Civil and Environmental Engineering Commons^™

Design Provisions For Sections Containing Unstiffened Elements Under Stress Gradients, M. R. Bambach, Kim J. R. Rasmussen

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

Current American design provisions treat unstiffened elements under stress gradients as if they were uniformly compressed for effective width calculations. This paper presents a design method for calculating the effective width of these elements, based on plate test results. Current international codes allow the capacity of sections that contain unstiffened elements under stress gradients to be calculated on the basis of initiation of yielding in the section. A non-iterative method for the calculation of the capacity, based on inelastic reserve capacity, is presented. The method is shown to be in good agreement with experimental data of I-sections and plain channels …

Finite Element Modelling Of Stainless Steel Columns With Variation In Mechanical Properties, M. Macdonald, J. Rhodes

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

This paper describes the results obtained from a finite element investigation into the column capacity of Type 304 stainless steel column members of lipped channel cross-section. Stress-strain curves derived from tests were incorporated into non-linear finite element analyses of eccentrically loaded stainless steel columns. The results obtained are compared with test results on stainless steel channel columns with the same properties and dimensions, and also with design code predictions.

The Behaviour Of Drive-In Storage Structures, M. H. R. Godley

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

The paper describes the behaviour of Drive-in and Drive-thru pallet rack structures. It proposes a number of simplified two-dimensional models for the analysis of such structures. These models are shown to be conservative and take account of the non-linear behaviour of the structures. The paper makes some comparisons between the output from these and a 3-D finite element program. The effects of friction between the pallet and the supporting rail is discussed briefly.

Optimum Design Of Cold-Formed Steel Z-Shape Purlins Using A Genetic Algorithm, Wei Lu, Pentti Makelainen, Jyrki Kesti

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

In this paper, a genetic algorithm is applied to optimize the dimensions of cold-formed Z-shape purlins continuous over two spans under gravity load. The optimization criterion is to maximize the load resistance per cross-section and the design variables are chosen from the discrete values based on the manufacturing requirements. Purlins are designed in accordance with Eurocode 3, Part 1.3. In addition, the modified Eurocode 3 method, in which the elastic local buckling stress and distortional buckling stress calculated using Finite Strip Method (FSM) are integrated into the design process, is used to determine the effective section properties. The results are …

Self-Drilling Screw Joints For Cold-Formed Channel Portal Frames, Julie Mills, Roger A. Laboube

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

Cold-formed C channel sections have been used in portal frame construction for agricultural sheds for many years in Australia. The knee joint designs have been copied from hot-rolled portal frames, regardless of the fact that many designers believe this is not realistic. Earlier testing conducted at the University of South Australia demonstrated that these concerns were justified and that the joint designs widely used in practice do not match the moment capacity of the sections and fail prematurely. An alternative joint design has been developed using self- drilling screws. The joint demonstrates excellent moment capacity and rigidity, and is simple …

Strength And Behavior Of Flare-Bevel And Flare-Vee Welded Connections In G450 Sheet Steel, Lip H. Teh, Gregory J. Hancock

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

G450 steel to AS 1397 is a cold-reduced sheet steel with in-line galvanizing. Its grade is 65 ksi (450 MPa) yield and 70 ksi (480 MPa) tensile strength. It is widely used in Australia for purlins, and is being used to fabricate light-weight portal frames, often by welding. The effect of welding on G450 sheet steel in the heat affected zone (HAZ) was unknown and so the project was performed to investigate the strength of flare-bevel and flare-vee welded connections. Flare-bevel and flare-vee welded connections in 0.06-in (1.5-mm) and 0.12-in (3.0-mm) sheet steels were tested to failure. The failure modes …

Compression Tests Of Cold-Reduced High Strength Steel Stub Columns, Demao Yang, Gregory J. Hancock

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

This paper describes a series of compression tests performed on stub columns fabricated from cold-formed high strength steel plates with nominal yield stress of 550 MPa. (80 ksi) The steel is classified as G550 to Australia Standard AS 1397. The test results presented in this paper are the first stage of an Australian Research Council research project entitled "Compression Stability of High Strength Steel Sections with Low Strain-Hardening". The tests include lipped-square and hexagonal sections, including 94 box-shaped fix-ended stub columns. The purpose of these tests was to determine the influence of low strain hardening of G550 steel on the …

Plastic Strength Of Thin-Walled Members, Dan Dubina, Viorel Ungureanu

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

Failure of thin-walled cold-formed members in compression is always characterized by a local plastic mechanisms, either a stub or slender column is referred. Starting from this observation, the authors suggest for the interactive local-overall buckling analysis to use instead of traditional "effective section", the sectional plastic mechanism strength. This is a new approach and for this reason it is compared with another one, namely the Direct Strength Method. Experimental results and advanced FEM simulations are used to evaluate the two methods. Comparisons with European and American relevant design codes are also presented in the paper.

Application Of A Finite Element Model To A Cold-Formed Steel C-Section With A Bearing Stiffener, G. W. Brodland, S. R. Fox

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

Described in this paper is the application of a finite element model to a cold-formed steel C-section with a bearing stiffener installed between its flanges. This model has been used to determine both the web crippling capacity of the joist, and the forces that develop in the fasteners connecting the bearing stiffener to the joist. The finite element model was also used to carry out parametric studies of the stiffened joist assembly to determine the impact on the web crippling capacity and the fastener forces caused by variations in the assembly. Based on the results of these finite element studies, …

Study Of Innovative Built-Up Cold-Formed Beams, Gianmaria Di Lorenzo, Raffaele Landolfo

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

In the present work innovative built-up cold-formed steel beams are presented. These are obtained by combining the pressing and cold-rolling forming techniques of steel sheets, along with the use of suitable connecting systems. Firstly, the beam shape features and the possible application fields, as well as the research project devoted to the assessment of their structural behaviour, are discussed. Then, experimental results concerning the characterization of both sheet material properties and connecting system performances are shown. In particular, the study of the sheet material is carried out by using an appropriate methodology of analysis, aiming at evaluating both mechanical and …

Effective Widths Of Unstiffened Elements Under Combined Compression And Bending, M. R. Bambach, Kim J. R. Rasmussen

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

Details of a dual-actuator rig developed for testing rectangular plates simply supported on three sides, with the remaining (longitudinal) edge free, under combined uni-axial compression and in-plane bending are presented. Particular attention is given to ensuring a constant strain eccentricity to the loaded ends, as opposed to a constant load eccentricity, in order to determine the post-buckling behavior and ultimate load and moment capacities of unstiffened thin-walled elements. Strain gradients varying from pure compression to pure bending are facilitated. The plate test results are presented in the form of strength curves, and are used to establish effective width equations for …

Interim Design Rules For Flexure In Cold-Formed Steel Webs, Benjamin W. Schafer, T. W. J. Trestain

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

The design of cold-formed steel webs in flexure is governed by section B2.3 of the AISI Specification. Harmonization of the AISI (1996) Specification with the Canadian Standard (S136 1994), for the development of the new North American Specification (NAS 2001) has brought to light shortcomings in both the U.S. and Canadian documents and lead to the adoption of an interim design approach in the NAS (2001). The interim approach employs the AISI (1996) rules for one class of members and the S136 (1994) rules for a second class. Assessment of the resulting method with existing bending tests on Cees and …

Web Crippling Of Cold-Formed Steel Members, B. Beshara, R. M. Schuster

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 (NAS 2001) has recently adopted a new web crippling approach, which is the approach contained in the Canadian S136 Standard (CSA 1994). The objective of this work was to develop new design coefficients for the web crippling strength design expression currently used in the Canadian S136 Standard (CSA 1994) and the North American Specification (NAS 2001). An extensive statistical analysis was performed using published test data up to 1999, from the United States, Canada and Australia. The resulting web crippling coefficients, calibrated resistance factors and respective factors of …

Adaptive Nonlinear Finite Element Analyses Of High Strength Steel Cladding Systems, M. Duan, Mahen Mahendran

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

In this paper, an adaptive nonlinear finite element method was developed and applied to the ultimate strength analysis of light gauge high strength steel cladding. Effect of mesh refinement on the solution accuracy was investigated for the nonlinear analysis of steel cladding systems under wind uplift loading. A comparison of numerical solutions was made with experimental results and a good agreement is shown using the adaptive finite element method. A parametric study was also conducted to investigate the factors that affect the ultimate strength behavior of high strength steel cladding systems. This paper presents the details of this study and …

Standard Test Method For Determining The Web Crippling Strength Of Cold-Formed Steel Members, Roger A. Laboube, R. Schuster

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

No abstract provided.

Standard Test Method For Determining The Web Crippling Strength Of Cold-Formed Steel Members, R. M. Schuster, Roger A. Laboube

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

No abstract provided.

Introducing Molecular Biology To Environmental Engineers: Through Development Of A New Course, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The introduction of a course "Molecular Methods in Environmental Engineering" is discussed. The course is developed to address the growing national need for integrating geonomics and molecular biology into the engineering curriculum. Fifteen graduate students were successfully introduced to molecular biology through lectures and hands-on laboratory excercises following the "full-cycle 165 rRNA approach". The course helps in providing supportive and independent learning environment to the students.

Calibrattions Of Cold-Formed Steel Welded Connections, F. M. Tangorra, R. M. Schuster, Roger A. Laboube

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

The purpose of this project was to recalibrate the welded connection equations currently contained in the American Iron and Steel Institute (AISI) Specification for the Design of Cold Formed Steel Structural Members (AISI 1996a). Only one factor of safety of 2.50 is presented for the each of the various types of welded connections when using allowable stress design (ASD), but different respective resistance factors are given for load and resistance factor design (LRFD). The data used was solely taken from the research conducted by Pekoz and McGuire (Pekoz and McGuire 1979). Calibrations were carried out and based on both the …

A Study On The Factors That Influence The Acoustic Performance Of A Steel Stud Wall Assembly, Hyun-Suk Chung, Gap-Deug Kim, Kwan-Seob Yang, Kyung-Woo Kim

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

With the recent introduction of light gauge steel framing systems in the concrete-dominated Korean construction industry, more buildings are built with drywall that is mainly composed of steel studs and gypsum boards. While load-bearing steel studs are extensively applied in residential construction, nonload-bearing steel studs are applied in various building fields such as commercial, educational, as well as residential. As building projects involving steel stud walls are becoming to increase, higher demands in performance are requested from architects and builders, especially in the field of sound performance. A series of acoustic test were performed in the nationally certified sound-testing laboratory …

Aisi Committee On Framing Standards Enabling The Widespread And Economic Useof Steel Framing, Kevin R. Bielat, Jay W. Larson

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

The American Iron & Steel Institute launched the Committee on Framing Standards in 1998 with the mission to eliminate regulatory barriers and increase the reliability and cost competitiveness of cold-formed steel framing through improved design and installation standards. Building on the internationally recognized AISI Specification, and working closely with the Steel Framing Alliance, Light Gauge Steel Engineers Association, Steel Stud Manufacturers Association and Canadian Sheet Steel Building Institute, this relatively new organization has developed and published four new ANSI-accredited consensus standards. Topics include General Provisions, Truss Design and Header Design, as well as a comprehensive Prescriptive Method for One and …

North American Specification For Design Of Cold-Formed Steel, Roger L. Brockenbrough, Helen H. Chen

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

For over fifty years, the American Iron and Steel Institute has published the widely used Specification for the Design of Cold-Fom1ed Steel Structural Members. Recently, as a result of collaborative efforts with representatives of Canada and Mexico, the AISI Specification was expanded into a new document for use in all three countries. Now known as the North American Specification for the Design of Cold-Formed Steel Structural Members, the new edition supersedes the previous AISI Specification and the Canadian Sl36 Standard. This paper reviews the differences between the previous AISI Specification and the new North American Specification. The basic core document …

Ccfss Technical Bulletin August 2002, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Ccfss News August 2002, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Evaluation And Carbon Fiber Reinforced Polymer Strengthening Of Existing Garage: Case Study, Milan Vatovec, Paul L. Kelley, Tarek Alkhrdaji, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The concrete-repair fiber reinforced polymer technology emerged in the United States during the past 10 years. Since 1995, carbon fiber reinforced polymer (CFRP) has been applied to strengthen concrete decks of a troubled posttensioned garage in Atlanta. During the construction of the garage, design deficiencies were found. A remedial repair, involving heavily reinforced, 7.6 cm (3 in.) thick Gunite (Shotcrete) beams, applied to the underside of the slab between drop panels in the east-west (E-W) direction, was developed in 1984. Since then, delamination of Gunite beams and other structural problems repeatedly occurred. Epoxy injection and other limited repairs were done …

Strength And Modulus Degradation Of Carbon Fiber-Reinforced Polymer Laminates From Fiber Misalignment, Xinbao Yang, Antonio Nanni, Stephen B. Haug, Chung Leung Sun

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber-reinforced polymer (FRP) laminates are being used as external reinforcement for strengthening concrete members. The performance of unidirectional FRP laminates is highly dependent on fiber orientation with respect to applied load direction. In the case of fabrication by manual layup, it is possible to have fiber plies installed with improper orientation. In this project, the degradation of strength and modulus of carbon FRP laminates from fiber misalignment was investigated experimentally using tensile coupons. The specimens consisted of one and two plies of unidirectional carbon FRP impregnated with a two-component epoxy. The misalignment angles varied from 0 to 40° for the …

Performance Of Cold-Formed Steel-Framed Shear Walls: Alternative Configurations, Kelly A. Morgan, Mark A. Sorhouet, Reynaud Serrette

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

This report presents the results of twenty shear wall tests that were conducted to evaluate the performance of wall configurations not currently (2002) permitted in the building codes. Ten (10) walls were evaluated under reversed cyclic loading and the other ten (10) under monotonic loading. Brief descriptions of the test program and results are presented in the following paragraphs. The reversed cyclic load tests comprised 4 ft. x 8 ft. 54- and 68-mil framed walls with 7/16-in. OSB rated sheathing on one or both sides of the wall and 33-mil framed walls with 27-mil sheet steel. The sheet steel wall …

Principles Of Biology In Environmental Engineering: Molecular Biology-Based Identification Of Microorganisms, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The various aspects of a course on use of technology from molecular biology to screen microorganism in environmental samples and to monitor microbial biocatalysts in reactors, is discussed. The objective of the course is to teach students to adapt techniques from molecular biology to address important issues in environmental engineering. In case of methanogens, design considerations in environmental engineering include stabilization of sewage sludge through anaerobic digestion and wastewater treatment. The hands-on format encourages students to develop scientific questions, learn appropriate methodology, conduct careful experimentation, and draw conclusions worthy of presentation.

Formal Engineering Of Residential Buildings, Joseph E. Minor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The performance of residential buildings during hurricanes is as important as the performance of other buildings. Buildings where people live and where they are likely to be when a hurricane strike must survive. If this premise is accepted, it follows that residential buildings should be afforded a degree of engineering attention that is commensurate with that given to industrial and commercial buildings. Building code authorities have not been blind to this need. In new procedures adopted for hurricane zones in the United States, common sizes and geometric shapes of timber and masonry residential buildings are formally engineered, and associated construction …

Standard For Cold-Formed Steel Framing -- General Provisions, American Iron And Steel Institute

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

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included in the General Provisions document. With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. …

Standard For Cold-Formed Steel - General Provisions, American Iron And Steel Institute

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

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included in the General Provisions document.

With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. …