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Unstiffened Elements - Some Interesting Features, J. Rhodes

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

The behaviour of members composed of unstiffened elements is examined with reference to three different sets of test results, on angle section struts, Tee section beams and shallow Vee section beams. The test results are explained on the basis of fairly simple analysis, and the variations of the behaviour from that predicted by modem design codes is discussed.

Recent Research And Developments In Cold-Formed Steel Design And Construction, Wei-Wen Yu, Roger A. Laboube

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

Unstiffened Elements - Some Interesting Features - Tests of Profiled Steel Decks with V-Stiffeners - Bending Strength of Beams with Non-Linear Analysis - Local and Distortional Buckling of Thin-Walled Beams - Design of C-Sections Against Deformational Lip Buckling - Lateral Buckling of Singly Symmetric Beams - Flexural Capacity of Discretely Braced C's and Z's - The Buckling Behaviour of Hollow Flange Beams - Experimental Investigations of I-Beams - Tests of Continuous Purlins Under Downwards Loading - Tests of Full-Scale Roofing Systems - Profiled Sheet Behaviour Under Concentrated Load - On Design of Profiled Sheets with Varying Cross Sections - Properties …

Prediction Of Corner Mechanical Properties For Stainless Steels Due To Cold Forming, P. Van Der Merwe, G. J. Van Den Berg

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

The results of a study of the degree of workhardening on stainless steel Types 304, 409, 430 and Type 3CR12 corrosion resisting steel due to cold work of forming are presented in this paper. Analytical inelastic stress-strain relationships are established for virgin tensile specimens. An equation for predicting the yield strength of comers are developed.

Stainless Steel Tubular Beams - Tests And Design, Gregory J. Hancock, Kim J. R. Rasmussen

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

The paper presents tests on square and circular stainless steel tubular beams. An important part of the test programme was to quantify the increase in bending strength resulting from cold-work during the fabrication process. Tension and compression tests on coupons cut from finished tubes were also included in the test programme. Stress-strain curves for shear were obtained using the coupon test results and the concept of affinity factors. A design method is proposed for stainless steel tubular beams. The method incorporates the increase in strength produced by the cold-rolling process and is validated by comparing it to the test strengths. …

Influence Of Deformed Metal Decking Composite Floors To Beam-Column Connections, Y. Xiao, D. A. Nethercot, B. S. Choo

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

A series of tests designed to investigate the interaction of a variety of different steel beam to column connection details with a composite metal deck floor is described. The main emphasis is on assessing the connections' moment capacity, rotational stiffness and rotation capacity. The full details of the experimental behaviour of the flush end plate and partial depth end plate connections will be described in this paper. A simple method for moment capacity calculation based on the test results is proposed herein.

The Bi-Axial Behaviour Of Shear Connectors In Composite Slabs And Beams, Chris T. Duffy, David O'Leary, Michel Montourcy

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

The use of composite beams which utilise steel beams together with a composite steel sheet/concrete floor slab is well developed. Many forms of steel profile are used and the form of attachment to the steel beam is generally by welded shear studs or shot-fired shear connectors. The design procedures for these beams require a knowledge of the shear capacity of the connectors which may be influenced by the type of profile being used for the beam. This shear capacity is often deduced from information obtained from standard push-off tests which mayor may not include in the test set-up the actual …

Activities Of The Center For Cold-Formed Steel Structures, Wei-Wen Yu, Roger A. Laboube

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

The Center for Cold-Formed Steel Structures was established at the University of Missouri-Rolla in May 1990 under the sponsorship of the American Iron and Steel Institute and the University of Missouri-Rolla. This paper summarizes the activities performed at the Center during the past two years.

Bending Strength Of Beams With Non-Linear Analysis, Pekka Salmi, Asko Talja

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

Bending strengths of open cross-section beams cold-formed from high-strength steel (HSS) are determined with non-linear analysis. Two kinds of beams are studied. The short beams are for examining the bending resistance of cross-sections and the long beams for studing the lateral buckling of open sections. The beams are modelled with shell elements and non-linear FEM analyses are carried out to predict the strengths of the models. Both material and geometrical non-linearities are included in the analyses. The results are compared with experimental results.

Local And Distortional Buckling Of Thin-Walled Beams, Reynaud Serrette, Teoman Pekoz

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

Recent research has characterized the behavior of panel beams with laterally unsupported compression flanges as either a complex local buckling mode or an overall buckling mode. Tests have shown that the behavior of the unsupported flange and web is similar to that of lateral buckling, except, rotation is enforced along the axis of the web and the tension flange--a behavior which may be described as distortional buckling. In the work described here, an analytical expression is presented for computing the elastic distortional buckling stress based on a model which treats the web and compression flange as an elastically restrained beam. …

Experimental Investigations Of I-Beams, Shang-Jian Chen, Shan-Feng Fang

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

I - beams made of cold - formed thin - walled channels, back to back, can be connected by resistance spot welding or arc-welding. Both stability and ultimate strength of these beams are different for welding method. The stability can be increased provided several battens are attached on the open sections of these beams.

Lateral Buckling Of Singly Symmetric Beams, Teoman Pekoz

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

General solutions for the elastic lateral buckling moment of singly symmetric sections are studied. The studies include the effect of the location of the load on the section as well as the effect of moment gradients on the lateral buckling moment. Design provisions are outlined for the case of moment gradients.

Tests On Full-Scale Roofing Systems, D. B. Moore

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

This report details an experimental investigation on three full-scale, cold-formed steel roofing systems. The test programme included both uniformly and variably distributed loadings representative of drifting snow. Comparisons between the performance of each roof subject to these distributions are made and recommendations for the design of roofs loaded with variably distributed loads are presented. Finally observations on the tests to failure are discussed.

Contrasting Behaviour Of Thin Steel Roof Claddings Uder Simulated Cyclonic Wind Loading, Mahen Mahendran

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

During an investigation on thin steel roof claddings under simulated cyclonic wind loading, it was found that trapezoidal roofing behaved quite differently to corrugated roofing due to the presence of overload cycles. This paper examines this contrasting behaviour of these two roofing profiles.

On Design Of Profiled Sheets With Varying Cross Sections, Laszlo Horvath, Miklos Nemeti, Bela Veroci

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

A short review is given on the effective width concept and about its use for determining of the moment capacity of sheets. A modified method, taking into account the varying flexural rigidity along the spans, is described and illustrated on examples carried out on first -generation panels.

Profiled Sheet Behaviour Under Concentrated Load, Mohsen M. Salaheldin, Lweis C. Schmidt

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

The behaviour of profiled sheets under concentrated static load is discussed. The effect of aspect ratio and the depth of the sheet on the redistribution of stresses is investigated. The stress concentration caused by the concentrated load can lead to an anomalous pattern of behaviour, where local plastic failure occurs at lower loads in shorter spans rather than in longer spans.

Properties For Cellular Decks In Negative Bending, K. Balaji, Larry D. Luttrell

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

Cellular roof and floor decks may be formed by attaching essentially flat sheets to a "hat-shapes" or to fluted profiles by spot welding along the contact lines. This leads to a closed cellular deck unit suitable for such purposes as in-floor power distribution or communication systems. In positive bending, or when the flat sheet is in tension and stable, cellular deck flexural properties can be determined following the American Iron and Steel Institute Cold Formed Steel Design Manual. When the flat sheet is in compression, its contribution is not described in the AISI Manual since it is not continuously connected …

Composite Slabs Analyzed By Block Bending Test, Li An, Krister Cederwall

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

A new small-scale test, concrete block bending test, was carried out to determine the amount of shear stress and the slip distribution at the interface between the steel sheet and the concrete. The result was then used in the finite element analysis to predict the behaviour of composite slabs. Good agreement has been shown between the analytical results and measured results from the full-scale composite slabs.

Repeated Point Loading Tests On Composite Slabs, Yoshimitsu Itoh, Kiyoshi Komori, Hiroshi Fujioka

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

Single span and double span composite slab specimens were tested by subjecting them to concentrated repeated point loading. From the test results, it was found that the control of concrete cracks caused by the negative moment over the interior support is important in the latter case.

Thermal Shielding Near Intermediate Supports Of Continuous Span Composite Slabs, Kees Both, Leen Twilt, Jan W. B. Stark

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

At TNO Building and Construction Research, in close co-operation with the Eindhoven University of Technology, research is carried out on the behaviour of fire-exposed composite steel/concrete slabs, in the framework of a research project co-sponsored by the ECSC (European Community for Steel and Coal). The paper describes the state of the art of the research project.

Design Of Channels Against Distortional Buckling, Y. B. Kwon, Gregory J. Hancock

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

Thin-walled lip-stiffened channel columns composed of high strength steel may fail in a distortional mode involving movement of the lip stiffener perpendicular to the flange plate it supports. In this report, test results for a simple lipped channel section(CH1) and an intermediate stiffened channel section (CH2) of thickness of approximately 1.1 mm (0.043 in) and 550 MPa (79.8 ksi) steel and undergoing distortional or mixed local-distortional buckling failure are compared with different design methods. The design methods compared are Australian Standard AS1538, EC3 Partl/ Annexe A, the ECCS Recommendations and the AISI Specification. In addition, new methods based on a …

Flexibly Connected Thin-Walled Space Frame Stability, Sundar Chandramouli, Shien T. Wang, George E. Blandford

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

The elastic stability of a cubic space frame composed of cold-formed steel members is studied for various bending and warping rigidities. A finite element technique is used to perform a parametric study of the elastic stability response of the flexibly connected frame. The results are compared with previously published observations for hot-rolled steel sections. The criterion used for deciding the significance of warping for hot-rolled sections is not found to be applicable to cold-formed sections.

Fault-Tolerant Distributed Deadlock Detection / Resolution, Pei-Yu Liu, Bruce M. Mcmillin

Computer Science Technical Reports

The problem of deadlock detection in a distributed system has been extensively studied in the past few years. Many algorithms on distributed deadlock detection have been proposed under the assumption that the processors and communication in the system are fault-free. However, in an unreliable distributed system, faulty processors may prevent a deadlock detection algorithm from properly detecting deadlocks. Few of the algorithms proposed in the literature address the issue of handling process failures in a distributed system. This paper proposes a fault-tolerant distributed deadlock detection algorithm which integrates a priority-based probe algorithm with a PMC-based diagnosis model. This algorithm detects …

The Missouri Miner, October 14, 1992

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, October 07, 1992

The Missouri Miner Newspaper

No abstract provided.

Relaxing Synchronization In Distributed Simulated Annealing, Chul-Eui Hong, Bruce M. Mcmillin

Computer Science Technical Reports

Simulated annealing is an attractive, but expensive, heuristic for approximating the solution to combinatorial optimization problems. Since simulated annealing is a general purpose method, it can be applied to the broad range of NP-complete problems such as the traveling salesman problem, graph theory, and cell placement with a careful control of the cooling schedule.

Attempts to parallelize simulated annealing, particularly on distributed memory multicomputers, are hampered by the algorithm’s requirement of a globally consistent system state. In a multicomputer, maintaining the global state S involves explicit message traffic and is a critical performance bottleneck. One way to mitigate this bottleneck …

A Process-Learning Pid Controller Algorithm Utilizing An On-Line Iterative Improvement Technique, Ryan Rosandich, Ralph W. Wilkerson

Computer Science Technical Reports

Three iterative improvement algorithms are presented for the determination of process controller gains. An offline algorithm is developed and tested as a basis for comparison, and a simple on-line algorithm is developed as an incremental step toward the final algorithm, proportional on-line iterative improvement. The algorithms are based on an Artificial Neural Network learning method, and this method is compared with other control optimization techniques. The performance of each of the algorithms was experimentally evaluated in numerous realistically simulated process control situations consisting of flow, level, and temperature control loops with various values of dead-time and process noise. The experimental …

Ecological Evaluation Of Proposed Dredged Material From Richmond Harbor, M. R. Pinza, J. A. Ward, H. L. Mayhew, J. Q. Word, Dev Niyogi, N. P. Kohn

Biological Sciences Faculty Research & Creative Works

During the summer of 1991, Battelle/Marine Sciences Laboratory (MSL) was contracted to conduct sampling and testing of sediments proposed for dredging of Richmond Harbor, California. The MSL collected sediment cores to a depth of [minus]40 ft MLLW ([minus]38 ft + 2 ft over depth) from 28 (12-in. core) and 30 (4-in. core) stations. The sediment cores were allocated to six composite samples referred to as sediment treatments, which were then subjected to physical, chemical, toxicological, and bioaccumulation testing. Physical and chemical parameters included grain size, total organic carbon (TOC), total volatile solids (TVS), oil and grease, total petroleum hydrocarbons (TPH), …

Axial Load Capacity Of Sheeted Cold-Formed C And Z Members, Neil J. Glaser, Richard C. Kaehler, James M. Fisher

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

No abstract provided.

State-Selective Capture In Collisions Of Protons With Noble Gases, Michael Schulz, D. M. Blankenship, S. W. Bross, A. D. Gaus, Timothy Gay, W. T. Htwe, John T. Park, Jerry Peacher

Physics Faculty Research & Creative Works

We have measured coincidences between neutral H atoms and Lyman-α photons for collisions between 50-keV protons and noble gases as a function of the projectile scattering angle. The coincidences are dominated by capture to the 2p state of the projectile. While the total cross sections depend strongly on the target, the shape of the angular distribution of the differential cross sections was found to depend only weakly on that parameter. The data indicate that electrons are captured predominantly from the outermost shell of the target atom for the collision systems studied here.

The Effect Of Additives On The Nucleation And Growth Of Copper Onto Stainless Steel Cathodes, M. Sun, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

A potentiostatic technique has been used to study the effects of chloride ion, glue, and thiourea on the initial electrodeposition of copper. A stainless steel (AISI 304) rotating disc electrode (RDE) with an electrolyte containing 40 g/1 Cu²⁺ and 180 g/1 H₂SO₄ at 40 °C was employed. The current transients from the potential step measurements for the additive-free electrolyte could be fitted to a model that assumed progressive nucleation followed by growth of three-dimensional (3-D) centers under diffusion control. The growth mechanism and the type of nuclei were also confirmed by scanning electron microscopy (SEM) of …