Uncertainty of estimated rainflow damage for random loads
Journal article, 2009

One way to assess the uncertainty in fatigue damage analysis is to use a so-called safety index. In the computation of such an index the coefficient of variation for the accumulated damage is needed. Employing the rainflow cycle count method for fatigue damage leads to, in most cases, complicated calculations. Here we present a new and simplified method to estimate the coefficient of variation for the accumulated damage when only one sample path of the load is available. Non-stationary, slowly changing, Gaussian loads are given special attention. The approach is illustrated by means of stationary Gaussian loads with nine different spectra, a measured non-Gaussian load, a skewed load and the wave load accumulated during one year in a "seasonally changing environment"

Coefficient of variation

Rainflow damage

Damage variability


Anders Bengtsson

Lund University

Klas Bogsjö

Scania AB

Igor Rychlik

University of Gothenburg

Chalmers, Mathematical Sciences, Mathematical Statistics

Marine Structures

0951-8339 (ISSN)

Vol. 22 261-274

Subject Categories

Computational Mathematics

Probability Theory and Statistics