Author(s): A. Varvani-Farahani
A fatigue-damage parameter for in-phase and out-of-phase loading is proposed.
A proposed fatigue-damage parameter has been developed to assess the various
materials fatigue lives for (i) constant-amplitude fatigue stressing where the
stresses are at the same and different frequencies, and (ii) variable-amplitude
In this parameter, the normal and shear stress and strain
ranges have been calculated from the largest stress and strain Mohrís circles.
total damage accumulation in a block-loading history has been calculated from
the summation of the normal and shear energies on the basis of a cycle-by-cycle
The normal and shear energies used in this parameter are divided by the
tensile and shear-fatigue properties, respectively, and the proposed parameter,
unlike many other parameters, does not use an empirical fitting factor.
proposed parameter successfully correlates fatigue lives of several materials for:
a) various in-phase and out-of phase fatigue-loading conditions, b) tests in which
a mean stress was applied normal to the maximum shear plane, and c) out-ofphase
tests in which there was additional hardening.
Varvani fatigue-damage model, in-phase and out-of-phase strain
paths, shear and normal energies, critical plane, mean stress effect, loading
frequency, strain hardening, constant and variable loading
Size: 1,566 kb
Paper DOI: 10.2495/1-85312-836-8/07
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This paper can be found in the following bookAdvances in Fatigue, Fracture and Damage Assessment of MaterialsBuy