Inelastic Cyclic Instability of 2024-T4 Aluminum and Cold-Rolled 1020 Steel.
Abstract
An investigation was made into the cyclic instabilities of cyclic strain hardening and cyclic strain softening materials. 2024-T4 aluminum and cold-rolled 1020 steel were selected respectively. Specimens had fixed ends with a slenderness ratio l/r equal to 40 and were cycled at .1 to .5 Hz. Under axial fully reversed constant load amplitude conditions, the cyclically strain softening steel became unstable at approximately two thirds the monotonic buckling stress. This decrease was attributed primarily to decreases in the tangent modulus, however tensile strain ratchetting also had an influence. For aluminum under the same loading conditions, cyclic instabilities and monotonic instabilities occurred at essentially the same stress level. Under fully reversed strain conditions with aluminum, slight increases in stress levels at initial bifurcation occurred when cycling was begun with compression first. Aluminum specimens used to determine the cyclic stress-strain curve also had slightly increased stress at initial bifurcation compared to monotonic values. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1971
- Accession Number
- AD0728838
Entities
People
- C. R. Prischmann
- R. I. Stephens
Organizations
- University of Iowa