Design of automotive structural components using high strength sheet steels influence of strain rate on the mechanical properties of sheet steels and structural performance of cold-formed steel members
Civil Engineering Study 92-3
The current design criteria for effective design width being used in the AISI Automotive Steel Design Manual 1 for the design of cold-formed steel members are based on tests under static loading condition. The primary objective of this investigation was to study the validity of these effective design width formulas for members subjected to dynamic loads. This report presents a detailed description of an experimental study. Selected steels with nominal yield strengths ranging from 25 ksi to 100 ksi were uniaxially tested under different strain rates. In order to study the structural behavior and strength of cold-formed steel members having stiffened and unstiffened compression elements, a total of 97 stub column specimens and 60 beam specimens were fabricated from 35XF and 50XF sheet steels and tested under dynamic loads. It was found from test results that the mechanical properties of sheet steels and strengths of cold-formed steel members increased with increasing strain rate. The amount of increase is dependent on the the material yield strengths, the stress-strain relationships, and the strain rates used in the tests. In the evaluation of the test data, it was found that the value of buckling coefficient, 0.43, used to calculate the effective width of unstiffened compression elements is conservative. For calculating the ultimate capacity of stub columns and beams, the values computed from Kalyanaraman's equations for unstiffened compression elements provide good agreements with test results. In addition, a better prediction for ultimate capacity of stub columns and beams can be obtained by using the dynamic yield strengths.
Civil, Architectural and Environmental Engineering
Wei-Wen Yu Center for Cold-Formed Steel Structures
American Iron and Steel Institute
Cold-Formed Steel Series
Missouri University of Science and Technology
© 1992 Missouri University of Science and Technology, All rights reserved.
Report - Technical
Pan, Chi-Ling and Yu, Wei-wen, "Design of automotive structural components using high strength sheet steels influence of strain rate on the mechanical properties of sheet steels and structural performance of cold-formed steel members" (1992). Center for Cold-Formed Steel Structures Library. Paper 95.