Design and Service Life of Weldments, Subjected to Both Constant Amplitude and Single Tensile Overloads

Abstract

The behaviour of fatigue crack growth at room temperature was gotten from 4140 parent steel. The parent steel was heat treated, as-welded and material under R",, 0 constant amplitude loading and single tensile overloads with an over load ratio of 2.5. The purpose of this research is to contribute to the needed information for safe design and service life of weldments, subjected to both constant amplitude and single tensile overloads. The data are essentially log-log linear and hence satisfy the region II Paris equation, the overload cycles to failure for a given R ratio fell within a factor of about 3.0 or less for all material test conditions, this again is a rather small variation between materials. The number of cycles of retardation, NR, varies from about 3.0 x 110 to 5.0 x 110cycles. This represents fatigue crack growth life increases from about 300 to 500% for R ≈ 0. This indicates that all the material conditions investigated responded favorably to the single tensile overloads. All four material conditions had the same constant amplitude fatigue crack growth resistance in the Paris log-log linear region. Differences in fatigue life and fatigue crack growth rates were within a factor or two.

Cite as

Imaekhai Lawrence. (2021). Design and Service Life of Weldments, Subjected to Both Constant Amplitude and Single Tensile Overloads. Research and Applications of Thermal Engineering, 4(1), 1–5.

http://doi.org/10.5281/zenodo.4892247