Engineering Commons^™

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 …

Distortional Buckling Of Cold-Formed Steel Z-Section Columns, P. Charnvarnichborikarn, Dimos Polyzois

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

Current North American guidelines for the design of cold-formed steel members consider the web of cold-formed steel sections under direct compression to be a fully stiffened element. This, however, may not be true if the flanges cannot provide sufficient restraint to the web. In this case, instability of the web element may cause distortional failure of the flange-edge stiffener component which may limit the load-carrying capacity of these sections with very little post-buckling strength being realized. In the present paper, the effect of web buckling on the load-carrying capacity of Z-sections with partially stiffened flanges is examined. The current design …

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.

Shah Alam Sports Complex Design And Construction Of Unistrut Space-Frame Roof Structure, Khaldoun Mhaimeed, Sun Chien Hsiao

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

The Shah Alam Sports Complex is a $100-million multiuse sports facility in Selangor, Malysia. The main feature of this complex is a 72000-seat multisport stadium. Seating on both sides of the stadium will be covered by a pair of barrel-vaulted acrylic sky roofs. Each roof is structurally supported by a Unistrut Space-Frame which in tum is supported at three of its four edges with a free span of 931 feet (284 m). The frame is cantilevered from the back 226 feet (69 m) over the seats. In this paper, design philosophy to satisfy serviceability and ultimate limit states is discussed. …

Calibration Of A Bending Model For Cold-Formed Sections, A. De Martino, A. Ghersi, Frederico M. Mazzolani

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

The calibration procedure of a numerical model based on the simulation of the moment-curvature relation for cold-formed steel beams is presented. The results of bending tests on beams with double-channel cross-section are used to assess the proper values to the parameters which quantify the model.

Observations And Comments Pertaining To Can/Csa-S136-M89, Aaron S. Dinovitzer, Majid Sohrabpour, R. M. Schuster

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

Contained in this paper are the results of two separate studies, namely, 1) partially stiffened compressive elements of both edge and single intermediate stiffened flanges and 2) deflection determination of multi-web deck profiles. Both of these studies were based on the Canadian cold formed steel design standard (CAN/CSA-S 136-M89), with the results also applicable to the AISI specification. In the case of partially stiffened compressive elements, discontinuities in effective width estimates for sections with similar flanges and stiffeners were observed, resulting from a sudden change in the behavioural states. Recommendations are presented to rectify this discontinuity and at the same …

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.

Some Applications Of Generalized Beam Theory, J. Michael Davies, Philip Leach

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

Generalised Beam Theory (GBT) has been developed by Professor R Schardt and his colleagues at the University of Darmstadt in Germany. The definitive reference at the present time is a recent German text(1) which describes the first-order theory. For the analysis of cold-formed sections, second-order theory may be required and this is less well documented. This paper will attempt to describe the principles involved and illustrate them by means of some practical examples. GBT unifies the conventional theories for the analysis of prismatic thin-walled structural members within a consistent notation. It then extends them into new territory. Conventional beam theory …

The Lateral Torsional Buckling Strength Of Cold-Formed Stainless Steel Lipped Channel Beams, P. Van Der Merwe, P. J. Bredenkamp, G. J. Van Den Berg

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

The findings of an investigation into the lateral buckling strength of cold-formed singly-symmetric stainless steel beams are reported in this study. The singly-symmetric sections under consideration were lipped channel sections fabricated from a modified AISI stainless steel Type 409 designated 3CR12, a ferritic corrosion resisting steel. The purpose of this study was to compare the experimental strengths of singly-symmetric sections to the theoretical predictions proposed by the new ASCE Specification for the Design of Cold-Formed Stainless Steel Structural Members. It was concluded in this investigation that the tangent modulus approach adopted in the design specification for stainless steels, compared well …

Testing And Design Of Bolted Connections In Cold Formed Steel Sections, F. Zadanfarrokh, E. R. Bryan

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

A detailed analysis of the strength and rigidity of bolted connections in cold formed steel has been carried out. Design expressions are proposed that improve on the existing equations for bearing strength, and for the first time, quantify the rigidity of such connections. The effects on the design of bolted joints are described and it is shown how, by incorporating the proposed expressions, it is now possible to select the correct semirigid joint and achieve economy without having to resort to testing.

Design Of C-Sections Against Deformational Lip Buckling, D. Buhagiar, J. C. Chapman, P. J. Dowling

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

Deformational lip buckling is one of the considerations affecting the choice of cross-section dimensions which were adopted for the C-sectlon chord members of a space frame system. No guidance on lip buckling of channel sections is given in the current British design specification. A method was therefore required for determining the lip buckling resistance of the members when subjected to axial compression or bending. A design procedure was formulated in which the lips are represented as a strut on an elastic foundation, the stiffness of which depends on the deformational stiffness of the section. The critical buckling stress and the …

New Asce Standards For Cold-Formed Steel Deck Slabs, Max L. Porter

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

This paper presents highlights of the newly approved and printed ASCE Standard on the design and construction of composite floor deck slabs utilizing cold-formed steel. In 1992 four documents are being published including the following: • "Standard for the Structural Design of Composite Slabs"--ASCE3-92, • "Standard Practice for Construction and Inspection of Composite Slabs"-ASCE9-92, and • A separate commentary on each of the two above Standards. These above four documents stem from a previously published ASCE Standard entitled "Specifications for the Design and Construction of Composite Slabs" and the associated commentary thereon. The Steel Deck with Concrete Committee of the …

Recent Developments In Cold Formed Steel, Robert W. Dannemann

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

During the last fifteen years the author has been working in the development of new products in cold formed steel, mainly in building applications. Cold formed steel makes possible practically an infinite variety of shapes, one for each need and function. This possibility is a continuous challenge for designers in finding, among many alternatives, the optimal solution for each problem. The author describes briefly a set of six proposals, which are either an already tested and proven product, or just its phase of design. As in any human doing, the author is conscious that these proposals may be accomplished and …

The 1989 Edition Of The Canadian Cold Formed Steel Design Standard, R. M. Schuster

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

This paper presents excerpts from the latest edition of the Canadian Standard for the design of cold formed steel structural members (CAN/CSA-SI36-M89). Considerable technical changes, reflecting the latest research developments, have been incorporated into this edition of the Standard. These changes are based on an increased understanding of the behaviour of cold formed steel structures, members, and elements and of cold formed steel as a structural material. Some of the more significant technical changes of the Standard are discussed in greater detail. Comparisons with the Standard's predecessor (CAN3-S136-M84), and whenever appropriate, with the 1986 AISI Specifications are also made.

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.

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.

A Gaze-Addressing Communication System Using Artificial Neural Networks, Gabriel Baud-Bovy

Dissertations and Theses

Severe motor disabilities can render a person almost completely incapable of communication. Nevertheless, in many cases, the sensory systems are intact and the eye movements are still under good control. In these cases, one can use a device such as the Brain Response Interface (BRI) to command a remote control (e.g. room temperature, bed position), a word-processor, a speech synthesizer, and so on.

The BRI is a gaze-addressing communication system that was developed by Dr. Erik E. Sutter at the Smith-Kettlewell Eye Research Institute, San-Francisco: a menu of communication objects (e.g. letter, word, command) is displayed on a TV screen; …

Thrust Vector Control Using Internal Airfoils, Eric J. Herup, Milton E. Franke, Jerold H. Friddell

AFIT Patents

A thrust vectoring exhaust nozzle structure for an engine, such as a ramjet, rocket or turbojet, which generates thrust by expulsion of gaseous fuel combustion products along a thrust axis is described which comprises a generally axisymmetric housing defined along a central thrust axis including a wall structure defining an exhaust duct, and an axially spaced radially inwardly convergent portion, throat and radically outwardly divergent portion, and at least one airfoil disposed on the wall structure of the divergent portion and mounted for rotation about an axis substantially perpendicular to the thrust axis.

Acuta Enews October 1992, Vol. 21, No. 10

ACUTA Newsletters

In This Issue

CMSU testing VISIT

President's message

A telecom intern's report

Annual ACUTA budget

Answers from "Regional Feud"

Membership Director's report

Short Pulse Generation Using Multisegment Mode-Locked Semiconductor Lasers, Dennis J. Derickson, R. J. Helkey, A. Mar, Judy R. Karin, J. G. Wasserbauer, J. E. Bowers

Electrical Engineering

No abstract provided.

Artificial Neural Networks For Robotics Coordinate Transformation, Stephen Aylor, Luis Rabelo, Sema E. Alptekin

Industrial and Manufacturing Engineering

Artificial neural networks with such characteristics as learning, graceful degradation, and speed inherent to parallel distributed architectures might provide a flexible and cost solution to the real time control of robotics systems. In this investigation artificial neural networks are presented for the coordinate transformation mapping of a two-axis robot modeled with Fischertechnik physical modeling components. The results indicate that artificial neural systems could be utilized for practical situations and that extended research in these neural structures could provide adaptive architectures for dynamic robotics control.

Waste-Surface Mapping Of The Fernald K-65 Silos Using A Structured Light Measurement System, B. L. Burks, Fred W. Depiero, M. A. Dinkins, J. C. Rowe, C. B. Selleck, D. L. Jacoboski

Electrical Engineering

During FY 1991, a remotely operated surface-mapping measurement system was developed by the Robotics & Process Systems Division at Oak Ridge National Laboratory for use in the K-65 waste-storage silos at Fernald, Ohio. The mapping system used three infrared line-generating laser diodes as illumination sources and three high-resolution, low-lux, calibrated, black-and-white, chargecoupled- device video cameras as receivers. These components were combined to form structured light source range and direction sensors with six different possible emitter-receiver pairs. A technology demonstration and predeployment tests were performed at Fernald during July and August 1991, using the empty Silo 4 into which was placed …

Morphology, Deformation, And Defect Structures Of Ticr2 In Ti-Cr Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston

Materials Engineering

The morphologies and defect structures of TiCr₂ in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr₂. The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking faul4 and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability.

Santa Clara Magazine, Volume 35 Number 1, Fall 1992, Santa Clara University

Santa Clara Magazine

11 - SENIOR SEMINAR Elderhostel brings a different kind of student to Santa Clara. By Christine Spielberger '69

14 - DAYS RICH WITH EMPTINESS A noted Catholic writer reflects on his annual retreat to a Trappist abbey, a respite from the daily stress of getting and spending. In a related article, he discusses "The Inner Experience," an unpublished book by Thomas Merton that examines the modern contemplative lifestyle. By Mitch Finley '73

22 - WHAT'S WRONG WITH THIS PICTURE? The image of an all -male Senate committee weighing the merits of Anita Hill 's charges against Clarence Thomas spurred a …

Ole Miss Engineer 1992

Ole Miss Engineer

No abstract provided.

The Calendar - October 1992, Nova University

The Calendar

No abstract provided.

Process And Policy: Resource-Bounded Non-Demonstrative Reasoning, Ronald P. Loui

All Computer Science and Engineering Research

This paper investigates the appropriateness of formal dialectics as a basis for non-monotonic and defeasible reasoning that takes computational limits seriously. Rules that can come into conflict should be regarded as policies, which are inputs to deliberative processes. Dialectical protocols are appropriate for such deliberations when resources are bounded and search is serial. AI, it is claimed here, is now perfectly positioned to correct many misconceptions about reasoning that have resulted from mathematical logic's enormous success in this century: among them (1) that all reasons are demonstrative, (2) that rational belief is constrained, not constructed, (3) that process and disputation …

Use Of High-Energy Radiation For Degradation Of Environmental Pollutants, Robert D. Guthrie, Manjiri Patwardhan

KWRRI Research Reports

The purpose of this project was to explore the advantages and/or limitations of high-energy radiation treatment as a method for degrading organic pollutants, particularly aryl halides, in an aqueous medium. We have done analyses of ⁶⁰Co-irradiated samples and kinetic studies using pulsed electron beams. For aryl halides containing no more than two fused rings, the main products detected are those of simple halogen replacement by hydrogen, although the amount of aryl halide destroyed was always greater than the total amount of products detected. To accomplish halogen replacement by H, the reaction solvent may not be pure water but must …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 8, Number 7, October 1992, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.