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Variability of Strain-Controlled Fatigue Properties of USS Dual Phase 80 Steel
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Abstract
Because sheet-steel users are requesting strain-controlled fatigue properties of sheet steels for automotive use, a program is being conducted to characterize single grades of steel and to examine the variability of their fatigue properties. As part of that program, monotonic tension tests and low-cycle strain-controlled fatigue tests were performed on smooth longitudinal and transverse specimens from sheets of USS Dual Phase 80 steel. An 0.096-inch (2.4 mm) thick sheet from one heat and 0.131 inch (3.3 mm) and 0.188-inch (4.8 mm) thick sheets from a second heat were evaluated. The sheets were tested in the “as-shipped” (unstrained) and prestrained conditions. Prestraining was accomplished with a single uniaxial tension load sufficient to cause strains as high as 8 percent prior to fatigue testing.
The results of this study showed that the unstrained material was cyclically stable; that is, the cyclic yield strength was approximately the same as the monotonic yield strength. However the prestrained material cyclically softened so that the cyclic yield strength was considerably less than the monotonic prestrained value and approached or was lower than the cyclic yield strength of the unstrained material.
In this study the strain-controlled fatigue properties of Dual Phase 80 steel did not vary more among sheets from different coils and subjected to different amounts of prior uniaxial tensile prestrains than within a single sheet. Therefore this study gives little evidence that sampling from more than a single sheet is necessary to estimate the fatigue properties of this grade of steel. This finding is consistent with previous results for high-strength low-alloy sheet steels.
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Holt, J. and Stewart, B., "Variability of Strain-Controlled Fatigue Properties of USS Dual Phase 80 Steel," SAE Technical Paper 801400, 1980, https://doi.org/10.4271/801400.Also In
References
- Landgraf R. W. LaPointe N. R. “Cyclic Stress-Strain Concepts Applied to Component Fatigue-Life Prediction,” Paper 740280 Automotive Engineering Conference Feb. 1974 Society of Automotive Engineers
- Jaske C. E. “Consideration of Experimental Techniques Used in the Development of Long-Life Fatigue Properties of Pressure Vessels and Piping Alloys,” ASME Symposium on Characterization of Materials for Elevated Temperature Service June 1978
- Barsom J. M. Klippstein K. H. Shoemaker A. K. “Interpretive Report on Fatigue Behavior of Sheet Steels for Automotive Applications,” AISI Project 1201-409D American Iron and Steel Institute 1979
- Holt J. M. Stewart B. K. “Variability of the Strain-Controlled Fatigue Properties of EX-TEN F50 Steel,” Paper 790460 SAE Congress March 1979 Society of Automotive Engineers
- Aichbhaumik D. “Steel Variability Effects on Low Cycle Fatigue Behavior of a Single Grade of High Strength Low Alloy Steel,” Metallurgical Transactions A American Society for Metals and the Metallurgical Society of AIME 10A March 1979 269 278
- “Standard Test Method for Tensile Strain-Hardening Exponents (n-Values) of Metallic Sheet Materials,” ASTM Designation E646-78; ASTM Book of Standards, Part 10
- “Standard Methods of Tension Testing of Metallic Materials,” ASTM Designation E8-78, ASTM Book of Standards, Part 10
- “Tentative Recommended Practice for Constant-Amplitude Low-Cycle Fatigue Testing,” ASTM Designation E606-77T, ASTM Book of Standards, Part 10
- Little R. E. Jebe E. H. “Statistical Design of Fatigue Experiments,” Halsted Press (John Wiley and Sons) New York, N. Y. 1975
- “Recommended Practice for the Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (e-N) Fatigue Data,” ASTM Committee E09 1979