Load and resistance factor design of cold-formed steel: Calibration of the AISI design provisions

In the design of steel buildings, the Allowable Stress Criteria have long been used for the design of cold-formed steel structural members in the United States and other countries.\u27 In view of the fact that the mathematical theory of probability, which has been so successfully applied in other fields of engineering, would seem to be equally applicable to cold-formed steel design by providing a more uniform degree of structural safety, the Limit State Design method based on the probabilistic concept has been used in Canada and Europe for the design of cold-formed steel structural members.\u27 In the United States, a research project on Load and Resistance Factor Design of Gold-Formed Steel Members was condudted by Rang, Supornsilaphachai, Snyder, Pan, Galambos, and Yu during the period from 1979 through 1985. The tentative load and resistance factor design (LRFD) criteria for cold-formed structural members were proposed in the Seventh Progress Report\u27 on the basis of the 1980 Edition of the AISI allowable stress design specification. In 1986, a major revision was made in the AISI Specification to reflect the results of recent research projects and improvements in design techniques. Consequently, the tentative LRFD criteria proposed in the Seventh Progress Report were revised in 1987. This progress report contains the calibrations of the AISI design provisions included in the 1986 Specification. The procedures used for calibration are summarized in Article II. Articles Ill through XI deal with (a) bending strength, (b) web crippling of beams, (c) combined bending and web crippling, (d) concentrically loaded compression members, (e) combined axial load and bending, (f) welded connections, (g) bolted connections, (h) stiffeners, and (i) wall studs and wall stud assemblies. The results of these calibrations will be used in the revision of the proposed LRFD Specification for cold-formed steel structural members

Load and resistance factor design of cold-formed steel load and resistance factor design specification for cold-formed steel structural members with commentary

FOREWORD This progress report contains the following two parts: Part I: Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. i-107). Part II: Commentary on the Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. 109-161). The load and resistance factor design specification proposed herein is the revised version of the design recommendations prepared in February 1988 and submitted to American Iron and Steel Institute as Tenth Progress Report. This document was prepared according to the 1986 edition of the AISI Specification for the Design of Cold-Formed Steel Structural Members. The selections of ϕ factors are discussed in the Commentary for various types of structural members and connections. This investigation was sponsored by American Iron and Steel Institute. The technical guidance provided by the AISI Subcommitte on Load and Resistance Factor Design and the AISI Staff is gratefully acknowledged. Members of the AISI Subcommitte are: K. H. Klippstein (Chairman), R. Bjorhovde, D. S. Ellifritt, S. J. Errera, T. V. Galambos, B. Hall, D. H. Hall, R. B. Heagler, N. Iwankiw, A. L. Johnson, D. L. Johnson, A. C. Kuentz, A. S. Nowak, T. B. Pekoz, C. W. Pinkham, R. M. Schuster, and W. W. Yu. Former members of theAISI Task Group on LRFD included R. L. Cary, N. C. Lind, R. B. Matlock, W. Mueller, F. J. Phillips, D. S. Wolford and Late Professor G. Winter. Special thanks are extended to T. V. Galambos, Consultant of the project, T. N. Rang, B. Supornsilaphachai, B. K. Snyder, L. C. Pan, and M.K. Ravindra for their contributions to the project

Load and resistance factor design of cold-formed steel load and resistance factor design specification for cold-formed steel structural members with commentary

FOREWORD This progress report contains the following two parts: Part I: Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. i-101). Part II: Commentary on the Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. 103-148). The load and resistance factor design specification proposed herein is the revised version of the design recommendations prepared in September 1985 and submitted to American Iron and Steel Institute as Seventh Progress Report. This document was prepared according to the 1986 edition of the AISI Specification for the Design of Cold-Formed Steel Structural Members. The selections of ϕ factors are discussed in the Commentary for various types of structural members and connections. This investigation was sponsored by American Iron and Steel Institute. The technical guidance provided by the AISI Subcommittee on Load and Resistance Factor Design and the AISI Staff is gratefully acknowledged. Members of the AISI Subcommittee are: K. H. Klippstein (Chairman), R. Bjorhovde, D. S. Ellifritt, S. J. Errera, T. V. Galambos, B. Hall, D. H. Hall, R. B. Heagler, N. Iwankiw, A. L. Johnson, D. L. Johnson, A. C. Kuentz, A. S. Nowak, T. B. Pekoz, C. W. Pinkham, R. M. Schuster, and W. W. Yu. Former members of the AISI Task Group on LRFD included R. L. Cary, N. C. Lind, R. B. Matlock, W. Mueller, F. J. Phillips, D. S. Wolford and Late Professor G. Winter. Special thanks are extended to T. V. Galambos, Consultant of the project, T. N. Rang, B. Supornsilaphachai, B. K. Snyder, L. C. Pan, and M. K. Rarindra for their contributions to the project

Load and resistance factor design of cold-formed steel reliability based criteria for cold-formed steel members

In the design of steel buildings, the Allowable Stress Design (ASD) method has long been used for cold-formed steel structural members in the United States and other countries. In this approach, member forces, or moments, determined on the basis of working loads should not exceed the allowable values. The allowable value is used to prevent the possible structural failure by using an appropriate factor of safety selected primarily on the basis of engineering judgment and long-time experience. Recently, in the United States, the concepts of risk and reliability analysis have been successfully applied to the Load and Resistance Factor Design criteria for steel buildings using hot-rolled shapes, and built-up members fabricated from steel plates. In order to develop reliability based design criteria for cold-formed steel members, a joint research project entitled Load and Resistance Factor Design (LRFD) of Cold-Formed Steel was conducted at the University of Missouri-Rolla, Washington University, and the University of Minnesota. This study included the selection of a reliability analysis model; the evaluation of load factors; the calibration of the design provisions; the determination of resistance factors; the comparative study of design methods for cold-formed steel; and the preparation of the LRFD design manual for cold-formed steel. However, only the development of the reliability based design criteria, and the comparative study of design methods for cold-formed steel are discussed in this dissertation