VIBRATIONAL PROCESSES IN MECHANICAL SYSTEMS M. D. Martynenko , N. A. Dokukova , and L. I. Boiko UDC 531.8 A method is presented and mathematically rigorously justified for calculating vibrational processes in mechanical systems described by nonlinear differential equations. An example of its implementation is considered and it is shown that this method leads to known self-oscillation conditions. JEPTER74920199920 JEPTER7492020