Alternative Title

Civil Engineering Study 90-1

Abstract

INTRODUCTION Since May 1988, the research project on automotive components sponsored by American Iron and Steel Institute (AISI) at University of Missouri-Rolla (UMR) has been concentrated on a study of the effect of strain rate on mechanical properties of sheet steels and the structural behavior and strength of cold-formed steel members subjected to impact loads. The results of the static and dynamic tensile mechanical properties of three selected sheet steels in the virgin condition as well as for the steels subjected to different amount of cold stretchings, were established in 1988 and early 1989. Details of the tension coupon tests were presented in the Eleventh Progress Report. 1 During the period from January through August 1989, the UMR study primarily involved the experimental determination of the static and dynamic mechanical properties in compression for the same sheet steels used in the Eleventh Progress Report. The strain rates used for these compression coupon tests were similar to those used for the tension tests. They ranged from 10-4 to 1.0 in. / in. /sec. Details of the compression coupon tests are discussed in the Twelfth Progress Report . 2 The study of the structural behavior and strength of cold-formed steel members subjected to impact loads (phase II of the project) was initiated in August 1989. Two materials (35XF and 50XF) were used in this phase of study. Up to January 1990, thirty-seven (37) stub-columns and thirty (30) beam specimens fabricated from 35XF sheet steel have been tested under different strain rates. Specimens using channel and I -shaped sections were tested to study the strength of structural members having unstiffened compression elements. Specimens using hat and box sections were tested to study the strength of structural members having stiffened compression elements. The ranges of w/t ratios varied from 8.93 to 20.87 for unstiffened compression elements and from 26.92 to 76.64 for stiffened compression elements. The strain rate ranged from 10 -5 to 0.1 in./in./sec. Chapter II includes review of the literature related to local buckling and post-buckling behavior of stiffened and unstiffened compression elements. Also discussed in chapter II is the available literature on the effect of the impact loads and strain rates on the structural strength of beams and columns. Details of test specimens, test procedures, and test results are presented in Chapter III. The test results are evaluated in Chapter IV. Finally, the research findings are summarized in Chapter V.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Laboratory(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Sponsor(s)

American Iron and Steel Institute

Appears In

Structural Series

Publisher

Missouri University of Science and Technology

Publication Date

5-1-1990

Document Version

Final Version

Rights

© 1990 Missouri University of Science and Technology, All rights reserved.

Comments

Thirteenth Progress Report

Document Type

Report - Technical

File Type

text

Language

English


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