Issue 78

F. Veschi et alii, Fracture and Structural Integrity, 78 (2026) 44-73; DOI: 10.3221/IGF-ESIS.78.04

Number of Fatigue Cycles Number of Amplitude Bins

N

bin N

Number of Harmonic Components in a SoR Signal PDF of Rainflow Counted Stress Amplitudes

h N

s p

PDF of Stress Peak Values

p s p

PDF of Instantaneous Values of a Random Signal

x p

PDF of Peak Values of a Random Signal

p x p

PDF of the Instantaneous Values of a Sinusoidal Signal

y p

PDF of Peak Values of a Sinusoidal Signal

p y p

PDF of the Instantaneous Values of a Sine on Random Signal

z p

PDF of the Peak Values of the Relative Displacement Response of an SDOF System

p Z p

PDF of Normalized Maxima of a Random Signal

ζ p

Pseudo Damage

PD

Pseudo Damage evaluated from RFC Counted Cycles

RFC PD

Quality Factor

Q

Autocorrelation Function Stress Cycle Amplitude Stress Instantaneous Values Stress Peak Values (Maxima)

xx R

s

inst s

p s

Double-Sided Power Spectral Density

xx S

Time

t

Duration of a Signal

T x

Stationary Gaussian Random Signal

Peak Values (Maxima) of a Stationary Gaussian Random Signal

p x

y

Sinusoidal Signal

Peak Values (Maxima) of a Sinusoidal Signal

p y

z

Sine on Random Signal

Relative Displacement Response of an SDOF System

Z

Peak Values (Maxima) of an SDOF System’s Relative Displacement Response Root Mean Square Value of the Sinusoidal Relative Displacement Response Root Mean Square Value of the Velocity of the Sinusoidal Relative Displacement Response Root Mean Square Value of the Acceleration of the Sinusoidal Relative Displacement Response

p Z

, S RMS Z , S RMS Z  ¨ , S RMS Z

Ratio between Sinusoidal and Random Responses

0 α



Irregularity Factor Gamma Function Dirac Delta Function

  

  

Frequency Band used for Sine to PSD Conversion

Δ f

Bandwidth Parameter



Normalized Maxima of a Random Signal

ζ

 

Transform Variable associated with the Characteristic Function

Argument of a Sinusoidal Function

Mean Value of a Stationary Gaussian Signal

x 

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