Spectral methods for estimating the integrity of structural components subjected to random loading

Critical Evaluation of Frequency-Domain Approach for Fatigue Damage Estimation

“…The Dirlik method is one of the most widely used frequency-domain methods that can be applied to any wide-band Gaussian process and is often cited to be among the most accurate [3,13,[15][16][17][18]. It is an empirically based method which determines the probability density function of stress cycle amplitudes pDK(i) based on four moments of PSD (Ao, ^-1,^2, A4).…”

“…For this reason, an alternative approach to lifetime prediction has been developed, which is based on the stress PSD [3,4,[7][8][9][10][11][12][13][14][15][16][17], On the other hand, the time-domain methods require each individ ual cycle to be counted from the stress history, the frequencydomain methods predict the probability density function of stress cycles from the stress PSD. Using the probability density function of stress cycles in combination with one of the conventional dam age accumulation rules and the material properties under cyclic loading the lifetime prediction can be made.…”

“…Using the probability density function of stress cycles in combination with one of the conventional dam age accumulation rules and the material properties under cyclic loading the lifetime prediction can be made. Several comparisons have been made between the different frequency-domain methods [3,13,[15][16][17][18], where the Dir lik method [19] has been proved to be among the most accurate and widely used in practice. Because the analytical deri vation of the solution for broad-band processes is very limited [8], most of them are empirically based, derived from a number of simulated stress histories from a predetermined set of different stress PSDs.…”

Vibration Fatigue Testing and Analysis

“…Bishop (1989Bishop ( , 1994 concluded that the Dirlik formula is far superior to other existing methods for estimating rainflow fatigue damage. Bishop (1989Bishop ( , 1994 concluded that the Dirlik formula is far superior to other existing methods for estimating rainflow fatigue damage.…”

“…Also of the wide-band damage methods, Ortiz-Chen's method is the most conservative while Dirlik's has been found by Bishop (Bishop & Sherratt, 1989;Bishop, 1994) to be the most accurate in practice. Furthermore, Figure 9.14 shows relative FDS plots based on IEC 60068-2-6, Classification III, and ISO 16750-3.…”