The modified life law applied to SAE-1045 steel

• Published in: International journal of fracture Vol. 31; no. 1; pp. 29 - 36
• Main Authors: DOWDELL, D.J, LEIPHOLZ, H.H.E, TOPPER, T.H
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-05-1986
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fractures; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals, semimetals and alloys; Metals. Metallurgy; Physics; Specific materials; Lifetime; Distribution; Fracture; Elongation; Fracture(mechanics); Dynamic load; Crack
• ISSN: 0376-9429; 1573-2673
• DOI: 10.1007/BF00033927

Miner's rule is seen to hold probabilistic significance. Erroneous predictions must therefore be caused by using inadequate data in the damage summation. Improved predictions can be made if the modified life law concept is applied. The modified life curve arises from the threshold lowering effect of compressive load cycles. In experimentation with three-level block loads under varied frequency of application, points on the modified life curve can be found. In solving for points on the modified curve, steps must be taken to reduce scatter amplification. Minimum modified life curves plotted from experimental data were used in the prediction of lives. Lives were verified by experiment. For peak loads corresponding to the peak load level used in establishing the modified life curve, predictions fell within expected accuracy limits. Implementation of the modified life curves gives a significant improvement in life predictions. 8 ref.--AA