Rainflow Matrix for Switching Random Loads

Often fatigue tests of materials are performed with constant amplitude loads. When dealing with variable amplitude loads, like random loads, one forms equivalent load cycles. The now commonly used cycle counting method is rainflow counting which was introduced by Endo in 1968. The equivalent definition of rainflow cycles as illustrated in Figure 1 is due to Rychlik [5]. The fatigue life of a component is often based on the Palmgren-Miner damage hypothesis together with the rainflow cycle method.