RATCHETING RESPONSE OF ELASTIC PERFECTLY PLASTIC OSCILLATORS UNDER RANDOM LOAD WITH NONZERO MEAN

A method is presented for characterizing the ratcheting response of li nearly elastic perfectly plastic single-degree-of-freedom (SDOF) oscil lators subjected to a stationary wide band random excitation with non- zero mean. Developed within the context of stochastic averaging, the m ethod is based on a generalized van der Pol transformation in which th e displacement response is split into a ratcheting component and a cyc lic component, and the rate of the ratcheting component and the angula r frequency of the cyclic component are taken to depend on the amplitu de of the cyclic component. The predictions of the method for the mean ratcheting rate and the standard deviation of the velocity are in goo d agreement with those of the Monte-Carlo simulation. (C) Academie des Sciences/Elsevier, Paris