Civil Engineering Study 84-1
INTRODUCTION In recent years, high strength steels have been used in automotive structural components to achieve weight reduction while complying with Federal safety standards. The current design recommendations, the "Guide for Preliminary Design of Sheet Steel Automotive Structural Components" 1 was issued by American Iron and Steel Institute (AISI) in February 1981. It was recommended for application to materials with yield strength up to 80 ksi. These design expressions are based primalily on the 1968 Edition of the AISI "Specification for the Design of Cold-Formed Steel Structural Members" 2 which was written for the design of buildings. The AISI Specification was revised in 1980. 3 Some of the design criteria were revised and others were added in keeping with technical developments and the results of continued research programs sponsored by the American Iron and Steel Institute. Furthermore, in view of the fact that many types of high strength steels with yield strengths from 80 to 190 ksi 4-8 are now used for automotive structural components, a comprehensive design guide is highly desirable. Since early 1982, a research project entitled "Structural Design of Automotive Structural Components Using High Strength Sheet Steels" has been conducted at the University of Missouri-Rolla under the sponsorship of the American Iron and Steel Institute. The main purpose of this project has been to develop additional design criteria for the use of a broader range of high strength steels in automotive structures 9,10. The strength of beam webs is one area that has been studied as a part of this research project and was discussed previously in the Third Progress Report 10, which was published in August 1983. Previous study was based on the tests conducted by Levy 5 and Vecchio 6 for the following design considerations 4: 1. Moment resisting capacity 2. Bending capacity of webs 3. Shear capacity of webs 4. Combined bending and shear in webs 5. Web crippling 6. Combined bending and web crippling. Also included in the Third Progress Report was a proposal for an additional experimental study on web crippling of hat sections and I-beams with material yield strengths ranging from 55.8 to 141.2 ksi. Since the issuance of the Third Progress Report, the possible development of design equations for web crippling under interior one-flange loading condition of single unreinforced webs has been continued. There have been some changes in the additional web crippling tests as proposed in the Third Progress Report. According to the recommendations of the AISI Task Force on Structural Research of the Transportation Department, the 80DF and the 80SK sheet steels have been omitted. This experimental program were completed in June 1984. After the evaluation of test data, new equations for the prediction of web crippling loads for single unreinforced webs under interior one-flange loading and end one-flange loading conditions were developed. The purpose of this report is to summarize and discuss the research work that has been done on the structural behavior of beam webs subjected to web crippling and the combination of web crippling and bending moment. This is the continuation of the study reported in the Third Progress Report. Section II is the review of design provisions for web crippling included in the 1981 Guide1 and the 1980 Specification 3. In Section III, the experimental study as proposed in the Third Progress Report is presented. Section IV contains an evaluation of the experimental results by using current AISI design procedures with some modification as proposed in the Third Progress Report. New equations for web crippling and combined bending and web crippling are developed and discussed in Section V. Several topics for future study are proposed in Section VI
Civil, Architectural and Environmental Engineering
Wei-Wen Yu Center for Cold-Formed Steel Structures
American Iron and Steel Institute
Missouri University of Science and Technology
© 1984 Missouri University of Science and Technology, All rights reserved.
Report - Technical
Santaputra, Chiravut and Yu, Wei-wen, "Design of automotive structural components using high strength sheet steels - structural behavior of beam webs subjected to web crippling and a combination of web crippling and bending" (1984). Center for Cold-Formed Steel Structures Library. Paper 99.