Page 218 - Biaxial Multiaxial Fatigue and Fracture

202 ?: UGODA ET AL.

Appendix: NOMENCLATURE

a - coescient including influence of amplitudes less
than the fatigue limit,
Young’s modulus,
relative mean error,
shear modulus,
direction cosines,
Wohler curve exponent,
number of cycles,
Palmgren-Miner
yield point,
tensile strength,
damage degree,
Serensen - Kogayev
time,
observation time,
strain energy parameter,
contraction,
angIe between the longitudinal axis of the specimen
and the normal direction of critical plane,
engineering shear stain,
Poisson’s ratio,
normal stress,
fatigue limit for tension,
shear stress,
fatigue limit for torsion.

Subscripts:
a - amplitude,
b - block,
cal - calculated,
eq - equivalent,
exp - experimental,
max - maximumvalue.

Function:
1 for x >O

-1 for x<O