehicular access doors are a commonly provided feature in metal building systems. The edges of the door slide freely during regular usage in tracks connected to cold-formed steel jambs. During an extreme wind event, the door engages the jambs with wind locks distributed along both vertical edges of the door to prevent excessive out-of-plane deformation. The goal of the study was to measure …


Direct Strength Design Of Cold-Formed C-Sections In Combined Bending And Shear, Cao Hung Pham, Gregory J. Hancock Nov 2010

Direct Strength Design Of Cold-Formed C-Sections In Combined Bending And Shear, Cao Hung Pham, Gregory J. Hancock

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

The paper describes a research program including tests on both plain C- and SupaCee ® purlin sections in combined bending and shear, and bending only. The high strength SupaCee ® profile steel sections contain additional return lips and web stiffeners which enhance the bending and shear capacity of the sections. They are used widely in Austra lia as purlins in roof and wall systems. The tests were performed at the University of Sydney with and without straps on the flange and thus allowed distortional buckling in the latter case. Design methods for these sections are normally specified in the Australian/New …


Lateral Torsional Instability Of Single Channels Restrained By Angle Cleats, G. M. Bukasa, M. Dundu Masce Nov 2010

Lateral Torsional Instability Of Single Channels Restrained By Angle Cleats, G. M. Bukasa, M. Dundu Masce

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

A series of experiments on the lateral tors ional instability of single channels is presented. The channels are restrained by a purlin – angle cleat connection and subjected to a two point loading system in order to simulate a distributed load. Failure of the channels occurred by local buckling of the compression zone of the flange and web and lateral torsional buckling of the channels between points of lateral support. Tests have shown the purlin–angle cleat connection to be capable of restraining the frames from failing due to lateral-torsional buckling. This eliminates the idea of having fly-bracings, which is normally …


On The Direct Strength Design Of Continuous Cold-Formed Steel Beams, Cilmar Basaglia, Dinar Camotim Nov 2010

On The Direct Strength Design Of Continuous Cold-Formed Steel Beams, Cilmar Basaglia, Dinar Camotim

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

The work reported in this paper concerns an ongoing investigation aimed at developing an efficient methodology to design continuous cold-formed steel beams failing in modes that combine local, distortional and global features. At this stage, it is intended to assess how accurately can the load-carrying capacity of lipped channel continuous (two and three-span) beams subjected to non-uniform bending be predicted by means of the current Direct Strength Method (DSM) design curves. “Exact” ultimate strength values yielded by geometrically and materially non-linear shell finite element analyses are compared with estimates provided by the DSM equations and, on the basis of this …


Extending Direct Strength Design To Cold-Formed Steel Beams With Holes, Christopher D. Moen, Benjamin W. Schafer Nov 2010

Extending Direct Strength Design To Cold-Formed Steel Beams With Holes, Christopher D. Moen, Benjamin W. Schafer

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

The extension of the American Iron and Steel Institute’s Direct Strength Method (DSM) to cold-formed steel beams with holes is nearly in place. DSM was first introduced to th e AISI specification in 2004 as an alternative to the effective width met hod, and is widely considered a major advancement in cold-formed steel component design. In DSM, the beam elastic buckling properties for a general cross-section are obtained with a computer analysis utilizing the finite strip method. A disadvantage of the finite strip method and DSM has been that discrete holes along the member length could not be easily accounted …


Load-Carrying Capacity Estimation On Cold-Formed Thin-Walled Steel Columns With Built-Up Box Section, Yuangqi Li, Xingyou Yao, Zuyan Shen, Rongkui Ma Nov 2010

Load-Carrying Capacity Estimation On Cold-Formed Thin-Walled Steel Columns With Built-Up Box Section, Yuangqi Li, Xingyou Yao, Zuyan Shen, Rongkui Ma

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

The use of cold-formed thin-walled steel structural members has increased in recent years, and most of their sections are open section with only one symmetrical axis, which would likely fail by twisting and interaction with the others buckling mode, such as local buckling and distortional buckling. To improve the ultimate strength of columns, built-up box section can be used. In this paper, a series of loading capacity tests on high-strength cold- formed steel columns with built-up bo x section are presented, including 21 axially-compressed columns and 19 eccentrically-compressed columns sub- jected to bending moments about weak axis as well as …


Flexural And Cyclic Behaviour Of Hollow And Concrete-Filled Steel Tubes, S. Arivalagan, S. Kandasamy Nov 2010

Flexural And Cyclic Behaviour Of Hollow And Concrete-Filled Steel Tubes, S. Arivalagan, S. Kandasamy

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

This paper presents a study on the flexural and cyclic behaviour of concrete filled steel hollow beam sections. The specimens in-filled with normal mix concrete, fly ash concrete, quarry waste concrete and low strength concrete (Brick-bat-lime concrete) and hollow steel sections were tested. Measurements of strains and deflections were made under two-point loading. A theoretical model was also developed to predict the moment carrying capacity. The capacities of the beams were compared with the ultimate capacity obtained using the international standards EC4-1994, ACI-2002 and AISC-LRFD-1999. The result of the experimental investigation showed that the moment carrying capacity increases based on …


Theoretical Analysis Of Cold-Formed Steel Battened Double Angle Members Under Compression, W. F. Maia, J. Munaiar Neto, M. Malite Nov 2010

Theoretical Analysis Of Cold-Formed Steel Battened Double Angle Members Under Compression, W. F. Maia, J. Munaiar Neto, M. Malite

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

In Brazil, battened double angle system is one of the systems most used in light truss, however, there are not any specific studies on its behavior, resulting in the fact that the standard procedures do not provide subsidies for the design of this section. Moreover, cold-formed steel si mple angles under compression, mostly with slender legs, have an interesting structural behavior compared to other cold-formed steel shapes. Two critical modes are observed in the elastic stability analysis: (i) global flexural mode in the case of longer members and (ii) a coincident local-plate/global flexural-torsional mode, which is critical for shorter members. …


Cyclic Elastoplastic Large Displacement Analysis Of Cold-Formed Steel Box Columns Under Combined Action Of Axial And Bidirectional Lateral Loading, Iraj H. P. Mamaghani, Saman Montazeri Nov 2010

Cyclic Elastoplastic Large Displacement Analysis Of Cold-Formed Steel Box Columns Under Combined Action Of Axial And Bidirectional Lateral Loading, Iraj H. P. Mamaghani, Saman Montazeri

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

This paper deals with the cyclic elastoplastic large displacement analysis of cold-formed steel box columns under combined action of axial and bidirectional lateral loading. Cold-formed steel box columns are very useful in highway bridge pier construction as they offer flexible space requirement and provide speedy construction. Behavior of cold-formed steel box columns under earthquake-induced loads is rather complicated as earthquakes occur in an oblique direction. However, modern seismic design philosophies have been based on the behavior of structures under independent actions of uni-directional loading in orthogonal directions. In this study, inelastic cyclic behavior of steel columns subjected to constant axial …


Test And Finite Element Analysis On Distortional Buckling Of Cold-Formed Thin-Walled Steel Lipped Channel Columns, Xingyou Yao, Yanli Guo, Zhiguang Huang Nov 2010

Test And Finite Element Analysis On Distortional Buckling Of Cold-Formed Thin-Walled Steel Lipped Channel Columns, Xingyou Yao, Yanli Guo, Zhiguang Huang

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

High-strength cold-formed thin-walled steel sections have been widely used in the recent several years. However, distortional buckli ng or interaction between it and local buckling can occur for high strength cold-formed thin- walled steel members. This paper desc ribes a series of compression tests performed on lipped channel section columns with V-shape intermediate stiffener in the web and flanges fabricated from cold-formed high strength steel of thickness 0.48 and 0.6mm with nominal yield stress 550MPa. The lipped channel sections were tested to failure with both ends of the columns fixed. The test results of 16 specimens show that the local …


Impact Of Corner Radius On Cold-Formed Steel Member Strength, V. Zeinoddini, B. W. Schafer Nov 2010

Impact Of Corner Radius On Cold-Formed Steel Member Strength, V. Zeinoddini, B. W. Schafer

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

The objectives of this paper are to expl ore (a) how corners of cold-formed steel members are included or ignored in current design methods, and (b) the effectiveness of recent proposals for modifying the strength prediction for local buckling to account for corners. The imp act of round corners is examined on the behavior and strength of isolated elements and on full members using material and geometric nonlinear collapse analysis with shell finite elements in ABAQUS. Comparisons between the available methods and the nonlinear finite element analysis are completed to explore the regimes in which the methods are accurate, as …


Evaluating The Lrfd Factor For Cold-Formed Steel Compression Members, Karthik Ganesan, Christopher D. Moen Nov 2010

Evaluating The Lrfd Factor For Cold-Formed Steel Compression Members, Karthik Ganesan, Christopher D. Moen

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

This paper summarizes recent work to determine if the LRFD resistance factor for cold-formed steel compression member s can be increased above its current value of φ c =0.85. An experimental database of 675 concentrically loaded columns with plain and lipped C-sections, plain and lipped Z-sections, hat sections and angle sections, including members with holes was compiled. The predicted strength of each specimen was calculated with the AISI-S100-07 Main Specification and Direct Strength Method (DSM). Test-to-predicted strength statistics were employed with the first order second moment reliability approach in AISI-S100-07 Chapter F to calculate the resistance factors. The observed trends …


Experimental Investigation Of Optimized Cold-Formed Steel Compression Members, D. J. Klingshirn, E. A. Sumner, N. A. Rahman Nov 2010

Experimental Investigation Of Optimized Cold-Formed Steel Compression Members, D. J. Klingshirn, E. A. Sumner, N. A. Rahman

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

In the past, standard C - shaped metal studs have been the only option for designers and contractors when selecting a cross section for load bearing compression members. T he sigma shaped section has recently emerged as an alternative to the C - section. The sigma shaped section is very similar to the C - shape, with the exception of having an intermediate web return and complex stiffeners. The experimental results of concentric axial compression tests of fifty - eight sigma shaped members are reported. Specimen s were tested at various lengths to force global, distortional, and local buckling failure …