This symposium held at Innsbruck/lgls on June 21-26 1987 is the fifth in a series of IUTAM-Symposia on the application of stochastic methods in mechanics. The flrst two meetings in Warwick (1972) and Southhampton (1976) concentrated on the stability of stochastic dynamical systems and stochastic methods in dynamics respectively. The third meeting in Frankfurt/Oder (1982) added aspects of reliability while the fourth symposium in Stockholm (1984) dealt mainly with fatigue and fracture problems. The general theme of the present symposium is devoted to nonlinear stochastic dynamics of engineering systems which is believed of great importance for providing the tools for basic development and progress in various fields of mechanical- structural- and aeronautical engineering particularly in the areas of vehicle dynamics multi-storey structural dynamics systems identiflcation offshore structural dynamics nuclear structures under various stochastic loading conditions (i. e. wind- earthquake- parametric excitations etc. ). The contributions collected in this volume cover a wide spectrum of topics ranging from more theoretical analytical and numerical treatment to practical application in various flelds. The truly international character of the meeting is accomplished by 42 contributions and 86 participants from as many as 19 countries and hence contributed to the original idea of IUTAM which is to foster international cooperation. It should be recalled that for getting this cooperation started again after the First World War Theodore von Kanmm and Tullio Levi-Civita called the world s flrst international (IUTAM) conference on hydro- and aerornechanics in 1922 in Innsbruck Austria.