SYSTEMATIC AXIAL LOAD FATIGUE TESTS USING UN-NOTCHED ALUMINUM ALLOY 2024-T4 EXTRUDED BAR SPECIMENS
Abstract
A series of axial-load fatigue tests were performed on Al Alloy 2024-T4 extruded bar, using a mean tensile stress of 16 ksi. The basic single-level SN relation was established using 9 specimens at each of 15 alternating stress amplitudes. The statistical behavior of the single-level fatigue endurances at the knee of the SN curve was discovered to be consistent with the rise and decay respectively of 2 endurance distributions, apparently representing the action of 2 different fatigue mechanisms. The logendurance population during transition became bimodal in nature, with the first distribution a continuation of the log normal distributions at stress amplitudes above this region. An extensive 2-level test program was carried out. By this procedure, areas of severe damage accumulation were delineated, as were areas of so-called healing which occur at certain high stress levels (0.1% proof stress), and at high numbers of cycles at low stress levels. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1960
- Accession Number
- AD0258552
Entities
People
- S.r. Swanson
Organizations
- University of Toronto